Microbial Degraders of Petroleum and Polycyclic Aromatic Hydrocarbons from Sod-Podzolic Soil

The paper deals with the phylogenetic and functional microbial diversity in the samples of umbric luvisol contaminated and uncontaminated with hydrocarbons and of urban stratozem. High-throughput sequencing of the V3-V4 region of the 16S rRNA gene revealed predomination of bacteria of the phyla Proteobacteria, Actinobacteria, and Acidobacteria in the studied soil samples. Bacteria of the genera Sphingomonas, Bradyrhizobium, and Pseudolabrys in the samples of umbric luvisol and bacteria of the genera Brevundimonas, Stenotrophomonas, and Streptomyces in urbostratozem had the greatest potential functional activity in conversion of nitrogen compounds, degradation of chloroalkanes, chloroalkenes, and benzoate. Strains of Stenotrophomonas maltophilia, which degraded oil, petroleum products, and polycyclic aromatic hydrocarbons (PAHs, phenanthrene, anthracene, and pyrene) were isolated from oil-contaminated soils. Under microcosm conditions, microorganisms of umbric luvisol efficiently degraded various components of naphthenic-methane and methane-naphthenic oil. While the content of aromatic components in naphthenic-methane oil degraded by the soil microbial community and by the community enriched with S. maltophilia strain P420c was almost the same, in the variant with bioaugmentation the degradation process of these components proceeded 14 days faster. The enrichment of soil with specific degraders of PAHs and aromatic compounds may be appropriate for the soils of northern regions with a low duration of the summer period, which are polluted with oil with a high content of aromatic and asphalt-resinous compounds.

Automated summary

This paper investigates the phylogenetic and functional microbial diversity in soils contaminated and uncontaminated with hydrocarbons. It identifies specific bacterial genera with potential functional activity in conversion of nitrogen compounds and degradation of hydrocarbons, and suggests the enrichment of soil with specific degraders as a potential strategy for polluted soils in northern regions.