title: Deep-sea bacteria enriched by oil and dispersant from the Deepwater Horizon spill.
abstract: The Deepwater Horizon oil spill resulted in a massive influx of hydrocarbons into the Gulf of Mexico (the Gulf). To better understand the fate of the oil, we enriched and isolated indigenous hydrocarbon-degrading bacteria from deep, uncontaminated waters from the Gulf with oil (Macondo MC252) and dispersant used during the spill (COREXIT 9500). During 20 days of incubation at 5°C, CO(2)  evolution, hydrocarbon concentrations and the microbial community composition were determined. Approximately 60% to 25% of the dissolved oil with or without COREXIT, respectively, was degraded, in addition to some hydrocarbons in the COREXIT. FeCl(2)  addition initially increased respiration rates, but not the total amount of hydrocarbons degraded. 16S rRNA gene sequencing revealed a succession in the microbial community over time, with an increase in abundance of Colwellia and Oceanospirillales during the incubations. Flocs formed during incubations with oil and/or COREXIT in the absence of FeCl(2) . Synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectromicroscopy revealed that the flocs were comprised of oil, carbohydrates and biomass. Colwellia were the dominant bacteria in the flocs. Colwellia sp. strain RC25 was isolated from one of the enrichments and confirmed to rapidly degrade high amounts (approximately 75%) of the MC252 oil at 5°C. Together these data highlight several features that provide Colwellia with the capacity to degrade oil in cold, deep marine habitats, including aggregation together with oil droplets into flocs and hydrocarbon degradation ability.
authors.affiliation: MS 70A-3317, 1 Cyclotron Rd., Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors.forename: Jacob
authors.initials: J
authors.lastname: Baelum
authors.forename: Sharon
authors.initials: S
authors.lastname: Borglin
authors.forename: Romy
authors.initials: R
authors.lastname: Chakraborty
authors.forename: Julian L
authors.initials: JL
authors.lastname: Fortney
authors.forename: Regina
authors.initials: R
authors.lastname: Lamendella
authors.forename: Olivia U
authors.initials: OU
authors.lastname: Mason
authors.forename: Manfred
authors.initials: M
authors.lastname: Auer
authors.forename: Marcin
authors.initials: M
authors.lastname: Zemla
authors.forename: Markus
authors.initials: M
authors.lastname: Bill
authors.forename: Mark E
authors.initials: ME
authors.lastname: Conrad
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Malfatti
authors.forename: Susannah G
authors.initials: SG
authors.lastname: Tringe
authors.forename: Hoi-Ying
authors.initials: HY
authors.lastname: Holman
authors.forename: Terry C
authors.initials: TC
authors.lastname: Hazen
authors.forename: Janet K
authors.initials: JK
authors.lastname: Jansson
mesh_terms: D034241:Alteromonadaceae / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D058491:Bacterial Load; D020563:Gammaproteobacteria / Q000235:genetics / Q000378:metabolism; D047830:Gulf War; D008055:Lipids; D010578:Petroleum / Q000378:metabolism*; D059392:Petroleum Pollution; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014871:Water Microbiology
chemical_list: D008055:Lipids; D010578:Petroleum; D012336:RNA, Ribosomal, 16S; C470995:corexit 9500