Abstract: α-Arbutin has been recently found to be a useful cosmetic ingredient since it has a stronger inhibitory effect on tyrosinase than β-arbutin that is widely used in cosmetics. However, α-arbutin is not a natural product and difficult to be chemically synthesized. In this paper, a bacterium of Xanthomonas BT-112 was isolated and used for the anomer-selective synthesis of α-arbutin from hydroquinone and sucrose. The effects of reaction temperature, shaking speed, hydroquinone concentration, and reactant composition were investigated. When the suspension of Xanthomonas BT-112 was incubated at 35 ℃ with 48 mmol/L hydroquinone and 96 mmol/L sucrose, only one form of hydroquinone glucoside, α-arbutin, was obtained as a product. Under these conditions, the conversion based on the amount of hydroquinone supplied reached 94.3%. The product was identified by 13C NMR and1H NMR.

Key words: α-arbutin, Xanthomonas, fermentation, biocatalysis, hydroquinone, sucrose, cosmetic