Fast production of ethanol from sweet potato starch by Zymomonas mobilis

Comparison of ethanol production was made among 4 Zymomonas mobilis strains(CICC10225, ATCC29191,CICC10232,IFFI10225)in composit fermentation media and in sweet potato media with different glucose concentration and it was found that the strain CICC10225 was the best one for ethanol production.The results from the further ethanol fermentation using Z.mobilis CICC10225 in sweet potato meida showed that this strain could fast metabolite substrates glucose into ethanol.During the fermentation in sweet potato media by using free Z.mobilis CICC10225 cells,the highest concentration of ethanol is 79.8 g/L,the highest ethanol productivity(Yp/s) was 0.49 and ethanol production reached 95.5%of the theoretical value.However,during the continuous fermentation using immobilized cells, fermentation time could greatly reduced to 8 h with the ethanol concentration and productivity of 88.03 g/L and 0.50,respectively.