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.
National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079.
I
I
Kelley
J P
JP
Freeman
C E
CE
Cerniglia
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