GROWTH, D-GLUCOSE UTILIZATION AND MALOLACTIC FERMENTATION BY LEUCONOSTOC-OENOS STRAINS IN 18 MEDIA DEFICIENT IN ONE AMINO-ACID

Six Leuconostoc aeons strains were used to study the effect of the deficiency of one amino acid on growth, heterofermentative pathway and malolactic fermentation. All strains had an absolute requirement for four amino acids (isoleucine, glutamic acid, tryptophan and arginine) and needed six other amino acids (valine, methionine, cysteine, leucine, aspartic acid and histidine) for optimum growth. Each deficiency in one amino acid had a particular effect on D-glucose utilization. Overproduction and underproduction of D-lactic acid were observed. The rate Of L-malic acid consumption in media deficient in one amino acid was lower than in the complete medium with all amino acids. Although some deficiencies (glycine, phenylalanine, proline or tyrosine) had no influence on the growth the noticeably limited the malolactic fermentation.