Production of Ethanol by Fed-Batch Fermentation

The production of ethanol, from glucose in batch and fed batch culture, was investigated. In the fed batch culture, the glucose feeding was added into the culture at 16th hour of fermentation. The effects of different glucose concentration feeding rates on ethanol fermentation were investigated for fed batch culture. The 2gL^-1hr^-1 glucose concentration feeding rate was found to give higher ethanol yield (2.47 g ethanol g glucose^-1), with respect to substrate consumed as compared to 8 gL^-1hr^-1 (0.23 g ethanol g glucose^-1) and 4 gL^-1hr^-1 (0.20 g ethanol g glucose^-1). The ethanol yield with respect to substrate consumed obtained in batch culture was 0.81 g ethanol g glucose^-1. The fed batch culture at 2 gL^-1hr^-1 glucose concentration feeding rate was proven to be a better fermentation system than the batch culture. The specific growth rate, specific glucose consumption rate and specific ethanol production rate for the fed batch fermentation, at 2 gL^-1hr^-1 glucose concentration feeding rate, were 0.065 hr^-1, 1.20 hr^-1 and 0.0009 hr^-1, respectively.