earticle

영어

Butanol production using immobilized cells of Clostridium saccharoperbutylacetonicum N1-4 (ATCC 27021T) was investigated in a semi-continuous fermentation process. Tests on the effect of glucose concentration, temperature, agitation, pH, medium modification through butyrate and/or without acetate addition, and inhibition of the hydrogenase activity of the cell have been done to optimize the yield in butanol production. Based on the results, the addition of 6.69 g/L
butyrate yielded the highest butanol concentration at 18.43 g/L using 60 g/L of initial glucose. A direct relationship to the improved butanol yield was found due to capability of the cell to uptake butyrate as a precursor for butanol formation during solventogenesis. Thus, in the final run, the addition of butyrate in the Ca-alginate immobilized cell was conducted. During the semi-continuous cultivation, butanol productivity of the immobilized cell was 0.64 g/L·h compared to 0.29 g/L·h for the free-cell. In comparison, this was slightly higher compared to previous reports considering the same conditions. Butanol toxicity test was also done to compare an immobilized to nonimmobilized cell. However, no significant deviation was observed. Both were susceptible to butanol intoxication.