BIODEGRADATION OF 2-NITROTOLUENE BY PSEUDOMONAS SP STRAIN JS42

A strain of Pseudomonas sp. was isolated from nitrobenzene-contaminate d soil and groundwater on 2-nitrotoluene as the sole source of carbon, energy, and nitrogen. Bacterial cells growing on 2-nitrotoluene relea sed nitrite into the growth medium. The isolate also grew on 3-methylc atechol, 4-methylcatechol, and catechol. 2-Nitrotoluene, 3-methylcatec hol, and catechol stimulated oxygen consumption by intact cells regard less of the growth substrate. Crude extracts from the isolate containe d catechol 2,3-dioxygenase and 2-hydroxy-6-oxohepta-2,4-dienoate hydro lase activity. The results suggest that 2-nitrotoluene is subject to i nitial attack by a dioxygenase enzyme that forms 3-methylcatechol with concomitant release of nitrite. The 3-methylcatechol is subsequently degraded via the meta ring fission pathway.