Bacterial community changes during bioremediation of aliphatic hydrocarbon-contaminated soil

Abstract

The microbial community response during the oxygen biostimulation process of aged oil-polluted soils is poorly documented and there is no reference for the long-term monitoring of the unsaturated zone. To assess the potential effect of air supply on hydrocarbon fate and microbial community structure, two treatments (0 and 0.056 mol h⁻¹ molar flow rate of oxygen) were performed in fixed bed reactors containing oil-polluted soil. Microbial activity was monitored continuously over 2 years throughout the oxygen biostimulation process. Microbial community structure before and after treatment for 12 and 24 months was determined using a dual rRNA/rRNA gene approach, allowing us to characterize bacteria that were presumably metabolically active and therefore responsible for the functionality of the community in this polluted soil. Clone library analysis revealed that the microbial community contained many rare phylotypes. These have never been observed in other studied ecosystems. The bacterial community shifted from Gammaproteobacteria to Actinobacteria during the treatment. Without aeration, the samples were dominated by a phylotype linked to the Streptomyces. Members belonging to eight dominant phylotypes were well adapted to the aeration process. Aeration stimulated an Actinobacteria phylotype that might be involved in restoring the ecosystem studied. Phylogenetic analyses suggested that this phylotype is a novel, deep-branching member of the Actinobacteria related to the well-studied genus Acidimicrobium.

Petroleum Hydrocarbon Spills in the Environment and Abundance of Microbial Community Capable of Biosurfactant Production

“…The current study showed that besides the above mentioned phyla Verrucomicrobia; Chloroflexi; Planctomycetes; WPS-2; Chloroflexi; Armatimonadetes; Gemmatimonadetes; WPS-2; TM7 bacterial phyla were observed in the creosote contaminated soil. Our results are in agreement with most studies showing the importance of the Proteobacteria, especially the Gamma division, in hydrocarbon-polluted soil microbial communities or natural asphalts [27,30]. Shared families in both samples were Enterobacteriaceae; Pseudomonadaceae; Xanthomonadaceae; Micrococcaceae; Brucellaceae; Bradyrhizobiaceae; Sphingomonadaceae; Bacillaceae; Comamonadaceae; Methylobacteriaceae; Oxalobacteraceae and Weeksellaceae.…”

“…A 454 sequencing run was performed on a 70_75 GS Pico Titer Plate using a GS FLX pyrosequencing system according to the manufacturer's instructions (Roche, Mannheim, Acidobacteria (1.6%). Proteobacteria have been identified in many studies as the predominant phylum in soil samples [27,28] playing an integral role in nutrient cycling [28].The Proteobacteria encompass enormous morphological, physiological and metabolic diversity, and are of great importance to global carbon, nitrogen and sulphur cycles [27].…”

Impact of Long-Term Diesel Contamination on Soil Microbial Community Structure

“…Furthermore, these phyla have been observed in soils contaminated with aliphatic or aromatic compounds, both in the polluted samples and the clean reference soil (7,29,38,39). Bacteroidetes, which were not dominant in this study, have been found in clean and contaminated samples at similar relative abundances (1.9% and 1.8%, respectively).…”

“…3; also see Tables S3 and S4 in the supplemental material). Proteobacteria have been identified in many studies as the predominant phylum in soil samples (5,13,14,29), playing an integral role in nutrient cycling (30). For example, the two mostabundant bacterial OTUs were classified within the genera Variovorax (OTU 7163, 4.1% of the total number of sequences, family Comamonadaceae, Betaproteobacteria), and Methylocystis (OTU 64060, 1.4%, family Methylocystaceae, Alphaproteobacteria).…”

Description of Immundisolibacter cernigliae gen. nov., sp. nov., a high-molecular-weight polycyclic aromatic hydrocarbon-degrading bacterium within the class Gammaproteobacteria, and proposal of Immundisolibacterales ord. nov. and Immundisolibacteraceae fam. nov.

“…The 16S rRNA gene sequences comprising PG2 from these SIP projects possessed a relatively high (!96 %) intragroup 16S rRNA gene identity. Other globally distributed environmental 16S rRNA gene sequences with high similarity to those designated as PG2 have been detected in hydrocarbon-impacted environments contaminated with oils [6][7][8], creosote [9], pyridine [10] and aliphatic compounds [11]. Other 16S rRNA gene sequences from PG2 have been recovered from natural asphalts [12] as well as pristine sediment [13] and water samples [14][15][16].…”