Biodegradation of p-nitrophenol via 1,2,4-benzenetriol by an Arthrobacter sp.
The degradation of p-nitrophenol (PNP) by Moraxella and Pseudomonas spp. involves an initial monooxygenase-catalyzed removal of the nitro group. The resultant hydroquinone is subject to ring fission catalyzed by a dioxygenase enzyme. We have isolated a strain of an Arthrobacter sp., JS443, capable of degrading PNP with stoichiometric release of nitrite. During induction of the enzymes required for growth on PNP, 1,2,4-benzenetriol was identified as an intermediate by gas chromatography-mass spectroscopy (GC-MS) and radiotracer studies. 1,2,4-Benzenetriol was converted to maleylacetic acid, which was further degraded by the beta-ketoadipate pathway. Conversion of PNP to 1,2,4-benzenetriol is catalyzed by a monooxygenase system in strain JS443 through the formation of 4-nitrocatechol, 4-nitroresorcinol, or both. Our results clearly indicate the existence of an alternative pathway for the biodegradation of PNP.
Jain
R K
RK
Armstrong Laboratory, Tyndall Air Force Base, Florida 32403-6001.
Dreisbach
J H
JH
Spain
J C
JC
D001173:Arthrobacter / Q000378:metabolism*; D001673:Biodegradation, Environmental; D006873:Hydroquinones / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D009596:Nitrophenols / Q000378:metabolism*; D010101:Oxygen Consumption
D006873:Hydroquinones; D009573:Nitrites; D009596:Nitrophenols; C013038:hydroxyhydroquinone; C024836:4-nitrophenol