Assessing seasonal and potential hydrocarbon and dispersant influences on coastal Alabama microbial populations

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dc.contributor Lu, Yuehan
dc.contributor Mortazavi, Behzad
dc.contributor.advisor Sobecky, Patricia A. Powell, Jessica Tierce 2017-04-26T14:22:24Z 2017-04-26T14:22:24Z 2012
dc.identifier.other u0015_0000001_0001032
dc.identifier.other Powell_alatus_0004M_11234
dc.description Electronic Thesis or Dissertation
dc.description.abstract The catastrophic oil spill on April 20, 2010, in which an estimated five million barrels of crude oil were released into the Gulf of Mexico from a depth of 1544 m, has been postulated to promote a bloom of disease causing Vibrios. To determine if Vibrio populations increased as a result of the Deepwater Horizon oil spill, water column and salt marsh sediment samples were collected from a coastal study site, Point Aux Pins, Alabama beginning in June 2010. During July 2010, tar balls, mousse, and oil sheens were observed at the salt marsh study site. A coupled microbiological and molecular approach was used to determine the frequency of known hydrocarbon degrading strains. PhyloChip 16S microarray analysis indicated significant increases in OTU richness from June 2010 to July 2010. Specifically, we detected high numbers of Gammaproteobacteria. Within the Gammaproteobacteria, Vibrio populations exhibited significant increases in OTU richness from June 2010 to July 2010 in the surficial Inlet sediments. A gene-based functional microarray based analysis, i.e., GeoChip, indicated significant increases in functional gene richness amongst the following categories: antibiotic resistance, metals resistance, organic remediation, stress, and virulence for the salt marsh microbial community. Increases in the abundances of Vibrio-associated genes were also seen amongst the same categories. In addition to the molecular analyses described, lab-based hydrocarbon and dispersant amendments yielded results that suggested that non-weathered MC252 oil stimulates microbial growth, while the dispersant (Corexit 9500) significantly inhibited microbial growth. The weathered MC252 tar balls and mousse that impacted the salt marsh study site were incubated under lab conditions to enrich and culture bacterial strains from samples collected at Point Aux Pins, Dauphin Island and Gulf Shores, Alabama. Preliminary results indicate that presumptive Vibrios comprised 86%, 100%, and 14% respectively from the three sampling sites. The observed shifts in the microbial community at Point Aux Pins, Alabama following the Deepwater Horizon oil spill indicated a rapid response by the salt marsh microbes such that potential hydrocarbon degrading genera were enriched, including Vibrio populations, although the propensity of Vibrios to degrade MC252 requires further investigation.
dc.format.extent 54 p.
dc.format.medium electronic
dc.format.mimetype application/pdf
dc.language English
dc.language.iso en_US
dc.publisher University of Alabama Libraries
dc.relation.ispartof The University of Alabama Electronic Theses and Dissertations
dc.relation.ispartof The University of Alabama Libraries Digital Collections
dc.relation.hasversion born digital
dc.rights All rights reserved by the author unless otherwise indicated.
dc.subject.other Microbiology
dc.title Assessing seasonal and potential hydrocarbon and dispersant influences on coastal Alabama microbial populations
dc.type thesis
dc.type text University of Alabama. Dept. of Biological Sciences Biological Sciences The University of Alabama master's M.S.

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