Role of malolactic fermentation in lactic acid bacteria

• Published in: Biochimie Vol. 70; no. 3; pp. 375 - 379
• Main Authors: Renault, Pierre, Gaillardin, Claude, Heslot, Henri
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.03.1988; Elsevier
• Subjects: ACIDE MALIQUE; ACIDO MALICO; BACTERIAS ACIDOLACTICAS; BACTERIE LACTIQUE; Biochemistry, Molecular Biology; Biological and medical sciences; chemiosmotic theory; Energy Transfer; energy-coupled reaction; FERMENTACION; FERMENTATION; Food industries; Food microbiology; Fundamental and applied biological sciences. Psychology; GLUCOSA; GLUCOSE; Hydrogen-Ion Concentration; Lactates - metabolism; Lactic Acid; LACTIC ACID BACTERIA; Lactobacillus - metabolism; Life Sciences; Malates - metabolism; MALIC ACID; malolactic fermentation; pH maintenance; STREPTOCOCCUS; Streptococcus lactis; chemiosmotic theory; energy-coupled reaction; malolactic fermentation; pH maintenance; Streptococcus lactis; Malolactic fermentation; Lactic acid bacteria; Microbiology; Metabolism; ACIDE LACTIQUE
• ISSN: 0300-9084; 1638-6183
• DOI: 10.1016/0300-9084(88)90210-6

Although decarboxylation of malate to lactate by malolactic enzyme does not liberate biologically available energy ( e.g., ATP, NADH), the growth rate of many malolactic bacteria is greatly enhanced by malolactic fermentation. The deacidification of the medium due to malate dissipation cannot fully account for this situation. The chemiosmotic theory postulates that another form of energy could generated by translocation of protons through the membrane coupled to end-product efflux. Konings et al. showed that this theory is indeed applicable to lactate efflux in Streptococcus cremoris at pH 7.0 A similar mechanism could account for the observed increased activity in malolactic bacteria. The study in wild type and mutant strains of Streptococcus lactis unable to carry out malolactic fermentation led us to the following conclusions: (1) under glucose non-limiting conditions, malolactic fermentation helps to maintain pH of the medium at a certain level; (2) during glucose limited growth, malolactic fermentation could be coupled with an energetic process independent from that mentioned above.