Gene mining, recombinant expression and enzymatic characterization of N-acetylglucosamine deacetylase

Objectives Glucosamine (GlcN) is an important bioactive substance that is widely used in medicine, dietary supplements, cosmetics, and other fields. The traditional method of producing GlcN is mainly through chitosan hydrolysis catalyzed by strong acid, but this process is usually accompanied by environmental pollution and high energy consumption. Therefore, the development of green and efficient production methods of glucosamine has become the focus of current research.Methods In this study, N-acetylglucosamine (GlcNAc) was used as the substrate to facilitate the enzymatic synthesis of GlcN by deacetylase. Four deacetylases (TkDAc, PkDAc, PpDAc and AbDAc) were selected from marine thermophilic microorganisms, and Escherichia coli (E. coli) was used as the host for recombinant expression.Results The soluble expression of PpDAc was poor, so several groups of solubilizing labels were tried, and the results showed that the soluble expression of recombinant plasmid ArsC-PpDAc carrying pro-solubilization labels was greatly improved.Conclusions The effects of temperature and pH on enzyme activity were investigated by single factor analysis. Kinetic parameters further revealed that ArsC-PpDAc exhibited the highest catalytic activity, with a Kcat/Km value of 7.29, and achieved a conversion rate of over 95 %. The condition of ArsC-PpDAc was optimized, and the results showed that ArsC-PpDAc showed good tolerance to organic solvents, and its catalytic activity was not significantly affected.