@article{chen_hyman_2023, title={Aerobic cometabolic biodegradation of 1,4-dioxane and its associated Co-contaminants}, url={https://doi.org/10.1016/j.coesh.2023.100442}, DOI={10.1016/j.coesh.2023.100442}, abstractNote={Cometabolism describes the biodegradation of a contaminant by microorganisms grown on compounds other than the contaminant itself. Aerobic cometabolic degradation of 1,4-dioxane (14D) offers several advantages over metabolism-based biodegradation processes in which microorganisms use this compound as a sole source of carbon and energy for growth. These include (a) the use of widely distributed rather than highly specialized microorganisms (b) the ability to treat low, environmentally relevant concentrations (≤100 μg/L) of 14D, and (c), the ability to concurrently degrade chlorinated co-contaminants that are frequently encountered with 14D. This review summarizes recent studies highlighting these key features as well as field studies and emerging novel cometabolism-based approaches aimed at treating both 14D and its associated chlorinated co-contaminants.}, journal={Current Opinion in Environmental Science & Health}, author={Chen, Weijue and Hyman, Michael}, year={2023}, month={Apr} }
 @article{bealessio_chen_krippaehne_murnane_hyman_semprini_2023, title={Alcohol-Dependent Cometabolic Degradation of Chlorinated Aliphatic Hydrocarbons and 1,4-Dioxane by Rhodococcus rhodochrous strain ATCC 21198}, volume={8}, ISSN={["1557-9018"]}, DOI={10.1089/ees.2023.0058}, abstractNote={Resting cell batch kinetic studies were performed to evaluate the alcohol-dependent cometabolic degradation of chlorinated aliphatic hydrocarbons (CAHs) and 1,4-dioxane (1,4-D) by Rhodococcus rhodochrous strain ATCC 21198. This strain grew on diverse alcohols, organic acids, esters, and other organic compounds. Only growth on 2-butanol resulted in labeling of monooxygenase enzymes and the ability to oxidize propylene, the cylic ether 1,4-D, and its close structural analog tetrahydrofuran. In single compound rate tests, 2-butanol-grown cells exhibited faster degradation rates for less chlorinated compounds. The rates of degradation are ranked as follows from high to low: vinyl chloride > cis-dichloroethene (cis-DCE) >1,1-dichoroethane >1,1-dichoroethene (1,1-DCE) >1,4-D > 1,1,1-trichoroethane (1,1,1-TCA) >1,1,2-trichoroethene. All rates were significantly lower than isobutane-grown cells. 2-Butanol-grown cells exhibited a lag period before cometabolic degradation of most CAHs, including cis-DCE; however, production of cis-1,2-dichloro-1,2-epoxyethane (cis-DCE epoxide) was detected with no lag. Cells grown on 1-butanol, 2-butanol, or 2-ethyl-1-butanol also cometabolically degraded 1,4-D and various CAHs. However, compared to cells grown on 1-butanol or 2-ethyl-1-butanol, cells grown on 2-butanol had a larger transformation capacity and faster degradation rates and were able to fully degrade (>99% removal) a mixture of 1,4-D, cis-DCE, and 1,1,1-TCA. With CAH mixtures, alcohol-grown cells degraded cis-DCE faster than both 1,1,1-TCA and 1,4-D. sec-Butyl-acetate (sBA) was demonstrated as a potential slow-release substrate that hydrolyzes to yield 2-butanol and acetate. Cells grown on this ester degraded a mixture of 1,1,1-TCA and 1,4-D at rates faster than 2-butanol-grown cells. The cometabolic transformation of 1,1,1-TCA and 1,4-D was also observed in reactors where growth occurred with sBA as the growth substrate.}, journal={ENVIRONMENTAL ENGINEERING SCIENCE}, author={Bealessio, Alisa D. D. and Chen, Weijue and Krippaehne, Krysta J. J. and Murnane, Riley A. A. and Hyman, Michael R. R. and Semprini, Lewis}, year={2023}, month={Aug} }
 @article{archaeal communities discovered in the phytotelmata of nepenthes alata blco. samples obtained from mt. makiling, philippines as revealed by high-throughput molecular sequencing analysis_2023, journal={International Journal of Agricultural Technology}, year={2023} }
 @article{mejia_hyman_2023, title={Diyne inactivators and activity-based fluorescent labeling of phenol hydroxylase in Pseudomonas sp. CF600}, volume={370}, ISSN={["1574-6968"]}, url={https://doi.org/10.1093/femsle/fnad002}, DOI={10.1093/femsle/fnad002}, abstractNote={An activity-based labeling (ABL) approach was investigated for the phenol-oxidizing bacterium, Pseudomonas sp. CF600. Phenol-grown cells were exposed to several different terminal diynes and following cell breakage, extracts of these cells were added to copper-catalyzed alkyne/azide cycloaddition (CuAAC) reactions containing AlexaFluor 647 azide. Analysis of total cell proteins by SDS-PAGE and near infrared (NIR) scanning demonstrated covalent fluorescent labeling of a 58 kDa and a 34 kDa polypeptide in all diyne treated cell types. Further studies using 1,4-diethynylbenzene (DEB) demonstrated these labeled polypeptides were consistently detected in cells grown on substrates that exhibited phenol dependent O2 uptake activity but not observed when cells were grown on substrates such as dextrose or catechol that did not support this activity. Fluorescent labeling of the two polypeptides in DEB-treated, phenol-grown cells was time dependent and was inhibited by several known substrates for phenol hydroxylase. These results suggest that diverse diynes act as mechanism-based inactivators of phenol hydroxylase in Pseudomonas sp. CF600 and that this effect can be exploited by ABL approaches to selectively label the major 58 and 34 kDa subunits of the hydroxylase component of this complex enzyme.}, journal={FEMS MICROBIOLOGY LETTERS}, author={Mejia, Alejandra P. Oyarzun and Hyman, Michael R.}, year={2023}, month={Jan} }
 @article{bingham_hyman_montoya_goshe_gracieux-singleton_2023, title={Identifying the enzyme responsible for initiating aerobic acetylene metabolism in Rhodococcus rhodochrous ATCC 33258}, volume={299}, ISSN={["1083-351X"]}, DOI={10.1016/j.jbc.2023.103703}, number={3}, journal={JOURNAL OF BIOLOGICAL CHEMISTRY}, author={Bingham, Johnna and Hyman, Michael and Montoya, Sarah and Goshe, Michael and Gracieux-Singleton, Cyndell}, year={2023}, pages={S369–S369} }
 @article{mcelroy_ogles_hyman_knappe_2023, title={Pilot-scale biofiltration of 1,4-dioxane at drinking water-relevant concentrations}, volume={231}, ISSN={["1879-2448"]}, url={https://doi.org/10.1016/j.watres.2023.119652}, DOI={10.1016/j.watres.2023.119652}, abstractNote={1,4-Dioxane is a drinking water contaminant of emerging concern. Because conventional and many advanced drinking water treatment technologies are ineffective for 1,4-dioxane removal, cost-effective technologies for the removal of 1,4-dioxane at drinking water-relevant concentrations are needed. In this research, a gravity-fed, cometabolic biofiltration system was developed to degrade 1,4-dioxane that was spiked into coagulated, settled surface water at a concentration of ∼10 µg/L. Objectives were to determine whether cometabolic degradation of trace levels of 1,4-dioxane can be sustained using n-butane as primary substrate and whether filter media properties and empty bed contact time (EBCT) affect biofiltration efficiency. A mixed culture of bacteria derived from the Cape Fear River basin and previously enriched using isobutane served as inoculum for biologically active filters. Two granular activated carbons (GACs) with different grain sizes and one carbonaceous resin were used as attachment media, and n-butane served as the primary substrate for biologically active filters. Non-inoculated controls with the same media were evaluated in parallel to distinguish between biological and adsorptive removals of 1,4-dioxane. For the duration of the pilot study (>3 months), 1,4-dioxane was degraded in inoculated biofilters receiving n-butane. In control filters containing larger and smaller grain GAC, 1,4-dioxane broke through completely within 750 and 1250 bed volumes, respectively, corresponding to 15 to 30 days of operation at an EBCT of 30 min. 1,4-Dioxane removal increased with increasing EBCT in all biologically active filters. At an EBCT of 30 min, the biologically active GAC filter containing the larger-grain GAC removed on average 87% of 1,4-dioxane at pseudo steady-state. When the hydraulic loading rate was decreased to achieve an overall EBCT of 60 min, 1,4-dioxane was removed to <1 µg/L in the biologically active GAC filter containing the larger-grain GAC. Activity-based labeling showed the presence of catalytically active monooxygenases in backwash water from biologically active filters that degraded 1,4-dioxane. Amplicon sequencing results showed that while taxa shifted after the initial inoculation of biologically active filters, taxa in biologically active filters remained more similar to the inoculum than those in the non-inoculated control filters. Overall, results of this research demonstrate that cometabolic degradation of 1,4-dioxane at trace levels is possible for extended periods of time in inoculated biofilters that receive n-butane as primary substrate.}, journal={WATER RESEARCH}, author={McElroy, Amie C. and Ogles, Matthew E. and Hyman, Michael R. and Knappe, Detlef R. U.}, year={2023}, month={Mar} }
 @article{rolston_hyman_semprini_2022, title={Single-well push-pull tests evaluating isobutane as a primary substrate for promoting in situ cometabolic biotransformation reactions}, volume={5}, ISSN={["1572-9729"]}, url={https://doi.org/10.1007/s10532-022-09987-w}, DOI={10.1007/s10532-022-09987-w}, abstractNote={["A series of single-well push-pull tests (SWPPTs) were performed to investigate the efficacy of isobutane (2-methylpropane) as a primary substrate for in situ stimulation of microorganisms able to cometabolically transform common groundwater contaminants, such as chlorinated aliphatic hydrocarbons and 1,4-dioxane (1,4-D). In biostimulation tests, the disappearance of isobutane relative to a nonreactive bromide tracer indicated an isobutane-utilizing microbial community rapidly developed in the aquifer around the test well. SWPPTs were performed as natural drift tests with first-order rates of isobutane consumption ranging from 0.4 to 1.4 day", {:sup=>"-1"}, ". Because groundwater contaminants were not present at the demonstration site, isobutene (2-methylpropene) was used as a nontoxic surrogate to demonstrate cometabolic activity in the subsurface after biostimulation. The transformation of isobutene to isobutene epoxide (2-methyl-1,2-epoxypropane) illustrates the epoxidation process previously shown for common groundwater contaminants after cometabolic transformation by alkane-utilizing bacteria. The rate and extent of isobutene consumption and the formation and transformation of isobutene epoxide were greater in the presence of isobutane, with no evidence of primary substrate inhibition. Modeled concentrations of isobutane-utilizing biomass in microcosms constructed with groundwater collected before and after each SWPPT offered additional evidence that the isobutane-utilizing microbial community was stimulated in the aquifer. Experiments in groundwater microcosms also demonstrated that the isobutane-utilizing bacteria stimulated in the subsurface could cometabolically transform a mixture of co-substrates including isobutene, 1,1-dichloroethene, cis-1,2-dichloroethene, and 1,4-D with the same co-substrate preferences as the bacterium Rhodococcus rhodochrous ATCC strain 21198 after growth on isobutane. This study demonstrated the effectiveness of isobutane as primary substrate for stimulating in situ cometabolic activity and the use of isobutene as surrogate to investigate in situ cometabolic reactions catalyzed by isobutane-stimulated bacteria."]}, journal={BIODEGRADATION}, author={Rolston, Hannah and Hyman, Michael and Semprini, Lewis}, year={2022}, month={May} }
 @article{chen_faulkner_smith_fruchte_hyman_2021, title={Draft Genome Sequences of Four Aerobic Isobutane-Metabolizing Bacteria}, volume={10}, ISSN={["2576-098X"]}, url={https://doi.org/10.1128/MRA.01381-20}, DOI={10.1128/MRA.01381-20}, abstractNote={Here, we report the draft genome sequences of four aerobic gaseous alkane-oxidizing bacteria isolated from soil by enrichment culture using isobutane (2-methylpropane) as the sole carbon and energy source. The sequences all reveal microorganisms with multiple alkane-oxidizing monooxygenases, including soluble di-iron monooxygenases (SDIMOs), copper-containing monooxygenases (CuMMOs), and alkane hydroxylases (AHs). ABSTRACT Here, we report the draft genome sequences of four aerobic gaseous alkane-oxidizing bacteria isolated from soil by enrichment culture using isobutane (2-methylpropane) as the sole carbon and energy source. The sequences all reveal microorganisms with multiple alkane-oxidizing monooxygenases, including soluble di-iron monooxygenases (SDIMOs), copper-containing monooxygenases (CuMMOs), and alkane hydroxylases (AHs).}, number={18}, journal={MICROBIOLOGY RESOURCE ANNOUNCEMENTS}, publisher={American Society for Microbiology}, author={Chen, Weijue and Faulkner, Nicholas and Smith, Christy and Fruchte, Megan and Hyman, Michael}, editor={Maresca, Julia A.Editor}, year={2021}, month={May} }
 @article{murnane_chen_hyman_semprini_2021, title={Long-term cometabolic transformation of 1,1,1-trichloroethane and 1,4-dioxane by Rhodococcus rhodochrous ATCC 21198 grown on alcohols slowly produced by orthosilicates}, volume={240}, ISSN={["1873-6009"]}, DOI={10.1016/j.jconhyd.2021.103796}, abstractNote={Long-term cometabolic transformation of 1,1,1-trichlorethane (1,1,1-TCA) and 1,4-dioxane (1,4-D) was achieved using slow release compounds (SRCs) as growth substrates for pure cultures of Rhodococcus rhodochrous ATCC 21198 (ATCC strain 21198). Resting cell transformation tests showed 1,4-D transformation occurred without a lag phase for cells grown on 2-butanol, while an induction period of several hours was required for 1-butanol grown cells. These observations were consistent with activity-based labeling patterns for monooxygenase hydroxylase components and specific rates of tetrahydrofuran (THF) degradation. 1,1,1-TCA and 1,4-D degradation rates for alcohol-grown cells were slower than those for cells grown on gaseous alkanes such as isobutane. Batch metabolism and degradation tests were performed, in the presence of 1,1,1-TCA and 1,4-D, with the growth of ATCC strain 21198 on alcohols produced by the hydrolysis of orthosilicates. Three orthosilicates were tested: tetrabutylorthosilicate (TBOS), tetra-s-butylorthosilicate (T2BOS), and tetraisopropoxysilane (T2POS). The measured rates of alcohol release in poisoned controls depended on the orthosilicate structure with TBOS, which produced a 1° alcohol (1-butanol), hydrolyzing more rapidly than T2POS and T2BOS, that produced the 2° alcohols 2-butanol and 2-propanol, respectively. The orthosilicates were added as light non-aqueous phase liquids (LNAPLs) with ATCC strain 21198 and formed dispersed droplets when continuously mixed. Continuous rates of oxygen (O2) consumption and carbon dioxide (CO2) production confirmed alcohol metabolism by ATCC strain 21198 was occurring. The rates of metabolism (TBOS > T2POS > T2BOS) were consistent with the rates of alcohol release via abiotic hydrolysis. 1,4-D and 1,1,1-TCA were continuously transformed in successive additions by ATCC strain 21198 over 125 days, with the rates highly correlated with the rates of metabolism. The metabolism of the alcohols was not inhibited by acetylene, while transformation of 1,4-D and 1,1,1-TCA was inhibited by this gas. As acetylene is a potent inactivator of diverse bacterial monooxygenases, these results suggest that monooxygenase activity was required for the observed cometabolic transformations but not for alcohol utilization. Alcohol concentrations in the biologically active reactors were maintained below the levels of detection, indicating they were metabolized rapidly after being produced. Much lower rates of O2 consumption were observed in the reactors containing T2BOS, which has benefits for in-situ bioremediation. The results illustrate the importance of the structure of the SRC when developing passive aerobic cometabolic treatment systems.}, journal={JOURNAL OF CONTAMINANT HYDROLOGY}, author={Murnane, Riley A. and Chen, Weijue and Hyman, Michael and Semprini, Lewis}, year={2021}, month={Jun} }
