Rizk Ziad, El Rayess Youssef, Ghanem Chantal, Mathieu Florence, Taillandier Patricia, Nehme Nancy
Lebanese Agricultural Research Institute (LARI), Fanar Station, P.O. Box 90-1965, Jdeidet El-Metn, Fanar, Lebanon; Faculty of Sciences, Holy Spirit University of Kaslik, P.O. Box 446, Jounieh, Lebanon; Laboratoire de Génie Chimique, UMR CNRS 5503, INPT-ENSAT, UPS, Université de Toulouse, 1 Avenue de l'Agrobiopôle, F-31326 Castanet-Tolosan, France.
Faculty of Agricultural and Food Sciences, Holy Spirit University of Kaslik, P.O. Box 446, Jounieh, Lebanon.
Int J Food Microbiol. 2016 Sep 16;233:90-96. doi: 10.1016/j.ijfoodmicro.2016.06.018. Epub 2016 Jun 17.
A previous study has shown that the malolactic fermentation (MLF) was inhibited during sequential fermentations performed with the pair Saccharomyces cerevisiae BDX/Oenococcus oeni Vitilactic F in synthetic grape juices. A yeast peptidic fraction with an apparent MW of 5-10kDa was involved in the inhibition. In the present study, the MLF was also inhibited in Cabernet Sauvignon and Syrah wines. The inhibition due to the peptidic fraction was maintained despite high phenolic contents. Kinetic studies showed that the peptidic fraction was gradually released during the alcoholic fermentation (AF). Its highest anti-MLF effect was reached when isolated from late stages of the AF stationary phase. The peptidic fraction was tested in vitro on cell-free bacterial cytosolic extracts containing the malolactic enzyme in a pH range between 3.5 and 6.7. Results showed that it was able to directly inhibit the malolactic enzyme activity with an increasing inhibitory kinetic correlated to the AF time at which it was collected.
先前的一项研究表明，在使用酿酒酵母BDX/酒酒球菌Vitilactic F对合成葡萄汁进行顺序发酵的过程中，苹果酸-乳酸发酵（MLF）受到了抑制。一种表观分子量为5-10kDa的酵母肽级分参与了这种抑制作用。在本研究中，赤霞珠和西拉葡萄酒中的MLF也受到了抑制。尽管酚类物质含量很高，但肽级分引起的抑制作用依然存在。动力学研究表明，该肽级分在酒精发酵（AF）过程中会逐渐释放。从AF稳定期后期分离出来时，其对MLF的抑制作用最强。在pH值为3.5至6.7的范围内，对含有苹果酸-乳酸酶的无细胞细菌胞质提取物进行了该肽级分的体外测试。结果表明，它能够直接抑制苹果酸-乳酸酶的活性，其抑制动力学与收集它时的AF时间相关且呈增加趋势。
