A metagenomic portrait of the microbial community responsible for two decades of bioremediation of poly-contaminated groundwater. (1st August 2022)

• Record Type: Journal Article
• Authors: Hauptfeld, Ernestina; Pelkmans, Jordi; Huisman, Terry T.; Anocic, Armin; Snoek, Basten L.; von Meijenfeldt, F.A. Bastiaan; Gerritse, Jan; van Leeuwen, Johan; Leurink, Gert; van Lit, Arie; van Uffelen, Ruud; Koster, Margot C.; Dutilh, Bas E.
• Is Part Of: Water research. Volume 221(2022)
• Publication Date: 2022-08-01
• Subjects: Biodegradation -- Bioremediation -- Anaerobic microbiology -- Groundwater contamination -- BTEX -- PAH; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2022.118767
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: Genome-resolved metagenomics unveiled bacteria degrading poly-contaminants. Distinct microbial communities were found in the park soil and the treatment plant. Sulfuricurvum dominated the park communities, Burkholderiales the treatment plant. Reinoculation of plant-derived sludge into the influent drove community composition. Known biodegradation pathways were abundant in the plant but not in the park. Abstract: Biodegradation of pollutants is a sustainable and cost-effective solution to groundwater pollution. Here, we investigate microbial populations involved in biodegradation of poly-contaminants in a pipeline for heavily contaminated groundwater. Groundwater moves from a polluted park to a treatment plant, where an aerated bioreactor effectively removes the contaminants. While the biomass does not settle in the reactor, sediment is collected afterwards and used to seed the new polluted groundwater via a backwash cycle. The pipeline has successfully operated since 1999, but the biological components in the reactor and the contaminated park groundwater have never been described. We sampled seven points along the pipeline, representing the entire remediation process, and characterized the changing microbial communities using genome-resolved metagenomic analysis. We assembled 297 medium- and high-quality metagenome-assembled genome sequences representing on average 46.3% of the total DNA per sample. We found that the communities cluster into two distinct groups, separating the anaerobic communities in the park groundwater from the aerobic communities inside the plant. In the park, the community is dominated by members of the genus Sulfuricurvum, while the plant is dominated by generalists from the order Burkholderiales . Known aromatic compound biodegradation pathways are four times more abundant in the plant-side communities compared to the park-side. Our findings provide a genome-resolved portrait of the microbial community in a highly effective groundwater treatment system that has treated groundwater with a complex contamination profile for two decades. Graphical Abstract: Graphical Abstract Image, graphical abstract .