Pentachlorophenol degradation by Pseudomonas stutzeri CL7 in the secondary sludge of pulp and paper mill

A pentachlorophenol (PCP) mineralizing bacterium was isolated from the secondary sludge of pulp and paper mill and identified as Pseudomonas stutzeri strain CL7. This isolate used PCP as its sole source of carbon and energy and was capable of degrading this compound as indicated by stoichiometric release of chloride and biomass formation. P. stutzeri (CL7) was able to mineralize a high concentration of PCP (600 mg/L) than any previously reported Pseudomonad with PCP as sole carbon source. As the concentration of PCP increased from 50 to 600 mg/L, the reduction in the cell growth was observed and the PCP degradation was more than 90% in all studied concentrations. This isolate was able to remove 66.8% of PCP from the secondary sludge of pulp and paper mill when supplemented with 100 mg/L of PCP and grown for two weeks. This study showed that the removal efficiency of PCP by CL7 was found to be very effective and can be used in PCP remediation of pulp paper mill waste in the environment.