黑曲霉(CGMCC 3.316)β-葡萄糖苷酶酿造因子耐性分析

Stabilities of β-glucosidases from Aspergillus niger (CGMCC 3.316) in Wine Brewing Conditions

为了确定黑曲霉（CGMCC 3.316）β-葡萄糖苷酶在葡萄酒增香中的应用潜力,考察了该酶对葡萄酒酿造温度、酒精的体积分数、p H值、糖的质量浓度及SO2的质量浓度等酿造因子的耐性。结果表明,该β-葡萄糖苷酶最适反应温度为60℃,酿造温度条件（20～30℃）下具有很高的耐性;少量的酒精对该酶有激活作用,酒精的体积分数大于0.08（酒精度大于8%vol）时耐性迅速降低;其最适反应p H值为4.55,酿造环境pH 3.4条件下活性较低,酸耐受性差;SO2的质量浓度低于40 mg/L时较稳定;该酶具有一定的葡萄糖耐受性。综合该酶对以上葡萄酒酿造因子的耐性,若用于葡萄酒的增香处理,建议处理时间控制在大约6～8 d。若要进一步提高葡萄酒增香效果,需提高该酶低温时的酶活性及其酸耐受性。

In order to evaluate the application potentiality of Aspergillus niger （CGMCC 3.316） β-glucosidases in wine aroma enhancing, the stabilities of the enzyme on the brewing temperature, alcohol content, sugar content and SO2 content were studied in this test. The results indicated that 60 ℃ was the optimal temperature for the enzyme, meanwhile it expressed very stable in brewing temperature （20～ 30 ℃ ）. A small content of alcohol could activate the enzyme activity, but the activity was greatly inhibited when the alcohol content over-passed 8% or more. pH4.55 would be the optimal for the enzyme, while its activity might be lower at brewing pH3.4 and it displayed unstable in such acidic condition. The enzyme was stable when the SOs content lowed 40 mg/L. The enzyme also showed some stability in the presents of different contents of sugar. Based on the above studies, 6～ 8 days treatment of the enzyme would be recommended when used in wine-making process. In addition, some engineering techniques could be employed to increase the enzyme activity in low temperature and its stability in acidic condition so as to enhance wine aroma.