Improvement of lipopeptide production in Bacillus subtilis HNDF2-3 by overexpression of the sfp and comA genes

Bacillus subtilis HNDF2-3 can produce a variety of lipopeptide antibiotics with lower production. To improve its lipopeptide production, three genetically engineered strains were constructed. The results of real-time PCR showed that the highest transcriptional levels of the sfp gene in F2-3sfp, F2-3comA and F2-3sfp-comA were 29.01, 6.65 and 17.50 times of the original strain, respectively, while the highest transcriptional levels of the comA gene in F2-3comA and F2-3sfp-comA were 10.44 and 4.13 times of the original strain, respectively. The results of ELISA showed that the malonyl-CoA transacylase activity of F2-3comA was the highest, reaching 18.53 IU/L at 24 h, the data was 32.74% higher than that of the original strain. The highest total lipopeptide production of F2-3sfp, F2-3comA and F2-3sfp-comA induced by IPTG at optimal concentration were 33.51, 46.05 and 38.96% higher than that of the original strain, respectively. The results of HPLC showed that iturin A production of F2-3sfp-comA was the highest, which was 63.16% higher than that of the original strain. This study laid the foundation for further construction of genetically engineered strains with high lipopeptide production.

Automated summary

In this study, three genetically engineered strains were constructed to improve the lipopeptide production of Bacillus subtilis HNDF2-3. Real-time PCR revealed that the transcriptional levels of the sfp gene in F2-3sfp, F2-3comA, and F2-3sfp-comA were significantly increased compared to the original strain. ELISA results showed that F2-3comA exhibited the highest malonyl-CoA transacylase activity, leading to a 32.74% increase in production compared to the original strain. Additionally, HPLC analysis demonstrated that F2-3sfp-comA had the highest iturin A production, which was 63.16% higher than the original strain. This study provides a foundation for the development of genetically engineered strains with high lipopeptide production.