一株产单宁酶酵母菌株的筛选

单宁酶全称单宁酯酰水解酶(Tannase,EC 3.11.20),能水解水解性单宁酸和没食子酸酯类中的酯键和缩酚羧键,生成没食子酸和葡萄糖。本实验从青柿、未完全成熟的香蕉、茶叶、茶园土壤等富含单宁酸的环境中取样,采用富集培养技术分离筛选出69株产单宁酶的菌株,并对其菌株的外在特性和产酶活力进行了研究和测定,最终获得一株产单宁酶活力较高的酵母菌株FC6-1。在未进行发酵条件优化前,该菌株所产单宁酶酶活达到2.86U/mL。采用薄层色谱法和SBA-40D生物传感分析仪等方法对该酶酶解产物分析,结果表明该菌株产生的单宁酶能够有效的水解单宁酸生成没食子酸和葡萄糖。

Screening of Tannase-producing strains

Tanin acyl hydrolase(E.C.3.11.20)commonly referred to as tannase,catalyzes the hydrolysis of ester and despide bonds in hydrolysable tannins,releasing glucose and gallic acid.In this study,69 tannase-producing yeast strains were isolated by using enrichment-culture technique from natural resources,such as persimmons,unripen bananas and the tea leave or soil of the tea trees.The characteristic and tannase-producing activity of the samples were investigated.Finally,one yeast strain FC6-1 with higher tannase activity was obtained.Before the optimization of the conditions of fermentation,the tannase-producing activity of this yeast strain FC6-1 was 2.86U/mL.This strain was able to hydrolyze tannin into gallic acid which was determined by thin layer chromatography(TLC)and glucose which was determined by Biosensor Analyzer.