Journal
JOURNAL OF MOLECULAR MICROBIOLOGY AND BIOTECHNOLOGY
Volume 14, Issue 4, Pages 163-175Publisher
KARGER
DOI: 10.1159/000112598
Keywords
respiratory chain; Zymomonas mobilis; NADH oxidase activity
Categories
Ask authors/readers for more resources
The respiratory chain of the ethanologenic bacterium Zymomonas mobilis was investigated, in which the pyruvate-to-ethanol pathway has been demonstrated to be mainly responsible for NADH oxidation and the tricarboxylic acid cycle is incomplete. Membranes from cells cultivated under aerobic or anaerobic growth conditions showed dehydrogenase and oxidase activities for NADH, D-lactate and D-glucose and ubiquinol oxidase activity. Intriguingly, the NADH oxidase activity level of membrane fractions from cells grown aerobically was found to be higher than that of membrane fractions from Escherichia coli or Pseudomonas putida grown aerobically, indicating a crucial role of the respiratory chain in NADH oxidation in the organism. Cyanide-resistant terminal oxidase activity was observed and appeared to be due to a bd-type ubiquinol oxidase as the only terminal oxidase encoded by the entire genome. The terminal oxidase with a relatively strong ubiquinol oxidase activity exhibited remarkably weak signals of cytochrome d. Considering these findings and the presence of a type-II NADH dehydrogenase but not a type-I, a simple respiratory chain that generates less energy may have evolved in Z. mobilis. Copyright (C) 2007 S. Karger AG, Basel.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available