纤维素降解细菌的分离鉴定和筛选方法的研究

Study on Isolation and Identification of Cellulose-Decomposing Bacteria and Its Screening Method

[目的]探索有效筛选纤维素降解细菌的方法。[方法]采用CMC-Na平板分离筛选具有高纤维素酶活性的细菌菌株并通过分子生物学手段对其进行鉴定。[结果]从秸秆和土壤中分离筛选获得了2株具有较高纤维素酶活性的细菌菌株xg1和h10,通过总DNA提取、PCR扩增,经16S rDNA测序及序列分析初步鉴定它们分别为枯草芽胞杆菌和蜡状芽胞杆菌。设计了一种根据水解透明圈直径的大小以初步确定菌株产酶活力高低的方法,发现菌株产酶酶活与透明圈直径之间呈现一定的函数关系。[结论]用CMC-Na平板筛选方法,可避免大量的盲目无效劳动,大大提高获得纤维素酶高产菌株的机率,是较好的筛选纤维素分解菌的方法。

[ Objective] The aim was to explore the method of screening cellulose-decomposing bacteria effectively. [ Method] The bacterial strains with high cellulase activity were isolated and screened by CMC-Na plate and identified by the molecular biology methods. [Result] Two bacterial strains of xgl and h10 with high cellulase ability were screened and isolated from straw and soil and they wore Bacillus subtilis and Bacillus cereus identified by 16S rDNA sequencing after total DNA extraction and PCR amplification. A method of initial confirming cellalase activity of bacterial strains was designed according to the diameter of hydrolysis transparent circle. There was a functional relationship between cellulase activity of bacterial strains and the diameter of transparent circle. [ Conclusion] The CMC-Na plate screening method could avoid a lot of blind and invalid labors, improve the probaility of obtaining high-yield cellulase strains greatly and it was a better method for screening cellulese-decomposing bacteria.