Iron Reducing Potential and Community Structure of Iron Reducing Microorganisms in Shale Gas Field

The soil iron reduction process driven by microorganisms plays an important role in the biogeochemical cycle of iron. This process can also be coupled with the conversion of soil heavy metals and the degradation of petroleum hydrocarbon organic pollutants. Shale gas contains organic pollutants such as polycyclic aromatic hydrocarbons and palates, so there is a potential risk of hydrocarbon organic pollution in gas field soil. This study used the soil in the shale gas field in Fuling, Chongqing as the object, measured the iron reducing potential (IRP) of the soil, and used Illumina Miseq sequencing to analyze the iron-reducing microbial groups in it. Then discussed the iron-reducing microbial activity, basic soil properties, and the relationship between microbial communities. The results showed that soil ammonium nitrogen and available phosphorus were significantly negatively correlated with soil iron reduction activity. Ammonium nitrogen and available phosphorus were significantly negatively correlated with soil based on OTU composition. The microbial community structure is significantly correlated. In general, the soil iron-reducing bacteria in this area mainly belong to Firmicutes, Proteobacteria, and Bacteroidetes.This study reveals the microbial mechanism that affects the iron reduction activity of typical shale gas fields. It also lays the foundation for further research on the microbial mechanism of soil organic pollutants removal under iron reduction conditions.