Identification of metabolites from degradation of naphthalene by a Mycobacterium sp.
A Mycobacterium sp. isolated from oil-contaminated sediments was previously shown to mineralize 55% of the added naphthalene to carbon dioxide after 7 days of incubation. In this paper, we report the initial steps of the degradation of naphthalene by a Mycobacterium sp. as determined by isolation of metabolites and incorporation of oxygen from 18O2 into the metabolites. The results indicate that naphthalene is initially converted to cis- and trans-1,2-dihydroxy-1,2-dihydronaphthalene by dioxygenase and monooxygenase catalyzed reactions, respectively. The ratio of the cis to trans-naphthalene dihydrodiol isomers was approximately 25: 1. Thin layer and high pressure liquid chromatographic and mass spectrometric techniques indicated that besides the cis- and trans-1,2-dihydroxy-1,2-dihydronaphthalene, minor amounts of ring cleavage products salicylate and catechol were also formed. Thus the formation of both cis and trans-naphthalene dihydrodiols by the Mycobacterium sp. is unique. The down-stream reactions to ring cleavage products proceed through analogous dioxygenase reactions previously reported for the bacterial degradation of naphthalene.
Kelley
I
I
National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079.
Freeman
J P
JP
Cerniglia
C E
CE
D001673:Biodegradation, Environmental; D006868:Hydrolysis; D009161:Mycobacterium / Q000378:metabolism*; D009281:Naphthalenes / Q000737:chemistry / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism
D009281:Naphthalenes; C031721:naphthalene; D010100:Oxygen