 @article{rasmussen_saito_hyman_semprini_2020, title={Co-encapsulation of slow release compounds and Rhodococcus rhodochrous ATCC 21198 in gellan gum beads to promote the long-term aerobic cometabolic transformation of 1,1,1-trichloroethane, cis-1,2-dichloroethene and 1,4-dioxane}, url={https://doi.org/10.1039/C9EM00607A}, DOI={10.1039/C9EM00607A}, abstractNote={Rhodococcus rhodochrous ATCC 21198 (strain ATCC 21198) was successfully co-encapsulated in gellan gum beads with orthosilicates as slow release compounds (SRCs) to support aerobic cometabolism of a mixture of 1,1,1-trichloroethane (1,1,1-TCA), cis-1,2-dichloroethene (cis-DCE), and 1,4-dioxane (1,4-D) at aqueous concentrations ranging from 250 to 1000 μg L-1. Oxygen (O2) consumption and carbon dioxide (CO2) production showed the co-encapsulated cells utilized the alcohols that were released from the co-encapsulated SRCs. Two model SRCs, tetrabutylorthosilicate (TBOS) and tetra-s-butylorthosilicate (T2BOS), which hydrolyze to produce 1- and 2-butanol, respectively, were encapsulated in gellan gum (GG) at mass loadings as high as 10% (w/w), along with strain ATCC 21198. In the GG encapsulated beads, TBOS hydrolyzed 26 times faster than T2BOS and rates were ∼4 times higher in suspension than when encapsulated. In biologically active reactors, the co-encapsulated strain ATCC 21198 effectively utilized the SRC hydrolysis products (1- and 2-butanol) and cometabolized repeated additions of a mixture of 1,1,1-TCA, cis-DCE, and 1,4-D for over 300 days. The transformation followed pseudo-first-order kinetics. Vinyl chloride (VC) and 1,1-dichloroethene (1,1-DCE) were also transformed in the reactors after 250 days. In the long-term treatment, the batch reactors with co-encapsulated T2BOS GG beads achieved similar transformation rates, but at much lower O2 consumption rates than those with TBOS. The results demonstrate that the co-encapsulation technology can be a passive method for the cometabolic treatment of dilute groundwater plumes.}, journal={Environmental Science: Processes & Impacts}, publisher={Royal Society of Chemistry (RSC)}, author={Rasmussen, Mitchell T. and Saito, Alyssa M. and Hyman, Michael R. and Semprini, Lewis}, year={2020} }
 @article{mcelroy_hyman_knappe_2019, title={1,4-Dioxane in drinking water: Emerging for forty years and still unregulated}, volume={7}, ISSN={2468-5844}, url={http://www.sciencedirect.com/science/article/pii/S2468584418300485}, DOI={10.1016/j.coesh.2019.01.003}, abstractNote={The likely human carcinogen 1,4-dioxane was first detected in drinking water more than 40 years ago, and a recent analysis suggests that almost 30 million people in the United States receive drinking water with 1,4-dioxane levels above the health-based reference concentration of 0.35 μg/L. The widespread occurrence of 1,4-dioxane has exposed the need for developing and implementing management and treatment approaches that protect drinking water sources and prevent human exposure to 1,4-dioxane through drinking water. In this review, we highlight recent advances in analytical methods, understanding of occurrence, and treatment processes. Findings are discussed in the context of managing 1,4-dioxane as a drinking water contaminant, and recommendations are made to address important knowledge gaps.}, journal={Current Opinion in Environmental Science & Health}, publisher={Elsevier BV}, author={McElroy, Amie C. and Hyman, Michael R. and Knappe, Detlef R. U.}, year={2019}, month={Jan}, pages={117–125} }
 @article{rolston_hyman_semprini_2019, title={Aerobic cometabolism of 1,4-dioxane by isobutane-utilizing microorganisms including Rhodococcus rhodochrous strain 21198 in aquifer microcosms: Experimental and modeling study}, volume={694}, ISSN={["1879-1026"]}, url={http://dx.doi.org/10.1016/j.scitotenv.2019.133688}, DOI={10.1016/j.scitotenv.2019.133688}, abstractNote={Aerobic cometabolism of the emerging contaminant 1,4-dioxane (1,4-D) by isobutane-utilizing microorganisms was assessed in pure culture and aquifer microcosm studies. The bacterium Rhodococcus rhodochrous strain ATCC 21198 transformed low, environmentally-relevant concentrations of 1,4-D when grown on isobutane. Microcosms were constructed with aquifer solids from Fort Carson, Colorado, a site contaminated with 1,4-D and trichloroethene (TCE). Multiple additions of isobutane and 1,4-D over 300 days were transformed in microcosms biostimulated with isobutane and microcosms bioaugmented with strain 21198. Results showed that, over time and with sufficient inorganic nutrients, biostimulation of native microorganisms with isobutane was just as effective as bioaugmentation with strain 21198 to achieve 1,4-D transformation in the microcosms. The presence of TCE at 0.2 mg/L did not inhibit 1,4-D transformation, though TCE itself was not readily transformed. An iterative process was used to determine kinetic parameter values to fit Michaelis-Menten/Monod models to experimental data for simultaneous isobutane utilization, biomass growth, and cometabolic transformation of 1,4-D. Parameter optimization resulted in good model fit to the data over multiple transformations of isobutane and 1,4-D in both short- and long-term experiments. Results suggest low concentrations of 1,4-D studied in the microcosms were cometabolically transformed according to a pseudo first-order rate of 0.37 L/mg TSS/day of 21198. Isobutane consumption was modeled with a maximum rate of 2.58 mg/mg TSS/day and a half saturation constant of 0.09 mg/L. 1,4-D transformation was competitively inhibited by the presence of isobutane and transformation rates were significantly reduced when inorganic nutrients were limiting. Simulations of the repeated additions found a first-order microbial endogenous decay coefficient of 0.03 day−1 fit the alternating periods of active transformation and stagnation between isobutane and 1,4-D additions over approximately one year. The model fitting process highlighted the importance of determining kinetic parameters from data representing low concentrations typically found in the environment.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Rolston, Hannah M. and Hyman, Michael R. and Semprini, Lewis}, year={2019}, month={Dec} }
 @article{ortiz-medina_grunden_hyman_call_2019, title={Nitrogen Gas Fixation and Conversion to Ammonium Using Microbial Electrolysis Cells}, volume={7}, ISSN={2168-0485 2168-0485}, url={https://doi.org/10.1021/acssuschemeng.8b05763}, DOI={10.1021/acssuschemeng.8b05763}, abstractNote={Ammonia (NH3) is an important industrial chemical that is produced using the energy- and carbon-intensive Haber-Bosch process. Recovering NH3 from microorganisms that fix nitrogen gas (N2) may provide a sustainable alternative because their specialized nitrogenase enzymes can reduce N2 to ammonium (NH4+) without the need for high temperature and pressure. This study explored the possibility of converting N2 into NH4+ using anaerobic, single-chamber microbial electrolysis cells (MECs). N2 fixation rates [based on an acetylene gas (C2H2) to ethylene gas (C2H4) conversion assay] of a microbial consortium increased significantly when the applied voltage between the anode and cathode increased from 0.7 to 1.0 V and reached a maximum of ∼40 nmol of C2H4 min–1 mg protein–1, which is comparable to model aerobic N2-fixing bacteria. The presence of NH4+, which can inhibit the activity of the nitrogenase enzyme, did not significantly reduce N2 fixation rates. Upon addition of methionine sulfoximine, an NH4+ uptake i...}, number={3}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Ortiz-Medina, Juan F. and Grunden, Amy M. and Hyman, Michael R. and Call, Douglas F.}, year={2019}, month={Jan}, pages={3511–3519} }
 @inbook{biodegradation of ether pollutants_2018, url={http://dx.doi.org/10.1007/978-3-319-44535-9}, DOI={10.1007/978-3-319-44535-9}, abstractNote={In this book international experts discuss the state-of-the-art in the biological degradation of hydrocarbons to meet remedial or disposal goals. The work focuses on practical applications, often on g}, booktitle={Consequences of Microbial Interactions with Hydrocarbons, Oils, and Lipids: Biodegradation and Bioremediation}, year={2018} }
 @article{chu_bennett_dolan_hyman_peacock_bodour_anderson_mackay_goltz_2018, title={Concurrent Treatment of 1,4-Dioxane and Chlorinated Aliphatics in a Groundwater Recirculation System Via Aerobic Cometabolism}, volume={38}, ISSN={1745-6592}, url={https://onlinelibrary.wiley.com/doi/abs/10.1111/gwmr.12293}, DOI={10.1111/gwmr.12293}, abstractNote={This research demonstrates that groundwater contaminated by a relatively dilute but persistent concentration of 1,4‐dioxane (1,4‐D), approximately 60 μg/L, and chlorinated aliphatic co‐contaminants (1.4 to 10 μg/L) can be efficiently and reliably treated by in situ aerobic cometabolic biodegradation (ACB). A field trial lasting 265 days was conducted at Operable Unit D at the former McClellan Air Force Base and involved establishing an in situ ACB reactor through amending recirculated groundwater with propane and oxygen. The stimulated indigenous microbial population was able to consistently degrade 1,4‐D to below 3 μg/L while the co‐contaminants trichloroethene (TCE) and 1,2‐dichloroethane (1,2‐DCA) were decreased to below 1 μg/L and 0.18 μg/L, respectively. A stable treatment efficiency of more than 95% removal for 1,4‐D and 1,2‐DCA and of more than 90% removal for TCE was achieved. High treatment efficiencies for 1,4‐D and all co‐contaminants were sustained even without propane and oxygen addition for a 2‐week period.}, number={3}, journal={Groundwater Monitoring & Remediation}, author={Chu, Min-Ying Jacob and Bennett, Peter J. and Dolan, Mark E. and Hyman, Michael R. and Peacock, Aaron D. and Bodour, Adria and Anderson, Richard Hunter and Mackay, Douglas M. and Goltz, Mark N.}, year={2018}, pages={53–64} }
 @article{bennett_hyman_smith_el mugammar_chu_nickelsen_aravena_2018, title={Enrichment with Carbon-13 and Deuterium during Monooxygenase-Mediated Biodegradation of 1,4-Dioxane}, volume={5}, url={https://doi.org/10.1021/acs.estlett.7b00565}, DOI={10.1021/acs.estlett.7b00565}, abstractNote={Recent technical developments have enabled the application of compound-specific isotope analysis (CSIA) of low (parts per billion) concentrations of 1,4-dioxane that are often found in groundwater at 1,4-dioxane-contaminated sites. However, to quantify 1,4-dioxane biodegradation, isotopic enrichment factors are needed to interpret the CSIA data obtained from field samples. In this study, the carbon and hydrogen isotopic enrichment factors (eC and eH, respectively) for 1,4-dioxane biodegradation have been determined for axenic propane- or isobutane-grown cultures of Rhodococcus rhodochrous ATCC 21198 and for tetrahydrofuran-grown cultures of Pseudonocardia tetrahydrofuranoxidans K1. The enrichment factors for propane-grown (eC = −2.7 ± 0.3‰, and eH = −21 ± 2‰) and isobutane-grown (eC = −2.5 ± 0.3‰, and eH = −28 ± 6‰) cells of strain 21198 were similar and substantially smaller than those determined for tetrahydrofuran-grown cells of strain K1 (eC = −4.7 ± 0.9‰, and eH = −147 ± 22‰). The presence of 1-butyn...}, number={3}, journal={Environmental Science & Technology Letters}, author={Bennett, Peter and Hyman, Michael and Smith, Christy and El Mugammar, Humam and Chu, Min-Ying and Nickelsen, Michael and Aravena, Ramon}, year={2018}, month={Mar}, pages={148–153} }
 @article{bennett_sadler_wright_yeager_hyman_2016, title={Activity-Based Protein Profiling of Ammonia Monooxygenase in Nitrosomonas europaea}, volume={82}, ISSN={0099-2240, 1098-5336}, url={https://aem.asm.org/content/82/8/2270}, DOI={10.1128/aem.03556-15}, abstractNote={ABSTRACT Nitrosomonas europaea is an aerobic nitrifying bacterium that oxidizes ammonia (NH3) to nitrite (NO2 −) through the sequential activities of ammonia monooxygenase (AMO) and hydroxylamine dehydrogenase (HAO). Many alkynes are mechanism-based inactivators of AMO, and here we describe an activity-based protein profiling method for this enzyme using 1,7-octadiyne (17OD) as a probe. Inactivation of NH4 +-dependent O2 uptake by N. europaea by 17OD was time- and concentration-dependent. The effects of 17OD were specific for ammonia-oxidizing activity, and de novo protein synthesis was required to reestablish this activity after cells were exposed to 17OD. Cells were reacted with Alexa Fluor 647 azide using a copper-catalyzed azide-alkyne cycloaddition (CuAAC) (click) reaction, solubilized, and analyzed by SDS-PAGE and infrared (IR) scanning. A fluorescent 28-kDa polypeptide was observed for cells previously exposed to 17OD but not for cells treated with either allylthiourea or acetylene prior to exposure to 17OD or for cells not previously exposed to 17OD. The fluorescent polypeptide was membrane associated and aggregated when heated with β-mercaptoethanol and SDS. The fluorescent polypeptide was also detected in cells pretreated with other diynes, but not in cells pretreated with structural homologs containing a single ethynyl functional group. The membrane fraction from 17OD-treated cells was conjugated with biotin-azide and solubilized in SDS. Streptavidin affinity-purified polypeptides were on-bead trypsin-digested, and amino acid sequences of the peptide fragments were determined by liquid chromatography-mass spectrometry (LC-MS) analysis. Peptide fragments from AmoA were the predominant peptides detected in 17OD-treated samples. In-gel digestion and matrix-assisted laser desorption ionization–tandem time of flight (MALDI-TOF/TOF) analyses also confirmed that the fluorescent 28-kDa polypeptide was AmoA.}, number={8}, journal={Appl. Environ. Microbiol.}, author={Bennett, Kristen and Sadler, Natalie C. and Wright, Aaron T. and Yeager, Chris and Hyman, Michael R.}, year={2016}, month={Apr}, pages={2270–2279} }
 @inbook{aerobic degradation of gasoline ether oxygenates_2016, url={http://dx.doi.org/10.1007/978-3-319-39782-5_16-1}, DOI={10.1007/978-3-319-39782-5_16-1}, booktitle={Aerobic Utilization of Hydrocarbons, Oils and Lipids}, year={2016} }
 @article{kottegoda_waligora_hyman_2015, title={Isolation and characterization of a 2-methylpropene (isobutylene)-metabolizing bacterium, Mycobacterium sp. ELW1}, volume={81}, journal={Applied and Environmental Microbiology}, author={Kottegoda, S. and Waligora, E. and Hyman, M.}, year={2015}, pages={1966–1976} }
 @article{kottegoda_waligora_hyman_2015, title={Metabolism of 2-Methylpropene (Isobutylene) by the Aerobic Bacterium Mycobacterium sp Strain ELW1}, volume={81}, ISSN={["1098-5336"]}, DOI={10.1128/aem.03103-14}, abstractNote={ABSTRACT An aerobic bacterium (Mycobacterium sp. strain ELW1) that utilizes 2-methylpropene (isobutylene) as a sole source of carbon and energy was isolated and characterized. Strain ELW1 grew on 2-methylpropene (growth rate = 0.05 h−1) with a yield of 0.38 mg (dry weight) mg 2-methylpropene−1. Strain ELW1 also grew more slowly on both cis- and trans-2-butene but did not grow on any other C2 to C5 straight-chain, branched, or chlorinated alkenes tested. Resting 2-methylpropene-grown cells consumed ethene, propene, and 1-butene without a lag phase. Epoxyethane accumulated as the only detected product of ethene oxidation. Both alkene consumption and epoxyethane production were fully inhibited in cells exposed to 1-octyne, suggesting that alkene oxidation is initiated by an alkyne-sensitive, epoxide-generating monooxygenase. Kinetic analyses indicated that 1,2-epoxy-2-methylpropane is rapidly consumed during 2-methylpropene degradation, while 2-methyl-2-propen-1-ol is not a significant metabolite of 2-methylpropene catabolism. Degradation of 1,2-epoxy-2-methylpropane by 2-methylpropene-grown cells led to the accumulation and further degradation of 2-methyl-1,2-propanediol and 2-hydroxyisobutyrate, two sequential metabolites previously identified in the aerobic microbial metabolism of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Growth of strain ELW1 on 2-methylpropene, 1,2-epoxy-2-methylpropane, 2-methyl-1,2-propanediol, and 2-hydroxyisobutyrate was fully inhibited when cobalt ions were omitted from the growth medium, while growth on 3-hydroxybutyrate and other substrates was unaffected by the absence of added cobalt ions. Our results suggest that, like aerobic MTBE- and TBA-metabolizing bacteria, strain ELW1 utilizes a cobalt/cobalamin-dependent mutase to transform 2-hydroxyisobutyrate. Our results have been interpreted in terms of their impact on our understanding of the microbial metabolism of alkenes and ether oxygenates.}, number={6}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Kottegoda, Samanthi and Waligora, Elizabeth and Hyman, Michael}, year={2015}, month={Mar}, pages={1966–1976} }
