Table 1.

Enzymes involved in biodegradation of petroleum hydrocarbons.

Enzymes	Substrates	Microorganisms	References
Soluble Methane Monooxygenases	C1–C8 alkanes alkenes and cycloalkanes	Methylococcus
		Methylosinus
		Methylocystis	McDonald et al. [46]
		Methylomonas
		Methylocella
Particulate Methane Monooxygenases	C1–C5 (halogenated) alkanes and cycloalkanes	Methylobacter
		Methylococcus,	McDonald et al. [46]
		Methylocystis
AlkB related Alkane Hydroxylases	C5–C16 alkanes, fatty acids, alkyl benzenes, cycloalkanes and so forth	Pseudomonas
		Burkholderia	Jan et al. [47]
		Rhodococcus,
		Mycobacterium
Eukaryotic P450	C10–C16 alkanes, fatty acids	Candida maltosa
		Candida tropicalis	Iida et al. [48]
		Yarrowia lipolytica
Bacterial P450 oxygenase system	C5–C16 alkanes, cycloalkanes	Acinetobacter
		Caulobacter	Van Beilen et al. [49]
		Mycobacterium
Dioxygenases	C10–C30 alkanes	Acinetobacter sp.	Maeng et al. [50]