适于同步糖化发酵产纤维素酶菌株的筛选

Screen of cellulase-producing strain suit for SSF

从土壤底层腐烂植物根茎中筛选出适应30℃条件下的多株纤维素酶产生菌,择优挑选其中5株,对它们逐级进行温度驯化,最终得到一株能适应40℃的菌株CE5′,其Cx酶活可达24.73 U/mL。通过对初始pH值、底物浓度、接种量3个影响因子的二次回归正交组合设计,得出各因素对菌株CE5′Cx酶活的影响顺序:接种量>初始pH值>底物浓度;各因素的最优水平取值:初始pH值6.49,底物浓度8.55 g/L,接种量6.66%。

Many cellulose-producing strains were isolated from the decaying plant roots under 30 ℃,5 of them were selected because of growing well,and they weredomestication cultured by temperature step by step.Finally,one strain named as CE5′was obtained which can adapt to 40 ℃.Its Cx enzymatic activity can reached 24.73 U/mL.Through the quadratic regression orthogonal combination designfor three fac- torssueh as initial pH value,substrateconcentration and inoeulationvolume,the sequence of Cx enzymatic activity of CE5′effected by them are as follows：inoculationvolume〉initial pH value〉substrateconcentra- tion.The optimal level value of three factors are as follows：initial pH value is 6.49,substrateconcentration is 8.55 g/L, inoculationvolume is 6.66%.