隨著文明的發展及人口的成長，人類對於新興乾淨能源的需求將更為迫切。而因應化石能源的短缺及環境污染的日益嚴重，開發新型替代能源為目前各國政府所積極推行，永續且潔淨的再生能源亦是關注焦點。再生能源中，氫氣具有高能量及不會造成二次污染的特性，且利用厭氧微生物產生氫氣除了是清潔能源的生產外亦具有資源再利用的優勢，極具發展潛力。

在厭氧生物產氫程序中，由於大量的酸生成將形成一個低pH的環境，而造成hydrogenase的活性下降或微生物代謝途徑的改變。因此利用clostridia為厭氧產氫程序的主要微生物時，pH的控制成為一個重要的控制因子。近來許多研究報告指出Clostridium屬為厭氧發酵產氫系統中之主要優勢菌種，本研究利用由厭氧發酵產氫系統中分離出之純菌Clostridium butyricum、Clostridium tyrobutyricum及Clostridium beijerinckii進行生物氫氣產能試驗(BHP test)，以10,000 mg/L glucose和peptone(3:2 (w/w))作為基質，溫度控制於35℃，且在pH控制為7、6、5和不控制pH狀況下探討其產氫特性。

在不控制pH的狀況之下，Clostridium tyrobutyricum有最佳之產氫量，產氫yield約為1.8 mmol /mmol glucose；在有控制pH的狀況之下，三株純菌皆在pH=6時有最佳的產氫量，其中以Clostridium beijerinckii和Clostridium butyricum產氫yield為1.7 mmol/mmol glucose最佳。此外，並利用數學模式模擬建立Clostridium菌種於批次實驗中降解葡萄糖之動力模式。此模式可正確描述葡萄糖降解、生物生長、乙酸、丁酸、氫氣及其他產物之生成趨勢。

在大部分的pH狀況下，Clostridium菌種降解葡萄糖產生揮發酸，其中以乙酸和丁酸為主要產物，但隨著pH的改變，微生物代謝途徑有移轉的現象，在pH控制為7的批次實驗中，觀察到揮發酸產物種類較多，包括乳酸、甲酸、乙酸、丙酸及丁酸，然而對於產氫量亦有一定的影響。

　　Due to the development of civilization, increasing population, and shortage of petrochemical energy in the near future, there is an urgent need to develope sustainable energy. Hydrogen is considered a clean and efficient energy among renewable resources, producing water as its only by-product when it burns. Moreover, hydrogen can be produced from renewable raw materials such as organic wastes by anaerobic microorganism. Therefore, hydrogen is a potential clean energy substitute for fossil fuels.

In anaerobic biological hydrogen production, a large amount of volatile fatty acids creates a low pH environment which causes the decrease of hydrogenase activity or alteration of metabolic pathways. Therefore, when using clostridia as the main microorganism in anaerobic hydrogen production process, the control of pH will be an important factor in overall hydrogen fermentation. Recent reports pointed out that Clostridium species were the dominant microorganisms in anaerobic hydrogen fermentation processes. The biochemical hydrogen potential (BHP) tests were conducted to investigate the metabolism and hydrogen production performance of various Clostridium species, including Clostridium butyricum, Clostridium tyrobutyricum and Clostridium beijerinckii isolated from hydrogen fermentation processes. The reactor batch experiments were operated at 35℃ with 10,000 mg/L glucose, peptone (3：2(w/w)) as substrate.The pH value were controlled at 7, 6, 5 and uncontrolled condition to investigate hydrogen production performance of Clostridium species.

Among the strains examined, Clostridium tyrobutyricum had the highest hydrogen production yield of 1.8 mmol/mmol glucose at uncontrolled pH condition；Clostridium butyricum and Clostridium beijerinckii had the highest hydrogen production yield of 1.7 mmol/mmol glucose when pH were controlled at 6. A kinetic model was developed to evaluate the metabolism of glucose fermentation of the three Clostridium species in the batch reactors. The model, in general, was able to accurately describe the profile of glucose degradation as well as the production of biomass, acetate, butyrate, hydrogen and other products observed in the batch tests.

Almost in all batch tests, Clostridium species degraded glucose to produce acetate and butyrate as the major volatile fatty acids. But the metabolism pathway shifted with the variation of pH. When pH was controlled at 7, many kinds of volatile fatty acid products were observed, including lactate, formate, acetate, propionate and butyrate. However, it would make some influences on hydrogen production performance.

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利用薄膜反應器於高溫厭氧產氫生物程序之研究，國立成功大學環境工程　學系碩士論文(2001)。

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鄭幸雄、白明德、蔡遠瑋、王永福、蕭嘉瑢
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鄭幸雄、白明德、趙禹杰
厭氧產氫菌分解高分子碳水化合物及peptone之產氫機制，第28　屆廢水研討會論文集(2003b)。

鄭幸雄、林秋裕、曾怡禎、李季眉、林信一、林明瑞、陳幸德
複合基質生物產氫機制及程　序應用之整合研究2002年，第28屆廢水研討會論文集(2003c)。

蕭嘉瑢、鄭幸雄
複合基質厭氧產氫發酵生物程序操控之功能評估及分生檢測生態之研究，國立成功大學環境工程學系碩士論文(2004)。

趙禹杰、鄭幸雄
澱粉及蛋白腖複合基質厭氧發酵程序之功能評估，國立成功大學環境工程　學系碩士論文(2004)。

洪國展、李季眉
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林佩瑩、吳怡儒、任維傑、李學霖、黃良銘 Clostridium屬菌株生物產氫：代謝途徑與數學模式模擬研究，第29屆廢水研討會論文集(2004)。

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