产单宁酶真菌的筛选及产酶条件

Study on screening and induction conditions of the tannase producing fungi

从铁冬青等4种植物的新鲜茎、叶组织中分离得到52株真菌,经平板透明圈法初筛得到18株产单宁酶菌株。初筛所得菌株经液体发酵,显示1株木霉属真菌(Trichoderma viride)(No.MY P07)酶活力最高,达0.248μmol/(min·mL)。采用单因素结合正交实验,得到菌株MYP07的最佳发酵条件为:单宁100g/L,蔗糖10g/L,(NH4)2SO43g/L,装液量为30mL(250mL锥形瓶),起始pH为5.0,温度30℃,转速140r/min。在此条件下,菌株MY-P-07发酵48h酶活力达到0.392μmol/(min·mL)。

Fifty-two strains of filamentous fungi were isolated from the fresh stems and/or leaves of 4 plants,and 18 tannase producing strains were obtained through the plate transparent zone method. Subsequently these strains were cultured in the liquid tannase-inducing medium,among which a fungal strain Trichoderma viride （No. MY P 07） showed the strongest activity （0. 248 μmol/（min·mL））. Through single factor and orthogonal experiments,the optimal fermentation conditions of the strain MY P 07 were determined as follows：tannin acid 100 g/L,sucrose 10 g/L,（NH4）2SO4 3 g/L,liquid volume 30 mL （in 250 mL flasks）,initial pH 5. 0,30 ℃,140 r/min for 48 h. In these conditions,the tannase activity of the strain was 0. 392 μmol/（min·mL）.