Abstract: Brevibacillus brevis X23 can produce non-ribosomal antibiotic edeines, which have been widely used in biological control of plant diseases. The edeB gene in the edeine biosynthetic gene cluster regulates the synthesis of edeines. In this study, the prokaryotic expression vector pET28a-edeB was constructed by homologous recombination technology with edeB gene as the recombinant fragment of exogenous gene, and was transformed into Escherichia coli BL21(DE) for induced expression. The transcription profile of edeB gene in different culture times (12, 18, 24, 30 and 36 h) of B. brevis was detected by transcriptome sequencing. The results showed that the edeB gene was 771 bp in length, encoding 256 amino acids. SDS-PAGE electrophoresis showed that a specific band with a molecular weight of 30 kD appeared, which is in consistent with the bioinformatics prediction results. EdeB protein mainly existed in the form of inclusion bodies. The results of transcription profile showed that edeB gene was expressed at all culture times, and the gene expression showed a pattern of increasing at first and then decreasing with a peak at 30 h. These results laid a foundation for further study on the molecular mechanism of edeB gene regulating the synthesis of edeines, and provided a theoretical basis for the construction of high-yield edeine strains of B. brevis.
Key words: Brevibacillus brevis; edeB gene; prokaryotic expression; transcription profile; transcriptome
（Acta Laser Biology Sinica, 2023, 32(2): 146-152）