AUTHOR=Zhang Jinfang , Zhu Baoyue , Li Xinyue , Xu Xiaojian , Li Dengke , Zeng Fang , Zhou Cuixia , Liu Yihan , Li Yu , Lu Fuping 

TITLE=Multiple Modular Engineering of Bacillus Amyloliquefaciens Cell Factories for Enhanced Production of Alkaline Proteases From B. Clausii

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2022.866066

DOI=10.3389/fbioe.2022.866066

ISSN=2296-4185

ABSTRACT=<p><italic>Bacillus amyloliquefaciens</italic> is a generally recognized as safe (GRAS) microorganism that presents great potential for the production of heterologous proteins. In this study, we performed genomic and comparative transcriptome to investigate the critical modular in <italic>B. amyloliquefaciens</italic> on the production of heterologous alkaline proteases (AprE). After investigation, it was concluded that the key modules affecting the production of alkaline protease were the sporulation germination module (Module I), extracellular protease synthesis module (Module II), and extracellular polysaccharide synthesis module (Module III) in <italic>B. amyloliquefaciens</italic>. In Module I, AprE yield for mutant BA Δ<italic>sigF</italic> was 25.3% greater than that of BA Δ<italic>upp</italic>. Combining Module I synergistically with mutation of extracellular proteases in Module II significantly increased AprE production by 36.1% compared with production by BA Δ<italic>upp</italic>. In Module III, the mutation of genes controlling extracellular polysaccharides reduced the viscosity and the accumulation of sediment, and increased the rate of dissolved oxygen in fermentation. Moreover, AprE production was 39.6% higher than in BA Δ<italic>upp</italic> when Modules I, II and III were engineered in combination. This study provides modular engineering strategies for the modification of <italic>B. amyloliquefaciens</italic> for the production of alkaline proteases.</p>