Bioremediation of oil-contaminated soil: Exploring the potential of endogenous hydrocarbon degrader Enterobacter sp. SAVR S-1

Abstract

Enterobacter is commonly found in oil-contaminated soil and plays a vital role in environmental bioremediation. This paper selected Enterobacter sp. SAVR S-1 as a representative to study the degradation potential at different concentrations of Total petroleum hydrocarbon (TPH) in soil during bioremediation. Genomic analysis indicated that genes involved in the metabolism of aromatic compounds (paa and hpa gene clusters) and fatty acid metabolism genes (fad gene cluster) might play important roles in TPH bioremediation. Through an increase (of up to 53.13%) in the abundance of microbial communities in oil-contaminated soils, TPH decreased, and Enterobacter was the dominant genus. The relative abundance of potential endogenous hydrocarbon degraders, i.e., halobacteria, greatly increased, including Aliifodinibius (1.26–1.59%), Filobacillus (0.02–0.66%), Pontibacillus (0.02–0.68%) and Halomonas (0.27–3.28%). Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis showed enhanced gene allocation for ABC transporters (4.22%), fatty acid (0.14%), benzoate (0.65%), butanoate (1.29%), propanoate (1.35%) metabolism and aromatic compound (0.28%) degradation on day 30. This study indicated that the addition of bacterial sources can induce community dynamics and their metabolic interactions in oil-contaminated soils to further accelerate bioremediation effects and provided a mechanistic basis for TPH degradation using the endogenous hydrocarbon degrader Enterobacter.