Optimization of Pretreatment of Persimmon Peel for Ethanol Production by Yeast Fermentation

摘要

A response surface method based on a central composite design experiment was used to determine the optimum conditions for pretreatment of persimmon peel. It was mathematically predicted that the maximum amount of reducing sugars would be obtained at an H_2SO_4 concentration of 1.77% (w/v) and a heat treatment time of 26.4 min. A reducing sugar concentration of 63.23 g/l was obtained under the optimum pretreatment conditions determined by RSM. Under anaerobic growth conditions, Saccharomyces cerevisiae NK28 produced 15.52 g/l of ethanol with a yield of 0.34 g ethanol/g glucose from pretreated persimmon peel, which corresponded to 14% and 26% enhancements in ethanol productivity and ethanol yield, respectively, compared with those obtained in aerobicgrowth conditions. This study suggests that persimmon peel might be a useful substrate for bioethanol production by yeast fermentation.