Influence of Carbon Substrates on Lactic Acid, Cell Mass and Diacetyl-Acetoin Production in Lactobacillus plantarum

Abstract

Production of diacetyl-acetoin, lactic acid and cell mass by L. plantarum strains ATCC 8014, ATCC 14431, ATCC 4008 and ATCC 8041 were examined in the growth medium of Craig and Snell (J. Bacteriol. 61:283,1951) containing glucose, lactose, citrate or pyruvate as substrates. The yield coefficient, μM lactate produced per mg cell dry weight, averaged 73.4 for glucose-grown cells and 64.9 for lactose-grown cells with no significant inter-strain difference. Strains that produced higher lactic acid concentrations did so because they produced more cell mass. Glucose and lactose reduced diacetyl-acetoin synthesis in all strains except 8041. Diacetyl-acetoin synthesis doubled when strains 14431 and 8014 were grown in medium containing 20 mM citrate, but was not markedly affected in strains 4008 and 8041. Pyruvate stimulated diacetyl-acetoin synthesis in all four strains 10- to 20-fold. Conversion of pyruvate to diacetyl and acetoin was ⩾30% of the theoretical molar yield for strains 8014, 8041 and 14431 grown in the presence of 20 mM pyruvate.

13C nuclear magnetic resonance analysis of glucose and citrate end products in an ldhL-ldhD double-knockout strain of Lactobacillus plantarum

“…1). Oxalacetate is usually decarboxylated to pyruvate, which is further dissipated into by-products, such as C 4 compounds (9,30,31). However, these metabolites were not observed with the wild-type strain in our experiments.…”

Conversion of Pyruvate to Acetoin Helps To Maintain pH Homeostasis in Lactobacillus plantarum

“…Exogenous pyruvate enhances acetoin production in Lactobacillus plantarum (19,21,22,27). When the organism is grown aerobically, acetoin production increases even in the absence of exogenous pyruvate (29).…”

Relationship between pyruvate utilization and acetoin production byLactobacillus plantarum:influence of carbon source, pyruvate concentration, and metabolic inhibitors

“…They also make small amounts of acetoin, diacetyl, 2,3-butanediol, acetate, acetaldehyde, and ethanol (Hegazi and Abo-Elnaga, 1978; Abo-Elnaga and Hegazi, 1981;deVries et al, 1970;Murphy and Condon 1984). Exogenously added pyruvate and citrate stimulate acetoin and diacetyl production (Cogan et al, 1981;El-Gendy et al, 1983a,b,c;Montville et al, 1987a). Under aerobic conditions, pyruvate oxidase is activated and acetate is produced in addition to lactate (Dirar and Collins, 1972;.…”