Effects of long-term petroleum and heavy metals pollution on the diversity and community structure of Pesudomonas populations in agricultural soils
长期石油和重金属污染对农田土壤假单胞菌种群多样性及结构的影响

By using PCR-DGGE method, this paper studied the diversity and community structure of Pseudomonas populations in long-term petroleum- and heavy metals-contaminated agricultural soils in Northeast China. The results showed that the Shannon diversity index of Pseudomonas was significantly higher in petroleum- than in heavy metals-contaminated soils. The diversity of Pseudo- monas in petroleum-contaminated soil was approached to that in clean soil but lower than that in polluted lowland rice soil, suggesting that contaminant type and cultivation mode were the main factors affecting the diversity of Pseudomonas in agricultural soils. The sequences of V6/V7 regions in 16S rRNA gene indicated that P. mendocina, P. stutzeri and P. aeruginosa were the dominant species in both petroleum- and heavy metals-contaminated soils, demonstrating that these three species were enriched under the stress of long-term pollution, which might correlate with the natural degradation of petroleum and the resistance of Pseudomonas to heavy metals.