Plasmid-determined alcohol dehydrogenase activity in alkane-utilizing strains of Pseudomonas putida.

We have identified an alcohol dehydrogenase activity in Pseudomonas putida strains carrying the CAM-OCT degradative plasmid that were grown on octane. The activity is nicotinamide adenine dinucleotide independent, sediments at 48,000 x g, and shows 20-fold greater activity with octanol rather than butanol as substrate. The enzyme is inducible by unoxidized alkane and is present only in strains that have the OCT plasmid genes for alkane degradation with a wild-type alcO locus. No analogous chromosomal dehydrogenase could be detected. Wild-type and actanol-negative mutants (alcA-) without plasmids both contain a constitutive nicotinamide adenine dinucleotide-linked soluble alcohol dehydrogenase activity. This means that alcA- mutants are cryptic for octanol oxidation and suggests that the particulate plasmid-coded alcohol dehydrogenase activity is active on surface- or membrane-bound substrate.