S. Alisadat et al., A NOVEL PATHWAY FOR THE BIODEGRADATION OF 3-NITROTOLUENE IN PSEUDOMONAS-PUTIDA, FEMS microbiology, ecology, 17(3), 1995, pp. 169-176
3-Nitrotoluene was degraded when incubated with the resting cells of P
seudomonas putida OU83. Most of the 3-nitrotoluene (70%) was metaboliz
ed via reduction of the nitro group to form 3-aminotoluene (3-AT). A m
inor portion (30%) was degraded through a novel pathway involving oxid
ation of 3-NT to form 3-nitrophenol through a series of intermediary m
etabolites: 3-nitrobenzyl alcohol, 3-nitrobenzaldehyde and 3-nitrobenz
oic acid. Degradation of 3-nitrophenol occurred with the formation of
a transient intermediary metabolite, hydroxynitroquinone, which was fu
rther degraded with the near stoichiometric release of nitrite into th
e medium. 3-Nitrotoluene-induced cells showed increased oxygen consump
tion with 3-nitrotoluene, 3-nitrobenzaldehyde, 3-nitrobenzoate, and 3-
nitrophenol as substrates in comparison to uninduced cells. Cell extra
cts prepared from strain OU83 contained benzylalcohol dehydrogenase an
d benzaldehyde dehydrogenase activities. The experimental evidence sug
gests a novel pathway for the degradation of 3-NT in which C-1 elimina
tion is catalyzed by a cofactor-independent deformylase, rather than a
decarboxylase or dioxygenase.