 @article{trippe_wolpert_hyman_ciuffetti_2014, title={RNAi silencing of a cytochrome P450 monoxygenase disrupts the ability of a filamentous fungus, Graphium sp., to grow on short-chain gaseous alkanes and ethers}, volume={25}, ISSN={1572-9729}, url={https://doi.org/10.1007/s10532-013-9646-1}, DOI={10.1007/s10532-013-9646-1}, abstractNote={Graphium sp. (ATCC 58400), a filamentous fungus, is one of the few eukaryotes that grows on short-chain alkanes and ethers. In this study, we investigated the genetic underpinnings that enable this fungus to catalyze the first step in the alkane and ether oxidation pathway. A gene, CYP52L1, was identified, cloned and functionally characterized as an alkane-oxidizing cytochrome P450 (GSPALK1). Analysis of CYP52L1 suggests that it is a member of the CYP52 cytochrome P450 family, which is comprised of medium- and long-chain alkane-oxidizing enzymes found in yeasts. However, phylogenetic analysis of GSPALK1 with other CYP52 members suggests they are not closely related. Post-transcriptional ds-RNA-mediated gene silencing of CYP52L1 severely reduced the ability of this fungus to oxidize alkanes and ethers, however, downstream metabolic steps in these pathways were unaffected. Collectively, the results of this study suggest that GSPALK1 is the enzyme that catalyzes the initial oxidation of alkanes and ethers but is not involved in the later steps of alkane or ether metabolism.}, number={1}, journal={Biodegradation}, author={Trippe, Kristin M. and Wolpert, Thomas J. and Hyman, Michael R. and Ciuffetti, Lynda M.}, year={2014}, month={Feb}, pages={137–151} }
 @article{hyman_2013, title={Biodegradation of gasoline ether oxygenates}, volume={24}, ISSN={1879-0429}, DOI={10.1016/j.copbio.2012.10.005}, abstractNote={Ether oxygenates such as methyl tertiary butyl ether (MTBE) are added to gasoline to improve fuel combustion and decrease exhaust emissions. Ether oxygenates and their tertiary alcohol metabolites are now an important group of groundwater pollutants. This review highlights recent advances in our understanding of the microorganisms, enzymes and pathways involved in both the aerobic and anaerobic biodegradation of these compounds. This review also aims to illustrate how these microbiological and biochemical studies have guided, and have helped refine, molecular and stable isotope-based analytical approaches that are increasingly being used to detect and quantify biodegradation of these compounds in contaminated environments.}, number={3}, journal={Current Opinion in Biotechnology}, author={Hyman, Michael}, year={2013}, month={Jun}, pages={443–450} }
 @article{lan_smith_hyman_2013, title={Oxidation of Cyclic Ethers by Alkane-Grown Mycobacterium vaccae JOB5}, volume={23}, ISSN={1520-6831}, url={https://onlinelibrary.wiley.com/doi/abs/10.1002/rem.21364}, DOI={10.1002/rem.21364}, abstractNote={In this study we investigated the cometabolic oxidation of six cyclic ethers by alkane-grown Mycobacterium vaccae JOB5. These ethers include, among others, tetrahydrofuran (THF), 1,4-dioxane (14D), 1,3-dioxolane (13DO), and tetrahydropyran (THP). Cells grown on propane, n-butane, n-pentane, isobutane, or isopentane oxidized all six ethers. Ether-degrading activity was inhibited by acetylene in alkane-grown cells and was largely absent from cells grown on dextrose-containing media. Propane competitively inhibited THF oxidation. γ-Butyrolactone (γBL) accumulated and was also further oxidized during THF oxidation by propane-grown cells. In contrast, no products were detected during 14D oxidation. Propane-grown cells also rapidly oxidized 3-hydroxytertrahydrofuran and exhibited strong hemiacetal-oxidizing activity in an assay following methyl formate production from mixtures of methanol and formaldehyde. These observations suggest γBL is likely generated during THF oxidation through further oxidation of 2-hydroxytetrahydrofuran. Limited growth of strain JOB5 was supported by several cyclic ethers and the corresponding lactones and diols potentially derived from these compounds. However, strain JOB5 grew more readily on 4-hydroxybutyrate, the product of γBL hydrolysis. The ability of strain JOB5 to productively assimilate THF-derived metabolites during growth on n-alkanes was examined in carbon-limited batch cultures. Relative to C-limited growth on n-pentane alone, culture growth increased up to twofold in the presence of THF while no stimulation of growth was observed in comparable experiments conducted with n-pentane and 14D. Our results are discussed in terms of their significance to our understanding of cyclic ether cometabolism and their potential impact on approaches for cyclic ether biodegradation in the environment. © 2013 Wiley Periodicals, Inc.}, number={4}, journal={Remediation Journal}, author={Lan, Renny S. and Smith, Christy A. and Hyman, Michael R.}, year={2013}, pages={23–42} }
 @article{hamilton_luginbuhl_hyman_2012, title={Preparing Science-Trained Professionals for the Biotechnology Industry: A Ten-Year Perspective on a Professional Science Master’s Program}, volume={13}, ISSN={1935-7877}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3577309/}, DOI={10.1128/jmbe.v13i1.375}, abstractNote={The biotechnology industry has a need for business-savvy scientists; however, this is not the way scientists are traditionally trained at universities and colleges. To address this need, universities have developed Professional Science Master’s (PSM) degree programs that offer advanced training in a technical field along with professional skills development through team-based projects and internships. Nearly ten years ago, the Department of Microbiology at NCSU started a PSM program in Microbial Biotechnology (MMB). This article provides an overview of the MMB program, and shares some of the lessons that we have learned.}, number={1}, journal={Journal of Microbiology & Biology Education : JMBE}, publisher={American Society for Microbiology}, author={Hamilton, Paul T. and Luginbuhl, Sarah C. and Hyman, Michael}, year={2012}, month={May}, pages={39–44} }
 @article{aslett_haas_hyman_2011, title={Identification of tertiary butyl alcohol (TBA)-utilizing organisms in BioGAC reactors using 13C-DNA stable isotope probing}, volume={22}, ISSN={1572-9729}, DOI={10.1007/s10532-011-9455-3}, abstractNote={Biodegradation of the gasoline oxygenates methyl tertiary-butyl ether (MTBE) and ethyl tertiary-butyl ether (ETBE) can cause tertiary butyl alcohol (TBA) to accumulate in gasoline-impacted environments. One remediation option for TBA-contaminated groundwater involves oxygenated granulated activated carbon (GAC) reactors that have been self-inoculated by indigenous TBA-degrading microorganisms in ground water extracted from contaminated aquifers. Identification of these organisms is important for understanding the range of TBA-metabolizing organisms in nature and for determining whether self-inoculation of similar reactors is likely to occur at other sites. In this study (13)C-DNA-stable isotope probing (SIP) was used to identify TBA-utilizing organisms in samples of self-inoculated BioGAC reactors operated at sites in New York and California. Based on 16S rRNA nucleotide sequences, all TBA-utilizing organisms identified were members of the Burkholderiales order of the β-proteobacteria. Organisms similar to Cupriavidus and Methylibium were observed in both reactor samples while organisms similar to Polaromonas and Rhodoferax were unique to the reactor sample from New York. Organisms similar to Hydrogenophaga and Paucibacter strains were only detected in the reactor sample from California. We also analyzed our samples for the presence of several genes previously implicated in TBA oxidation by pure cultures of bacteria. Genes Mpe_B0532, B0541, B0555, and B0561 were all detected in (13)C-metagenomic DNA from both reactors and deduced amino acid sequences suggested these genes all encode highly conserved enzymes. One gene (Mpe_B0555) encodes a putative phthalate dioxygenase-like enzyme that may be particularly appropriate for determining the potential for TBA oxidation in contaminated environmental samples.}, number={5}, journal={Biodegradation}, author={Aslett, Denise and Haas, Joseph and Hyman, Michael}, year={2011}, month={Sep}, pages={961–972} }
 @article{house_hyman_2010, title={Effects of gasoline components on MTBE and TBA cometabolism by Mycobacterium austroafricanum JOB5}, volume={21}, ISSN={1572-9729}, url={https://doi.org/10.1007/s10532-009-9321-8}, DOI={10.1007/s10532-009-9321-8}, abstractNote={In this study we have examined the effects of individual gasoline hydrocarbons (C(5-10,12,14) n-alkanes, C(5-8) isoalkanes, alicyclics [cyclopentane and methylcyclopentane] and BTEX compounds [benzene, toluene, ethylbenzene, m-, o-, and p-xylene]) on cometabolism of methyl tertiary butyl ether (MTBE) and tertiary butyl alcohol (TBA) by Mycobacterium austroafricanum JOB5. All of the alkanes tested supported growth and both MTBE and TBA oxidation. Growth on C(5-8) n-alkanes and isoalkanes was inhibited by acetylene whereas growth on longer chain n-alkanes was largely unaffected by this gas. However, oxidation of both MTBE and TBA by resting cells was consistently inhibited by acetylene, irrespective of the alkane used as growth-supporting substrate. A model involving two separate but co-expressed alkane-oxidizing enzyme systems is proposed to account for these observations. Cyclopentane, methylcyclopentane, benzene and ethylbenzene did not support growth but these compounds all inhibited MTBE and TBA oxidation by alkane-grown cells. In the case of benzene, the inhibition was shown to be due to competitive interactions with both MTBE and TBA. Several aromatic compounds (p-xylene > toluene > m-xylene) did support growth and cells previously grown on these substrates also oxidized MTBE and TBA. Low concentrations of toluene (<10 microM) stimulated MTBE and TBA oxidation by alkane-grown cells whereas higher concentrations were inhibitory. The effects of acetylene suggest strain JOB5 also has two distinct toluene-oxidizing activities. These results have been discussed in terms of their impact on our understanding of MTBE and TBA cometabolism and the enzymes involved in these processes in mycobacteria and other bacteria.}, number={4}, journal={Biodegradation}, author={House, Alan J. and Hyman, Michael R.}, year={2010}, month={Jul}, pages={525–541} }
 @article{smith_hyman_2010, title={Oxidation of gasoline oxygenates by closely related non-haem-iron alkane hydroxylases in Pseudomonas mendocina KR1 and other n-octane-utilizing Pseudomonas strains}, volume={2}, ISSN={1758-2229}, url={https://doi.org/10.1111/j.1758-2229.2010.00155.x}, DOI={10.1111/j.1758-2229.2010.00155.x}, abstractNote={Pseudomonas mendocina KR1 oxidizes the gasoline oxygenate methyl tertiary butyl ether (MTBE) to tertiary butyl alcohol (TBA) during growth on C5 -C8 n-alkanes. We have further explored oxidation of ether oxygenates by this strain to help identify the enzyme that catalyses these reactions. High levels of MTBE-oxidizing activity occurred in resting cells grown on C5 -C8 n-alkanes. Lower activities occurred in cells grown on longer-chain n-alkanes (C9 -C11 ) and 1°-alcohols (C5 -C10 ). N-octane-grown cells also oxidized tertiary amyl methyl ether (TAME) to tertiary amyl alcohol (TAA), but did not oxidize ethyl tertiary butyl ether (ETBE), TBA or TAA. A 39 kDa polypeptide in whole cell extracts of n-octane-grown cells strongly cross-reacted with an anti-AlkB polyclonal antiserum in an SDS-PAGE/immunoblot. This polypeptide was absent or less abundant in cells grown on dextrose, dextrose plus dicyclopropylketone or 1-octanol. N-octane-grown cells of Pseudomonas aeruginosa strains KSLA-473 and ATCC 17423 oxidized MTBE and TAME but not ETBE. N-hexadecane-grown cells of these strains and strain PAO1 did not oxidize any of the oxygenates tested. Our results indicate ether oxygenate-degrading activity in alkane-utilizing pseudomonads is consistently observed with close homologues of the GPo1 non-haem-iron alkane hydroxylases but is otherwise not a consistent catalytic feature of these diverse enzymes.}, number={3}, journal={Environmental Microbiology Reports}, author={Smith, Christy A. and Hyman, Michael R.}, year={2010}, month={Jun}, pages={426–432} }
 @article{helping educational reforms to succeed in a microbiology department_2009, url={http://dx.doi.org/10.1128/microbe.4.219.1}, DOI={10.1128/microbe.4.219.1}, abstractNote={D uring the past decade, a rising chorus has called for major reforms in how we teach science, technology, engineering, and mathematics. Part of the impetus for those reforms comes from concerns over growing numbers of students leaving the sciences, the eroding stature of the United States in the sciences compared with countries such as China and India, and also losses of personnel to fields such as biotechnology. In response to such pressures, one path to reform is the development of educational practices that explicitly engage students while enhancing how they learn science. These practices, including inquiry-based laboratory exercises and peer instruction, find empirical support from studies that help to explain the underlying psychological processes that are integral to learning science or other technical subjects. The monograph How People Learn, issued in 2000 by the National Academy of Sciences, further supports approaches in which students are actively engaged in the learning process. Meanwhile, the National Science Foundation and various nongovernment foundations support curricular innovation in the sciences. When it comes to reforming a science curriculum, however, innovation is not enough. Thus, despite spotty reform efforts, U.S. colleges and universities are generally proving slow to change their educational practices. Departments need to be ready for change and then need to develop and implement a vision if those reforms are to take hold. Instead of doing so, too many instructors, particularly those teaching introductory science courses, continue to stupefy their students with rote information. Further, undergraduate curricula in the sciences typically remain an afterthought to research agendas. Thus, we need to understand what makes some reform efforts successful to improve the chances of disseminating these successes to other institutions.}, journal={Microbe Magazine}, year={2009}, month={May} }
 @article{lee_m_2009, title={Helping educational reforms to succeed in a Microbiology Department}, volume={4}, journal={Microbe}, author={Lee, V.S. and M, Hyman}, year={2009}, pages={219–223} }
 @article{mckelvie_hyman_elsner_smith_aslett_lacrampe-couloume_sherwood lollar_2009, title={Isotopic Fractionation of Methyl tert-Butyl Ether Suggests Different Initial Reaction Mechanisms during Aerobic Biodegradation}, volume={43}, ISSN={0013-936X}, url={https://doi.org/10.1021/es803307y}, DOI={10.1021/es803307y}, abstractNote={Carbon isotopic enrichment factors (epsilonC) measured during cometabolic biodegradation of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME) by Pseudonocardia tetrahydrofuranoxydans strain K1 were -2.3 +/- 0.2 per thousand, -1.7 +/- 0.2 per thousand, and -1.7 +/- 0.3 per thousand, respectively. The measured carbon apparent kinetic isotope effect was 1.01 for all compounds, consistent with the expected kinetic isotope effects for both oxidation of the methoxy (or ethoxy) group and enzymatic SN1 biodegradation mechanisms. Significantly, delta13C measurements of the tert-butyl alcohol and tert-amyl alcohol products indicated that the tert-butyl and tert-amyl groups do not participate in the reaction and confirmed that ether biodegradation by strain K1 involves oxidation of the methoxy (or ethoxy) group. Measured hydrogen isotopic enrichment factors (epsilonH) were -100 +/- 10 per thousand, -73 +/- 7 per thousand, and -72 +/- 20 per thousand for MTBE, ETBE, and TAME respectively. Previous results reported for aerobic biodegradation of MTBE by Methylibium petroleiphilum PM1 and Methylibium R8 showed smaller epsilonH values (-35 per thousand and -42 per thousand, respectively). Plots of Delta2H/Delta13C show different slopes for strain K1 compared with strains PM1 and R8, suggesting that different mechanisms are utilized by K1 and PM1/R8 during aerobic MTBE biodegradation.}, number={8}, journal={Environmental Science & Technology}, author={McKelvie, Jennifer R. and Hyman, Michael R. and Elsner, Martin and Smith, Christy and Aslett, Denise M. and Lacrampe-Couloume, Georges and Sherwood Lollar, Barbara}, year={2009}, month={Apr}, pages={2793–2799} }
