AUTHOR=Jiang Cong , Ye Changwen , Liu Yongfeng , Huang Kuo , Jiang Xuedeng , Zou Dian , Li Lu , Han Wenyuan , Wei Xuetuan 

TITLE=Genetic engineering for enhanced production of a novel alkaline protease BSP-1 in Bacillus amyloliquefaciens

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2022.977215

DOI=10.3389/fbioe.2022.977215

ISSN=2296-4185

ABSTRACT=<p>Alkaline protease has been widely applied in food, medicine, environmental protection and other industrial fields. However, the current activity and yield of alkaline protease cannot meet the demand. Therefore, it is important to identify new alkaline proteases with high activity. In this study, we cloned a potential alkaline protease gene <italic>bsp-1</italic> from a <italic>Bacillus subtilis</italic> strain isolated in our laboratory<italic>.</italic> BSP-1 shows the highest sequence similarity to subtilisin NAT (S51909) from <italic>B. subtilis</italic> natto<italic>.</italic> Then, we expressed BSP-1 in <italic>Bacillus amyloliquefaciens</italic> BAX-9 and analyzed the protein expression level under a collection of promoters. The results show that the P43 promoter resulted in the highest transcription level, protein level and enzyme activity. Finally, we obtained a maximum activity of 524.12 U/mL using the P43 promoter after fermentation medium optimization. In conclusion, this study identified an alkaline protease gene <italic>bsp-1</italic> from <italic>B. subtilis</italic> and provided a new method for high-efficiency alkaline protease expression in <italic>B. amyloliquefaciens</italic>.</p>