高酶活·高抑菌活性芽孢杆菌的分离及筛选

Isolation and Screening of Bacillus with High Enzyme Activity and High Antibacterial Activity

[目的]从土壤和动物肠道分泌物中筛选具有蛋白酶、纤维素酶和淀粉酶活性,且具有抑菌作用的肠道益生微生物,为开发可供人类或动物直接使用和喂食的活菌制剂提供技术基础。[方法]通过酪素培养基、淀粉培养基和纤维素培养基分别筛选蛋白酶、淀粉酶和纤维素酶活性菌株,通过琼脂扩散法测定活性菌株的抑菌活性,对菌株进行初步鉴定后进行紫外诱变,测定比较正变菌株的蛋白酶、纤维素酶、淀粉酶活性及抑菌效果,通过10次传代培养分析菌株的遗传稳定性。[结果]诱变复筛得到1株高酶活,高抑菌的芽孢杆菌菌株,其摇瓶发酵液中蛋白酶活、纤维素酶活和淀粉酶活分别为39.100、0.093和1.353 U/ml,比原有菌株分别提高4.08%、7.90%和67.00%,以滤纸片法测得抑菌效果为对金黄色葡萄球菌的抑菌圈直径达1.03 cm,对大肠杆菌的抑菌圈直径为0.85 cm,抑菌效果也明显增强。[结论]分离得到的菌株酶活性、抑菌活性均较高,遗传稳定性较好,具有一定的开发价值。

[ Objective ] The beneficial intestinal micro-organisms that had the activity of protease, cellulase and amylase, as well as the bacteriostasis role were isolated from soil and the animal intestinal secretion, which would provide the technical basis of the development of the living bacterial preparation that could be directly taken by the human or animal. [ Method ] The living strains of protease, amylase and cellulase were screened through the Casein Medium, Starch Medium and Cellulose Medium and the bacteriostasis activity of the strains was tested with the Agar Diffusion Method. The strains were mutated by UV after their preliminary identification and the activity of protease, cellulase and amylase, as well as the bacteriostasis role of beneficial mutants were tested and compared. The genetic stability of the strains was analyzed after 10 times＇ culturing. [Results] One bacillus strain with high enzyme activity and bacteriostasis role was obtained after its mutation and screening and the activity of protease, cellulase and amylase in shake fermentation liquid of the strain was 39. 100, 0. 093 and 1. 353 U/ml, respectively, which were 4.08% , 7.90% and 67.00% higher than that of original strain. The diameter of its inhibition circle to Staphylococcus aureus showed in the Method of Filter Paper Measure was 1.03 cm and to E. coli,0. 85 cm, which effect was significant. [ Conclusion] The strain isolated was with high enzyme activity, antibacterial activity and good genetic stabihty, and also was with a certain development value.