P. frederiksbergensis alkane monooxygenase was cloned in order to increase the understanding of the enzyme system involved in aerobic alkane degradation. The sequence comparisons and ORFS of DNA fragment results revealed that the regulation and the genes organization involved in alkane oxidation represented in Pseudomonas frederiksberghensis varies among the different known alkane degrading bacteria. Such genomes encode messages on both strands of the DNA, or in an overlapping but different reading frames, of the same strand of DNA. The gene culster of P. frederiksbergensis contained alkane monooxygenase and putative flavin-binding monooxygenase (hypothetical protein with unknown function) which was oriented in the same direction. Alcohol dehydrogenase oriented in the opposite direction.