Screening of a PCBs-degrading Halophilic Bacterium and Its Enzyme-producing Conditions

Polychlorinated biphenyls(PCBs) are persistent organic pollutants(POPs).This experiment screened a halophilic bacterium from the deep sea sediments,which could grow at the salinity of 15%,and designated as B2.6.The cells of this strain were rod shaped,Gram negative,motile,could grow in pH 5.0~9.0 and 10~37 ℃.This bacterium could make growth using PCBs as the sole source of carbon and energy.The experiment indicated that at 30 ℃,pH 7 and 8,the inoculation amount 5 mL,the concentration of PCBs below 3 mg·L-1,the degradation ratio of PCBs could reach 90% at 72 h.The traditional morphology,physiological and biochemical properties as well as identified system of Biolog were applied to the bacteria classification.The pattern of PCBs-degrading enzyme production of strain B2.6 was continuous synthesis.The activity of PCBs-degrading enzyme could be enhanced by the ions of ⅠA,such as Na+ and K+,while it might be inhibited by the transitional metal ions,such as Co2+,Mn2+,Cu2+,Fe2+ and Fe3+ in a certain degree.The optimal temperature,pH value and concentration of NaCl for the PCBs-degrading enzyme were 25~35 ℃,pH 6~8 and 50 g·L-1,respectively.