ISSN:
1432-072X
Keywords:
Candida maltosa
;
Cytochrome P-450
;
Alkane hydroxylation
;
Oxygen-limitation
;
Carbon monoxide-inhibition
;
Enzyme regulation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Transition of n-hexadecane utilizing cultures of Candida maltosa to oxygen-limited growth caused an up to 6-fold increase of the cellular cytochrome P-450 content. Enhanced cytochrome P-450 formation required protein de novo synthesis and was not due to a change of the apo/holo-enzyme ratio as demonstrated by cycloheximide inhibition and immunological quantitation. The effect of low oxygen concentration (pO2=3–5%) was simulated by selective inhibition of alkane hydroxylation with carbon monoxide (at a pO2 of 70–75%). Enhanced cytochrome P-450 formation occurred even when a constant growth rate was maintained through utilization of a second non-repressive growth substrate. However, the presence of n-alkanes was an essential precondition. It was concluded, that the cytochrome P-450 formation was mainly regulated by the intracellular inducer concentration which depends on the relative rates of alkane transport into the cell and the actual alkane hydroxylating activity of the enzyme system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00463483
