@article{little_cruz-martinez_st fort_pagan-medina_page_perez-perez_taveirne_lee_arroyo-gonzalez_santiago-ortiz_et al._2022, title={Vegetable fermentations brined with low salt for reclaiming food waste}, ISSN={["1750-3841"]}, DOI={10.1111/1750-3841.16084}, abstractNote={Fermentation of eight vegetables was studied as an alternative for reclamation of surplus volumes. Fermentation performance was predicted by comparing the amounts of acid that could be produced from the intrinsic sugar content with that buffered by the fresh vegetable matrices prior to reaching an inhibitory pH for fermentative microbes (3.30). Native fermentations were brined with 345.0 mM sodium chloride, 40.0 mM calcium chloride, 6.0 mM potassium sorbate, and vinegar to adjust the initial pH to 4.70. High-performance liquid chromatography analysis, pH, and carbon dioxide measurements and spiral plating on selective media were employed to monitor the progress of fermentations. The average colony counts for yeast and/or molds and Enterobacteriaceae declined to undetectable levels from 3.6 ± 1.5 log CFU/ml within 7 days of fermentation. The fermentation of sugars produced lactic, acetic, succinic, and/or malic acids, and ethanol. As predicted, the fermentation of vegetables with low sugar content, such as broccoli, green leaf lettuce, and green pea proceeded to completion. The fermentation of vegetables with a moderate sugar content, such as green bell pepper, red ripened tomato, and green bean were incomplete at pH 3.1 ± 0.2. The fermentation of high sugar vegetables including sweet potato and corn were expected and observed to be incomplete. It is concluded that the intrinsic sugar content and buffer capacity of surplus vegetables are relevant parameters in obtaining complete fermentations. PRACTICAL APPLICATION: Vegetables are the second most wasted commodity in the United States and a substantial constituent of the global food waste. Development of fermentation to reclaim surplus vegetables from farms, grocery stores, and farmer's markets offers opportunities to ameliorate economic losses and environmental impact and add value to waste. The research described here suggests that a fraction of vegetables could be fermented in cover brines while others, with high sugar content, need specialized handling. Evidently, optimization of vegetable fermentation with starter cultures and added buffers represent an opportunity to stimulate complete bioconversions useful for reclaiming surplus volumes.}, journal={JOURNAL OF FOOD SCIENCE}, author={Little, Connor and Cruz-Martinez, Viviana and St Fort, Datricia Pearl and Pagan-Medina, Christian and Page, Clinton A. and Perez-Perez, Yobet and Taveirne, Michael E. and Lee, Alice M. and Arroyo-Gonzalez, Nancy and Santiago-Ortiz, Cariluz and et al.}, year={2022}, month={Mar} }
 @article{taveirne_sikes_olson_2009, title={Molybdenum and tungsten in Campylobacter jejuni: their physiological role and identification of separate transporters regulated by a single ModE-like protein}, volume={74}, ISSN={["1365-2958"]}, DOI={10.1111/j.1365-2958.2009.06901.x}, abstractNote={Campylobacter jejuni is an important human pathogen that causes millions of cases of food-borne enteritis each year. The C. jejuni respiratory chain is highly branched and contains at least four enzymes predicted to contain a metal binding pterin (MPT), with the metal being either molybdenum or tungsten. Also predicted are two separate transport systems, one for molybdenum encoded by modABC and a second for tungsten encoded by tupABC. Both transport systems were mutated and the activities of the four predicted MPT-containing enzymes were assayed in the presence of molybdenum and tungsten in wild-type and mod and tup backgrounds. Results indicate that mod is primarily a molybdenum transporter that can also transport tungsten, while tup is a tungsten-specific transporter. The MPT-containing enzymes nitrate reductase, sulphite oxidase, and SN oxide reductase are strict molybdoenzymes while formate dehydrogenase prefers tungsten. A ModE-like protein regulates both transporters, repressing mod in the presence of both molybdenum and tungsten and tup only in the presence of tungsten. Like other ModE proteins, the C. jejuni ModE binds DNA through a helix–turn–helix DNA binding domain, but unlike other members of the ModE family it does not have a metal binding domain.}, number={3}, journal={MOLECULAR MICROBIOLOGY}, author={Taveirne, Michael E. and Sikes, Michael L. and Olson, Jonathan W.}, year={2009}, month={Nov}, pages={758–771} }
 @article{weingarten_taveirne_olson_2009, title={The Dual-Functioning Fumarate Reductase Is the Sole Succinate: Quinone Reductase in Campylobacter jejuni and Is Required for Full Host Colonization}, volume={191}, ISSN={["1098-5530"]}, DOI={10.1128/JB.00166-09}, abstractNote={ABSTRACT Campylobacter jejuni encodes all the enzymes necessary for a complete oxidative tricarboxylic acid (TCA) cycle. Because of its inability to utilize glucose, C. jejuni relies exclusively on amino acids as the source of reduced carbon, and they are incorporated into central carbon metabolism. The oxidation of succinate to fumarate is a key step in the oxidative TCA cycle. C. jejuni encodes enzymes annotated as a fumarate reductase (Cj0408 to Cj0410) and a succinate dehydrogenase (Cj0437 to Cj0439). Null alleles in the genes encoding each enzyme were constructed. Both enzymes contributed to the total fumarate reductase activity in vitro. The frdA :: cat + strain was completely deficient in succinate dehydrogenase activity in vitro and was unable to perform whole-cell succinate-dependent respiration. The sdhA :: cat + strain exhibited wild-type levels of succinate dehydrogenase activity both in vivo and in vitro. These data indicate that Frd is the only succinate dehydrogenase in C. jejuni and that the protein annotated as a succinate dehydrogenase has been misannotated. The frdA :: cat + strain was also unable to grow with the characteristic wild-type biphasic growth pattern and exhibited only the first growth phase, which is marked by the consumption of aspartate, serine, and associated organic acids. Substrates consumed in the second growth phase (glutamate, proline, and associated organic acids) were not catabolized by the the frdA :: cat + strain, indicating that the oxidation of succinate is a crucial step in metabolism of these substrates. Chicken colonization trials confirmed the in vivo importance of succinate oxidation, as the frdA :: cat + strain colonized chickens at significantly lower levels than the wild type, while the sdhA :: cat + strain colonized chickens at wild-type levels.}, number={16}, journal={JOURNAL OF BACTERIOLOGY}, author={Weingarten, Rebecca A. and Taveirne, Michael E. and Olson, Jonathan W.}, year={2009}, month={Aug}, pages={5293–5300} }