以筛选出的腈水解酶131粗酶作为催化剂,可将3-氰基吡啶直接水解生成烟酸,且反应过程中没有烟酰胺生成.经过反应条件的优化后,确定了这个酶催化水解反应的最适温度为30℃、最适pH=8.0和初始底物质量浓度为8～10 g/L.在这个最优条件下,采用分批补料法可将加入的3-氰基吡啶完全转化为烟酸,此时反应液中烟酸的积累量达到118 g/L,底物和酶的实际质量分数为50∶1,产物纯品收率为85%左右. The selected nitrilase 131 crude enzyme as a catalyst, 3-cyanopyridine can be directly hydrolyzed nicotinic acid, and no nicotinamide generated during the reaction After the optimization of the reaction conditions to determine the enzyme catalyzed hydrolysis reaction The optimal temperature was 30 ℃, the optimum pH was 8.0 and the initial substrate concentration was 8 ~ 10 g / L. Under this optimum condition, the added 3-cyanopyridine can be completely transformed by fed-batch method Nicotinic acid. At this point, the accumulation of niacin in the reaction solution reached 118 g / L, the actual mass fraction of substrate and enzyme was 50: 1, and the yield of pure product was about 85%.