@article{thomas_chapman_jaykus_phister_2014, title={Tracing Temperature Patterns of Cut Leafy Greens during Service in North Carolina School Food Service}, volume={77}, ISSN={["1944-9097"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84906969253&partnerID=MN8TOARS}, DOI={10.4315/0362-028x.jfp-14-121}, abstractNote={Contaminated fresh produce has been increasingly identified as a cause of foodborne illnesses. Because of concerns about pathogen growth on these food items at retail, the 2009 U.S. Food and Drug Administration Food Code established that cut leafy greens (lettuce, spinach, spring mix, cabbage, arugula, and kale) must have time and temperature controls for safety and hence should be kept at refrigerated temperatures (5°C or lower). The purpose of this study was to determine the temperature profiles of cut leafy greens in single-serving clamshell containers provided as part of the North Carolina School Lunch Program and to compare the two policies that North Carolina has in place to control the temperature of these products (the 3-day rule and time in lieu of temperature). Temperatures were recorded with data loggers in 24 schools during a 3-day period. In all cases, substantial temperature variability was found for these products, including temperatures above 5°C for at least 1 h on each of the 3 days. In some cases, temperatures reached above 5°C for more than 3 h throughout the serving time. The results demonstrate the importance of developing a protocol for continuous temperature monitoring of leafy greens served in school lunch programs.}, number={9}, journal={JOURNAL OF FOOD PROTECTION}, author={Thomas, Ellen M. and Chapman, Benjamin and Jaykus, Lee-Ann and Phister, Trevor}, year={2014}, month={Sep}, pages={1495–1500} }
 @misc{ivey_massel_phister_2013, title={Microbial interactions in food fermentations}, volume={4}, journal={Annual review of food science and technology, vol 4}, author={Ivey, M. and Massel, M. and Phister, T. G.}, year={2013}, pages={141–162} }
 @article{pittet_phister_ziola_2013, title={Transcriptome Sequence and Plasmid Copy Number Analysis of the Brewery Isolate Pediococcus claussenii ATCC BAA-344(T) during Growth in Beer}, volume={8}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0073627}, abstractNote={Growth of specific lactic acid bacteria in beer leads to spoiled product and economic loss for the brewing industry. Microbial growth is typically inhibited by the combined stresses found in beer (e.g., ethanol, hops, low pH, minimal nutrients); however, certain bacteria have adapted to grow in this harsh environment. Considering little is known about the mechanisms used by bacteria to grow in and spoil beer, transcriptome sequencing was performed on a variant of the beer-spoilage organism Pediococcus claussenii ATCC BAA-344T (Pc344-358). Illumina sequencing was used to compare the transcript levels in Pc344-358 growing mid-exponentially in beer to those in nutrient-rich MRS broth. Various operons demonstrated high gene expression in beer, several of which are involved in nutrient acquisition and overcoming the inhibitory effects of hop compounds. As well, genes functioning in cell membrane modification and biosynthesis demonstrated significantly higher transcript levels in Pc344-358 growing in beer. Three plasmids had the majority of their genes showing increased transcript levels in beer, whereas the two cryptic plasmids showed slightly decreased gene expression. Follow-up analysis of plasmid copy number in both growth environments revealed similar trends, where more copies of the three non-cryptic plasmids were found in Pc344-358 growing in beer. Transcriptome sequencing also enabled the addition of several genes to the P . claussenii ATCC BAA-344T genome annotation, some of which are putatively transcribed as non-coding RNAs. The sequencing results not only provide the first transcriptome description of a beer-spoilage organism while growing in beer, but they also highlight several targets for future exploration, including genes that may have a role in the general stress response of lactic acid bacteria.}, number={9}, journal={PLOS ONE}, author={Pittet, Vanessa and Phister, Trevor G. and Ziola, Barry}, year={2013}, month={Sep} }
