초록
When Saccharomyces cerevisiae was cultivated under ∼200gglucose/l condition, the time point at which glucose was completely utilized coincided with the moment at which the slope of a redox potential profile changed from negative or zero to positive. Based on this feature, a redox potential-driven glucose-feeding fermentation operation was developed, and resulted in a self-cycling period of 14.25+/-0.4h. The corresponding ethanol concentration was maintained at 88.4+/-1.0g/l with complete glucose conversion, and the cell viabilities increased from 80% in the transition period to 97.2+/-1.1%, implying the occurrence of yeast acclimatization. In contrast, a pre-determined 36-h manually adjusted period was chosen to oscillate yeast cells under ∼250gglucose/l conditions, which resulted in 106.76+/-0.7g ethanol/l and 15.19+/-1.3gglucose/l remaining at the end of each cycle. Compared to the equivalent batch and continuous ethanol fermentation processes, the annual ethanol productivity of the reported fermentation operation is 2.4% and 13.2% greater, respectively in ∼200g feeding glucose/l conditions.