AEROBIC DEGRADATION AND DECHLORINATION OF 2-CHLOROPHENOL, 3-CHLOROPHENOL AND 4-CHLOROPHENOL BY A PSEUDOMONAS-PICKETTII STRAIN

A Gram-negative aerobic bacterium capable of using 2-chlorophenol (2-C P), 3-chlorophenol (3-CP) and 4-chlorophenol (4-CP) as sole carbon sou rces was isolated and characterized. The bacterium, designated LD1, wa s identified to be a Pseudomonas pickettii strain. LD1 was able to tot ally degrade and dechlorinate 2-CP (initial concentration: 1.51 mmol l (-1)), 3-CP (initial concentration: 0.57 mmol l(-1)) and 4-CP (initial concentration: 0.75 mmol l(-1)) within 30, 30 and 40 h of incubation, respectively, under growing-cell batch conditions. LD1 was also found to be able to metabolize chlorocatechols in growing- and resting-cell conditions. This suggests that the bacterium degrades monochloropheno ls through a chlorocatechol pathway. In addition, LD1 was found to be capable of readily metabolizing other organic compounds such as phenol , benzoic acid, hydroxybenzoic acids and hydroquinone. Because of the broad spectrum of monochlorophenols and organic compounds that LD1 can degrade, this bacterium appears to have the potential for being succe ssfully used in the biotreatment of wastewaters and in soil decontamin ation.