초록
Initial pH, sugar and nitrogen are important parameters for bio-butanol production. To improve butanol production efficiency, an L<SUB>9</SUB> (3<SUP>4</SUP>) orthogonal array design was used to obtain high levels of butanol production from sugarcane molasses by Clostridium beijerinckii TISTR 1461. The three parameters optimized were initial pH (5.5-7.5), sugar concentration (40-80gl<SUP>-1</SUP>) and urea level (0.27-1.35gl<SUP>-1</SUP>). The results showed that the optimal conditions were an initial pH of 6.5, a sugar concentration of 40gl<SUP>-1</SUP> and a urea level of 0.81gl<SUP>-1</SUP>. The magnitude of these parameters' influence on butanol and ABE concentrations was initial pH>sugar>urea. The fermentation under the optimal conditions in a 2-L fermenter with agitation rate of 100rpm revealed that the butanol and ABE concentrations were 12.55 and 17.96gl<SUP>-1</SUP>, respectively. Without nutrient supplementation, they were 7.45 and 11.21g l<SUP>@?1</SUP>, respectively, using molasses as a substrate. When a gas stripping system was connected to the fermenter, the butanol and ABE values increased to 14.13 and 18.90gl<SUP>-1</SUP>, respectively, with butanol productivity and sugar utilization of 0.29gl<SUP>-1</SUP>h<SUP>-1</SUP> and 90.50%, respectively.