纤维素降解菌的筛选及其混合发酵研究

Research on the Screening and Mixed Fermentation of Cellulose-decomposing Microorganisms

[目的]为纤维素的高效降解提供理论依据。[方法]从森林落叶土、腐烂的秸秆和农家堆肥等含有木质纤维素降解菌的样品中筛选出能较好降解纤维素的菌株,对其进行单独与混合发酵培养。[结果]最终筛选出4株能较好降解纤维素的菌株,初步判断为3株细菌,1株放线菌。菌株的混合培养在一定程度上提高了纤维素酶活,菌株组合D6/D7的酶活72 h达67.12 U,相当于其单独培养时的2倍。多数菌株的纤维素酶活随时间的变化曲线表现为先上升后下降再上升的趋势,但菌株组合D6/D7的稳定性较好。[结论]菌株的混合培养可以提高纤维素酶活,尤其是菌株组合D6/D7。

[Objective] The aim of the research was to supply theoretical basis for high efficient decomposition of cellulose. [Method] The strains that could decompose cellulose better were screened out from samples cantaining lignoeellulose-decompnsing microorganisms, such as forest defoliation soil, rotten straw and farmhouse compost. They were cultured solely and by mixed fermentation. [Result] Four strains that could decompose cellulose better were screened out finally, and they were judged a,s 3 swains of bacteria and 1 swain of actinomycete preliminarily. The mixed culture of swains enhanced cellulase activity to some degree, the enzyme activity of strain combination 136/D7 reached 67.12 U in 72 h and was equal to 2 times of that in its sole culture. The variant curve of cellulase activity in most strains varying with time showed the ascending-descending-ascending trend, hut the stability of strain combi natian D6/D7 was better. [Conclusion] The mixed culture of strains could enhance cellulase activity, especially for strain combination D6/D7.