The Effect of Salts on Enzymes of the Respiratory Chain of Marine Bacterium Strain 1055-1

The effect of salts on components of the respiratory chain of marine bacterium 1055-1 has been studied. Sodium ions activated the NADH oxidase system. This was not due to activation of NADH dehydrogenase but resulted from the activation of some other components that were membrane-bound. One of these activated components was involved in the 2-heptyl-4-hydroxyquinoline N-oxide (HOQNO)-sensitive reduction of ubiquinone. In contrast, succinate oxidase was inhibited by high concentrations of salts and it was concluded that the inhibited component was succinate dehydrogenase.