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Chinese Journal Of Biological Control ›› 2020, Vol. 36 ›› Issue (4): 564-574.DOI: 10.16409/j.cnki.2095-039x.2020.04.017

• RESEARCH REPORTS • Previous Articles     Next Articles

Effect of Transcription Factor AbrB on the Biosynthesis of Antibiotic Edeines in Biocontrol Bacteria Brevibacillus brevis X23

ZHANG Liang1, Lü Cui2, DUAN Caichen3, WANG Yunsheng2, HUANG Jun3, DU Jie3, LI Dingjun1,4, LIU Qingshu3, CHEN Wu2   

  1. 1. College of Agronomy, Hunan Agricultural University, Changsha 410128, China;
    2. College of Plant Protection, Hunan Agricultural University, Changsha 410128, China;
    3. Hunan Province Microbiology Institute, Applied Fungi laboratory, Changsha 410009, China;
    4. Hunan University of Technology and Business, Changsha 410205, China
  • Received:2019-12-26 Online:2020-08-08 Published:2020-08-07

Abstract: Non-ribosomal antibiotic edeines are the main bacteriostatic secondary metabolites in Brevibacillus brevis strain X23. Increasing their yields could contribute to improving the bio-control efficiency of X23. Whole-genome sequencing and bioinformatics analysis was used to discover global transcription factors. The global negative transcription factor deletion mutants of X23 were constructed by double-crossover homologous recombination via a temperature-sensitive knockout vector based on Red/ET homologous recombination. Then, the varieties on antibacterial activity, edeines production and the transcription level of Biosynthetic Gene Cluster (BGC) were evaluated by plate antibacterial assay, liquid chromatography-mass spectrometry (HPLC-MS) and real-time quantitative PCR at different growth stages, respectively. A global negative transcription factor AbrB was deleted from the genome of Br. brevis X23, and then the transcription level of the edeBGC operon significantly increased in the early growth stage. The total yields of edeine A and edeine B in the abrB mutant increased by 1.1 times compared with the original strain after 48 h fermentation in conventional fermentation medium. It was proved that AbrB is a negative regulator of edeines biosynthesis processing in Br. brevis X23 and lacking regulation caused by abrB can increase edeines yields.

Key words: Brevibacillus brevis, edeine, transcription factor, abrB, Red/ET recombination

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