Université de Toulouse, INPT-ENSIACET, Laboratoire de Génie Chimique UMR CNRS 5503, 4 allée Emile Monso, BP 74233, F-31432 Toulouse cedex 04, France.
Food Microbiol. 2010 Feb;27(1):150-7. doi: 10.1016/j.fm.2009.09.008. Epub 2009 Sep 22.
The present study was aimed to evaluate the impact of the co-culture on the output of malolactic fermentation and to further investigate the reasons of the antagonism exerted by yeasts towards bacteria during sequential cultures. The Saccharomyces cerevisiae D strain/Oenococcus oeni X strain combination was tested by applying both sequential culture and co-culture strategies. This pair was chosen amongst others because the malolactic fermentation was particularly difficult to realize during the sequential culture. During this traditional procedure, malolactic fermentation started when alcoholic fermentation was achieved. For the co-culture, both fermentations were conducted together by inoculating yeasts and bacteria into a membrane bioreactor at the same time. Results obtained during the sequential culture and compared to a bacterial control medium, showed that the inhibition exerted by S. cerevisiae D strain in term of decrease of the malic acid consumption rate was mainly due to ethanol (75%) and to a peptidic fraction (25%) having an MW between 5 and 10 kDa. 0.4 g l(-1) of L-malic acid was consumed in this case while 3.7 g l(-1) was consumed when the co-culture was applied. In addition, there was no risk of increased volatile acidity during the co-culture. Therefore, the co-culture strategy was considered effective for malolactic fermentation with the yeast/bacteria pair studied.
本研究旨在评估共培养对苹果酸-乳酸发酵产物的影响，并进一步探讨酵母在顺序培养过程中对细菌产生拮抗作用的原因。通过应用顺序培养和共培养策略，测试了酿酒酵母 D 株/Oenococcus oeni X 株的组合。之所以选择这个组合，是因为在顺序培养过程中，苹果酸-乳酸发酵特别难以实现。在这个传统的程序中，当酒精发酵完成时，就开始进行苹果酸-乳酸发酵。对于共培养，通过同时将酵母和细菌接种到膜生物反应器中，同时进行两种发酵。在顺序培养中获得的结果与细菌对照培养基进行比较表明，酿酒酵母 D 株在降低苹果酸消耗率方面的抑制作用主要归因于乙醇（75%）和一种分子量在 5 到 10 kDa 之间的肽段（25%）。在这种情况下，消耗了 0.4 g l(-1)的 L-苹果酸，而当应用共培养时，消耗了 3.7 g l(-1)。此外，在共培养过程中，挥发性酸度没有增加的风险。因此，对于所研究的酵母/细菌对，共培养策略被认为是有效的苹果酸-乳酸发酵方法。
