Effects of Vitamins on the Direct Fermentative Production of L-serine in Corynebacterium glutamicum SYPS-062
维生素对谷氨酸棒杆菌SYPS-062直接发酵合成L-丝氨酸的影响

The effects of six vitamins on a novel isolate,Corynebacterium glutamicum SYPS-062,which could directly produce L-serine from carbohydrates were investigated.The results show that all these tested vitamins-VB1,biotin,VB2,VB6,folate and VB12 could enhance the growth of C.glutamicum SYPS-062 and improve the production of L-serine.However,the mechanisms of their metabolic regulations were different.Although VB1,biotin and VB6 could enhance the L-serine degradation,the significant increasing of biomass induced the increment of L-serine accumulation,which was 31%,28% and 11% higher than the control;VB2 improved both the biomass and the L-serine production equally,however didn't influence the distribution of metabolic pathway of L-serine;folate and VB12 could diminish L-serine degradation flux ratio and increase the YP/S and YP/X by accelerating the efficiency of the one carbon units metabolism.The final L-serine productions were 39% and 82% higher than the control.Finally,the fermentation period was 6 h shorter by adding all these vitamins at their optimal doses than by adding biotin only,and the accumulation of L-serine and the biomass were 9.0g/L and 11g/L,which were 70% and 76% higher than the control.