| 摘要: | 本研究是利用疏水性離子液體，對Clostridium acetobutylicum進行丁醇萃取式醱酵並探討其影響及可行性。Clostridium acetobutylicum在進行ABE醱酵時，當產物丁醇達到10 g/L時，其菌體會受到產物抑制效應的影響而失活，萃取式醱酵可以降低產物濃度改善此問題，而本實驗將探討一項新的製程，利用離子液體[BMIM][PF6]、[HMIM][PF6]及[OMIM][PF6]作為萃取劑，實驗其最佳萃取體積、接觸時間長短對菌體的毒性及大型醱酵槽萃取式醱酵，其中以離子液體[HMIM][PF6]作為萃取劑效果最佳，在醱酵進行至48 小時進行萃取，萃取時間5 分鐘，其可將丁醇由7.956 g/L萃取至7.017 g/L，且在醱酵進行至第84 小時可達最大產量9.895 g/L，產率為0.118 g/L/hr，雖然產量和產率皆稍低於控制組實驗之10.111 g/L和0.140 g/L/hr，但其單位基質對菌重之轉化率及單位菌重對丁醇之轉化率皆略優於控制組實驗，即是其萃取後，使菌體較不被受到產物抑制效應影響，其利用葡萄糖維持自身活性的比例下降、生產丁醇的比例上升，因此利用離子液體作為萃取劑之製程的可行性，值得深入研究探討。In this research, we use hydrophobic ionic liquid to butanolextractive fermentation of Clostridium acetobutylicum, then discuss its effect and feasibility. When the concentration of butanol get 10 g/L in ABE fermentation, the Clostridium acetobutylicum will be inhibited by the product, butanol, and lose activation. The extractive fermentation will improve this problem by reducing the concentration of butanol. The experiment will explore a new process using ionic liquid [BMIM][PF6], [HMIM][PF6] and [OMIM][PF6] as the extractants, test the optimum volume of extraction, the toxic of contact time, and extractive fermentation of large fermentor. The best extractant in this experiment is ionic liquid [HMIM][PF6], when the fermentation gets to 48 hours, we extract by [HMIM][PF6] in 5 minutes, the concentration of butanol extracted from 7.956 g/L to 7.017 g/L. After 84 hours, the maximum yield of butanol is 9.895 g/L, and the productivity is 0.118 g/L/hr. Though the yield and productivity are little less than controlled experiment,10.111 g/L and 0.140 g/L/hr, the Yx/s and Yp/x are more better than controlled. Because the broth after extracted, the bacteria used glucose to maintain itself is less, more used to produce butanol. Therefore, the process feasibility of using ionic liquids as extractant, is worth in-depth study. |
