Improvement surfactin production by substitution of promoters in Bacillus subtilis TD7

Surfactin is one of the most representative biosurfactants and exhibits excellent surface activity plus other biological effects. It has potential applications in microbial enhanced oil recovery, environmental bioremediation, agricultural bio-control, pharmacy, cosmetics food industries. The low yield surfactant from wild strains a key restriction for industrial applications. construction genetically engineered bacteria by promoter substitution an effective method to enhance surfactin production, as element gene expression. This study focuses on constructing with efficient production replacing native srfA strong promoters. In this study, two different patterns homology arm positions were used substitution. installation way was identified sequence between transcriptions start site ribosome binding srfA. Moreover, eight endogenous auto-inducible phase-dependent promoters chosen substitute using CRISPR-Cas9 system. As result, high yielding application industry constructed. According results, three constructed P43, PspoVG, PyvyD showed increased yields 3.5, 2.8, 2.3 times over stain B. subtilis TD7.