Effect of ccpA gene on the production of aminopeptidase in Bacillus cereus

Abstract:

[Objective] We constructed Bacillus cereus CZ ccpA deletion strains to explore its effect on carbon metabolism and aminopeptidase production. [Methods] Through homologous recombination mediated by the temperature-sensitive plasmid pKSV7, we acquired the mutant strain CZΔccpA successfully. We also constructed ccpA gene revertant strain CZ1 for phenotypic validation of knockout strains. We compared the metabolic differences of three strains cultured with different carbon source and optimized aminopeptidase fermentation conditions. [Results] The ccpA deletion strain CZΔccpA and the revertant strain CZ1 were successfully constructed. There was no difference in the growth of the three strains in LB medium. When fermented with sodium citrate or mannan oligosaccharides as a single carbon source, the CZΔccpA showed significant metabolic differences from the CZ and CZ1. Besides, the activity of aminopeptidase increased by 48.25 percent when D-xylose was used as the sole carbon source. [Conclusion] Bacillus cereus CZ ccpA gene affects the production of aminopeptidase by regulating the carbon metabolism process and we can raise aminopeptidase production by ccpA gene knockout.

Key words:Bacillus cereus;gene deletion mutants;catabolite control protein A;aminopeptidase