多氯联苯污染农田土壤的细菌群落结构差异及其影响因素

VARIATION OF MICROBIAL COMMUNITIES IN PCBS-CONTAMINATED AGRICULTURAL SOILS AND INFLUENCING FACTORS

应用PCR—DGGE技术分析多氯联苯长期污染农田土壤的细菌群落结构，并主要运用统计学方法探讨了多氯联苯总量和土壤理化因子对细菌群落结构的影响。结果显示：不同水平多氯联苯污染农田土壤中细菌群落结构存在差异，较高水平多氯联苯（64．0～484．5ngg^-1dw）污染土壤的细菌群落结构较为接近；相对于其他土壤理化因子（如有效磷、pH、有机质等），多氯联苯显著影响农田土壤中的细菌群落结构（P〈0．05）。这表明在多氯联苯胁迫下土壤细菌整体群落结构发生改变，提示多氯联苯污染对土壤微生物生态的影响，这可能导致土壤生态环境质量发生变化，是潜在的生态风险因素。

Microbial community composition in PCBs-contaminated paddy field soils was analyzed by PCR-DGGE. Impacts of PCBs and soil physico-chemical properties on soil microbial composition were investigated by canonical correspondence analysis. Results show that soil microbial community composition varied with soil PCBs level, and soils relatively higher in PCBs content （64.0 - 484.5 ng g^-1 dw） were quite close in community structure. Moreover,PCBs contamination affected more significantly （p 〈 0.05） bacterial species composition in comparison with other soil physico-chemical factors such as available phosphorus, pH,organic matter, etc. ,suggesting that under the stress of PCBs, the entire soil microbial community changed. In conclusion, PCBs pose a potential ecological risk to the microbial ecosystem in contaminated paddy soils.