| Title | Respiratory Chain-Linked Components of the Marine Bacterium Vibrio alginolyticus Affect Each Other |
|---|---|
| Author | Young Jae Kim |
| Address | Department of Microbiology, College of Natural Sciences, Changwon National University, Sarim-dong, Changwon, Kyungnam 641-773, Korea |
| Bibliography | Journal of Microbiology, 40(2),125-128, 2002, |
| DOI | |
| Key Words | marine bacterium, Vibrio alginolyticus, respiratory chain, Na^+ -dependent NADH oxidase, Na^+ -indep |
| Abstract | The aerobic respiratory chain of Vibrio alginolyticus possesses two different kinds of NADH oxidase systems, i.e., an Na^+ -dependent NADH oxidase system and an Na^+ -independent NADH oxidase system. When deamino-NADH, which is the only substrate for the Na^+ -dependent NADH oxidase system, was used as a substrate, the maximum activities of Na^+ -dependent NADH:quinone oxidoreductase and Na^+ -dependent NADH oxidase were obtained at about 0.06 M and 0.2 M NaCl, respectively. When NADH, which is a substrate for both Na^+ -dependent and Na^+ -independent NADH oxidase systems was used as a substrate, the NADH oxidase activity had a pH optimum at about 8.0. In contrast, when deamino-NADH was used as a substrate, the NADH oxidase activity had a pH optimum at about 9.0. On the other hand, inside-out membrane vesicles prepared from the wild-type bacterium generated only a very small [delta]pH by the NADH oxidase system, whereas inside-out membrane vesicles prepared from Nap1, which is a mutant defective in the Na^+ pump, generated [delta]pH to a considerable extent by the NADH oxidase system. On the basis of the results, it was concluded that the respiratory chain-linked components of V. alginolyticus affect each other. |
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