一株纤维素酶高产菌的筛选、鉴定与产酶研究

Screening,Identification and Enzyme-Producing Study of A High Cellulase-producing Strain

从蘑菇培养基质中筛选到一株纤维素酶高产菌株，将其命名为SAISA10，经形态学及分子生物学鉴定，确认该菌为真菌Hypocreales sp.。发酵产酶条件分析结果表明，该菌株最佳发酵条件为：发酵时间3 d、发酵温度40 ℃、pH值4. 0、m（羧甲基纤维素钠）：m（麸皮）=1 ： 1（g ： g）、（NH4）2SO4含量0. 8 g ·（100 mL）^-1 。酶学性质初步研究结果表明，该菌株所产纤维素酶的最适酶解条件为：温度45～55 ℃、pH值4. 0;最佳稳定条件为：温度40 ℃、pH值4. 5。菌株SAISA10是一株高产纤维素酶的真菌，在高温和低pH值下仍有高活性和稳定性，具有较高的开发价值。

A high cellulase-producing strain was screened from the mushroom cultivation matrix,and named as SAISA10. It was identified as Hypocreales sp. by morphological observation and DNA sequence identifica- tion. Results showed that,the optimum fermentation conditions for strain SAISA10 were as follows= fermenta- tion time of 3 d,fermentation temperature of 40 ℃ ,pH value of 4.0,the mass ratio of sodium carboxymethyl cellulose and bran of 1 ： l（g ：g）,（NH4）2SO4 content of 0.8 g · （100 mL）^-1. The preliminary research results of enzymatic properties showed that, the optimum enzymatic hydrolysis conditions were as follows.temperature of 45~55 ℃ ,pH value of 4.0,and the optimum stable conditions were as follows：temperature of 40 ℃,pH val- ue of 4.5. The strain SAISA10 is a high cellulase-producing strain with high activity and stability at high tem- perature or low pH value,which has high exploration potential. Keywords. cellulase ; fungus ; screening ; identification; fermentation condition ; HyDocreales sp.