产纤维素酶芽孢杆菌的筛选及鉴定

Screening and identification of cellulase producing Bacillus

研究旨在通过定向筛选获得能够产纤维素酶的芽孢杆菌。试验从生境中筛选到产纤维素酶较高的一株芽孢杆菌,通过菌株形态学和分子生物学对菌株进行了鉴定,并对这株菌的耐模拟肠液性、产酶特性和抑菌能力进行评定。结果显示,所筛选的芽孢杆菌B13为解淀粉芽孢杆菌,产纤维素内切葡聚糖酶酶活为7.31 U/ml,纤维素外切葡聚糖酶酶活为5.26 U/ml,木聚糖酶酶活为32.46 U/ml,能够产淀粉酶和蛋白酶,耐模拟胃液能力较强,而耐模拟肠液能力较弱,不能产生抗金黄色葡萄球菌的物质。结果提示,本试验筛选到的解淀粉芽孢杆菌B13能够产生纤维素酶并具有良好生物学特性,为降低粮食加工副产物中纤维素含量、提高其利用率提供了参考。

This experiment was conducted to screen a high cellulose producing Bacillus strain and study its biological characteristics. In this research, a Bacillus strain that produces more cellulose were isolated from habitats. We identified this strain based on morphological features and molecular biology features, then simulated small intestine fluid resistance, cellulose activity and antimicrobial activity were determined. Strain B13 with strong simulated gastric acid resistance is a Bacillus amyloliquefacicns, while simulated small intestine fluid resistance is poor. The endoglucanase activity, exoglucanase activity and xylanase activity of the fermented corn fiber and soybean dregs were 7.31 U/ml, 5.26 U/ml and 32.46 U/ml, respectively. This strain showed no inhibitory activity against Saphylococ- cus aureus. These results indicated that Strain B13 can produce high yield of cellulose and had good biological characteristics. All of those provide a basis theory to improve the utilization of grain processing by-product and ruduce cellulose content.