title: Depletion and biodegradation of hydrocarbons in dispersions and emulsions of the Macondo 252 oil generated in an oil-on-seawater mesocosm flume basin.
abstract: Physically and chemically (Corexit 9500) generated Macondo 252 oil dispersions, or emulsions (no Corexit), were prepared in an oil-on-seawater mesocosm flume basin at 30-32 °C, and studies of oil compound depletion performed for up to 15 days. The use of Corexit 9500 resulted in smaller median droplet size than in a physically generated dispersion. Rapid evaporation of low boiling point oil compounds (C⩽15) appeared in all the experiments. Biodegradation appeared to be an important depletion process for compounds with higher boiling points in the dispersions, but was negligible in the surface emulsions. While n-alkane biodegradation was faster in chemically than in physically dispersed oil no such differences were determined for 3- and 4-ring PAH compounds. In the oil dispersions prepared by Corexit 9500, increased cell concentrations, reduction in bacterial diversity, and a temporary abundance of bacteria containing an alkB gene were associated with oil biodegradation.
authors.affiliation: SINTEF Materials and Chemistry, Environmental Technology, Dept. Applied Environmental Biology and Chemistry, N-7465 Trondheim, Norway. Electronic address: odd.brakstad@sintef.no.
authors.forename: Odd G
authors.initials: OG
authors.lastname: Brakstad
authors.affiliation: SINTEF Materials and Chemistry, Environmental Technology, Dept. Applied Environmental Biology and Chemistry, N-7465 Trondheim, Norway.
authors.forename: Per S
authors.initials: PS
authors.lastname: Daling
authors.affiliation: SINTEF Materials and Chemistry, Environmental Technology, Dept. Applied Environmental Biology and Chemistry, N-7465 Trondheim, Norway.
authors.forename: Liv-G
authors.initials: LG
authors.lastname: Faksness
authors.affiliation: SINTEF Materials and Chemistry, Environmental Technology, Dept. Applied Environmental Biology and Chemistry, N-7465 Trondheim, Norway.
authors.forename: Inger K
authors.initials: IK
authors.lastname: Almås
authors.affiliation: SINTEF Materials and Chemistry, Environmental Technology, Dept. Applied Environmental Biology and Chemistry, N-7465 Trondheim, Norway.
authors.forename: Siv-H
authors.initials: SH
authors.lastname: Vang
authors.affiliation: The Norwegian University of Science and Technology, Institute of Biotechnology, N-7491 Trondheim, Norway.
authors.forename: Line
authors.initials: L
authors.lastname: Syslak
authors.affiliation: SINTEF Materials and Chemistry, Environmental Technology, Dept. Applied Environmental Biology and Chemistry, N-7465 Trondheim, Norway.
authors.forename: Frode
authors.initials: F
authors.lastname: Leirvik
mesh_terms: D000473:Alkanes / Q000378:metabolism; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004655:Emulsions / Q000737:chemistry*; D006838:Hydrocarbons / Q000737:chemistry / Q000378:metabolism*; D010578:Petroleum / Q000032:analysis*; D012623:Seawater / Q000737:chemistry*
chemical_list: D000473:Alkanes; D004655:Emulsions; D006838:Hydrocarbons; D010578:Petroleum
keywords: Biodegradation; Depletion; Emulsions; Flume basin; Hydrocarbons; Oil dispersions