报告主题：Butanol Fermentation by Archaeal Hyperthermophiles: from an Enzyme to New Pathways

主 讲 人：Kesen Ma（滑铁卢大学）

主 持 人：李 猛 教授

时 间：2026年10月26日（一）10：00

地 点：致知楼706

嘉宾简介：

Dr. Ma obtained his PhD from Philipps-University Marburg, Germany. He was a Max-Planck-Institute fellow and worked as a research associate at the University, and a postdoctoral fellow and then an assistant research scientist and a graduate faculty at the University of Georgia, United States. He is a professor in the Department of Biology at the University of Waterloo, Canada. Dr. Ma's research has a focus on physiology, enzymology and alcohol metabolism of hyperthermophiles, a group of microorganisms growing optimally at 80°C and above or capable of growing at 90°C and above.

报告摘要：

A group of microorganisms that grow optimally at 80°C and above is called hyperthermophiles, some of which produce alcohols as their fermentative end products. Pyruvate is a central intermediate of carbohydrates and peptides metabolism, which can be converted into ethanol or butanol. Bioethanol is considered to be an important part of biofuels and its production pathways in hyperthermophilic bacteria and archaea are elucidated based on the study of key enzymes functioning in various pathways. There is an increasing demand for biobutanol, which can be used as a renewable biofuel and an industrial chemical. Although the acetone-butanol-ethanol (ABE) fermentation is well-known in clostridia, the use of hyperthermophilic microorganisms capable of producing butanol at high temperatures may provide a new way to achieve better production effiency. However, there is a lack of understanding of their metabolic patheways and key enzymes involved. Hyperthermus butylicus is a hyperthermophilic crenarchaeon that grows optimally between 95°C and 106°C and produces 1-butanol and other solvents as end products. A thermostable H. butylicus alcohol dehydrogenase (HbADH2) is characterized for being the key enzyme responsible for the production of 1-butanol. The gene that encodes HbADH2s is identified, and this enzyme is a primary-secondary ADH capable of using a wide range of substrates including ethanol, 1-propanol, 2-propanol, butanol, acetaldehyde, propanal, butyaldehyde and acetone. Based on its substrate specificity, enzyme kinetics, thermostability, and gene sequence identification, HbADH2 is considered for being the enzyme catalyzing the production of 1-butanol in H. butylicus. Experimental results support the operation of new butanol production pathways functioning at high temperatures.