 @article{layfield_phister_sheppard_2011, title={Characterization of Hybrid Strains of Saccharomyces pastorianus for Desiccation Tolerance}, volume={69}, ISSN={["1943-7854"]}, DOI={10.1094/asbcj-2011-0301-01}, abstractNote={This study examines the impact of desiccation on the viability and fermentation performance of multiple strains of Saccharomyces pastorianus. S. pastorianus is a hybrid resulting from a cross between S. cerevisiae and S. bayanus. It has been proposed that S. pastorianus can be categorized into two distinct types: S. pastorianus-Saaz type, which has lost a significant amount of the genomic content contained within S. cerevisiae, and S. pastorianus-Frohberg type, which has retained almost all of the genomic content of S. cerevisiae. Both types of S. pastorianus, along with S. cerevisiae and S. bayanus strains, were desiccated by spray-drying and then rehydrated before assessing the extent of the damage to the cells. The viability of rehydrated cultures was determined using microscopic enumeration, capacitance, and plating. Fermentation performance was tested by inoculating equal amounts of viable rehydrated cells into brewer's wort and monitoring changes in cell count, carbohydrate utilization, and alcohol concentration until completion. The findings suggest that S. pastorianus-Frohberg type is less tolerant to desiccation than either S. cerevisiae or S. pastorianus-Saaz type. Selection of the correct type of S. pastorianus for use in active dry yeast could reduce the possibility of contamination or extended lag phases leading to stuck fermentations.}, number={2}, journal={JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS}, author={Layfield, J. Blake and Phister, Trevor G. and Sheppard, John D.}, year={2011}, pages={108–115} }
 @article{gray_rawsthorne_dirks_phister_2011, title={Detection and enumeration of Dekkera anomala in beer, cola, and cider using real-time PCR}, volume={52}, ISSN={["1472-765X"]}, DOI={10.1111/j.1472-765x.2011.03008.x}, abstractNote={Aims:  In this article, a quantitative real‐time PCR assay for detection and enumeration of the spoilage yeast Dekkera anomala in beer, cola, apple cider, and brewing wort is presented as an improvement upon existing detection methods, which are very time‐consuming and not always accurate.}, number={4}, journal={LETTERS IN APPLIED MICROBIOLOGY}, author={Gray, S. R. and Rawsthorne, H. and Dirks, B. and Phister, T. G.}, year={2011}, month={Apr}, pages={352–359} }
 @misc{ivey_phister_2011, title={Detection and identification of microorganisms in wine: a review of molecular techniques}, volume={38}, number={10}, journal={Journal of Industrial Microbiology & Biotechnology}, author={Ivey, M. L. and Phister, T. G.}, year={2011}, pages={1619–1634} }
 @article{beckner_ivey_phister_2011, title={Microbial contamination of fuel ethanol fermentations}, volume={53}, ISSN={["1472-765X"]}, DOI={10.1111/j.1472-765x.2011.03124.x}, abstractNote={Microbial contamination is a pervasive problem in any ethanol fermentation system. These infections can at minimum affect the efficiency of the fermentation and at their worse lead to stuck fermentations causing plants to shut down for cleaning before beginning anew. These delays can result in costly loss of time as well as lead to an increased cost of the final product. Lactic acid bacteria (LAB) are the most common bacterial contaminants found in ethanol production facilities and have been linked to decreased ethanol production during fermentation. Lactobacillus sp. generally predominant as these bacteria are well adapted for survival under high ethanol, low pH and low oxygen conditions found during fermentation. It has been generally accepted that lactobacilli cause inhibition of Saccharomyces sp. and limit ethanol production through two basic methods; either production of lactic and acetic acids or through competition for nutrients. However, a number of researchers have demonstrated that these mechanisms may not completely account for the amount of loss observed and have suggested other means by which bacteria can inhibit yeast growth and ethanol production. While LAB are the primary contaminates of concern in industrial ethanol fermentations, wild yeast may also affect the productivity of these fermentations. Though many yeast species have the ability to thrive in a fermentation environment, Dekkera bruxellensis has been repeatedly targeted and cited as one of the main contaminant yeasts in ethanol production. Though widely studied for its detrimental effects on wine, the specific species–species interactions between D. bruxellensis and S. cerevisiae are still poorly understood.}, number={4}, journal={LETTERS IN APPLIED MICROBIOLOGY}, author={Beckner, M. and Ivey, M. L. and Phister, T. G.}, year={2011}, month={Oct}, pages={387–394} }
