Screening of endogenous promoters of Bacillus amyloliquefaciens and application of them in the expression of alkaline pectinase

Abstract:

[Objective] To screen out the strong promoters suitable for the expression of alkaline pectinase in Bacillus amyloliquefaciens based on the transcription level and expression of the target gene and further analyze the selected strong promoters. [Methods] The promoter fragments were predicted and screened out by bioinformatics tools on the basis of the relative fluorescence intensity and enzyme activity. Further, real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was carried out to determine the transcription levels of different promoters. [Results] The activities of PrapA, PmetE-1, and Phin-1 expressing alkaline pectinase were 9.8, 4.8, and 3.0 times that of P43 promoter, respectively. The three strong promoters screened out laid a foundation for the expression of other heterologous genes in B. amyloliquefaciens. [Conclusion] The strong promoters PrapA, PmetE-1, and Phin-1 screened out in this study can effectively improve the expression of alkaline pectinase.