Abstract
A 4-nitrophenol (4-NP) degrading bacterium Rhodococcus sp. strain PNI can degrade polynitrophenols such as 2, 4-dinitrophenol (2, 4-DNP) and 2, 4, 6-trinitrophenol (picric acid) . To characterize picric acid degradation by this bacterium, degradation tests were carried out using resting PN1 cells. The results revealed that picric acid degradation by strain PN1 is induced by 2, 4-DNP and the hydride Meisenheimer complex of picric acid accumulates as a metabolite, suggesting that the initial reaction is a hydride transfer to the aromatic-ring of picric acid. The same resting cells could degrade 2, 4-DNP, 2, 5-dinitrophenol and 4, 6-dinitro-o-cresol (DNOC), but not 2, 6-dinitrophenol and 2-sec-butyl-4, 6-dinitrophenol (Dinoseb) . These results describe that strain PN1 has a reductive degradation mechanism for polynitrophenols in addition to an oxidative one for 4-NP.
