Effect of oxygen limitation on the content of n-hexadecane-inducible cytochrome P-450 in Acinetobacter calcoaceticus strain EB 104.
The content of cytochrome P-450 as a function of oxygen supply was studied during growth of Acinetobacter on n-hexadecane in batch cultures at constant pH and agitation. The rate of growth and the content of cytochrome P-450 were not affected as long as the dissolved oxygen tension ranged above 3 to 5% of saturation. The amount of cytochrome P-450 increased when the oxygen tension declined to zero. Cytochrome P-450 levels of about 0.3 to 0.4 nmol/mg protein, i.e. a more than a threefold increase, were observed under conditions where oxygen supply was strictly limited and allowed to maintain only a minimum of metabolism or growth. Limited oxygen supply exerted a special effect on the induction of the cytochrome P-450 as concluded from an increasing ratio between cytochrome P-450 and cytochrome o, and from the absence of cytochrome d in cells with elevated content of cytochrome P-450. The increased formation of cytochrome P-450 was a reversible process.
D000150:Acinetobacter / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D000473:Alkanes / Q000494:pharmacology*; D000693:Anaerobiosis; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D004790:Enzyme Induction; D007700:Kinetics
D000473:Alkanes; D003577:Cytochrome P-450 Enzyme System; C007932:n-hexadecane