play an important role in the microbial degradation of
oil, chlorinated hydrocarbons, fuel additives, and many
other compounds [77]. Depending on the chain length,
enzyme systems are required to introduce oxygen in
the substrate to initiate biodegradation (Table 1). Higher
eukaryotes generally contain several different P450 families
that consist of large number of individual P450 forms
that may contribute as an ensemble of isoforms to the
metabolic conversion of given substrate. In microorganisms
such P450 multiplicity can only be found in few species [78].
Cytochrome P450 enzyme systems was found to be involved
in biodegradation of petroleum hydrocarbons (Table 1). The
capability of several yeast species to use n-alkanes and
other aliphatic hydrocarbons as a sole source of carbon and
energy is mediated by the existence of multiple microsomal
Cytochrome P450 forms. These cytochrome P450 enzymes
had been isolated from yeast species such as Candida maltosa,
Candida tropicalis, and Candida apicola [79]. The diversity
of alkaneoxygenase systems in prokaryotes and eukaryotes
that are actively participating in the degradation of alkanes
under aerobic conditions like Cytochrome P450 enzymes,
integral membrane di-iron alkane hydroxylases (e.g., alkB),
soluble di-iron methane monooxygenases, and membranebound
copper containing methane monooxygenases have
been discussed by Van Beilen and Funhoff [80].