嗜麦芽黄单胞菌游离细胞催化合成α-熊果苷

The Biosynthesis of α-arbutin by Xanthomona maltophilia BT-112

摘要:

研究了利用嗜麦芽黄单胞菌BT-112(Xanthomonas maltophilia BT-112)游离细胞生物催化合成α-熊果苷，系统探讨了温度、对苯二酚浓度、对苯二酚与蔗糖摩尔比、反应时间、转速、细胞浓度、磷酸缓冲溶液pH值和浓度对反应转化率的影响。最佳反应条件为：反应温度为25℃，菌体对对苯二酚的最大耐受度为30mmol/L，蔗糖和对苯二酚的摩尔比为20∶1，反应时间为45h,摇床转速为160r/min，细胞浓度为85g/L，磷酸缓冲溶液浓度为25mmol/L、pH值为8.0。在此条件下α-熊果苷转化率高达86.7%(以对苯二酚计算)。

Abstract:

α-arbutin is biosynthesized by whole cell method with Xanthomona maltophilia BT-112. The conditions for cell biosynthesized α-arbutin are investigated as follows: temperature, 25℃; concentration of hydroquinone, 30mmol/L; mol ratio of sucrose and hydroquinone, 20∶1； time course of α-arbutin biosynthesis, 45 hours; rotational speed, 160r/min; concentration of Xanthomona maltophilia BT-112, 85g/L; concentration of K₂HPO₄-KH₂PO₄ buffer solution, 25mmol/L; pH of K₂HPO₄-KH₂PO₄ buffer solution, 8.0. Under the above optimal conditions, the maximum of molar conversion yield based on the amount of hydroquinone supplied reaches 86.7%.