Stimulatory Effect of Malo-Lactic Fermentation on the Growth Rate of Leuconostoc oenos.

Although l-malic acid is not an energy source for the malo-lactic organism Leuconostoc oenos (L. citrovorum) ML 34, the growth rate of the organism was found to be greatly increased by malo-lactic fermentation (the decarboxylation of l-malic acid to l-lactic acid). The stimulation was especially striking at the low pH (below pH 4) of wine, the natural habitat of this bacterium. The stimulation of growth did not result from changes in pH that accompany malo-lactic fermentation. Thus, these results suggest a biological function of malo-lactic fermentation.