1株降解玉米秸秆放线菌的筛选

Screening of a Strain of Actinomycetes Degrading Corn Stalk Cellulose

[目的]筛选出能够降解玉米秸秆的微生物。[方法]以植物园土层下5 cm取得的腐殖质土壤为样品进行富集培养,通过刚果红染色法进行初步筛选,滤纸崩解法进行二次筛选;以玉米秸秆粉为唯一碳源,经25℃、180 r/min摇床培养72 h,测定纤维素酶活性;通过形态观察对菌株进行初步鉴定。[结果]筛选出1株纤维素酶活性最大的菌株WZ16,滤纸酶活性为620 U,CMC酶活性为72 U,通过形态观察初步鉴定WZ16为链霉菌属放线菌。[结论]最终筛选得到1株有较高纤维素酶活性的链霉菌属放线菌,为综合利用玉米秸秆作为生物质能源提供了参考。

[Objective] To screen a strain of actinomycetes that can degrade corn stalk cellulose. [Method] Enrichment culture was carried out with 5 cm humus subsurface soil at botanical garden as the sample. Preliminary screening was carried out by Congo red staining. Secondary screening was conducted by paper disintegration method. With corn stalk powder as the only carbon source,shake cultivation was carried out at 25 ℃ under 180 r/min for 72 h. Cellulase activity was detected. Strains were preliminarily identified by morphological observation. [Result] A strain WZ16 with maximum cellulase activity was obtained. Filter paper enzyme activity was 620 U,CMC enzymes activity was 72 U.Morphologic observation showed that WZ16 was streptomyces actinomycetes. [Conclusion] A streptomyces actinomycetes with relatively high cellulase activity is finally obtained,which provides references for the comprehensive utilization of corn stalk as biomass energy.