 @article{aguilar-uscanga_garcia-alvarado_gomez-rodriguez_phister_delia_strehaiano_2011, title={Modelling the growth and ethanol production of Brettanomyces bruxellensis at different glucose concentrations}, volume={53}, ISSN={["1472-765X"]}, DOI={10.1111/j.1472-765x.2011.03081.x}, abstractNote={Aim:  To study the effect of glucose concentrations on the growth by Brettanomyces bruxellensis yeast strain in batch experiments and develop a mathematical model for kinetic behaviour analysis of yeast growing in batch culture.}, number={2}, journal={LETTERS IN APPLIED MICROBIOLOGY}, author={Aguilar-Uscanga, M. G. and Garcia-Alvarado, Y. and Gomez-Rodriguez, J. and Phister, T. and Delia, M. L. and Strehaiano, P.}, year={2011}, month={Aug}, pages={141–149} }
 @article{rawsthorne_phister_2009, title={Detection of viable Zygosaccharomyces bailii in fruit juices using ethidium monoazide bromide and real-time PCR}, volume={131}, ISSN={["1879-3460"]}, DOI={10.1016/j.ijfoodmicro.2009.01.031}, abstractNote={In this study, we use ethidium monoazide (EMA) a dye commonly used to differentiate viable and nonviable populations of bacteria in real-time PCR (QPCR) assays to eliminate the nonviable cells from the Z. bailii population. Thus we are able to determine the viable Z. bailii population using QPCR plus EMA. To do this we first, optimized the EMA exposure conditions; EMA concentration of 50 microg/ml with an incubation at 30 degrees C in the dark for 5 min. Followed by light exposure on ice, for 5 min using a 500 W halogen lamp at a distance of 12 cm. Using these optimized conditions, we determined that the assay could detect as few as 12.5 viable Z. bailii cells in the presence of 10(5) CFU/ml of heat killed-cells. The EMA assay was also more consistent at determining viable cell counts when compared to plating than fluorescent microscopy viable cell counts. Finally, we used the assay to determine the viable population in heat-treated (72 degrees C, 2 min), ethanol-treated and raspberry cranberry juice Z. bailii cultures. When examining Z. bailii cells treated with 70% ethanol the QPCR assay with EMA (1.22 x 10(2)) showed a better correlation with plating (4.5 x 10(1) CFU/ml) compared to the QPCR assay without EMA (5.31 x 10(6) CFU/ml) and this was also seen in the other two injured populations. Thus we feel that we have designed an assay which will be useful for the detection of viable spoilage yeasts in various fruit juices.}, number={2-3}, journal={INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY}, author={Rawsthorne, Helen and Phister, Trevor G.}, year={2009}, month={May}, pages={246–250} }
 @article{rawsthorne_phister_jaykus_2009, title={Development of a Fluorescent In Situ Method for Visualization of Enteric Viruses}, volume={75}, ISSN={["1098-5336"]}, DOI={10.1128/AEM.01986-09}, abstractNote={ABSTRACT Studying the interactions between enteric pathogens and their environment is important to improving our understanding of their persistence and transmission. However, this remains challenging in large part because of difficulties associated with tracking pathogens in their natural environment(s). In this study, we report a fluorescent labeling strategy which was applied to murine norovirus (MNV-1), a human norovirus surrogate, and hepatitis A virus (HAV). Specifically, streptavidin-labeled Quantum dots (Q-Dots) were bound to biotinylated capsids of MNV-1 and HAV (bio-MNV-1 and bio-HAV); the process was confirmed by using a sandwich-type approach in which streptavidin-bound plates were reacted with biotinylated virus followed by a secondary binding to Q-Dots with an emission range of 635 to 675 nm (Q-Dots 655). The assay demonstrated a relative fluorescence of 528 ± 48.1 and 112 ± 8.6 for bio-MNV-1 and control MNV-1, respectively. The biotinylation process did not impact virus infectivity, nor did it interfere with the interactions between the virus and host cells or model produce items. Using fluorescent microscopy, it was possible to visualize both bio-HAV and bio-MNV-1 attached to the surfaces of permissive mammalian cells and green onion tissue. The method provides a powerful tool for the labeling and detection of enteric viruses (and their surrogates) which can be used to track virus behavior in situ.}, number={24}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Rawsthorne, Helen and Phister, Trevor G. and Jaykus, Lee-Ann}, year={2009}, month={Dec}, pages={7822–7827} }
 @article{rawsthorne_phister_2009, title={The presence of Saccharomyces cerevisiae DNA in various media used to propagate yeasts and its removal by ethidium monoazide}, volume={49}, ISSN={["1472-765X"]}, DOI={10.1111/j.1472-765X.2009.02707.x}, abstractNote={Aims:  In this study we demonstrate the interference of yeast extract in enumeration of Saccharomyces cerevisiae using real‐time PCR and develop a method for its removal from the media using ethidium monoazide (EMA).}, number={5}, journal={LETTERS IN APPLIED MICROBIOLOGY}, author={Rawsthorne, H. and Phister, T. G.}, year={2009}, month={Nov}, pages={652–654} }