Hydrocarbon biodegradation by Arctic sea-ice and sub-ice microbial communities during microcosm experiments, Northwest Passage (Nunavut, Canada)

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DOIResolve DOI: https://doi.org/10.1093/femsec/fiw130
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Name affiliation
  1. National Research Council of Canada. Energy, Mining and Environment
FormatText, Article
Journal titleFEMS Microbiology Ecology
ISSN0168-6496
1574-6941
Subjectarctic; sea ice; hydrocarbon biodegradation; bioremediation; 16S ribosomal RNA gene sequencing; microbial community fingerprinting
Abstract
The increasing accessibility to navigation and offshore oil exploration brings risks of hydrocarbon releases in Arctic waters. Bioremediation of hydrocarbons is a promising mitigation strategy but challenges remain, particularly due to low microbial metabolic rates in cold, ice-covered seas. Hydrocarbon degradation potential of ice-associated microbes collected from the Northwest Passage was investigated. Microcosm incubations were run for 15 days at -1.7°C with and without oil to determine the effects of hydrocarbon exposure on microbial abundance, diversity and activity, and to estimate component-specific hydrocarbon loss. Diversity was assessed with automated ribosomal intergenic spacer analysis and ion torrent 16S rRNA gene sequencing. Bacterial activity was measured by 3H-leucine uptake rates. After incubation, sub-ice and sea-ice communities degraded 94% and 48% of the initial hydrocarbons, respectively. Hydrocarbon exposure changed the composition of sea-ice and sub-ice communities; in sea-ice microcosms, Bacteroidetes (mainly Polaribacter) dominated whereas in sub-ice microcosms, Epsilonproteobacteria contribution increased, but that of Alphaproteobacteria and Bacteroidetes decreased. Sequencing data revealed a decline in diversity and increases in Colwellia and Moritella in oil-treated microcosms. Low concentration of dissolved organic matter (DOM) in sub-ice seawater may explain higher hydrocarbon degradation when compared to sea ice, where DOM was abundant and composed of labile exopolysaccharides.
Publication date
PublisherFederation of European Microbiological Societies
LanguageEnglish
Peer reviewedYes
NPARC number23000460
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Record created2016-07-20
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