基于Gluconobacter oxydans膜结合脱氢酶的静息细胞催化合成2-酮基-D-葡萄糖酸

High-yield production of 2-keto-D-gluconate by resting cells of Gluconobacter oxydans

摘要: 基于G.oxydans DSM2003膜结合葡萄糖酸-2-脱氢酶（GA-2-DH）的催化特性,利用静息细胞催化技术合成D-异抗坏血酸（EA）的主要前体2-酮基-D-葡萄糖酸（2-KGA）。利用高浓度底物自适应筛选技术,筛选到高产2-KGA菌株并对其摇瓶催化进行优化,优化后最适条件为:温度30℃,pH6.0,细胞浓度20g/L,底物浓度1100mmol/L,摇床转速250rmin,此时时空产率为24.68mmol/L/h;摇瓶优化工艺基础上在7L发酵罐中对重点影响参数（转速与底物浓度）进行了进一步优化,优化后2-KGA的时空产率提高到74mmol/L/h,并且催化细胞可有效重复利用3次。

Abstract: Resting cells of G.oxydans DSM2003 is used to produce the 2-keto-gluco-nate, which is a primary precursor for the synthesis of D-erythoribic acid (EA) .One bacterium with high-yield production capacity was obtained by self-adapting to the high concentration of substrate, and the conversion rate had reached 24.68mmol/L/h in flask (temperature at 30℃, pH at 6.0, cell concentration at 20g/L, substrate concentration at 1100mmol/L, shaking rate at 250r/min) .While catalysis was carried in the 7L fermentor under the optimum condition, the conversion rate of 2-KGA could reach 74mmol/L/h and the cell could be reused effectively for three times.