C-13 NUCLEAR-MAGNETIC-RESONANCE ANALYSIS OF GLUCOSE AND CITRATE END-PRODUCTS IN AN LDHL-LDHD DOUBLE-KNOCKOUT STRAIN OF LACTOBACILLUS-PLANTARUM

We have examined the metabolic consequences of knocking out the two ld h genes in Lactobacillus plantarum using C-13 nuclear magnetic resonan ce. Unlike its wild-type isogenic progenitor, which produced lactate a s the major metabolite under all conditions tested, ldh null strain TF 103 mainly produced acetoin, A variety of secondary end products were also found, including organic acids (acetate, succinate, pyruvate, and lactate), ethanol, 2,3-butanediol, and mannitol.