title: Response of the bacterial community associated with a cosmopolitan marine diatom to crude oil shows a preference for the biodegradation of aromatic hydrocarbons.
abstract: Emerging evidence shows that hydrocarbonoclastic bacteria (HCB) may be commonly found associated with phytoplankton in the ocean, but the ecology of these bacteria and how they respond to crude oil remains poorly understood. Here, we used a natural diatom-bacterial assemblage to investigate the diversity and response of HCB associated with a cosmopolitan marine diatom, Skeletonema costatum, to crude oil. Pyrosequencing analysis and qPCR revealed a dramatic transition in the diatom-associated bacterial community, defined initially by a short-lived bloom of Methylophaga (putative oil degraders) that was subsequently succeeded by distinct groups of HCB (Marinobacter, Polycyclovorans, Arenibacter, Parvibaculum, Roseobacter clade), including putative novel phyla, as well as other groups with previously unqualified oil-degrading potential. Interestingly, these oil-enriched organisms contributed to the apparent and exclusive biodegradation of substituted and non-substituted polycyclic aromatic hydrocarbons (PAHs), thereby suggesting that the HCB community associated with the diatom is tuned to specializing in the degradation of PAHs. Furthermore, the formation of marine oil snow (MOS) in oil-amended incubations was consistent with its formation during the Deepwater Horizon oil spill. This work highlights the phycosphere of phytoplankton as an underexplored biotope in the ocean where HCB may contribute importantly to the biodegradation of hydrocarbon contaminants in marine surface waters.
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Mishamandani
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.|School of Life Sciences, Heriot-Watt University, Edinburgh, UK.
authors.forename: Tony
authors.initials: T
authors.lastname: Gutierrez
authors.affiliation: Division of Microbial Ecology, Department of Microbiology and Ecosystems Science, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
authors.forename: David
authors.identifier: 0000-0002-8997-608X
authors.initials: D
authors.lastname: Berry
authors.affiliation: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Aitken
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D017377:Diatoms / Q000382:microbiology*; D006841:Hydrocarbons, Aromatic / Q000378:metabolism*; D010578:Petroleum / Q000378:metabolism; D059392:Petroleum Pollution; D010839:Phytoplankton / Q000382:microbiology*; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D012623:Seawater / Q000382:microbiology
chemical_list: D006841:Hydrocarbons, Aromatic; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons