Essential Amino Acid Requirements For Oenococcus Oeni Growth And Their Effects On Malolatic Fermentation

Oenococcus oeni is a Gram-positive, catalase negative, microaerophilic andheterofermentative coccus. Oenococcus oeni has numerous nutritional requirements forgrowth, especially nitrogen sources, so it has particular significance on the wine-making ifwe know the nutritional demands of Oenococcus oeni. Generally, the nitrogen source ofOenococcus oeni consists of protein, polypeptide, ammonium and amino acid, while themain nitrogen source in wine only makes up of ammonium and amino acid. For that matter,the variety and concentration of free amino acid in wine plays an essential role in themetabolism of Oenococcus oeni. Meanwhile, those amino acid which restore in wine afterfermentation are soaked up by consumers directly, so it has an important significance onboth of the technology and quality of wine. In this essay, we analysed the essential aminoacid of Oenococcus oeni SD-2a and the effect of organic acid metabolism on essentialamino acid, and detected the concentration of amino acid in wine before and after MLF.1. Cultivating Oenococcus oeni SD-2a in19different media lack of a kind of aminoacid, and accompanied by bacterial colony and data analysis. The result shows L-glutamineacid and L-cystenine acid are the essential amino acid for Oenococcus oeni SD-2a, andL-arginine, L-proline, L-aspartic, L-asparagine, L-threonine and L-histidine have themotivate effect for the growth of Oenococcus oeni SD-2a.2. Cultivating Oenococcus oeni SD-2a in different BM media that was addedL-malate and/or citric acid, and adjusted the concentration of essential amino acid in BMmedia in order to analyse the growth and the capacity of deacidfication of Oenococcus oeniSD-2a. The result said that L-malate and citric acids favoured Oenococcus oeni SD-2agrowth and the capacity of deacidfication under the condition that lack essential amino acid.The optimal concentration of L-glutamine acid is1mmol/L, and that of L-cystenine acid is6mmol/L.3. Oenococcus oeni SD-2a was cultivated in wine which made by Cabernet Gernischtand induced MLF. The concentration of amino acids in wine was detected before and afterMLF. The result indicated that the concentration of cystenine and methionine wereincreaced by5mg/L and17.03mg/L respectively, and others were all consumed above50%, owning to the metabolism of Oenococcus oeni SD-2a.