Microbial Community Structure and Carbon Sequestration Potential of Petroleum-contaminated Soil.

In order to explore the characteristics of microbial community structure and the potential of pollution reduction and carbon sequestration in petroleum contaminated soil, four typical oil and gas field enterprises in-service well sites of eastern, central, northwestern and southwestern China are selected as the research areas, combined with 16S rRNA high-through put sequencing and bioinformatics technology, the changes of microbial community structure and main environmental driving factors of potential pollution reduction and carbon sequestration in surface soil (0-20 cm) of different oil fields were explored, and the metabolic pathways related to pollution reduction and carbon sequestration were predicted and functionally annotated. The results show that total nutrient and microbial biomass of soil in different oil fields generally exhibit the highest levels in the eastern oilfields, relatively close levels in the southwestern and northwestern oil fields, and the lowest levels in the central oil fields. The dominant bacteria in the soil of the study area were Proteobacteria, Actinobacteriota, Chloroflexi, Bacteroidota and Acidobacteriota. Based on the results of VPA and RDA analysis, MBC, MBN, RubisCO enzyme activity and TPH were the main driving environmental factors affecting the change of microbial community structure in contaminated soil. Among them, TPH (r2=0.67, P=0.001), MBC (r2=0.36, P=0.004 2), MBN (r2=0.74, P=0.003) and RubisCO enzyme activity (r2=0.37, P=0.004 1) were significantly correlated with microbial community structure. The functional annotation results of KEGG database showed that the relative abundance of metabolic pathways related to microbial carbon sequestration in contaminated soils of different oilfields was significantly higher than that of metabolic pathways related to the degradation of organic matter such as petroleum hydrocarbons, and the relative abundance of the above two types of pathways was small among different oilfields. The results are of great significance to support the development of pollution reduction and sink increase technology in petroleum and petrochemical industry under the new situation. [ABSTRACT FROM AUTHOR]