초록
In this research, Scheffersomyces stipitis and Saccharomyces cerevisiae in immobilized and suspended state were used to convert pentose and hexose sugars to ethanol. In batch and continuous systems, S. stipitis and S. cerevisiae co-culture performance was better than S. cerevisiae. Continuous ethanol production was performed in packed bed immobilized cell reactor (ICR). In ICR, S. stipitis cells were found to be more sensitive to oxygen concentration and other possible mass transfer limitations as compared to S. cerevisiae. Use of co-immobilized S. stipitis and S. cerevisiae resulted in maximum xylose consumption (73.92%) and 41.68g/Lday ethanol was produced at HRT (hydraulic retention time) of 6h with wheat straw hydrolysate. At HRT of 0.75h, the highest amount of ethanol with the values of 356.21 and 235.43g/Lday was produced when synthetic medium and wheat straw hydrolysate were used as feeding medium in ICR, respectively.