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Succinate production and citrate catabolism by Cheddar cheese nonstarter lactobacilli
Author(s) -
Dudley E.G.,
Steele J.L.
Publication year - 2005
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2004.02440.x
Subject(s) - lactobacillus casei , lactobacillus plantarum , lactobacillus rhamnosus , lactic acid , biochemistry , succinic acid , lactobacillaceae , chemistry , lactobacillus , citric acid cycle , food science , enzyme , biology , bacteria , fermentation , genetics
Aims: To identify strains of Cheddar cheese nonstarter lactobacilli that synthesize succinate from common precursors and characterize the biochemical pathways utilized. Methods and Results: Whole cell incubations of Lactobacillus plantarum , Lactobacillus casei , Lactobacillus zeae and Lactobacillus rhamnosus , were used to identify strains that accumulated succinate from citrate, l ‐lactate, aspartic acid or isocitrate. In vivo 13 C‐nuclear magnetic resonance spectroscopy ( 13 C‐NMR) identified the biochemical pathway involved at pH 7·0, and under conditions more representative of the cheese ripening environment (pH 5·1/4% NaCl/13°C). Enzyme assays on cell‐free extracts were used to support the pathway suggested by 13 C‐NMR. Conclusions: The Lact. plantarum strains studied synthesize succinate from citrate by the reductive tricarboxylic acid (TCA) cycle at either pH 7·0 or pH 5·1/4% NaCl/13°C. Lactobacillus casei , Lact. zeae and Lact. rhamnosus strains lack one or more enzymatic activities present in this pathway, and do not accumulate succinate from any of the four precursors studied. Significance and Impact of the Study: The addition of Lact. plantarum strains to milk during cheese manufacture may increase the accumulation of the flavour enhancer succinate.