• Journal of Microbiology and Biotechnology
• /
• v.15 no.5
• /
• pp.1080-1086
• /
• 2005

Membranes prepared from Vibrio natriegens oxidized both NADH and deamino-NADH as substrates. The maximum activity of the membrane-bound NADH oxidase was obtained at about pH 8.5 in the presence of 0.2 M NaCl, whereas that of the NADH:ubiquinone oxidoreductase was obtained at about pH 7.5 in the presence of 0.2 M NaCl. Electron transfer from NADH or deamino-NADH to ubiquinone-l or oxygen generated a considerable membrane potential (${\Delta}{\psi}$), which occurred even in the presence of $20{\mu}M$ carbonylcyanide m-chlorophenylhydrazone (CCCP). However, the ${\Delta}{\psi}$ was completely collapsed by the combined addition of $10{\mu}M$ CCCP and $20{\mu}M$ monensin. On the other hand, the activity of the NADH oxidase and the ${\Delta}{\psi}$ generated by the NADH oxidase system were inhibited by about $90\%$ with $10{\mu}M$ HQNO, whereas the activity of the NADH:ubiquinone oxidoreductase and the ${\Delta}{\psi}$ generated at the NADH:ubiquinone oxidoreductase segment were inhibited by about $60\%$. Interestingly, the activity of the NADH:ubiquinone oxidoreductase and the ${\Delta}{\psi}$ generated at the NADH:ubiquinone oxidoreductase segment were resistant to the respiratory chain inhibitors such as rotenone, capsaicin, and $AgNO_3$, and the activity of the NADH oxidase and the ${\Delta}{\psi}$ generated by the NADH oxidase system were very sensitive only to $AgNO_3$. It was concluded, therefore, that V. natriegens cells possess a $AgNO_3$-resistant respiratory $Na^+$ pump that is different from the $AgNO_3$-sensitive respiratory $Na^+$ pump of a marine bacterium, Vibrio alginolyticus.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2005.04a
• /
• pp.77-77
• /
• 2005

• Journal of Food Hygiene and Safety
• /
• v.15 no.2
• /
• pp.128-136
• /
• 2000

Twenty-four Vibrio strains were isolated from imported frozen seafoods and identified according to their physiological and biochemical properties. They included two V cholerae non-01 sp., two V. diazotrophicus sp., one V. hollisae sp., five V. natriegens sp., eight V. fluvialis sp., and four V. nereis sp.. Two of them were not identified as Vibrio species. When these strains were tested using API-2OE kit fur identification, however, only the results for two V. cholerae and five of the V. fluvialis strains matched the results obtained previously. Due to the importance of detecting V cholerae from foods, phylogenetic identification of the strains was attempted based on restriction fragment length polymorphism (RFLP) of the 16S rDNAs amplified by PCR. The results suggested that the two strains had identical RFLP patterns which were more closely related to that of V. proteolyticus than V. cholerae. The problems associated with identification of pathogens originated from seafoods demand development of accurate and rapid identification methods.