Effects of oil pollution on soil microbial diversity in the Loess hilly areas, China

Abstract Purpose Data support and theoretical basis for bioremediation and treatment of petroleum-contaminated soils in the Loess hills of Yan’an, northern Shaanxi. Methods The evolutionary characteristics of soil microbial diversity and community structure under different levels of oil pollution were studied by field sampling, indoor simulation experiments, and analyzed through assays, using the mine soils from Yan’an, Shaanxi Province, as the research object. Results Compared with clean soil, the microbial species in contaminated soil were significantly reduced, the dominant flora changed, and the flora capable of degrading petroleum pollutants increased significantly. The soil microbial diversity and community structure differed, although not significantly, between different pollution levels, but significantly from clean soil. In the uncontaminated soil (CK), the dominant soil microbial genera were mainly Pantoea, Sphingomonas, Thiothrix, and Nocardioides. The abundance of Pseudomonas, Pedobacter, Massilia, Nocardioides, and Acinetobacter in the soil increased after oil contamination, while Thiothrix, Sphingomonas, and Gemmatimonas decreased significantly. Conclusions After the soil was contaminated with petroleum, the microbial species in the soil decreased significantly, the dominant genera in the soil changed, and the relative abundance of bacteria groups capable of degrading petroleum pollutants increased. The genera that can degrade petroleum pollutants in the petroleum-contaminated soil in the study area mainly include Pseudomonas, Acinetobacter, Pedobacter, Acinetobacter, and Nocardioides, which provide a scientific basis for exploring It provides a scientific basis for exploring remediation methods suitable for petroleum-contaminated soil in this region