title: Microbial community analysis of a coastal salt marsh affected by the Deepwater Horizon oil spill.
abstract: Coastal salt marshes are highly sensitive wetland ecosystems that can sustain long-term impacts from anthropogenic events such as oil spills. In this study, we examined the microbial communities of a Gulf of Mexico coastal salt marsh during and after the influx of petroleum hydrocarbons following the Deepwater Horizon oil spill. Total hydrocarbon concentrations in salt marsh sediments were highest in June and July 2010 and decreased in September 2010. Coupled PhyloChip and GeoChip microarray analyses demonstrated that the microbial community structure and function of the extant salt marsh hydrocarbon-degrading microbial populations changed significantly during the study. The relative richness and abundance of phyla containing previously described hydrocarbon-degrading bacteria (Proteobacteria, Bacteroidetes, and Actinobacteria) increased in hydrocarbon-contaminated sediments and then decreased once hydrocarbons were below detection. Firmicutes, however, continued to increase in relative richness and abundance after hydrocarbon concentrations were below detection. Functional genes involved in hydrocarbon degradation were enriched in hydrocarbon-contaminated sediments then declined significantly (p<0.05) once hydrocarbon concentrations decreased. A greater decrease in hydrocarbon concentrations among marsh grass sediments compared to inlet sediments (lacking marsh grass) suggests that the marsh rhizosphere microbial communities could also be contributing to hydrocarbon degradation. The results of this study provide a comprehensive view of microbial community structural and functional dynamics within perturbed salt marsh ecosystems.
authors: Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, United States of America.
authors: Melanie J
authors: MJ
authors: Beazley
authors: Robert J
authors: RJ
authors: Martinez
authors: Suja
authors: S
authors: Rajan
authors: Jessica
authors: J
authors: Powell
authors: Yvette M
authors: YM
authors: Piceno
authors: Lauren M
authors: LM
authors: Tom
authors: Gary L
authors: GL
authors: Andersen
authors: Terry C
authors: TC
authors: Hazen
authors: Joy D
authors: JD
authors: Van Nostrand
authors: Jizhong
authors: J
authors: Zhou
authors: Behzad
authors: B
authors: Mortazavi
authors: Patricia A
authors: PA
authors: Sobecky
mesh_terms: D000407:Alabama; D017753:Ecosystem; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D005843:Geography; D019015:Geologic Sediments; D060851:Gulf of America; D006838:Hydrocarbons / Q000737:chemistry; D020411:Oligonucleotide Array Sequence Analysis; D010578:Petroleum / Q000378:metabolism; D059392:Petroleum Pollution; D016133:Polymerase Chain Reaction; D058441:Rhizosphere; D012492:Salts / Q000737:chemistry; D017422:Sequence Analysis, DNA; D053833:Wetlands
chemical_list: D006838:Hydrocarbons; D010578:Petroleum; D012492:Salts