一株高产木质纤维素酶红侧耳菌株的筛选及鉴定

Screening and Identification of a Strain with High-yield Lignocellulose-degrading Enzymes from Pleurotus djamor

高产木质纤维素酶菌株的筛选及鉴定对玉米秸秆生物质资源的综合利用具有重要意义。以前期采用原生质体诱变技术获得的3株红侧耳菌株CM12、CM13和CM16为试验材料,通过拮抗试验、生长速度测定试验进行优势突变菌株的初筛,漆酶、锰过氧化物酶、木聚糖酶、纤维素酶活力的测定进行高产木质纤维素酶突变菌株最终筛选,并对其进行ITS-PCR鉴定。结果表明:3株菌株与原菌株均产生明显拮抗;CM13菌株在PDA固体培养基中的生长速度最快,高于CM12、CM16及原菌株;CM13菌株在纯玉米秸秆粉培养基中漆酶、锰过氧化物酶、木聚糖酶和纤维素酶活力均最高,分别为121.23,144.11,793.38,238.92 U/L,比原菌株酶活力分别提高了13.07%、12.90%、19.93%和30.22%。ITS-PCR结果表明,CM13菌株在分子水平上发生了变异。

Screening and identification of strains with high-yield lignocellulose-degrading enzymes are of great significance for the comprehensive utilization of corn stalk biomass resources. Three strains CM12, CM13 and CM16 obtained before using protoplast mutagenesis technique were used as experimental materials. Preliminary screening of dominant mutant strains was carried out by antagonism test and growth rate test. Then, screening of the mutant strains with high-yield lignocellulose-degrading enzymes were carried out through the determination of laccase, manganese peroxidase, xylanase and cellulase activities, and its identification was performed by ITS-PCR technology. The results showed that the three strains were antagonistic to the control strain. Strain CM13 had the highest growth rate in PDA solid medium, higher than that of strain CM12, strain CM16 and the control strain. Strain CM13 in pure corn stalk liquid medium had the highest laccase, manganese peroxidase, xylanase and cellulase activities, reaching 121.23 U/L, 144.11 U/L and 793.38 U/L and 238.92 U/L, respectively, which increased by 13.07%, 12.90%, 19.93% and 30.22%, respectively, compared with the control strain. ITS-PCR results showed that strain CM13 mutated at the molecular level.