The Study Of Displaying α-glucosidase On The Cell Surface Of E.Coliand Bioconversion Of Hydroquinone To α-Arbutin

In cosmetic preparations a-arbutin is widely used to lighten the skin. a-arbutin is most synthesized by enzymatic methods. Our laboratory performed an experiment whereby the gene corresponding to transglucosidase (XgtA) of Xanthomonas MaltopHilia BT-112 was functionally expressed on the cell surface of Escherichia coli using the ice nucleation protein (Inak) of Pseudomonas syringae as an anchoring motif. Localization of the XgtA on the cell surface of E.coli was confirmed by immunofluorescence microscopy and flow cytometry analysis by binding FITC antibody.The optimum induced conditions were using 0.4mM IPTG as inducers at 15℃ for 24h. Then, we selected a hydroquinone resistance strain (the resistance concentration is 4%) from a variety of recombinant.The displayed XgtA on the cell surface of Escherichia coli using an Inak anchoring motif can be used for biocatalytic applications. The optimum reaction for synthesis of a-arbutin was at 25℃ in neutral pH for 72h when hydroquinone (150mM) and maltose was 1:10.In the presence of Smmol-L-1 ascorbic acid, a total a-arbutin concentration was increased 43.4% than blank control trial. Similarly, a total a-arbutin concentration was increased 53.4% by adding 0.1% xanthan into reaction mixture.In our research, macroporous resin H103 was utilized to immobilize hydroquinone to synthesize a-arbutin. The reaction with hydroquinone, a glycosyl acceptor, and malto, the donor, resulted in a significant amount of a-arbutin with an increased yield of 23.2% in the reaction mixture than before.This project aims at selecting and protecting target strain by overcoming the toxicity of hydroquinone, which could provide reference for future productions of a-arbutin via cell surface display.