 @article{skinner_cuiffetti_hyman_2009, title={Metabolism and Cometabolism of Cyclic Ethers by a Filamentous Fungus, a Graphium sp.}, volume={75}, ISSN={0099-2240, 1098-5336}, url={https://aem.asm.org/content/75/17/5514}, DOI={10.1128/AEM.00078-09}, abstractNote={ABSTRACT The filamentous fungus Graphium sp. (ATCC 58400) grows on gaseous n-alkanes and diethyl ether. n-Alkane-grown mycelia of this strain also cometabolically oxidize the gasoline oxygenate methyl tert-butyl ether (MTBE). In this study, we characterized the ability of this fungus to metabolize and cometabolize a range of cyclic ethers, including tetrahydrofuran (THF) and 1,4-dioxane (14D). This strain grew on THF and other cyclic ethers, including tetrahydropyran and hexamethylene oxide. However, more vigorous growth was consistently observed on the lactones and terminal diols potentially derived from these ethers. Unlike the case in all previous studies of microbial THF oxidation, a metabolite, γ-butyrolactone, was observed during growth of this fungus on THF. Growth on THF was inhibited by the same n-alkenes and n-alkynes that inhibit growth of this fungus on n-alkanes, while growth on γ-butyrolactone or succinate was unaffected by these inhibitors. Propane and THF also behaved as mutually competitive substrates, and propane-grown mycelia immediately oxidized THF, without a lag phase. Mycelia grown on propane or THF exhibited comparable high levels of hemiacetal-oxidizing activity that generated methyl formate from mixtures of formaldehyde and methanol. Collectively, these observations suggest that THF and n-alkanes may initially be oxidized by the same monooxygenase and that further transformation of THF-derived metabolites involves the activity of one or more alcohol dehydrogenases. Both propane- and THF-grown mycelia also slowly cometabolically oxidized 14D, although unlike THF oxidation, this reaction was not sustainable. Specific rates of THF, 14D, and MTBE degradation were very similar in THF- and propane-grown mycelia.}, number={17}, journal={Appl. Environ. Microbiol.}, author={Skinner, Kristin and Cuiffetti, Lynda and Hyman, Michael}, year={2009}, month={Sep}, pages={5514–5522} }
 @article{skinner_martinez-prado_hyman_williamson_ciuffetti_2008, title={Pathway, inhibition and regulation of methyl tertiary butyl ether oxidation in a filamentous fungus, Graphium sp}, volume={77}, ISSN={["1432-0614"]}, url={https://doi.org/10.1007/s00253-007-1268-2}, DOI={10.1007/s00253-007-1268-2}, abstractNote={The filamentous fungus Graphium sp. (ATCC 58400) co-metabolically oxidizes the gasoline oxygenate methyl tertiary butyl ether (MTBE) after growth on gaseous n-alkanes. In this study, the enzymology and regulation of MTBE oxidation by propane-grown mycelia of Graphium sp. were further investigated and defined. The trends observed during MTBE oxidation closely resembled those described for propane-grown cells of the bacterium Mycobacterium vaccae JOB5. Propane-grown mycelia initially oxidized the majority ( approximately 95%) of MTBE to tertiary butyl formate (TBF), and this ester was biotically hydrolyzed to tertiary butyl alcohol (TBA). However, unlike M. vaccae JOB5, our results collectively suggest that propane-grown mycelia only have a limited capacity to degrade TBA. None of the products of MTBE exerted a physiologically relevant regulatory effect on the rate of MTBE or propane oxidation, and no significant effect of TBA was observed on the rate of TBF hydrolysis. Together, these results suggest that the regulatory effects of MTBE oxidation intermediates proposed for MTBE-degrading organisms such as Mycobacterium austroafricanum are not universally relevant mechanisms for MTBE-degrading organisms. The results of this study are discussed in terms of their impact on our understanding of the diversity of aerobic MTBE-degrading organisms and pathways and enzymes involved in these processes.}, number={6}, journal={APPLIED MICROBIOLOGY AND BIOTECHNOLOGY}, author={Skinner, Kristin M. and Martinez-Prado, Adriana and Hyman, Michael R. and Williamson, Kenneth J. and Ciuffetti, Lynda M.}, year={2008}, month={Jan}, pages={1359–1365} }
 @article{lee_hyman_luginbuhl_2007, title={The Concept of Readiness in the Academic Department: A Case Study of Undergraduate Education Reform}, volume={32}, ISSN={1573-1758}, url={https://doi.org/10.1007/s10755-006-9032-6}, DOI={10.1007/s10755-006-9032-6}, number={1}, journal={Innovative Higher Education}, author={Lee, Virginia S. and Hyman, Michael R. and Luginbuhl, Geraldine}, year={2007}, month={Jun}, pages={3–18} }
 @article{johnson_hyman_2006, title={Propane and n-butane oxidation by Pseudomonas putida GPo1}, volume={72}, ISSN={["1098-5336"]}, url={https://europepmc.org/articles/PMC1352225}, DOI={10.1128/aem.72.1.950-952.2006}, abstractNote={ABSTRACT Propane and n-butane inhibit methyl tertiary butyl ether oxidation by n-alkane-grown Pseudomonas putida GPo1. Here we demonstrate that these gases are oxidized by this strain and support cell growth. Both gases induced alkane hydroxylase activity and appear to be oxidized by the same enzyme system used for the oxidation of n-octane.}, number={1}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Johnson, EL and Hyman, MR}, year={2006}, month={Jan}, pages={950–952} }
 @article{johnson_smith_kt o'reilly_hyman_2004, title={Induction of methyl Tertiary butyl ether (MTBE)-oxidizing activity in Mycobacterium vaccae JOB5 by MTBE}, volume={70}, ISSN={["0099-2240"]}, url={https://europepmc.org/articles/PMC348811}, DOI={10.1128/AEM.70.2.1023-1030.2004}, abstractNote={ABSTRACT Alkane-grown cells of Mycobacterium vaccae JOB5 cometabolically degrade the gasoline oxygenate methyl tertiary butyl ether (MTBE) through the activities of an alkane-inducible monooxygenase and other enzymes in the alkane oxidation pathway. In this study we examined the effects of MTBE on the MTBE-oxidizing activity of M. vaccae JOB5 grown on diverse nonalkane substrates. Carbon-limited cultures were grown on glycerol, lactate, several sugars, and tricarboxylic acid cycle intermediates, both in the presence and absence of MTBE. In all MTBE-containing cultures, MTBE consumption occurred and tertiary butyl alcohol (TBA) and tertiary butyl formate accumulated in the culture medium. Acetylene, a specific inactivator of alkane- and MTBE-oxidizing activities, fully inhibited MTBE consumption and product accumulation but had no other apparent effects on culture growth. The MTBE-dependent stimulation of MTBE-oxidizing activity in fructose- and glycerol-grown cells was saturable with respect to MTBE concentration (50% saturation level = 2.4 to 2.75 mM), and the onset of MTBE oxidation in glycerol-grown cells was inhibited by both rifampin and chloramphenicol. Other oxygenates (TBA and tertiary amyl methyl ether) also induced the enzyme activity required for their own degradation in glycerol-grown cells. Presence of MTBE also promoted MTBE oxidation in cells grown on organic acids, compounds that are often found in anaerobic, gasoline-contaminated environments. Experiments with acid-grown cells suggested induction of MTBE-oxidizing activity by MTBE is subject to catabolite repression. The results of this study are discussed in terms of their potential implications towards our understanding of the role of cometabolism in MTBE and TBA biodegradation in gasoline-contaminated environments.}, number={2}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Johnson, EL and Smith, CA and KT O'Reilly and Hyman, MR}, year={2004}, month={Feb}, pages={1023–1030} }
 @article{johnson_smith_o'reilly_hyman_2004, title={Induction of methyl tertiary butyl ether (MTBE)-oxidizing activity in Mycobacterium vaccae JOB5 by MTBE}, volume={70}, ISSN={0099-2240}, number={2}, journal={Applied and Environmental Microbiology}, author={Johnson, Erika L. and Smith, Christy A. and O'Reilly, Kirk T. and Hyman, Michael R.}, year={2004}, month={Feb}, pages={1023–1030} }
 @article{smith_hyman_2004, title={Oxidation of methyl tert-butyl ether by alkane hydroxylase in dicyclopropylketone-induced and n-octane-grown Pseudomonas putida GPo1}, volume={70}, ISSN={0099-2240}, url={https://europepmc.org/articles/PMC492405}, DOI={10.1128/AEM.70.8.4544-4550.2004}, abstractNote={ABSTRACT The alkane hydroxylase enzyme system in Pseudomonas putida GPo1 has previously been reported to be unreactive toward the gasoline oxygenate methyl tert-butyl ether (MTBE). We have reexamined this finding by using cells of strain GPo1 grown in rich medium containing dicyclopropylketone (DCPK), a potent gratuitous inducer of alkane hydroxylase activity. Cells grown with DCPK oxidized MTBE and generated stoichiometric quantities of tert-butyl alcohol (TBA). Cells grown in the presence of DCPK also oxidized tert-amyl methyl ether but did not appear to oxidize either TBA, ethyl tert-butyl ether, or tert-amyl alcohol. Evidence linking MTBE oxidation to alkane hydroxylase activity was obtained through several approaches. First, no TBA production from MTBE was observed with cells of strain GPo1 grown on rich medium without DCPK. Second, no TBA production from MTBE was observed in DCPK-treated cells of P. putida GPo12, a strain that lacks the alkane-hydroxylase-encoding OCT plasmid. Third, all n-alkanes that support the growth of strain GPo1 inhibited MTBE oxidation by DCPK-treated cells. Fourth, two non-growth-supporting n-alkanes (propane and n-butane) inhibited MTBE oxidation in a saturable, concentration-dependent process. Fifth, 1,7-octadiyne, a putative mechanism-based inactivator of alkane hydroxylase, fully inhibited TBA production from MTBE. Sixth, MTBE-oxidizing activity was also observed in n-octane-grown cells. Kinetic studies with strain GPo1 grown on n-octane or rich medium with DCPK suggest that MTBE-oxidizing activity may have previously gone undetected in n-octane-grown cells because of the unusually high Ks value (20 to 40 mM) for MTBE.}, number={8}, journal={Applied and Environmental Microbiology}, author={Smith, Christy A. and Hyman, Michael R.}, year={2004}, month={Aug}, pages={4544–4550} }
 @book{lee_greene_wellman_al._2004, title={Teaching and learning through inquiry: A guidebook for institutions and instructors}, publisher={Sterling, Va.: Stylus Pub.}, author={Lee, V. S. and Greene, D. B. and Wellman, D. J. and al.}, year={2004} }
 @article{pon_hyman_semprini_2003, title={Acetylene inhibition of trichloroethene and vinyl chloride reductive dechlorination}, volume={37}, ISSN={["1520-5851"]}, DOI={10.1021/es026352i}, abstractNote={Kinetic studies reported here have shown that acetylene is a potent reversible inhibitor of reductive dehalogenation of trichloroethene (TCE) and vinyl chloride (VC) by a mixed dehalogenating anaerobic culture. The mixed culture was enriched from a contaminated site in Corvallis, OR, and exhibited methanogenic, acetogenic, and reductive dehalogenation activities. The H2-fed culture transformed TCE to ethene via cis-dichloroethene (c-DCE) and VC as intermediates. Batch kinetic studies showed acetylene reversibly inhibited reduction of both TCE and VC, and the levels of inhibition were strongly dependent on acetylene concentrations in both cases. Acetylene concentrations of 192 and 12 microM, respectively, were required to achieve 90% inhibition in rates of TCE and VC transformation at an aqueous concentration of 400 microM. Acetylene also inhibited methane production (90% inhibition at 48 microM) but did not inhibit H2-dependent acetate production. Mass balances conducted during the studies of VC inhibition showed that acetogenesis, VC transformation to ethene, and methane production were responsible for 52%, 47%, and 1% of the H2 consumption, respectively. The results indicate that halorespiration is the dominant process responsible for VC and TCE transformation and that dehalorespiring organisms are the target of acetylene inhibition. Acetylene has potential use as a reversible inhibitor to probe the biological activities of reductive dechlorination and methanogenesis. It can be added to inhibit reactions and then removed to permit reactions to proceed. Thus, it can be a powerful tool for investigating intrinsic and enhanced anaerobic remediation of chloroethenes at contaminated sites. The results also suggest that acetylene produced abiotically by reactions of chlorinated ethenes with zero-valent iron could inhibit the biological transformation of VC to ethene.}, number={14}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Pon, G and Hyman, MR and Semprini, L}, year={2003}, month={Jul}, pages={3181–3188} }
 @article{smith_kt o'reilly_hyman_2003, title={Characterization of the initial reactions during the cometabolic oxidation of methyl tert-butyl ether by propane-grown Mycobacterium vaccae JOB5}, volume={69}, ISSN={["0099-2240"]}, url={https://europepmc.org/articles/PMC143618}, DOI={10.1128/AEM.69.2.796-804.2003}, abstractNote={ABSTRACT}, number={2}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Smith, CA and KT O'Reilly and Hyman, MR}, year={2003}, month={Feb}, pages={796–804} }
 @article{smith_o'reilly_hyman_2003, title={Characterization of the initial reactions during the cometabolic oxidation of methyl tert-butyl ether by propane-grown Mycobacterium vaccae JOB5}, volume={69}, ISSN={0099-2240}, number={2}, journal={Applied and Environmental Microbiology}, author={Smith, Christy A. and O'Reilly, Kirk T. and Hyman, Michael R.}, year={2003}, month={Feb}, pages={796–804} }
 @article{smith_kt o'reilly_hyman_2003, title={Cometabolism of methyl tertiary butyl ether and gaseous n-alkanes by Pseudomonas mendocina KR-1 grown on C(5) to C(8) n-alkanes}, volume={69}, ISSN={["0099-2240"]}, url={https://europepmc.org/articles/PMC309952}, DOI={10.1128/AEM.69.12.7385-7394.2003}, abstractNote={ABSTRACT Pseudomonas mendocina KR-1 grew well on toluene, n-alkanes (C5 to C8), and 1° alcohols (C2 to C8) but not on other aromatics, gaseous n-alkanes (C1 to C4), isoalkanes (C4 to C6), 2° alcohols (C3 to C8), methyl tertiary butyl ether (MTBE), or tertiary butyl alcohol (TBA). Cells grown under carbon-limited conditions on n-alkanes in the presence of MTBE (42μ mol) oxidized up to 94% of the added MTBE to TBA. Less than 3% of the added MTBE was oxidized to TBA when cells were grown on either 1° alcohols, toluene, or dextrose in the presence of MTBE. Concentrated n-pentane-grown cells oxidized MTBE to TBA without a lag phase and without generating tertiary butyl formate (TBF) as an intermediate. Neither TBF nor TBA was consumed by n-pentane-grown cells, while formaldehyde, the expected C1 product of MTBE dealkylation, was rapidly consumed. Similar Ks values for MTBE were observed for cells grown on C5 to C8n-alkanes (12.95 ± 2.04 mM), suggesting that the same enzyme oxidizes MTBE in cells grown on each n-alkane. All growth-supporting n-alkanes (C5 to C8) inhibited MTBE oxidation by resting n-pentane-grown cells. Propane (Ki = 53 μM) and n-butane (Ki = 16 μM) also inhibited MTBE oxidation, and both gases were also consumed by cells during growth on n-pentane. Cultures grown on C5 to C8n-alkanes also exhibited up to twofold-higher levels of growth in the presence of propane or n-butane, whereas no growth stimulation was observed with methane, ethane, MTBE, TBA, or formaldehyde. The results are discussed in terms of their impacts on our understanding of MTBE biodegradation and cometabolism.}, number={12}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Smith, CA and KT O'Reilly and Hyman, MR}, year={2003}, month={Dec}, pages={7385–7394} }
