Effects of soil properties, heavy metals, and PBDEs on microbial community of e-waste contaminated soil

Heavy metals and polybrominated diphenyl ethers (PBDEs) are ubiquitous pollutants at electronic waste (e-waste) contaminated sites, their individual impacts on soil microbial community has attracted wide attention, however, limited research is available on the combined effects of heavy metals and PBDEs on microbial community of e-waste contaminated. Therefore, combined effects of heavy metals and PBDEs on the microbial community in the e-waste contaminated soil were investigated in this study. Samples were collected from Ziya e-waste recycling area in Tianjin, northern China, and the soil microbial communities were then analyzed by the high-throughput MiSeq 16S rRNA sequencing to assess the effects of soil properties, heavy metals, and PBDEs on the soil microbial community. Candidatus Nitrososphaera, Steroidobacter and Kaistobacter were the dominant microbial species in the soils. Similar microbial metabolic functions, including amino acid metabolism, carbohydrate metabolism and membrane transport, were found in all soil samples. Redundancy analysis and variation partition analysis revealed that the microbial community was mainly influenced by PBDEs (including BDE 183, BDE 99, BDE 100 and BDE 154) in horizontal soil samples. However, TN, biomass, BDE 100, BDE 99 and BDE 66 were the major drivers shaping the microbial community in vertical soil samples.