Detection of Diverse Cytochrome P450-Dependent Biooxygenation Catalysts in Microorganisms Using a Multipurpose Inducer

Screening for new microbial cytochromes P450 to create a useful pool of oxygenating biocatalysts can be facilitated by applying multivalent inducers for it. The broad inducer spectrum for cytochrome P450 of Acinetobacter calcoaceticus EB 104 has been analyzed as a model for structure-function relationships governing the inducer recognition of hydrocarbon-oxidizing microbial cytochromes P450 with the aim to deduce structural requirements for the desired multivalent inducer. The cytochrome was induced by all compounds of adequate hydrophobicity that contain coplanar structural elements. It was concluded that due to the inherent low specificity of hydrophobic binding forces some few simple-structured hydrocarbons with a sterically flexible backbone can induce a variety of different hydrocarbon-oxidizing microbial cytochromes P450. This approach has been proved to be successfull by induction of cytochrome P450 with the help of n-hexane in Bacillus megaterium, in various strains of the genus Rhodococcus and in the yeast Candida apicola. Cytochrome P450 of Rhodococcus rhodochrous IMET 7278, that has partially been purified from n-hexane-induced cells, exhibited an induction profile differing to P450 of Acinetobacter.