 @article{smith_o'reilly_hyman_2003, title={Cometabolism of methyl tertiary butyl ether and gaseous n-alkanes by Pseudomonas mendocina KR-1 grown on C5 to C8 n-alkanes}, volume={69}, ISSN={0099-2240}, number={12}, journal={Applied and Environmental Microbiology}, author={Smith, Christy A. and O'Reilly, Kirk T. and Hyman, Michael R.}, year={2003}, month={Dec}, pages={7385–7394} }
 @article{chang_hyman_williamson_2002, title={Cooxidation of naphthalene and other polycyclic aromatic hydrocarbons by the nitrifying bacterium, Nitrosomonas europaea}, volume={13}, number={6}, journal={Biodegradation (Dordrecht)}, author={Chang, S. W. and Hyman, M. R. and Williamson, K. J.}, year={2002}, pages={373–381} }
 @article{cooxidation of naphthalene and other polycyclic aromatic hydrocarbons by the nitrifying bacterium, nitrosomonas europaea._2002, url={https://doi.org/10.1023/a:1022811430030}, DOI={10.1023/a:1022811430030}, abstractNote={The soil nitrifying bacterium Nitrosomonas europaea has shown the ability to transform cometabolically naphthalene as well as other 2- and 3-ringed polycyclic aromatic hydrocarbons (PAHs) to more oxidized products. All of the observed enzymatic reactions were inhibited by acetylene, a selective inhibitor of ammonia monooxygenase (AMO). A strong inhibitory effect of naphthalene on ammonia oxidation by N. europaea was observed. Naphthalene was readily oxidized by N. europaea and 2-naphthol was detected as a major product (85%) of naphthalene oxidation. The maximum naphthol production rate was 1.65 nmole/mg protein-min in the presence of 240 microM naphthalene and 10 mM NH4+. Our results demonstrate that the oxidation between ammonia and naphthalene showed a partial competitive inhibition. The relative ratio of naphthalene and ammonia oxidation, depending on naphthalene concentrations, demonstrated that the naphthalene was oxidized 2200-fold slower than ammonia at lower concentration of naphthalene (15 microM) whereas naphthalene was oxidized only 100-fold slower than ammonia oxidation. NH4(+)- and N2H4-dependent O2 uptake measurement demonstrated irreversible inhibitory effects of the naphthalene and subsequent oxidation products on AMO and HAO activity.}, journal={Biodegradation}, year={2002}, month={Jan} }
 @article{o'reilly_moir_taylor_smith_hyman_2001, title={Hydrolysis of tert-Butyl Methyl Ether (MTBE) in Dilute Aqueous Acid}, volume={35}, ISSN={0013-936X}, url={https://doi.org/10.1021/es001431k}, DOI={10.1021/es001431k}, abstractNote={tert-Butyl methyl ether (MTBE) is generally considered to be resistant to chemical transformation in aqueous solution. This lack of reactivity has led to concerns of the long-term impacts of MTBE in groundwater. Although hydrolysis in the presence of strong acids has been recognized as a mechanism for MTBE transformation, it has been discounted as a significant reaction under environmental conditions. In this study, we have examined the fate of MTBE and other ether oxygenates under moderately acidic conditions (> or=pH 1). The results demonstrate that MTBE is sensitive to acid-catalyzed hydrolysis reaction that generates tert-butyl alcohol (TBA) and methanol as products. The reaction is first-order with respect to the concentration of MTBE and hydronium ion with a second-order rate constant of about 0.9 x 10(-2) M(-1) h(-1) at 26 degrees C. Commercially available acidic ion-exchange resins were also shown to catalyze the hydrolysis of MTBE at near neutral pH. Pseudo-first-order rate constants were observed to be as high as 0.03 h(-1) at 25 degrees C and 0.12 h(-1) at 35 degrees C. These findings are discussed in terms of their possible implications for the treatment and environmental fate of MTBE and other gasoline oxygenates.}, number={19}, journal={Environmental Science & Technology}, author={O'Reilly, Kirk T. and Moir, Michael E. and Taylor, Christine D. and Smith, Christy A. and Hyman, Michael R.}, year={2001}, month={Oct}, pages={3954–3961} }
 @article{arp_yeager_hyman_2001, title={Molecular and cellular fundamentals of aerobic cometabolism of trichloroethylene}, volume={12}, number={2}, journal={Biodegradation (Dordrecht)}, author={Arp, D. J. and Yeager, C. M. and Hyman, M. R.}, year={2001}, pages={81–103} }
 @article{molecular and cellular fundamentals of aerobic cometabolism of trichloroethylene._2001, url={https://doi.org/10.1023/a:1012089908518}, DOI={10.1023/a:1012089908518}, abstractNote={Cometabolism recognizes that microorganisms can transform non-growth-supporting substrates. The term "cometabolism" was first introduced over 30 years ago and has been redefined, criticized, and used widely ever since. In this review we have examined the aerobic cometabolism of chlorinated solvents, with a particular emphasis on the cometabolism of trichloroethylene. Monooxygenases or dioxygenases with relaxed substrate ranges initiate these transformations. The physiological role of the oxygenases is to initiate the metabolism of growth-supporting substrates (e.g., methane, propane, butane, toluene, ethylene, and ammonia). Diverse enzymes catalyze these oxidative reactions with chlorinated solvents. Synthesis of most of these enzymes is induced by the presence of the growth-supporting substrate and is largely regulated at the level of gene transcription. The genes that code for a given oxygenase are usually clustered together in a single operon and often share homology with counterparts that code for the subunits of related oxygenases in other bacteria. During cometabolism the growth-supporting and non-growth-supporting substrates can both bind to the oxygenase. Transformation of chlorinated solvents by these enzymes presents the cell with a new set of compounds. Some of these compounds are toxic to the cells, others are stable products that are expelled from the cell, and in a few cases the cells utilize the products. The combined effects of cometabolism can have a profound influence on a cell.}, journal={Biodegradation}, year={2001}, month={Jan} }
 @article{vancheeswaran_hyman_semprini_1999, title={Anaerobic Biotransformation of Trichlorofluoroethene in Groundwater Microcosms}, volume={33}, ISSN={0013-936X}, url={https://doi.org/10.1021/es9811952}, DOI={10.1021/es9811952}, abstractNote={The biological reduction of trichlorofluoroethene (TCFE) was investigated in anaerobic groundwater microcosms. TCFE was reductively dehalogenated by microorganisms to produce three dichlorofluoroethene isomers, with cis-1,2-dichlorofluoroethene (c-DCFE) being the main isomer formed. Further sequential biological transformation of these compounds to mono-chlorofluoroethene isomers was incomplete and occurred at much slower rates. The rates of TCFE reduction were compared to the rates of reduction of two common chlorinated solvents, perchloroethene (PCE) and trichloroethene (TCE), when present at similar concentrations. Aqueous concentrations ranged from 7.0 to 14.0 mg/L for TCFE and from 7.5 to 15.0 mg/L for PCE and TCE. Similar rates of PCE and TCE transformation relative to TCFE were observed in single-compound tests (PCE, TCE, and TCFE in separate microcosms) and when the contaminants were present together as mixtures in the microcosms. The close similarities between the time course and kinetics of TCFE...}, number={12}, journal={Environmental Science & Technology}, author={Vancheeswaran, Sanjay and Hyman, Michael R. and Semprini, Lewis}, year={1999}, month={Jun}, pages={2040–2045} }
 @article{cometabolism of chlorinated solvents by nitrifying bacteria: kinetics, substrate interactions, toxicity effects, and bacterial response _1999, url={https://doi.org/10.1002/(sici)1097-0290(19990620)63:6<756::aid-bit14>3.0.co;2-z}, DOI={10.1002/(sici)1097-0290(19990620)63:6<756::aid-bit14>3.0.co;2-z}, abstractNote={Pure cultures of ammonia-oxidizing bacteria, Nitrosomonas europaea, were exposed to trichloroethylene (TCE), 1,1-dichloroethylene (1,1-DCE), chloroform (CF), 1,2-dichloroethane (1,2-DCA), or carbon tetrachloride (CT), in the presence of ammonia, in a quasi-steady-state bioreactor. Estimates of enzyme kinetics constants, solvent inactivation constants, and culture recovery constants were obtained by simultaneously fitting three model curves to experimental data using nonlinear optimization techniques and an enzyme kinetics model, referred to as the inhibition, inactivation, and recovery (IIR) model, that accounts for inhibition of ammonia oxidation by the solvent, enzyme inactivation by solvent product toxicity, and respondent synthesis of new enzyme (recovery). Results showed relative enzyme affinities for ammonia monooxygenase (AMO) of 1,1-DCE approximately TCE > CT > NH(3) > CF > 1,2-DCA. Relative maximum specific substrate transformation rates were NH(3) > 1,2-DCA > CF > TCE approximately 1,1-DCE > CT (=0). The TCE, CF, and 1,1-DCE inactivated the cells, with 1,1-DCE being about three times more potent than TCE or CF. Under the conditions of these experiments, inactivating injuries caused by TCE and 1,1-DCE appeared limited primarily to the AMO enzyme, but injuries caused by CF appeared to be more generalized. The CT was not oxidized by N. europaea while 1,2-DCA was oxidized quite readily and showed no inactivation effects. Recovery capabilities were demonstrated with all solvents except CF. A method for estimating protein yield, the relationship between the transformation capacity model and the IIR model, and a condition necessary for sustainable cometabolic treatment of inactivating substrates are presented. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 54: 520-534, 1997.}, journal={Biotechnology and bioengineering}, year={1999}, month={Jun} }
 @article{yeager_bottomley_arp_hyman_1999, title={Inactivation of toluene 2-monooxygenase in Burkholderia cepacia G4 by alkynes}, volume={65}, ISSN={0099-2240}, number={2}, journal={Applied and Environmental Microbiology}, author={Yeager, C. M. and Bottomley, P. J. and Arp, D. J. and Hyman, M. R.}, year={1999}, month={Feb}, pages={632–639} }
 @article{inactivation of toluene 2-monooxygenase in burkholderia cepacia g4 by alkynes._1999, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/9925593/?tool=EBI}, journal={Applied and environmental microbiology}, year={1999}, month={Feb} }
 @article{schroth_istok_conner_hyman_haggerty_o'reilly_1998, title={Spatial Variability in In Situ Aerobic Respiration and Denitrification Rates in a Petroleum-Contaminated Aquifer}, volume={36}, ISSN={1745-6584}, url={https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1745-6584.1998.tb02099.x}, DOI={10.1111/j.1745-6584.1998.tb02099.x}, abstractNote={An extensive series of single‐well, push‐pull tests was performed to quantify horizontal and vertical spatial variability in aerobic respiration and denitrification rates in a petroleum‐contaminated aquifer. The results indicated rapid consumption of injected O2 or NO3− in shallow and deep test intervals across a large portion of the site. Computed first‐order rate coefficients for aerobic respiration ranged from 0.15 to 1.69 h−1 in the shallow test interval, and from 0.08 to 0.83 h−1 in the deep test interval. The largest aerobic respiration rates occurred on the upgradient edge of the contaminant plume where concentrations of petroleum hydrocarbons and dissolved O2 were relatively high. Computed first‐order rate coefficients for denitrification ranged from 0.09 to 0.42 h−1 in the shallow test interval, and from 0.11 to 0.28 h−1 in the deep test interval. The largest denitrification rates occurred on the downgradient edge of the plume where hydrocarbon concentrations were relatively high but dissolved oxygen concentrations were small. The rates reported here represent maximal rates of aerobic respiration and denitrification, as supported by high concentrations of electron acceptors in the injected test solutions. Production of dissolved CO2 during aerobic respiration and denitrification tests provided evidence that O2 and NO3− consumption was largely due to microbial activity. Additional evidence for microbial NO3− consumption was provided by reduced rates of NO3−consumption when dissolved O2 was injected with NO3−, and by increased N2O production when C2H2 was injected with NO3−.}, number={6}, journal={Groundwater}, author={Schroth, M. H. and Istok, J. D. and Conner, G. T. and Hyman, M. R. and Haggerty, R. and O'Reilly, K. T.}, year={1998}, pages={924–937} }
 @article{ely_williamson_hyman_arp_1997, title={Cometabolism of chlorinated solvents by nitrifying bacteria: kinetics, substrate interactions, toxicity effects, and bacterial response}, volume={54}, ISSN={0006-3592}, url={https://doi.org/10.1002/(SICI)1097-0290(19970620)54:6<520::AID-BIT3>3.0.CO;2-L}, DOI={10.1002/(SICI)1097-0290(19970620)54:6<520::AID-BIT3>3.0.CO;2-L}, abstractNote={Pure cultures of ammonia-oxidizing bacteria, Nitrosomonas europaea, were exposed to trichloroethylene (TCE), 1,1-dichloroethylene (1,1-DCE), chloroform (CF), 1,2-dichloroethane (1,2-DCA), or carbon tetrachloride (CT), in the presence of ammonia, in a quasi-steady-state bioreactor. Estimates of enzyme kinetics constants, solvent inactivation constants, and culture recovery constants were obtained by simultaneously fitting three model curves to experimental data using nonlinear optimization techniques and an enzyme kinetics model, referred to as the inhibition, inactivation, and recovery (IIR) model, that accounts for inhibition of ammonia oxidation by the solvent, enzyme inactivation by solvent product toxicity, and respondent synthesis of new enzyme (recovery). Results showed relative enzyme affinities for ammonia monooxygenase (AMO) of 1,1-DCE ≈ TCE > CT > NH3 > CF > 1,2-DCA. Relative maximum specific substrate transformation rates were NH3 > 1,2-DCA > CF > TCE ≈ 1,1-DCE > CT (=0). The TCE, CF, and 1,1-DCE inactivated the cells, with 1,1-DCE being about three times more potent than TCE or CF. Under the conditions of these experiments, inactivating injuries caused by TCE and 1,1-DCE appeared limited primarily to the AMO enzyme, but injuries caused by CF appeared to be more generalized. The CT was not oxidized by N. europaea while 1,2-DCA was oxidized quite readily and showed no inactivation effects. Recovery capabilities were demonstrated with all solvents except CF. A method for estimating protein yield, the relationship between the transformation capacity model and the IIR model, and a condition necessary for sustainable cometabolic treatment of inactivating substrates are presented. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 54: 520–534, 1997.}, number={6}, journal={Biotechnology and Bioengineering}, author={Ely, R. L. and Williamson, K. J. and Hyman, M. R. and Arp, D. J.}, year={1997}, month={Jun}, pages={520–534} }
 @article{hardison_curry_ciuffetti_hyman_1997, title={Metabolism of Diethyl Ether and Cometabolism of Methyl tert-Butyl Ether by a Filamentous Fungus, a Graphium sp}, volume={63}, ISSN={0099-2240}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1389222/}, number={8}, journal={Applied and Environmental Microbiology}, author={Hardison, L. K. and Curry, S. S. and Ciuffetti, L. M. and Hyman, M. R.}, year={1997}, month={Aug}, pages={3059–3067} }
 @article{metabolism of diethyl ether and cometabolism of methyl tert-butyl ether by a filamentous fungus, a graphium sp._1997, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16535667/?tool=EBI}, journal={Applied and environmental microbiology}, year={1997}, month={Aug} }
 @article{regulation of the synthesis and activity of ammonia monooxygenase in nitrosomonas europaea by altering ph to affect nh(inf3) availability._1997, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16535741/?tool=EBI}, journal={Applied and environmental microbiology}, year={1997}, month={Nov} }
 @article{stein_arp_hyman_1997, title={Regulation of the synthesis and activity of ammonia monooxygenase in Nitrosomonas europaea by altering pH to affect NH3 availability}, volume={63}, journal={Applied and Environmental Microbiology}, author={Stein, L.Y. and Arp, D.J. and Hyman, M.R.}, year={1997}, pages={4588–4592} }
