Effect of arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) on microorganism of phenanthrene and pyrene contaminated soils

A pot experiment was performed to investigate the effect of phytoremediation (CK, using tall fescue), fungi remediation (GV, using Glomus versiforme), bacterial remediation (PS, using Pseudomonas fluorescens Ps2-6), and microbial-phytoremediation (GVPS, using three species) on removing polycyclic aromatic hydrocarbons (PAHs) and the microbial diversity in soils. Inoculation with G. versiforme and P. fluorescens could increase the biomass of tall fescue and the accumulation of phenanthrene (PHE) and pyrene (PYR) in plants. Among them, the highest PHE and PYR removal efficiencies and highest biomass of tall fescue were observed in the GVPS treatment and the microbial diversity in contaminated soil was changed, the result revealed that Proteobacteria and Ascomycota were the dominant bacterial phylum and fungal phylum in all treatments, while more Proteobacteria were detected in GVPS treatment. At the genus level, the abundance of Sphingomonas (3.17%), Pseudomonas (2.05%), and Fusarium (8.65%) treated with GVPS increased compared with other treatments. These pieces of evidence contribute to a better understanding of the mechanisms involved in the combined microbial-phytoremediation strategies for PAHs-contaminated soils, especially the effects of microbial-phytoremediation on rhizosphere microbial diversity. NOVELTY STATEMENT Inoculation with G. versiforme and P. fluorescens could increase PHE and PYR removal efficiencies, the biomass of tall fescue, microbial diversity, and the abundance of Proteobacteria, Sphingomonas, Pseudomonas, and Fusarium in (PHE + PYR)-contaminated soils.

Automated summary

In a pot experiment, the effects of phytoremediation, fungi remediation, bacterial remediation, and microbial-phytoremediation on the removal of PAHs and microbial diversity in soils were investigated. Inoculation with Glomus versiforme and Pseudomonas fluorescens increased the biomass of tall fescue and the accumulation of phenanthrene and pyrene in plants. The highest removal efficiencies of phenanthrene and pyrene were observed in the microbial-phytoremediation treatment, along with changes in the microbial diversity in contaminated soil.