Comparative genomics of isolates obtained during the Deepwater Horizon Disaster - metabolic plasticity and nutrient acquisition.

Rachael Karns1, Tony Gutierrez2 and Samantha B Joye1, (1)University of Georgia, Department of Marine Sciences, Athens, GA, United States, (2)Heriot-Watt University, United Kingdom
Abstract:
The 2010 Deepwater Horizon oil well blowout had long withstanding effects on the Gulf of Mexico ecosystem but also offered unique opportunities for discovery. Isolated strains in this study include: Alcanivorax sp. TY-5, Alcanivorax sp. TK40, Cycloclasticus sp. TK-8, Halomonas sp. GOS-1, Marinobacter sp. TT-1, Marinobacter SP. TK-36, Pseudoalteromonas sp. TK105, and Thalassospira sp. TK-46(2). All 8 isolated strains show prevalence of genes associated with oil degradation and other metabolisms of interest such as nitrate, methane, DMSP, ammonium, and trace metal metabolism. Most isolates showed pronounced metabolic plasticity as the genome contained machinery for both aliphatic and aromatic hydrocarbon degradation. Such plasticity allows for survival under a range of environmental conditions and makes these organisms well suited to respond to anthropogenic or natural environmental inputs of oil at varying levels. Interestingly, Thalassospira sp. TK-46(2) and Marinobacter sp. TK-36, which were both isolated from the surface slicks, encoded for genes involved in denitrification, suggesting that they may occupy low oxygen niches in the water column such as those associated with particles / marine snow. Spatial variation (deepwater plume vs. surface slick) show differences in metabolic capabilities, which suggest some specialization resulting from the biogeochemical fingerprints of the source environment.