 @article{istok_humphrey_schroth_hyman_o'reilly_1997, title={Single-Well, “Push-Pull” Test for In Situ Determination of Microbial Activities}, volume={35}, ISSN={1745-6584}, url={https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1745-6584.1997.tb00127.x}, DOI={10.1111/j.1745-6584.1997.tb00127.x}, abstractNote={A single‐well, “push‐pull” test method is proposed for the in situ determination of microbial metabolic activities in ground‐water aquifers. The method consists of the pulse‐type injection (“push”) of a test solution into the saturated zone of an aquifer through the screen of an existing monitoring well followed by the extraction (“pull”) of the test solution/ground‐water mixture from the same well. The test solution contains a tracer and one or more reactive solutes selected to investigate specific microbial activities. During the injection phase, the test solution flows radially away from the monitoring well into the aquifer. Within the aquifer, biologically reactive components of the test solution are converted to various products by the indigenous microbial community. During the extraction phase, flow is reversed and solute concentrations are measured to obtain breakthrough curves, which are used to compute the quantities of reactant(s) consumed and/or product(s) formed during the test and reaction rates. Tests were performed to determine rates of aerobic respiration, denitrification, sulfate reduction, and methanogenesis in a petroleum contaminated aquifer in western Oregon. High rates of oxygen, nitrate, nitrite, and hydrogen utilization and nitrite, and carbon dioxide production support the hypothesis that petroleum contamination has resulted in an increase in microbial activity in the anaerobic portion of the site. The results suggest that the push‐pull test method should be useful for obtaining quantitative information on a wide range of in situ microbial processes.}, number={4}, journal={Groundwater}, author={Istok, J. D. and Humphrey, M. D. and Schroth, M. H. and Hyman, M. R. and O'Reilly, K. T.}, year={1997}, pages={619–631} }
 @article{curry_ciuffetti_hyman_1996, title={Inhibition of Growth of a Graphium sp. on Gaseous n-Alkanes by Gaseous n-Alkynes and n-Alkenes}, volume={62}, ISSN={0099-2240}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1388884/}, number={6}, journal={Applied and Environmental Microbiology}, author={Curry, S. and Ciuffetti, L. and Hyman, M.}, year={1996}, month={Jun}, pages={2198–2200} }
 @article{inhibition of growth of a graphium sp. on gaseous n-alkanes by gaseous n-alkynes and n-alkenes._1996, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16535346/?tool=EBI}, journal={Applied and environmental microbiology}, year={1996}, month={Jun} }
 @article{ely_williamson_guenther_hyman_arp_1995, title={A cometabilic kinetics model incorporating enzyme inhbition, inactivation, and recovery: I. Model development, analysis, and testing}, volume={46}, ISSN={0006-3592}, url={https://doi.org/10.1002/bit.260460305}, DOI={10.1002/bit.260460305}, abstractNote={Cometabolic biodegradation prcesses are important for bioremediation of hazardous waste sites. However, these proceeses are not well understood and have not been modeled thoroughly. Traditional Michaelis–Menten kinetics models often are used, but toxic effects and bacterial responses to toxicity may cause changes in enzyme levels, rendering such models inappropriate. In this article, a conceptual and mathematical model of cometabolic enzyme kinetics i described. Model derivation is based on enzyme/growth‐substrate/nongrowth‐substrate interaction and incorporates enzyme inhibition (caused by the presence of a cometabolic compound), inactivation (resulting from toxicity of a cometabolic product), and recovery (associated with bacterial synthesis of new enbzyme in response to inactivation). The mathematical model consists of a system of two, nonlinear ordinary differential equations that can be solved implicitly using numerical methods, providing estimates of model parameters. Model analysis shows that growth substraate adn nongrowth substrate oxidation rates are related by a dimensionless constant. Reliability of tehy model solution prcedure is verifiedl by abnalyzing data ses, containing random error, from simulated experimentss with trichhloroethyylene (TCE) degradation by ammonia‐oxidizing bacterialunder various conditions. Estimation of the recovery rate contant is deterimined to be sensitive to intial TCE concentration. Model assumptions are evaluated in a companion article using data from TCE degradation experiments with amoniaoxidizing bacteria. © 1995 John Wiley & Sons, Inc.}, number={3}, journal={Biotechnology and Bioengineering}, author={Ely, R. L. and Williamson, K. J. and Guenther, R. B. and Hyman, M. R. and Arp, D. J.}, year={1995}, month={May}, pages={218–231} }
 @article{ely_hyman_arp_guenther_williamson_1995, title={A cometabolic kinetics model incoroporating enzyme inhibition, inactivation, and recovery: II. Trichloroethylene degradaation experiments}, volume={46}, ISSN={0006-3592}, url={https://doi.org/10.1002/bit.260460306}, DOI={10.1002/bit.260460306}, abstractNote={A Cometabolism enzyme kinetics model has been presented which takes into account changes in bacterial activity associated with enzyme inhibitiion, inactivation, inactivation of enzyme resulting from product toxicty, and respondent synthesis of new enzyme. Although this process is inherently unsteady‐state, the model assumes that cometabolic degradation of a compound exhibiting product toxicity can be modeled as pseudo‐steady‐staate under certain conditions. In its simplified from, the model also assumes that enzyme inactivation is directly propoertional to nongrawth substrate oxidation, and that recovery is directly proportionla to growth substrate oxidation. In part 1, model drivation, simplification, and analyses were described. In this articles, model assuptiions are tested by analyzing data from experiments exmining trichloroethylene (TCE) degradation by the ammoniaoxidizing baceterium Nitrosomonas europaea in a quasisteady‐state bioreactor. Model solution results showed steady‐state bioreactor. Model solution results showed TCE to be a competitive inhibitoer of ammonia oxidation, with TCE affinity for ammonia monooxygenase (AMO) being about four times greater than that of ammonia for the enzyme. Inhibition was independent fo TCE oxidation and occurred essentially instantly upon exposure to TCE. In contrast, inactivation of AMO occurred more gradually and was proportional to the rate and amount of TCE oxidized. Evaluation of other O2‐dependent enzymes and electron transport proteins suggested that TCE‐related damage was predominantly confined to AMO. In response to inhibition and/or inactivation, bacterial recovery was initiated, even in the presence of TCE, implying that membranes adn protein synthesis systems were functioning. Analysis of data and comparison of model results showed the inhibition/inactivation/recovery concept to provide a reasonable basis for understandign the effects fo TCE on AMO function and bacterial response. The model assumptions were verified except tht questions remain regarding the factores controlling recovery and its role in the long term. © 1995 John Wiley & Sons, Inc.}, number={3}, journal={Biotechnology and Bioengineering}, author={Ely, R. L. and Hyman, M. R. and Arp, D. J. and Guenther, R. B. and Williamson, K. J.}, year={1995}, month={May}, pages={232–245} }
 @article{hyman_arp_1995, title={Effects of ammonia on the de novo synthesis of polypeptides in cells of Nitrosomonas europaea denied ammonia as an energy source}, volume={177}, ISSN={0021-9193}, number={17}, journal={Journal of Bacteriology}, author={Hyman, M. R. and Arp, D. J.}, year={1995}, month={Sep}, pages={4974–4979} }
 @article{effects of ammonia on the de novo synthesis of polypeptides in cells of nitrosomonas europaea denied ammonia as an energy source._1995, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/7665474/?tool=EBI}, DOI={10.1128/jb.177.17.4974-4979.1995}, abstractNote={The effects of ammonium on the de novo synthesis of polypeptides in the soil-nitrifying bacterium Nitrosomonas europaea have been investigated. Cells were incubated in the presence of both acetylene and NH4+. Under these conditions, the cells were unable to utilize NH4+ as an energy source. Energy to support protein synthesis was supplied by the oxidation of hydroxylamine or other alternative substrates for hydroxylamine oxidoreductase. De novo protein synthesis was detected by 14C incorporation from 14CO2 into polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. In the presence of NH4+, acetylene-treated cells synthesized the 27-kDa polypeptide of ammonia monoxygenase (AMO) and two other major polypeptides (with sizes of 55 and 65 kDa). The synthesis of these polypeptides was completely inhibited by chloramphenicol and attenuated by rifampin. The optimal concentration of hydroxylamine for the in vivo 14C-labeling reaction was found to be 2 mM. The effect of NH4+ concentration was also examined. It was shown to cause a saturable response with a Ks of approximately 2.0 mM NH4+. Labeling studies conducted at different pH values suggest cells respond to NH3 rather than NH4+. No other compounds tested were able to influence the synthesis of the 27-kDa component of AMO, although we have also demonstrated that this polypeptide can be synthesized under anaerobic conditions in cells utilizing pyruvate- or hydrazine-dependent nitrite reduction as an energy source. We conclude that ammonia has a regulatory effect on the synthesis of a subunit of AMO in addition to providing nitrogen for protein synthesis.}, journal={Journal of bacteriology}, year={1995}, month={Sep} }
 @article{hyman_russell_ely_williamson_arp_1995, title={Inhibition, Inactivation, and Recovery of Ammonia-Oxidizing Activity in Cometabolism of Trichloroethylene by Nitrosomonas europaea}, volume={61}, ISSN={0099-2240}, number={4}, journal={Applied and Environmental Microbiology}, author={Hyman, M. R. and Russell, S. A. and Ely, R. L. and Williamson, K. J. and Arp, D. J.}, year={1995}, month={Apr}, pages={1480–1487} }
 @article{inhibition, inactivation, and recovery of ammonia-oxidizing activity in cometabolism of trichloroethylene by nitrosomonas europaea._1995, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16534997/?tool=EBI}, journal={Applied and environmental microbiology}, year={1995}, month={Apr} }
 @article{juliette_hyman_arp_1995, title={Roles of bovine serum albumin and copper in the assay and stability of ammonia monooxygenase activity in vitro}, volume={177}, ISSN={0021-9193}, number={17}, journal={Journal of Bacteriology}, author={Juliette, L. Y. and Hyman, M. R. and Arp, D. J.}, year={1995}, month={Sep}, pages={4908–4913} }
 @article{roles of bovine serum albumin and copper in the assay and stability of ammonia monooxygenase activity in vitro._1995, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/7665467/?tool=EBI}, DOI={10.1128/jb.177.17.4908-4913.1995}, abstractNote={We investigated the effects of bovine serum albumin (BSA) on both the assay and the stability of ammonia-oxidizing activity in cell extracts of Nitrosomonas europaea. Ammonia-dependent O2 uptake activity of freshly prepared extracts did not require BSA. However, a dependence on BSA developed in extracts within a short time. The role of BSA in the assay of ammonia-oxidizing activity apparently is to absorb endogenous free fatty acids which are present in the extracts, because (i) only proteins which bind fatty acids, e.g., BSA or beta-lactoglobulin, supported ammonia-oxidizing activity; (ii) exogenous palmitoleic acid completely inhibited ammonia-dependent O2 uptake activity; (iii) the inhibition caused by palmitoleic acid was reversed only by proteins which bind fatty acids; and (iv) the concentration of endogenous free palmitoleic acid increased during aging of cell extracts. Additionally, the presence of BSA (10 mg/ml) or CuCl2 (500 microM) stabilized ammonia-dependent O2 uptake activity for 2 to 3 days at 4 degrees C. The stabilizing effect of BSA or CuCl2 was apparently due to an inhibition of lipolysis, because both additives inhibited the increase in concentrations of free palmitoleic acid in aging extracts. Other additives which are known to modify lipase activity were also found to stabilize ammonia-oxidizing activity. These additives included HgCl2, lecithin, and phenylmethylsulfonyl fluoride.}, journal={Journal of bacteriology}, year={1995}, month={Sep} }
 @article{hyman_page_arp_1994, title={Oxidation of methyl fluoride and dimethyl ether by ammonia monooxygenase in Nitrosomonas europaea}, volume={60}, ISSN={0099-2240}, number={8}, journal={Applied and Environmental Microbiology}, author={Hyman, M. R. and Page, C. L. and Arp, D. J.}, year={1994}, month={Aug}, pages={3033–3035} }
 @article{oxidation of methyl fluoride and dimethyl ether by ammonia monooxygenase in nitrosomonas europaea._1994, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/8085841/?tool=EBI}, journal={Applied and environmental microbiology}, year={1994}, month={Aug} }
 @article{hyman_arp_1993, title={An electrophoretic study of the thermal- and reductant-dependent aggregation of the 27 kDa component of ammonia monooxygenase from Nitrosomonas europaea}, volume={14}, ISSN={0173-0835}, number={7}, journal={Electrophoresis}, author={Hyman, M. R. and Arp, D. J.}, year={1993}, month={Jul}, pages={619–627} }
 @article{an electrophoretic study of the thermal- and reductant-dependent aggregation of the 27 kda component of ammonia monooxygenase from nitrosomonas europaea._1993, url={https://doi.org/10.1002/elps.1150140197}, DOI={10.1002/elps.1150140197}, abstractNote={Standard protocols for sample preparation for sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) typically involve the combined use of heat and a reductant to fully disrupt protein‐protein interactions and allow for constant ratios of SDS‐binding to individual polypeptides. However, 14C‐labeled forms of the membrane‐bound, active‐site‐containing 27 kDa polypeptide of ammonia monooxygenase from Nitrosomonas europaea undergo an aggregation reaction when cells or membranes are heated in the presence of SDS‐PAGE sample buffer. The aggregate produced after heating at 100°C is a soluble complex which fails to enter the stacking gel in discontinuous SDS‐PAGE gels. The extent of the aggregation reaction is dependent on the temperature of sample preparation, and the reaction exhibits first‐order kinetics at 65°C and 100°C (rates constants = 0.07 and 0.35 min−1, respectively). The rate of the aggregation reaction is further dependent on the concentration of reductant used in the sample buffer. However, the concentration of SDS does not significantly affect the rate of aggregation. The aggregated form of the 27 kDA polypeptide can be isolated by gel‐permeation chromatography in the presence of SDS. The aggregated protein can also be returned to the monomeric state by incubation at high pH in the presence of SDS. The aggregation reaction also occurs with 14C2H2‐labeled polypeptides in other species of autotrophic nitrifiers and a methanotrophic bacterium which expresses the particulate form of methane monooxygenase. We conclude that strongly hydrophobic amino acid sequences present in ammonia monooxygenase are responsible for the aggregation phenomenon.}, journal={Electrophoresis}, year={1993}, month={Jul} }
