Abstract
Lactic acid bacteria are characterized by numerous nutritional requirements. The influence of amino acids on the growth of Oenococcus oeni SD-2a and metabolism of organic acids were determined. The microorganism in basal medium grew to 2.47×108CFU·ml-1 biomass with maximum growth rate of 0.0072 h-1. When glutamic acid and cysteine were independently omitted from basal medium, no growth was observed, indicating that these amino acids are essentials for bacterial growth. When L-malate and citric acids were added individually or together to basal media deficient in glutamic acid or cysteine, they played a beneficial role in bacterial growth and L-malic acid utilization; and both acid combined had a stimulatory effect on the rate of growth and L-malic acid utilization. When glutamic acid or cysteine concentration increased in the same media, bacterial maximum growth rate (μmax) and final biomass production increased; the rate of L-malate acid utilization, L-lactic acid production or citric acid consumption also increased. Key words: Oenococcus oeni, amino acids, organic acids. 
Highlights
Oenococcus oeni is the main lactic acid bacteria (LAB) species involved in malolactic fermentation (MLF) in wine, which is a very important stage of sparkling in wine production (Lonvaud-Funel, 1999; Versari et al, 1999)
Strains were cultivated in 19 different synthetic media lacking one amino acid, prepared by modifying the composition of amino acids mixture of the basal media (Table 1), and the basal medium (BM) is used as reference (Saguir et al, 2002)
The individual lack of the amino acids of the glutamate family, glutamic acid, proline and arginine from BM shows that no growth was observed in the medium without glutamate, and a diminution of 29.2 and 22.2% was observed on the growth rate due to lack of proline and argnine, respectively
Summary
Oenococcus oeni is the main lactic acid bacteria (LAB) species involved in malolactic fermentation (MLF) in wine, which is a very important stage of sparkling in wine production (Lonvaud-Funel, 1999; Versari et al, 1999). Fourcassie et al (1992), studying the effect of 18 amino acids on growth, D-glucose fermentation and malolactic activity of six strains of O. oeni, found that all strains had an absolute requirement for four amino acids and needed six others for optimum growth. Saguir and Manca de Nadra (2002) reported that for O. oeni growing in the absence of amino acids of the aspartate family, no growth was observed when the essential amino acid, L-asparagine or L- isoleucine was remo-
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