Screening and characterisation of wine related enzymes produced by wine associated lactic acid bacteria

[摘要] Among the factors contributing to wine complexity and quality, wine aroma is one of themost important factors. Wine aroma is the outcome of interaction among differentcompounds produced from the grapes, during fermentation as well as during the ageingprocess. Apart from its origin from grapes, fungi and yeasts, wine aroma can also bederived from the metabolic activity of wine lactic acid bacteria (LAB). Thesemicroorganisms are usually associated with malolactic fermentation (MLF) which normallyoccurs after alcoholic fermentation. MLF is beneficial to wine due to its contribution todeacidification, microbiological stabilisation and wine aroma formation, with the latter beingthe most important area of interest in our study. The production of volatile aromaticcomponents in wine can, in part, be achieved through the hydrolytic action of enzymesproduced by LAB associated with wine. These enzymes include β-glucosidase, protease,esterase, lipase and glucanase. Most of the work done on bacterial enzymes has been onLAB from food sources other than wine, in which these enzymes contribute to the flavourdevelopment of some cheeses, yoghurt and other fermented foods. The activity of theseenzymes during wine fermentation has mostly been concerned with β-glucosidase fromOenococcus oeni. Only in recent years has there been a renewed interest in evaluatingthe activity of β-glucosidase in other genera of wine LAB.The overriding goal of this study was to screen and characterise wine-related enzymesproduced by LAB associated with wine. All the LAB isolates tested in this study wereobtained from IWBT culture collection and were previously isolated from five differentwineries situated in the Western Cape region, South Africa. We first screened isolatesusing classical methods. The isolates were grown on agar medium supplemented withappropriate substrate analogues in order to evaluate the activity of enzymes (i.e. β-glucosidase, glucanase, lipase and esterase). The colonies exhibiting enzymatic activity ...

[发布机构] Stellenbosch University