Fermentation scale up for α-arbutin production by Xanthomonas BT-112.

α-Arbutin is a glycosylated hydroquinone that has an inhibitory function against tyrosinase. The aim of the present study is to develop an efficient and inexpensive method for large-scale production of α-arbutin by using Xanthomonas BT-112 as biocatalyst. To accomplish this goal, various surfactants were tested to enhance the α-arbutin production, and the optimal operational conditions for 30L jar fermenter were scaled up for a production level of 3000L with using a constant volumetric oxygen transfer coefficient (KLa) and the volumetric aeration rate per volume unit (Q/V) as scale-up criteria. Under the optimized conditions, the α-arbutin produced in the presence of 0.4% (w/v) Tween-80 was 124.8% higher than that of the control, and the yield of α-arbutin in 3000L fermenter was 38.2g/L with a molar conversion ratio of 93.7% based on the amount of hydroquinone supplied. This result is comparable to the results from laboratory-scale fermenter. Hence, 100-fold scale-up was successfully achieved.