两株高产纤维素酶细菌的筛选、鉴定及酶学特性

从腐烂枯叶及附近土壤筛选分离得到2株产纤维素酶的菌株。经细菌形态观察、生理生化实验并结合16S rRNA序列分析,将其初步鉴定为地衣芽孢杆菌CT1(Bacillus licheniformis CT1)和枯草芽孢杆菌CM2(Bacillus subtilis CM2)。经摇瓶发酵,测定其CMCase、FPA酶活力,结果表明CT1和CM2在液体摇瓶培养4 d后的CMC酶活最大,分别可达163.3 U/mL和167.17 U/mL;CT1摇瓶培养2 d后,FPA酶活达到了211.17 U/mL,CM2摇瓶培养3 d后,FPA酶活为207.83 U/mL。进行不同碳源对菌株产酶能力影响的试验,并通过SDS-聚丙烯酰胺凝胶电泳、银染后初步分析纤维素酶谱条带,发现菌株对不同来源纤维素的降解能力及产纤维素酶的种类均有所不同。

Isolation, identification and enzymatic characteristics of cellulose-producing strains with high cellulase activity

Two cellulose producing strains were isolated from decayed leaf and soil around it. According to morphology, biochemical and physiological characterization, and 16S rRNA sequence analysis, CT1 was identified as Bacillus licheniformis and CM2 was identified as Bacillus subtilis. Through deteminations of CMC enzyme activity and filter paper enzyme activity using liquid fermentation. The result of the CMCasae activity of CT1 is 163.3 U/mL and CM2 is 167.17 U/mL after 4 d, the FPA activity of CT1 is 211.17 U/mL after 2 d and CM2 is 207.83 U/mL after 3 d. The effect of carbon sources on the optimum cellulase-producing conditions of these strains were studied. By silver staining after SDS-polyacrylamide gel electrophoresis preliminary separation cellulose enzyme special bands. The result showed that the utilization capabilities to different source cellulose were different.