Ragsdale Stephen W
Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.
Ann N Y Acad Sci. 2008 Mar;1125:129-36. doi: 10.1196/annals.1419.015.
The biochemistry of acetogenesis is reviewed. The microbes that catalyze the reactions that are central to acetogenesis are described and the focus is on the enzymology of the process. These microbes play a key role in the global carbon cycle, producing over 10 trillion kilograms of acetic acid annually. Acetogens have the ability to anaerobically convert carbon dioxide and CO into acetyl-CoA by the Wood-Ljungdahl pathway, which is linked to energy conservation. They also can convert the six carbons of glucose stoichiometrically into 3 mol of acetate using this pathway. Acetogens and other anaerobic microbes (e.g., sulfate reducers and methanogens) use the Wood-Ljungdahl pathway for cell carbon synthesis. Important enzymes in this pathway that are covered in this review are pyruvate ferredoxin oxidoreductase, CO dehydrogenase/acetyl-CoA synthase, a corrinoid iron-sulfur protein, a methyltransferase, and the enzymes involved in the conversion of carbon dioxide to methyl-tetrahydrofolate.
本文综述了产乙酸作用的生物化学。描述了催化产乙酸作用核心反应的微生物，并重点关注该过程的酶学。这些微生物在全球碳循环中发挥着关键作用，每年产生超过10万亿千克的乙酸。产乙酸菌能够通过与能量守恒相关的伍德-柳格达尔途径将二氧化碳和一氧化碳厌氧转化为乙酰辅酶A。它们还可以利用该途径将葡萄糖的六个碳原子按化学计量转化为3摩尔乙酸盐。产乙酸菌和其他厌氧微生物（如硫酸盐还原菌和产甲烷菌）利用伍德-柳格达尔途径进行细胞碳合成。本综述涵盖的该途径中的重要酶包括丙酮酸铁氧化还原酶、一氧化碳脱氢酶/乙酰辅酶A合成酶、类咕啉铁硫蛋白、甲基转移酶以及参与将二氧化碳转化为甲基四氢叶酸的酶。
