一株纤维素降解真菌的筛选及鉴定

Isolation and identification of a cellulose degrading fungi

【目的】分离筛选高效降解纤维素的真菌菌株,并研究其产酶能力。【方法】利用刚果红染色法从甘蔗地土壤中分离纤维素降解真菌,再通过测定滤纸的降解率及发酵酶活复筛。【结果】综合考虑水解圈,水解圈和菌株直径的比值(HC值),滤纸的降解率和复筛酶活,对试验真菌降解纤维素的能力进行综合评价,筛选到具有较强纤维素降解能力的真菌菌株SJ1,经形态学观察及分子生物学鉴定,该菌属于草酸青霉。其滤纸酶活、内切葡聚糖酶酶活(CMC酶活)、β-葡聚糖苷酶酶活和外切葡聚糖酶酶活(CBH酶活)分别为25.15、740.42、58.03和2.442 U/mL。【结论】菌株SJ1是一株十分具有研究开发潜力的纤维素酶生产菌株。

Objective The aim of this study was to screen efficient cellulose degrading strains and to investigate their cellulase-producing conditions. Methods The fungus were screened from sugarcane soil by using the Congo red dye test, then measured the degradation rate of filter paper and the enzyme activity for second-screening. [Results] The hydrolyzation zone, clearing zone ratios （clearing zone diameter/colony diameter）, the degradation rate of filter paper and cellulose activity were taken as evaluating selection criteria. We isolated one fungi with cellulose degrading ability, of which S J1 was identified as Penicillium oxalicum by morphological and molecular technology. The results showed that the filter paper activity （FPA）, endoglucanase activity （CMCase activity）, β-glucosidase activity and exoglucanase activity （CBH activity） of SJ1 were 25.15 U/mL, 740.42 U/mL, 58.03 U/mL and 2.442 U/mL, respectively. [Conclusion] Strain S J1 was a cellulase-producing strain with broad development potential.