Isolation and Identification of the Antimicrobial Substance Produced by Bacillus subtilis fmbR

【Objective】Isolation and identification of the antimicrobial substances produced by Bacillus subtilis fmbR was studied in this paper.The study aimed to determine the structure and component of the antimicrobial substances.【Method】With HPLC and TLC methods,the antimicrobial substances from Bacillus subtilis fmbR were isolated and purified.Through ESI-MS and MALDI-MS analysis,the structure and component of the antimicrobial substances were identified.【Result】HPLC showed that one of the antimicrobial substances had the similar retention time similar to surfactin.In addition,the antimicrobial substances were proved to include the closed circle peptide band by TLC,and one of them had the migrating rate similar to surfactin.Furthermore,ESI-MS analysis indicated that Bacillus subtilis fmbR could produce three homologues of surfactin,such as m/z1009.1,m/z1023.2 and m/z1037.0.While other antimicrobial substance with the [M+H]+ ion peak at m/z 3403.95 from Bacillus subtilis fmbR,which is very similar to molecular mass of subtilosin produced by Bacillus subtilis 168 was detected by MALDI-TOF-MS analysis 【Conclusion】The antimicrobial substances from Bacillus subtilis fmbR were composed of three homologues of surfactinA(C13-C15) and a lantibiotics named subtilosin