Several Strains Of The Preliminary Separation Of The Production Of Antimicrobial Substances Bacillus Identification And Antibacterial Substances

Strain BL-1 and strain BL-3 were two bacteria with strong antibacterial activity, which can inhibit the growth of many kinds of microorganisms including some plant fungal pathogen and some grams negative and grams positive bacteria.The results of the mycological characteristics, the physiological and biochemical properties, and the 16SrDNA sequence analysis of the two strains showed that strains BL-1 and BL-3 were all identified as Bacillus laterosporus. But the antibacterial spectrum of them indicated that the inhibitor ability of strain BL-1 was superior to that of strain BL-3. So the antibacterial material produced by strain BL-1 was further studied.An optimal media prescription of strain BL-1 for producing antibacterial material was obtained by orthogonal test. It was composed of starch 3g/L (A2), peptone 4g/L (B2), beef extract 1g/L (C1), NaCl 5g/L(D4). It presumed the superior combination was A₂B₂C-1D₄ While other optimum fermentation conditions were consisted of as follows. That were FeSO₄ 0.02g/L, MgS0₄0.04g/L, initial pH7.0-8.0, inoculation quantity 4% with 50 mL medium in 250mL flask, 180 r/min, 30℃, and culture time 72 h.The properties of the antibacterial material of strain BL-1 were studied. The results suggested that it was very likely protein because its activity stability was so bad when it was hot up and treatmented with enzyme.The proteins were separated and purified from the fermentation liquid of strain BL-1 with many methods. The crude proteins were deposited by ammonium sulphate solution at concentration of 50% to 90%. Then the saturation was purified by column chromatography on CM-Sepharose Fast Flow, Sephadex G-50 and Sephadex G-25. At last, there were two kinds of antibacterial protein were proved to be purified by polyxrylamide gel electrophoresis (PAGE), which were name component A and component B,...