FATTY-ACID COMPOSITION OF LEUCONOSTOC-OENOS, INCIDENCE OF GROWTH-CONDITIONS AND RELATIONSHIP WITH MALOLACTIC EFFICIENCY

Total methyl fatty acids of Leuconostoc oenos were analysed on cell pellets by gas chromatography. Fatty acid composition varied according to growth phase: during culture in a semi-synthetic medium, cis-vaccenic acid decreased when lactobacillic acid increased. It also varied according to growth medium: the unsaturated:saturated fatty acid ratio increased when fatty acids or wine were added to the medium and decreased in the presence of 10% (v/v) ethanol. On the other hand, the malolactic efficiency of these L. oenos cultures varied according to growth conditions. Only cells cultivated in medium to which wine had been added were able to achieve malolactic fermentation after direct inoculation in red wine. Results concerning both fatty acid composition and malolactic activity of several strains in different conditions were subjected To principal component analysis, in order to detect a possible relationship between the fatty acid composition of cells, and their ability to achieve malolactic fermentation, but no clear correlation appeared. Other components of the plasma membrane are also probably involved in the adaptation of L. oenos cells to wine. (C) 1995 Academic Press Limited.