Efficient Whole-Cell Biotransformation for α-Arbutin Production through the Engineering of Sucrose Phosphorylase Combined with Engineered Cell Modification

alpha-Arbutin is extensively used in cosmetic industries. The lack of highly active enzymes and the cytotoxicity of hydroquinone limit the biosynthesis of alpha-arbutin. In this study, a whole-cell biocatalytic approach based on enzyme engineering and engineered cell modification was identified as effective in enhancing alpha-arbutin production. First, a sucrose phosphorylase (SPase) mutant with higher enzyme activity was obtained by experimental screening. Next, to avoid the oxidation of hydroquinone, we established an anaerobic process to improve the robustness of the cells by knocking out lytC, sdpC, and skfA in Bacillus subtilis and overcoming the inhibitory effect of a high concentration of hydroquinone. Finally, the engineered strain was used for biotransformation in a 5 L fermenter with batch feeding for 24 h. The final yield of alpha-arbutin achieved was 129.6 g/L, which may provide a basis for the large-scale industrial production of alpha-arbutin.

Automated summary

In this study, a whole-cell biocatalytic approach based on enzyme engineering and engineered cell modification was found to be effective in enhancing alpha-arbutin production, overcoming the inhibitory effect of a high concentration of hydroquinone. The final yield of alpha-arbutin achieved was 129.6 g/L, providing a basis for large-scale industrial production.