초록
Eight trace elements were screened for increasing efficiency of ethanol yield from sweet sorghum juice using the Plackett-Burman design method. MnCl<SUB>2</SUB>.4H<SUB>2</SUB>O, CoCl<SUB>2</SUB>.6H<SUB>2</SUB>O and biotin was screened as the significant variables which have positive effects on ethanol production from sweet sorghum juice. The values of MnCl<SUB>2</SUB>.4H<SUB>2</SUB>O, CoCl<SUB>2</SUB>.6H<SUB>2</SUB>O and biotin, optimized by Box-Behnken design method, were 7.70 mg L<SUP>-1</SUP>, 15.74 mg L<SUP>-1</SUP> and 11.97 mg L<SUP>-1</SUP>, respectively. The experimental efficiency of ethanol yield under optimal conditions was 89.30 +/- 0.10%, which enhances the efficiency of ethanol yield by 5.63% by the addition of MnCl<SUB>2</SUB>.4H<SUB>2</SUB>O, CoCl<SUB>2</SUB>.6H<SUB>2</SUB>O and biotin. The results from this study have identified optimal conditions as a foundation for pilot scale ethanol production.