一株降解小麦秸秆丝状真菌的筛选、鉴定及初步研究

Screening,Identification and Preliminary Study of a Wheat Straw-Degrading Filamentous Fungi

利用涂布平板法从腐烂秸秆及枯枝烂叶中分离出71株丝状真菌.通过比较菌株秸秆粉降解产物对小麦生长的促进作用,获得一株可有效降解秸秆并促进小麦生长的菌株2-5-2.对其进行形态分析和rRNA序列鉴定,结果显示,该菌株为木霉属真菌.该菌株可产生纤维素酶、木质素酶、半纤维素酶、几丁质酶、蛋白酶、壳聚糖酶.平板对峙培养显示,该菌对多种病原真菌的生长有抑制或阻碍作用.固态发酵培养时,纤维素酶、半纤维素酶酶活在第11d达到最高;第28d,纤维素降解率达到21.13%,半纤维素降解率达到28.53%.

71 fungi strains were isolated from rotten straw,leaves and stalks by spreading plate method.The strain designated 2-5-2 was screened out because high growth-promotion effect of its solid fermentation product to wheat seedlings.2-5-2 was identified as Trichoderma viride by the analysis of its morphology and 18S rRNA gene sequence.This strain has enzymatic activities of cellulase,hemicellulase,laccse,ehitosanase,chitinase and protease.The inhibition or impedance of 2-5-2 on plant pathogenic fungus was also observed by means of dual-culture tests.After 28 d of solid fermentation,the degradation rate of cellulase,hemicellulase reached 21.13% and 28.53%.