玉米秸秆纤维素降解菌的分离及发酵条件优化

Optimization of the Separation and Fermentation Conditions of Corn Straw Cellulose-Degrading Fungus

[目的]研究玉米秸秆纤维素降解菌的分离与产酶条件。[方法]从富含腐烂玉米秸秆的土壤中分离筛选到1株能降解纤维素的真菌C01,经形态观察和ITS序列分析,初步鉴定该菌种,并对该菌产酶条件进行优化。[结果]玉米秸秆纤维素降解真菌最佳接种种龄5 d,培养液初始pH为5,接种量12%;培养时间5 d的优化条件下,酶活力达1.76 IU/ml。该菌株对玉米秸秆降解效果较好,优化条件下,7 d降解率达66.8%。[结论]该研究可为提高玉米秸秆的利用率提供优质的菌种资源。

[ Objective ] The research aimed to study the separation and enzyme-production conditions of corn straw cellulose-degradation fun- gus. [ Method] A cellulose-decomposing fungus strain was isolated from soil containing abundant rotten corn straw. Based on morphology and ITS sequence analysis, this strain named C01 was initially classified into the genus of Penicillium. Then the enzyme-producing conditions of C01 was optimized. [ Result] The results showed that the optimum conditions for CMCase production were determined as follows： seed age of five days, initial pH value of 5, inoculum concentration of 12%, culture time of five days. Under the optimal conditions, the CMCase activity reached 1.76 IU/ml. The strain C01 could degrade corn straw effectively, and the degradation rate reached 66.8% in seven days. [ Conclu- sion] This research could provide high quality strain for the improvement of corn straw utilization rate.