BIOREMEDIATION OF p-NITROPHENOL USING SOIL MICROCOSMS

摘要

The microorganisms were isolated from a variety of Indian soils, i.e. agriculture field soil, garden soil, and pond soil and from unfertilized soil. Higher percentages of p-nitrophenol (PNP) degraders were obtained by direct soil isolation method from vegetable field soil while low percentages were obtained from garden soil and pond soil whereas no PNP degrader could be recovered from unfertile soil. Further characterization of soils resulted in isolation of three different PNP degraders designated as ORJ-1, ORJ-2 and ORJ-3. In addition, a PNP-degrading strain Arthrobacter protophormiae RKJ100 available in the laboratory was employed for PNP degradation studies in broth and in soil microcosms. In these studies, approximately 95-99% PNP depletion was achieved with concomitant release of nitrite molecules in broth and thereafter in static soil microcosms. Natural degradation capacity of Arthrobacter protophormiae RKJ100 were performed in soil microcosms on various PNP concentration (0.01 mM, 0.1 mM, 0.5 mM, 1.0 mM and 1.5mM). The results indicated that 0.5 mM PNP could easily be degraded by the organism. Further, the residual level of PNP was also degraded from the natural vegetable soil sample in static soil microcosm conditions by Arthrobacter protophormia RKJ100.