[Cytochrome P-450 induction during yeast organism growth on various substrates]

The induction of cytochrome P-450 was studied in Torulopsis candida and other yeast species in the process of their growth on glucose, hexadecane, ethanol, hexadecanol and palmitate. Cytochrome P-450 was induced in all of the studied alkane oxidizing yeast strains during their growth on hexadecane or on the intermediates of its oxidation, viz. hexadecanol and palmitate. However, the maximal content of P-450 in the cells was 3-4 times lower during the growth on hexadecanol and palmitate as compared to the growth on hexadecane. In Candida utilis incapable of growing on n-alkanes but growing on hexadecanol and palmitate, cytochrome P-450 was not detected upon the yeast growth on these substrates. Cytochrome P-450 was not induced in any of the strains during their growth on ethanol. In the course of growth on glucose, cytochrome P-450 was found only in T. candida; it was induced in its cells just prior to the stationary phase caused by the exhaustion of the carbon source.