 @article{in vitro activation of ammonia monooxygenase from nitrosomonas europaea by copper._1993, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/8458839/?tool=EBI}, DOI={10.1128/jb.175.7.1971-1980.1993}, abstractNote={The effect of copper on the in vivo and in vitro activity of ammonia monooxygenase (AMO) from the nitrifying bacterium Nitrosomonas europaea was investigated. The addition of CuCl2 to cell extracts resulted in 5- to 15-fold stimulation of ammonia-dependent O2 consumption, ammonia-dependent nitrite production, and hydrazine-dependent ethane oxidation. AMO activity was further stimulated in vitro by the presence of stabilizing agents, including serum albumins, spermine, or MgCl2. In contrast, the addition of CuCl2 and stabilizing agents to whole-cell suspensions did not result in any stimulation of AMO activity. The use of the AMO-specific suicide substrate acetylene revealed two populations of AMO in cell extracts. The low, copper-independent (residual) AMO activity was completely inactivated by acetylene in the absence of exogenously added copper. In contrast, the copper-dependent (activable) AMO activity was protected against acetylene inactivation in the absence of copper. However, in the presence of copper both populations of AMO were inactivated by acetylene. [14C]acetylene labelling of the 27-kDa polypeptide of AMO revealed the same extent of label incorporation in both whole cells and optimally copper-stimulated cell extracts. In the absence of copper, the label incorporation in cell extracts was proportional to the level of residual AMO activity. Other metal ions tested, including Zn2+, Co2+, Ni2+, Fe2+, Fe3+, Ca2+, Mg2+, Mn2+, Cr3+, and Ag+, were ineffective at stimulating AMO activity or facilitating the incorporation of 14C label from [14C]acetylene into the 27-kDa polypeptide. On the basis of these results, we propose that loss of AMO activity upon lysis of N. europaea results from the loss of copper from AMO, generating a catalytically inactive, yet stable and activable, form of the enzyme.}, journal={Journal of bacteriology}, year={1993}, month={Apr} }
 @article{ensign_hyman_arp_1993, title={In vitro activation of ammonia monooxygenase from Nitrosomonas europaea by copper.}, volume={175}, ISSN={0021-9193}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC204278/}, number={7}, journal={Journal of Bacteriology}, author={Ensign, S A and Hyman, M R and Arp, D J}, year={1993}, month={Apr}, pages={1971–1980} }
 @article{juliette_hyman_arp_1993, title={Inhibition of Ammonia Oxidation in Nitrosomonas europaea by Sulfur Compounds: Thioethers Are Oxidized to Sulfoxides by Ammonia Monooxygenase}, volume={59}, ISSN={0099-2240}, number={11}, journal={Applied and Environmental Microbiology}, author={Juliette, L. Y. and Hyman, M. R. and Arp, D. J.}, year={1993}, month={Nov}, pages={3718–3727} }
 @article{inhibition of ammonia oxidation in nitrosomonas europaea by sulfur compounds: thioethers are oxidized to sulfoxides by ammonia monooxygenase._1993, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16349086/?tool=EBI}, journal={Applied and environmental microbiology}, year={1993}, month={Nov} }
 @article{juliette_hyman_arp_1993, title={Mechanism-Based Inactivation of Ammonia Monooxygenase in Nitrosomonas europaea by Allylsulfide}, volume={59}, ISSN={0099-2240}, number={11}, journal={Applied and Environmental Microbiology}, author={Juliette, L. Y. and Hyman, M. R. and Arp, D. J.}, year={1993}, month={Nov}, pages={3728–3735} }
 @article{mechanism-based inactivation of ammonia monooxygenase in nitrosomonas europaea by allylsulfide._1993, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16349087/?tool=EBI}, journal={Applied and environmental microbiology}, year={1993}, month={Nov} }
 @article{hyman_arp_1992, title={14C2H2- and 14CO2-labeling studies of the de novo synthesis of polypeptides by Nitrosomonas europaea during recovery from acetylene and light inactivation of ammonia monooxygenase}, volume={267}, ISSN={0021-9258}, number={3}, journal={The Journal of Biological Chemistry}, author={Hyman, M. R. and Arp, D. J.}, year={1992}, month={Jan}, pages={1534–1545} }
 @article{14c2h2- and 14co2-labeling studies of the de novo synthesis of polypeptides by nitrosomonas europaea during recovery from acetylene and light inactivation of ammonia monooxygenase._1992, journal={The Journal of biological chemistry}, year={1992}, month={Jan} }
 @article{acetylene inhibition of azotobacter vinelandii hydrogenase: acetylene binds tightly to the large subunit._1992, url={https://doi.org/10.1021/bi00127a016}, DOI={10.1021/bi00127a016}, abstractNote={Acetylene is a slow-binding inhibitor of the Ni- and Fe-containing dimeric hydrogenase isolated from Azotobacter vinelandii. Acetylene was released from hydrogenase during the recovery from inhibition. This indicates that no transformation of acetylene to another compound occurred as a result of the interaction with hydrogenase. However, the release of C2H2 proceeds more rapidly than the recovery of activity, which indicates that release of C2H2 is not sufficient for recovery of activity. Acetylene binds tightly to native hydrogenase; hydrogenase and radioactivity coelute from a gel permeation column following inhibition with 14C2H2. Acetylene, or a derivative, remains bound to the large 65,000 MW subunit (and not to the small 35,000 MW subunit) of hydrogenase following denaturation as evidenced by SDS-PAGE and fluorography of 14C2H2-inhibited hydrogenase. This result suggests that C2H2, and by analogy H2, binds to and is activated by the large subunit of this dimeric hydrogenase. Radioactivity is lost from 14C2H2-inhibited protein during recovery. The inhibition is remarkably specific for C2H2: propyne, butyne, and ethylene are not inhibitors.}, journal={Biochemistry}, year={1992}, month={Mar} }
 @article{jin-hua_hyman_arp_1992, title={C2H2 Inhibition of Azotobacter vinelandii hydrogenase: C2H2 binds tightly to the large subunit}, volume={31}, journal={Biochemistry}, author={Jin-Hua, S. and Hyman, M.R. and Arp, D.J.}, year={1992}, pages={3158–3165} }
 @article{ensign_hyman_arp_1992, title={Cometabolic degradation of chlorinated alkenes by alkene monooxygenase in a propylene-grown Xanthobacter strain}, volume={58}, ISSN={0099-2240}, number={9}, journal={Applied and Environmental Microbiology}, author={Ensign, S. A. and Hyman, M. R. and Arp, D. J.}, year={1992}, month={Sep}, pages={3038–3046} }
 @article{cometabolic degradation of chlorinated alkenes by alkene monooxygenase in a propylene-grown xanthobacter strain._1992, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/1444418/?tool=EBI}, journal={Applied and environmental microbiology}, year={1992}, month={Sep} }
 @article{hyman_seefeldt_morgan_arp_mortenson_1992, title={Kinetic and spectroscopic analysis of the inactivating effects of nitric oxide on the individual components of Azotobacter vinelandii nitrogenase}, volume={31}, ISSN={0006-2960}, number={11}, journal={Biochemistry}, author={Hyman, M. R. and Seefeldt, L. C. and Morgan, T. V. and Arp, D. J. and Mortenson, L. E.}, year={1992}, month={Mar}, pages={2947–2955} }
 @article{kinetic and spectroscopic analysis of the inactivating effects of nitric oxide on the individual components of azotobacter vinelandii nitrogenase._1992, url={https://doi.org/10.1021/bi00126a015}, DOI={10.1021/bi00126a015}, abstractNote={The effects of nitric oxide (NO) on the individual components of Azotobacter vinelandii nitrogenase have been examined by kinetic and spectroscopic methods. Incubation of the Fe protein (Av2) for 1 h with stoichiometries of 4- and 8-fold molar excesses of NO to Av2 dimer resulted in a complete loss of activity of Av2 in C2H2-reduction assays. The kinetics of inactivation indicated that the minimum stoichiometry of NO to Av2 required to fully inactivate Av2 lies between 1 and 2. The rate of inactivation of Av2 activity by NO was stimulated up to 2-fold by the presence of MgATP and MgADP but was unaffected by the presence of sodium dithionite. Unexpectedly, complete inactivation of Av2 by low ratios of NO to Av2 also resulted in a complete loss of its ability to bind MgATP and MgADP. UV-visible spectroscopy indicated that the effect of NO on Av2 involves oxidation of the [4Fe-4S] center. EPR spectroscopy revealed that the loss of activity during inactivation of Av2 by NO correlated with the loss of the S = 1/2 and S = 3/2 signals. Appearance of the classical and intense iron-nitrosyl signal (g = 20.3) was only observed when Av2 was incubated with large molar excesses of NO and the appearance of this signal did not correlate with the loss of Av2 activity. The effects of NO on the MoFe protein (Av1) were more complex than for Av2. A time-dependent inactivation of Av1 activity (C2H2 reduction) was observed which required considerably higher concentrations of NO than those required to inactivate Av2 (up to 10 kPa).(ABSTRACT TRUNCATED AT 250 WORDS)}, journal={Biochemistry}, year={1992}, month={Mar} }
 @article{rasche_hyman_arp_1991, title={Factors Limiting Aliphatic Chlorocarbon Degradation by Nitrosomonas europaea: Cometabolic Inactivation of Ammonia Monooxygenase and Substrate Specificity}, volume={57}, ISSN={0099-2240}, number={10}, journal={Applied and Environmental Microbiology}, author={Rasche, M. E. and Hyman, M. R. and Arp, D. J.}, year={1991}, month={Oct}, pages={2986–2994} }
 @article{factors limiting aliphatic chlorocarbon degradation by nitrosomonas europaea: cometabolic inactivation of ammonia monooxygenase and substrate specificity._1991, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16348568/?tool=EBI}, journal={Applied and environmental microbiology}, year={1991}, month={Oct} }
 @article{kinetic analysis of the interaction of nitric oxide with the membrane-associated, nickel and iron-sulfur-containing hydrogenase from azotobacter vinelandii._1991, url={https://doi.org/10.1016/0167-4838(91)90261-w}, DOI={10.1016/0167-4838(91)90261-w}, abstractNote={The effects of nitric oxide (NO) on the membrane-associated form of the nickel and iron-sulfur-containing hydrogenase from Azotobacter vinelandii have been investigated. In the presence of H2 and an electron acceptor (turnover conditions), NO acts as a noncompetitive inhibitor vs. methylene blue (Ki = 12 microM). There is no element of competition between NO and H2, implying that the site of NO action is not the H2-activating site of the hydrogenase. When the membrane-associated hydrogenase is incubated under non-turnover conditions, the enzyme is irreversibly inactivated by NO in a time-dependent process. The inactivation is a non-saturable, pseudo-first-order process which is consistent with a direct chemical reaction between NO and the hydrogenase. Kinetic evidence is presented which is compatible with an interaction between NO and a redox-active component other than the H2-activating site on the enzyme. The complex inhibition pattern of NO has been interpreted in terms of two distinct interactions of NO with iron-sulfur centers of the hydrogenase.}, journal={Biochimica et biophysica acta}, year={1991}, month={Jan} }
 @article{hyman_arp_1991, title={Kinetic analysis of the interaction of nitric oxide with the nickel and iron-sulfur-containing membrane-bound hydrogenase from Azotobacter vinelandii}, volume={1076}, journal={Biochimica Biophysica Acta}, author={Hyman, M.R. and Arp, D. J.}, year={1991}, pages={167–174} }
 @article{rasche_hyman_arp_1990, title={Biodegradation of Halogenated Hydrocarbon Fumigants by Nitrifying Bacteria}, volume={56}, ISSN={1098-5336}, number={8}, journal={Applied and Environmental Microbiology}, author={Rasche, Madeline E. and Hyman, Michael R. and Arp, Daniel J.}, year={1990}, month={Aug}, pages={2568–2571} }
 @article{biodegradation of halogenated hydrocarbon fumigants by nitrifying bacteria._1990, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16348264/?tool=EBI}, journal={Applied and environmental microbiology}, year={1990}, month={Aug} }
 @article{hyman_kim_arp_1990, title={Inhibition of ammonia monooxygenase in Nitrosomonas europaea by carbon disulfide}, volume={172}, ISSN={0021-9193}, number={9}, journal={Journal of Bacteriology}, author={Hyman, M. R. and Kim, C. Y. and Arp, D. J.}, year={1990}, month={Sep}, pages={4775–4782} }
 @article{inhibition of ammonia monooxygenase in nitrosomonas europaea by carbon disulfide._1990, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/2118501/?tool=EBI}, DOI={10.1128/jb.172.9.4775-4782.1990}, abstractNote={Carbon disulfide has long been recognized as a potent inhibitor of nitrification, and it is the likely active component in several nitrification inhibitors suitable for field use. The effects of this compound on Nitrosomonas europaea have been investigated, and the site of action has been determined. Low concentrations of CS2 (less than 400 microM) produced a time-dependent inhibition of ammonia-dependent O2 uptake but did not inhibit hydrazine-oxidizing activity. CS2 also produced distinct changes in difference spectra of whole cells. These results suggest that ammonia monooxygenase (AMO) is the site of action of CS2. Unlike the case for thiourea and acetylene, saturating concentrations of CS2 did not fully inhibit AMO, and the inhibition resulted in a low but significant rate of ammonia-dependent O2 uptake. The effects of CS2 were not competitive with respect to ammonia concentration, and the inhibition by CS2 did not require the turnover of AMO to take effect. The ability of CS2-treated cells to incorporate [14C]acetylene into the 28-kilodalton polypeptide of AMO was used to demonstrate that the effects of CS2 are compatible with a mode of action which involves a reduction of the rate of turnover of AMO without effects on the catalytic mechanism. It is proposed that CS2 may act on AMO by reversibly reacting with a suitable nucleophilic amino acid in close proximity to the active site copper.}, journal={Journal of bacteriology}, year={1990}, month={Sep} }
 @article{rasche_hicks_hyman_arp_1990, title={Oxidation of monohalogenated ethanes and n-chlorinated alkanes by whole cells of Nitrosomonas europaea}, volume={172}, ISSN={0021-9193}, number={9}, journal={Journal of Bacteriology}, author={Rasche, M. E. and Hicks, R. E. and Hyman, M. R. and Arp, D. J.}, year={1990}, month={Sep}, pages={5368–5373} }
 @article{oxidation of monohalogenated ethanes and n-chlorinated alkanes by whole cells of nitrosomonas europaea._1990, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/2394686/?tool=EBI}, DOI={10.1128/jb.172.9.5368-5373.1990}, abstractNote={We have investigated the substrate specificity of ammonia monooxygenase in whole cells of the nitrifying bacterium Nitrosomonas europaea for a number of aliphatic halogenated hydrocarbons. To determine the effect of the halogen substituent and carbon chain length on substrate reactivity, we measured the rates of oxidation of the monohalogenated ethanes (fluoroethane, chloroethane, bromoethane, and iodoethane) and n-chlorinated C1 to C4 alkanes by whole cells of N. europaea. For monohalogenated ethanes, acetaldehyde was the major organic product and little or none of any of the alternate predicted products (2-halogenated alcohols) were detected. The maximum rate of haloethane oxidation increased with decreasing halogen molecular weight from iodoethane to chloroethane (19 to 221 nmol/min per mg of protein). In addition, the amount of substrate required for the highest rate of haloethane oxidation increased with decreasing halogen molecular weight. For the n-chlorinated alkanes, the rate of dechlorination, as measured by the appearance of the corresponding aldehyde product, was greatest for chloroethane and decreased dramatically for chloropropane and chlorobutane (118, 4, and 8 nmol of aldehyde formed per min per mg of protein, respectively). The concentration profiles for halocarbon oxidation by ammonia monooxygenase showed apparent substrate inhibition when ammonia was used as the reductant source. When hydrazine was used as the electron donor, no substrate inhibition was observed, suggesting that the inhibition resulted from reductant limitation.}, journal={Journal of bacteriology}, year={1990}, month={Sep} }
 @article{hyman_arp_1990, title={The small-scale production of [U-14C] acetylene from Ba14C-CO3: Application to labelling of ammonia monooxygenase in autotrophic nitrifying bacteria}, volume={190}, journal={Analytical Biochemistry}, author={Hyman, M.R. and Arp, D.J.}, year={1990}, pages={348–353} }
