Abstract: Twelve halophilic bacterial strains were extracted from deep sea sludge, which could grow at the salinity between 15% and 20%. These halophilic bacterial strains were separated, purified and enriched. After morphological observation and dye identification, one strain was selected which grows very well to do the experiments of influence on degrading polychlorinated biphenyls at last.The optimal experimental conditions of PCBs-degrading were obtained according to the changes of pH, inoculation amount and PCBs concentration. The experiment indicated that the degradation ratio could reach to 90% when the temperature was 30℃, pH was 7 to 8, inoculation amount was 5 mL, the concentration of PCBs was below 3mg/L.

Key words: halophilic, polychlorinated biphenyls, biodegradation