The gene for the alkane-inducible cytochrome P450, P450alk, has been isolated from the yeast Candida tropicalis by immunoscreening a lambda gt11 library. Isolation of the gene has been identified on the basis of its inducibility and partial DNA sequence. Transcripts of this gene were induced by alkane to levels 500 to 1000 fold over those detected in glucose-grown cells. The nucleotide sequence of the 3' portion of this gene revealed a coding sequence for the heme binding segment characteristic of the P450 gene family.