| α-Arbutin is emerging, natural and activity skin whitening agents. It is non-irritating, non-irritability and high compatibility. It has better whitening effect and security thanβ-Arbutin. This essay explore biosynthesis of a-Arbutin with Xanthomona maltophilia BT-112 by three methods, fermentation mothod, free cells mothod and immobilized cells mothod. It also makes comparision between three methods about percent conversion and concentration ofα-Arbutin. It has some merits aboutα-Arbutin of Biosynthesis with Xanthomona maltophilia BT-112．For example, it has simple rough material; reactionary condition is eary to control; the time of reaction is short; the pureness of a-Arbutin is high; it did not produce toxic organic solvent, and so on. So it has industrialization significance.This essay systematically optimizes reaction conditions of three reaction system. At the same time, it comes to conclusion(the capacity of reaction system is one liter).The first method is fermentation method. Through the study of reaction conditions, it determines the best reaction conditions. The temperature is 35℃. The concentration of hydrochinone is 48mmol·L-1 . The mol ratio between sucrosum and hydrochinone is 2:1．The reaction time is 48h. The speed of rotation is 180 r·min-1 .The second method is free cells method. This essay studys the reaction conditions, and then determines the best reaction conditions. The temperature is 25℃. The concentration of hydrochinone is 48mmol·L-1 . The mol ratio between sucrosum and hydrochinone is 20．The reaction time is 48h. The speed of rotation is 160 r·min-1 . The cell concentration is 85g·L-1 . The pH of buffer solution is 7．0, and the concentration is 25 mmol·L-1 .The third method is immobilized cells mothod. Though the study of immobilized conditions and reaction conditions, it determines the best result. The concentration of sodium is 5085g·L-1 . The cell concentration is 120g·L-1 . The concentration of Ca2+ is 20g·L-1 . The temperature is 22℃. The pH of buffer solution is 7．0．The solid-to-liquid ratio is 15:20．The concentration of hydrochinone is 48mmol·L-1 . |
