Ethanol cycle in an ethanologenic bacterium

FEBS Letters

Kalnenieks, U¹  Marjutina, U¹  Galinina, N¹  Toma, M.M¹ 

[1] Institute of Microbiology and Biotechnology, University of Latvia, Kronvalda boulv. 4, Riga LV-1586, Latvia

关键词: Alcohol dehydrogenase;    Futile cycle;    Respiration;    Chemostat;    NADH channeling;    Zymomonas mobilis;   

DOI  :  10.1016/S0014-5793(02)02923-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A novel redox cycle is suggested, performing interconversion between acetaldehyde and ethanol in aerobically growing ethanologenic bacterium Zymomonas mobilis. It is formed by the two alcohol dehydrogenase (ADH) isoenzymes simultaneously catalyzing opposite reactions. ADH I is catalyzing acetaldehyde reduction. The local reactant ratio at its active site probably is shifted towards ethanol synthesis due to direct channeling of NADH from glycolysis. ADH II is oxidizing ethanol. The net result of the cycle operation is NADH shuttling from glycolysis to the membrane respiratory chain, and ensuring flexible distribution of reducing equivalents between the ADH reaction and respiration.

【 授权许可】

Unknown