 @article{the small-scale production of [u-14c]acetylene from ba14co3: application to labeling of ammonia monooxygenase in autotrophic nitrifying bacteria._1990, url={https://doi.org/10.1016/0003-2697(90)90206-o}, DOI={10.1016/0003-2697(90)90206-o}, abstractNote={A small-scale method has been adapted from an established procedure for the generation of [U-14C]acetylene from inexpensive and commonly available precursors. The method involves the fusing of Ba14CO3 with excess barium metal to produce Ba14C2. The BaC2 is reacted with water to generate acetylene which is then selectively dissolved into dimethyl sulfoxide (DMSO). The results presented demonstrate the effect of Ba:BaCO3 ratio on the concentrations of various gases released during the hydrolysis reaction and quantify the selectivity of the DMSO-trapping process for each gas. [U-14C]-Acetylene generated by this method has been used to inactivate ammonia monooxygenase in three species of autotrophic nitrifying bacteria: Nitrosomonas europaea, Nitrosococcus oceanus, and Nitrosolobus multiformis. Our results demonstrate that acetylene inactivation of this enzyme in all three species results in the covalent incorporation of radioactive label into a polypeptide of apparent Mr of 25,000–27,000, as determined by sodium dodecylsulfate-polyacrylamide gel electrophoresis and fluorography.}, journal={Analytical biochemistry}, year={1990}, month={Nov} }
 @article{hyman_ensign_arp_ludden_1989, title={Carbonyl sulfide inhibition of CO dehydrogenase from Rhodospirillum rubrum}, volume={28}, ISSN={0006-2960}, url={https://doi.org/10.1021/bi00443a007}, DOI={10.1021/bi00443a007}, abstractNote={Carbonyl sulfide (COS) has been investigated as a rapid-equilibrium inhibitor of CO oxidation by the CO dehydrogenase purified from Rhodospirillum rubrum. The kinetic evidence suggests that the inhibition by COS is largely competitive versus CO (Ki = 2.3 microM) and uncompetitive versus methylviologen as electron acceptor (Ki = 15.8 microM). The data are compatible with a ping-pong mechanism for CO oxidation and COS inhibition. Unlike the substrate CO, COS does not reduce the iron-sulfur centers of dye-oxidized CO dehydrogenase and thus is not an alternative substrate for the enzyme. However, like CO, COS is capable of protecting CO dehydrogenase from slow-binding inhibition by cyanide. A true binding constant (KD) of 2.2 microM for COS has been derived on the basis of the saturable nature of COS protection against cyanide inhibition. The ability of CO, CO2, COS, and related CO/CO2 analogues to reverse cyanide inhibition of CO dehydrogenase is also demonstrated. The kinetic results are interpreted in terms of two binding sites for CO on CO dehydrogenase from R. rubrum.}, number={17}, journal={Biochemistry}, author={Hyman, Michael R. and Ensign, Scott A. and Arp, Daniel J. and Ludden, Paul W.}, year={1989}, month={Aug}, pages={6821–6826} }
 @article{ensign_hyman_ludden_1989, title={Nickel-specific, slow-binding inhibition of carbon monoxide dehydrogenase from Rhodospirillum rubrum by cyanide}, volume={28}, ISSN={0006-2960}, url={https://doi.org/10.1021/bi00438a011}, DOI={10.1021/bi00438a011}, abstractNote={The inhibition of purified carbon monoxide dehydrogenase from Rhodospirillum rubrum by cyanide was investigated in both the presence and absence of CO and electron acceptor. The inhibition was a time-dependent process exhibiting pseudo-first-order kinetics under both sets of conditions. The true second-order rate constants for inhibition were 72.2 M-1 s-1 with both substrates present and 48.9 and 79.5 M-1 s-1, respectively, for the reduced and oxidized enzymes incubated with cyanide. CO partially protected the enzyme against inhibition after 25-min incubation with 100 microM KCN. Dissociation constants of 8.46 microM (KCN) and 4.70 microM (CO) were calculated for the binding of cyanide and CO to the enzyme. Cyanide inhibition was fully reversible under an atmosphere of CO after removal of unbound cyanide. N2 was unable to reverse the inhibition. The competence of nickel-deficient (apo) CO dehydrogenase to undergo activation by NiCl2 was unaffected by prior incubation with cyanide. Cyanide inhibition of holo-CO dehydrogenase was not reversed by addition of NiCl2. 14CN- remained associated with holoenzyme but not with apoenzyme through gel filtration chromatography. These findings suggest that cyanide is a slow-binding, active-site-directed, nickel-specific, reversible inhibitor of CO dehydrogenase. We propose that cyanide inhibits CO dehydrogenase by being an analogue of CO and by binding through enzyme-bound nickel.}, number={12}, journal={Biochemistry}, author={Ensign, Scott A. and Hyman, Michael R. and Ludden, Paul W.}, year={1989}, month={Jun}, pages={4973–4979} }
 @article{acetylene inhibition of metalloenzymes_1988, url={http://dx.doi.org/10.1016/0003-2697(88)90181-9}, DOI={10.1016/0003-2697(88)90181-9}, journal={Analytical Biochemistry}, year={1988}, month={Sep} }
 @article{hyman_arp_1988, title={Acetylene inhibition of metalloenzymes}, volume={173}, ISSN={0003-2697}, number={2}, journal={Analytical Biochemistry}, author={Hyman, M. R. and Arp, D. J.}, year={1988}, month={Sep}, pages={207–220} }
 @article{hyman_seefeldt_arp_1988, title={Aerobic, inactive forms of Azotobacter vinelandii hydrogenase: activation kinetics and insensitivity to C2H2 inhibition}, volume={957}, ISSN={0006-3002}, number={1}, journal={Biochimica Et Biophysica Acta}, author={Hyman, M. R. and Seefeldt, L. C. and Arp, D. J.}, year={1988}, month={Nov}, pages={91–96} }
 @article{aerobic, inactive forms of azotobacter vinelandii hydrogenase: activation kinetics and insensitivity to c2h2 inhibition._1988, url={https://doi.org/10.1016/0167-4838(88)90160-4}, DOI={10.1016/0167-4838(88)90160-4}, abstractNote={Azotobacter vinelandii hydrogenase (EC class 1.12), either purified or membrane-associated, was obtained aerobically in an inactive state. The kinetics of activation by treatment with a reductant (H2 or dithionite) were determined. Three distinct phases of the activation were observed. Aerobically prepared, inactive hydrogenase was insensitive to acetylene inhibition, but could be rendered acetylene-sensitive by reduction with dithionite. These findings indicate that acetylene inhibition of hydrogenase requires catalytically active enzyme.}, journal={Biochimica et biophysica acta}, year={1988}, month={Nov} }
 @article{hyman_murton_arp_1988, title={Interaction of Ammonia Monooxygenase from Nitrosomonas europaea with Alkanes, Alkenes, and Alkynes}, volume={54}, ISSN={0099-2240}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC204451/}, number={12}, journal={Applied and Environmental Microbiology}, author={Hyman, Michael R. and Murton, Ian B. and Arp, Daniel J.}, year={1988}, month={Dec}, pages={3187–3190} }
 @article{interaction of ammonia monooxygenase from nitrosomonas europaea with alkanes, alkenes, and alkynes._1988, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16347810/?tool=EBI}, journal={Applied and environmental microbiology}, year={1988}, month={Dec} }
 @article{hyman_arp_1988, title={Reversible and irreversible effects of nitric oxide on the soluble hydrogenase from Alcaligenes eutrophus H16}, volume={254}, ISSN={0264-6021, 1470-8728}, url={http://www.biochemj.org/content/254/2/469}, DOI={10.1042/bj2540469}, abstractNote={The effects of NO on the H2-oxidizing and diaphorase activities of the soluble hydrogenase from Alcaligenes eutrophus H16 were investigated. With fully activated enzyme, NO (8-150 nM in solution) inhibited H2 oxidation in a time- and NO-concentration-dependent process. Neither H2 nor NAD+ appeared to protect the enzyme against the inhibition. Loss of activity in the absence of an electron acceptor was about 10 times slower than under turnover conditions. The inhibition was partially reversible; approx. 50% of full activity was recoverable after removal of the NO. Recovery was slower in the absence of an electron acceptor than in the presence of H2 plus an electron acceptor. The diaphorase activity of the unactivated hydrogenase was not affected by NO concentrations of up to 200 microM in solution. Exposure of the unactivated hydrogenase to NO irreversibly inhibited the ability of the enzyme to be fully activated for H2-oxidizing activity. The enzyme also lost its ability to respond to H2 during activation in the presence of NADH. The results are interpreted in terms of a complex inhibition that displays elements of (1) a reversible slow-binding inhibition of H2-oxidizing activity, (2) an irreversible effect on H2-oxidizing activity and (30 an irreversible inhibition of a regulatory component of the enzyme. Possible sites of action for NO are discussed.}, number={2}, journal={Biochemical Journal}, author={Hyman, M. R. and Arp, D. J.}, year={1988}, month={Sep}, pages={469–475} }
 @article{hyman_fox_arp_1988, title={Role of hydrogen in the activation and regulation of hydrogen oxidation by the soluble hydrogenase from Alcaligenes eutrophus H16}, volume={254}, ISSN={0264-6021}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1135100/}, number={2}, journal={Biochemical Journal}, author={Hyman, M R and Fox, C A and Arp, D J}, year={1988}, month={Sep}, pages={463–468} }
 @article{role of hydrogen in the activation and regulation of hydrogen oxidation by the soluble hydrogenase from alcaligenes eutrophus h16._1988, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/3052435/?tool=EBI}, DOI={10.1042/bj2540463}, abstractNote={The activation kinetics of the H2-oxidizing activity of the soluble hydrogenase from Alcaligenes eutrophus H16 were investigated. Activation with Na2S2O4 plus 101 kPa H2 resulted in a rapid increase in activity over 1 h and constant activity after 3 h incubation. Less-stable activations were achieved if enzyme was incubated with Na2S2O4 under 1 kPa H2 or 101 kPa N2. The enzyme could also be partly activated either with NADH alone or with H2 alone. The level of activity obtained with both 101 kPa H2 and NADH present was greater than that obtained with either 101 kPa H2 or NADH alone. Activation with H2 plus NADH was virtually independent of NADH concentration but highly dependent on H2 concentration. The effects of various concentrations of H2 and constant concentration of NADH on the level of activation were the same whether H2 oxidation was assayed by H2-dependent Methylene Blue or NAD+ reduction. Diaphorase activity did not require activation and was little affected by the treatments that activated H2-oxidizing activity. The results suggest that H2 plays an important role in regulating the level of H2-oxidizing activity in this soluble hydrogenase.}, journal={The Biochemical journal}, year={1988}, month={Sep} }
 @article{hyman_arp_1987, title={Acetylene is an active-site-directed, slow-binding, reversible inhibitor of Azotobacter vinelandii hydrogenase}, volume={26}, ISSN={0006-2960}, url={https://doi.org/10.1021/bi00394a023}, DOI={10.1021/bi00394a023}, abstractNote={The inhibition of purified and membrane-bound hydrogenase from Azotobacter vinelandii by dihydrogen-free acetylene was investigated. The inhibition was a time-dependent process which exhibited first-order kinetics. Both H/sub 2/ and CO protected against the inhibition by acetylene. K/sub protect(app)/ values of 0.41 and 24 ..mu..M were derived for these gases, respectively. Both H/sub 2/-oxidizing activity and the tritium exchange capacity of the purified enzyme were inhibited at the same rate by acetylene. Removal of acetylene reversed the inhibition for both the purified and the membrane-associated form of the enzyme. The purified hydrogenases from both Rhizobium japonicum and Alcaligenes eutrophus H16 were also inhibited by acetylene in a time-dependent fashion. These findings suggest that acetylene is an active-site-directed, slow-binding, reversible inhibitor of some membrane-bound hydrogenases from aerobic bacteria.}, number={20}, journal={Biochemistry}, author={Hyman, Michael R. and Arp, Daniel J.}, year={1987}, month={Oct}, pages={6447–6454} }
 @article{hyman_arp_1987, title={Quantification and removal of some contaminating gases from acetylene used to study gas-utilizing enzymes and microorganisms}, volume={53}, ISSN={0099-2240}, number={2}, journal={Applied and Environmental Microbiology}, author={Hyman, M. R. and Arp, D. J.}, year={1987}, month={Feb}, pages={298–303} }
 @article{quantification and removal of some contaminating gases from acetylene used to study gas-utilizing enzymes and microorganisms._1987, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/16347278/?tool=EBI}, journal={Applied and environmental microbiology}, year={1987}, month={Feb} }
 @article{hyman_sansome-smith_shears_wood_1985, title={A kinetic study of benzene oxidation to phenol by whole cells of Nitrosomonas europaea and evidence for the further oxidation of phenol to hydroquinone}, volume={143}, ISSN={1432-072X}, url={https://doi.org/10.1007/BF00411254}, DOI={10.1007/BF00411254}, number={3}, journal={Archives of Microbiology}, author={Hyman, Michael R. and Sansome-Smith, Alastair W. and Shears, Jeremy H. and Wood, Paul M.}, year={1985}, month={Dec}, pages={302–306} }
 @article{suicidal inactivation and labelling of ammonia mono-oxygenase by acetylene._1985, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/4004794/?tool=EBI}, DOI={10.1042/bj2270719}, abstractNote={Acetylene brings about a progressive inactivation of ammonia mono-oxygenase, the ammonia-oxidizing enzyme in Nitrosomonas europaea. High NH4+ ion concentrations were protective. The inactivation followed first-order kinetics, with a rate constant of 1.5 min-1 at saturating concentrations of acetylene. If acetylene was added in the absence of O2, the cells remained active until O2 was re-introduced. A protective effect was also demonstrated with thiourea, a reversible non-competitive inhibitor of ammonia oxidation. Incubation of cells with [14C]acetylene was found to cause labelling of a single membrane polypeptide. This ran on dodecyl sulphate/polyacrylamide-gel electrophoresis with an Mr value of 28 000. It is concluded that acetylene is a suicide substrate for the mono-oxygenase. The labelling experiment provides the first identification of a constituent polypeptide of ammonia mono-oxygenase.}, journal={The Biochemical journal}, year={1985}, month={May} }
 @article{hyman_wood_1985, title={Suicidal inactivation and labelling of ammonia mono-oxygenase by acetylene.}, volume={227}, ISSN={0264-6021}, url={https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1144898/}, number={3}, journal={Biochemical Journal}, author={Hyman, M R and Wood, P M}, year={1985}, month={May}, pages={719–725} }
 @inbook{bromocarbon oxidation by nitrosomonas europaea_1984, booktitle={Microbial Growth on C1 Compounds}, year={1984} }
 @article{hyman_wood_1984, title={Ethylene oxidation by Nitrosomonas europaea}, volume={137}, ISSN={1432-072X}, url={https://doi.org/10.1007/BF00414458}, DOI={10.1007/BF00414458}, number={2}, journal={Archives of Microbiology}, author={Hyman, Michael R. and Wood, Paul M.}, year={1984}, month={Feb}, pages={155–158} }
 @article{hyman_wood_1983, title={Methane oxidation by Nitrosomonas europaea}, volume={212}, ISSN={0264-6021}, number={1}, journal={The Biochemical Journal}, author={Hyman, M. R. and Wood, P. M.}, year={1983}, month={Apr}, pages={31–37} }
 @article{methane oxidation by nitrosomonas europaea._1983, url={https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/6870854/?tool=EBI}, DOI={10.1042/bj2120031}, abstractNote={Methane inhibited NH4+ utilization by Nitrosomonas europaea with a Ki of 2mM. O2 consumption was not inhibited. In the absence of NH4+, or with hydrazine as reductant, methane caused nearly a doubling in the rate of O2 uptake. The stimulation was abolished by allylthiourea, a sensitive inhibitor of the oxidation of NH4+. Analysis revealed that methanol was being formed in these experiments, with yields approaching 1 mol of methanol per mol of O2 consumed under certain conditions. When cells were incubated with NH4+ under an atmosphere of 50% methane, 50 microM-methanol was generated in 1 h. It is concluded that methane is an alternative substrate for the NH3-oxidizing enzyme (ammonia mono-oxygenase),m albeit with a much lower affinity than for methane mono-oxygenase of methanotrophs.}, journal={The Biochemical journal}, year={1983}, month={Apr} }
 @article{ensign_hyman_ludden, title={Nickel-specific, slow-binding inhibition of carbon monoxide dehydrogenase from Rhodospirillum rubrum by cyanide}, volume={28}, journal={Biochemistry}, author={Ensign, S.A. and Hyman, M.R. and Ludden, P.W.}, pages={4973–4979} }