Eco-toxicological Effect Of Decabromodiphenyl Ether And Copper Combined Pollution On Soil Microbe

In the present study, soil in and around e-waste recycling site were sampled, polybrominated diphenyl ethers (PBDEs) and heavy metals were determined, among these contaminants decabromodiphenyl ether (BDE209) and copper (Cu) were widespread, yet their combined effect on microbes within the soil was not reported. So in this study, the effects of both single and combined pollution of BDE209 and Cu at different concentrations on culturable soil microbial, soil enzyme activities and microbial community structure were studied under laboratory conditions. Our results are showed as follow:(1)Culturable soil microbial were sensitive to the single or combined pollution, the inhibited effects of combined pollutants were higher than that single ones. The sensitiveness of culturable soil microbial to the single or combined pollutants followed the order:fungi>actinomycetes> bacterial.(2)Soil catalase, urease and saccharase were sensitive to BDE209 and Cu, and the joint effects of both BDE209 and Cu were higher than the single ones. The sensitiveness of soil enzyme to the single or combined pollutants followed the order:saccharase>urease>catalase.(3)Stepwise regression analysis indicated that, the action and interaction between Cu and BDE209 were largely dependent on the exposure dose and incubation time, as the inhibited effects varied in different treated soil samples, and the combined effects were synergistic, antagonistic or toxic addition at different incubation time.(4)Denaturing Gradient Gel Electrophoresis (DGGE) analysis indicated that BDE209 and Cu could alter the bacterial community structure, the existence of these pollutants in soil could reduces the microbial diversity, and the microbial diversity in combined treatments were lower than the single exposure soil. The combined effects of BDE209 and Cu on the microbial community structure were synergistic. In addition, as the exposure time extend, the bacterial community structure of the tested soil changed a lot, and tolerance strains emerged.