Anaerobic l-lactate degradation by Lactobacillus plantarum |
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Authors: | Sven E Lindgren Lars T Axelsson Roger F McFeeters |
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Institution: | Department of Microbiology, Swedish University of Agricultural Sciences, Uppsala, Sweden;Food Fermentation Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Department of Food Science, North Carolina State University, Raleigh, NC, U.S.A. |
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Abstract: | Abstract Lactobacillus plantarum strains used as silage inoculants were investigated for their ability to metabolize lactic acid anaerobically after prolonged incubation (7–30 days) when glucose was absent from the medium. When citrate was present in the medium together with glucose during the initial fermentation, the lactic acid produced was degraded. Citrate was concomitantly degraded, resulting in accumulation of formic, acetic and succinic acids along with CO2. The anaerobic degradation was confirmed by the use of l 14C(U) labelled lactate. The existence of pyruvate formate lyase in L. plantarum was indicated by using 14C-labelled pyruvate and HPLC identification of end-products. The 1-14C-carboxylic acid group of pyruvate was converted to formic acid, and the 3-14C was found in acetic acid. The key enzyme(s) in this metabolic pathway appears to require anaerobic conditions and induction by citrate. |
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Keywords: | Lactobacillus plantarum Lactate degradation Pyruvate formate lyase |
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