A novel, repeated fed-batch, ethanol production system with extremely long term stability achieved by fully recycling fermented supernatants

Using Saccharomyces cerevisiae, a novel, repeated fed-batch ethanol production system from corn flour by fully recycling fermented supernatants is demonstrated. With recovery of ethanol by evaporation coupled with consecutive removal of the insoluble and soluble inhibitory substances accumulated, either completely or partially by filtration, the concentrations of the soluble inhibitors in the system could be maintained at their equilibria. As a result, a sustained high concentration of ethanol (up to 15% v/ v) and significant pollution control performance were obtained.