Long-Term Pollution Does Not Inhibit Denitrification and DNRA by Adapted Benthic Microbial Communities

• Published in: Microbial ecology Vol. 86; no. 4; pp. 2357 - 2372
• Main Authors: Broman, Elias, Abdelgadir, Mohanad, Bonaglia, Stefano, Forsberg, Sara C., Wikström, Johan, Gunnarsson, Jonas S., Nascimento, Francisco J. A., Sjöling, Sara
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2023; Springer Nature B.V
• Subjects: Ammonium; Ammonium Compounds; Baltic and East European studies; Baltic Sea; Benthos; Biomedical and Life Sciences; Chlorinated dibenzofurans; Contaminants; Cycles; Denitrification; Dioxins; Ecology; Ekologi; Environmental Sciences; Environmental Studies; Eutrophication; Farmakologi och toxikologi; Genes; Geochemistry; Geoecology/Natural Processes; Geokemi; Hydrophobicity; Life Sciences; Metagenome; Metagenomics; Metals; Microbial activity; Microbial Ecology; Microbiology; Microbiomes; Microbiota; Microorganisms; Miljövetenskap; Miljövetenskapliga studier; Nature Conservation; Nitrate reduction; Nitrates; Nitrogen; Nitrogen cycling; Organic compounds; Organic contaminants; Oxidation-Reduction; Pharmacology and Toxicology; Pollution; Sediment; Sediment pollution; Sediments; Water Quality/Water Pollution; Östersjö- och Östeuropaforskning; Baltic Sea; Dioxins; Chlorinated dibenzofurans; Sediment; Metagenome; Baltic Sea; Nitrogen cycling
• ISSN: 0095-3628; 1432-184X; 1432-184X
• DOI: 10.1007/s00248-023-02241-7

  Denitrification in sediments is a key microbial process that removes excess fixed nitrogen, while dissimilatory nitrate reduction to ammonium (DNRA) converts nitrate to ammonium. Although microorganisms are responsible for essential nitrogen (N) cycling, it is not yet fully understood how these microbially mediated processes respond to toxic hydrophobic organic compounds (HOCs) and metals. In this study, we sampled long-term polluted sediment from the outer harbor of Oskarshamn (Baltic Sea), measured denitrification and DNRA rates, and analyzed taxonomic structure and N-cycling genes of microbial communities using metagenomics. Results showed that denitrification and DNRA rates were within the range of a national reference site and other unpolluted sites in the Baltic Sea, indicating that long-term pollution did not significantly affect these processes. Furthermore, our results indicate an adaptation to metal pollution by the N-cycling microbial community. These findings suggest that denitrification and DNRA rates are affected more by eutrophication and organic enrichment than by historic pollution of metals and organic contaminants.