Isolation and identification of lipopeptide antibiotic produced by Bacillus amyloliquefaciens B10-6-1 antagonistic to Aspergillus flavus
The lipopeptide antibiotic related genes of Bacillus amyloliquefaciens B10-6-1 antagonistic to Aspergillus flavus were cloned, and the components of the antibiotics were separated and structurally identified. Synthesis genes ItuA, ItuB, ItuC, ItuD, FenA, FenB, FenD, Sfp, bmyA, bmyB, bmyC were amplified by PCR amplification using genomic DNA of Bacillus amyloliquefaciens B10-6-1 as template. The crude extract of lipopeptide antibiotics was obtained from the fermentation broth through centrifugation, acid precipitation and methanol extraction. The extract was separated by high performance liquid chromatography (HPLC), and antifungal activity test in vitro of the elution peak components collected was carried out. The components with antimicrobial activity were analyzed by high performance liquid chromatography combined with multi-stage electrospray tandern mass spectrometry (HPLC-ESI-MS). PCR amplification test results showed that B10-6-1 antagonistic to Aspergillus flavus was able to amplify the ItuA, ItuC, ItuD, FenA, FenD, Sfp, bmyA, bmyB, bmyC synthesis genes, but failed to amplify the ItuB, FenB synthesis genes. Seven components were collected by HPLC and antibiotic test in vitro results showed that components 5 and 7 exhibited antimicrobial activity. HPLC-ESI-MS determination results showed that component 5 is lipopeptide antibiotic C14bacillomycin D and component 7 is lipopeptide antibiotic C15bacillomycin D. This study laid a theoretical foundation of biological control of Aspergillus flavus by using natural antimicrobial activity of antagonistic bacteria.
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NSTL
万方数据
维普
