中国主要葡萄酒产区酒酒球菌糖苷酶活性

Glycosidase Activities of Oenococcus oeni from Major Wine-Producing Regions in China

在苹果酸乳酸发酵(malolactic fermentation,MLF)过程中,一些酒酒球菌产生的糖苷酶活性受葡萄酒环境的影响,筛选并利用在酿酒环境中具有高活力糖苷酶的菌株进行MLF,有助于提升葡萄酒的香气复杂性。本实验以中国5个酿酒产区19株酿酒特性优良的酒酒球菌和一株商业菌为实验菌株,通过测定5种糖苷酶活性,对其中5株糖苷酶活性高的菌株研究其在葡萄酒环境中糖苷酶的酶学性质。结果表明:20株菌在相应底物作用下均含有可检测到的糖苷酶活力,不同菌株酶活性差异显著,地区间差异不显著。5株糖苷酶活性高的菌株最适p H值为4.0,最适温度为45℃,在低水平(4%乙醇+0.1 g/100 m L果糖)时有促进作用,高水平(14%乙醇+2 g/100 m L果糖)时抑制作用显著,葡萄糖则表现为抑制作用,但各种酶活性表现为菌株依赖性。在模拟酒条件下,菌株相对酶活力仅是菌株酶活力的9.805%~32.331%。总之,在所选菌株中,SD-1f在葡萄酒环境中的糖苷酶活性最高。

The wine-related lactic acid bacteria, especially Oenococcus oeni, can produce glycosidase and release volatile aroma compounds through hydrolysis of grape-derived aroma precursors by undertaking malolactic fermentation(MLF), thus improving the aroma complexity of the wine. To investigate five glycosidase activities, 19 strains of O. oeni from five wine-producing regions in China and a commercial strain were selected, and then five strains with higher glycosidase activities were used to explore glycosidase properties in model wine environment. The results showed that all these 20 strains produced detectable glycosidase activities towards the corresponding substrates. Significant differences were observed among different strains, while no difference was observed among different wine regions. The optimum p H was 4.0 and optimum temperature was 45 ℃ for glycosidase. Ethanol and fructose could stimulate at lower concentrations(4%ethanol + 0.1 g/100 m L fructose) but significantly inhibit at higher concentrations(14% ethanol + 2 g/100 m L fructose) glycosidase activity, which, however, was inhibited by glucose at all investigated concentrations. Furthermore, the responses of the enzyme activities were strain-dependent. In the model wine environment, only 9.805%-32.331% of glycosidase activity remained. In conclusion, SD-1f displayed the highest glycosidase activity among all selected strains.