Enhanced production of iturin A in Bacillus amyloliquefaciens by genetic engineering and medium optimization

In this study, the promoter of iturin A synthetase cluster of Bacillus amyloliquefaciens HZ-12 was respectively replaced by promoters P43, PbacA, PsrfA and Pylb, our results implied that transcriptional level of gene ituD and iturin A titer showed consistent change trends, and PbacA was proven as the most efficient promoter, iturin A titer of which reached 950.08 ± 19.43 mg/L. Furthermore, regulator gene abrB was deleted to release the repression effect of AbrB on PbacA, ituD transcriptional level and iturin A titer were increased by 133.25% and 20.88%, respectively. Then, the maximum iturin A titer reached 2013.43 ± 32.86 mg/L by optimizing fermentation medium, increased by 392.15% compared to the original (408.97 ± 21.35 mg/L). Finally, our results demonstrated that enhancing iturin A synthetic capability benefited the suppression of A. alternate. Collectively, this study provided a promising strain with an efficient fermentation medium for large-scale industrial production of iturin A.Graphical abstract
Source: Process Biochemistry - Category: Biochemistry Source Type: research