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

[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 stability,and also was with a certain development value.