Rajeev KaushikDHARMENDRA KUMAR2016-06-222016-06-222013http://krishikosh.egranth.ac.in/handle/1/67674T-8841The present study was carried out for isolation, identification and characterization of pentachlorophenol biotransforming bacteria from pulp and paper mill effluent irrigated soils of Lal Kuan, Uttrakhand. PCP is a high molecular weight, recalcitrant, hydrophobic aromatic hydrocarbon compound toxic to all forms of life since it is an inhibitor of oxidative phosphorylation. In solving the serious problems of pollution caused by PCP, it is important to assess the potential of bacterial strains indigenous to sites contaminated with PCP for their ability to degrade PCP. Twenty two bacterial isolates were identified through 16S rDNA sequencing, which grew well at 500 ppm of PCP as sole C source in minimal salt medium. However, reduction in their growth was observed at 700 ppm PCP. Out of 22 isolates, 19 isolates belonged to class - Proteobacteria, matched with sequences of Pseudomonas and Enterobacter. Two isolates, Ochrobactrum sp (LK59) and Ensifer adhaerens (LK 4) belonged to α- Proteobacteria. The single isolate of Firmicutes phyla was identified as Lysinibacillus fusiformis (LK156) which could show significantly higher growth at 300 and 500 ppm of PCP than other isolates. PCP degradation by Ensifer adhaerens and Lysinibacillus fusiformis is reported for the first time in the present study and these might represent new chlorophenoldegrading taxa. HPLC studies revealed decrease in the residual PCP and formation of intermediates such as tetrachlorohydroquinone (TeCH) and dichlorophenols (DCP) by selected isolates. Removal of PCP from sterile soil by selected isolates, viz. Ensifer adhaerens, Pseudomonas putida and Lysinibacillus fusiformis , was studied in a 30 d experiment under controlled condition. These isolates were used alone and in combination. PCP removal by mixed inoculum was significantly higher (68.81%) than single inoculation after 30 d of incubation. The results of this study indicate that ability to degrade pentachlorophenol is widely distributed amongst phylogenetically diverse group of bacteria in agricultural soils irrigated with effluent discharged from pulp and paper mill. The enriched mixed inoculum has better potential in scavenging PCP from soil as compared to individual isolates. The potential isolates obtained in the present study can be used for developing consortium for bioremediation of sites contaminated with PCP.grain, rice, planting, yields, developmental stages, genotypes, genetics, fertilizers, biological phenomena, phenotypesThesis