This project will evaluate the impact and evolution of microbial communities impacted by the ongoing Deepwater Horizon oil spill in the Gulf of Mexico. The project involves a collaborative team that brings together strengths in all the requisite areas. Dr. Pam Morris is a highly qualified marine microbiologist and Dr. Joe Suflita is an expert in the microbiology of hydrocarbon-impacted microbial communities. This is a timely and cutting edge application of the latest types of analyses that will combine microbial metabolomic and metagenomic approaches to provide meaningful answers regarding the response of the microbe communities in question.
The work will take advantage of on-going sampling efforts on-site and have already organized the appropriate arrangements to have the samples collected in a manner conducive to the proposed microbial work. To do this, the PIs are working closely with two national/federal laboratories on this effort: Dr. Terry Hazen (US DOE Lawrence Berkeley National Laboratory) and Dr. Richard Coffin (Naval Research Laboratory). This will allow sampling of both contaminated in-plume and coastal sediment samples, as well as uncontaminated control samples. Thus, the project will bring to bear very high-tech approaches in a manner that will have direct ecological relevance.
Broader Impacts: The Deepwater Horizon oil spill is now considered the largest offshore spill in U.S. history. This project will generate important information on the impacts of the spill on specific natural microbial systems. As such, it is an unfortunate, yet useful, experimental opportunity to develop solid scientific understanding of such events. The project should help provide the knowledge required for fact-centered policy decisions regarding exploration and drilling enterprise. This is a new collaboration between investigators from two EPSCoR states (South Carolina & Oklahoma), and brings together their complementary expertise. The PIs each have long histories of training and education at all levels. Though the short timeline precludes some of the normally anticipated activities, the PIs will endeavor to find research opportunities, especially for undergraduates, to participate in the research. Clearly, such a research experience could prove both exciting and influential.
Marine deep-sea sediments house abundant and diverse microbial communities that are proposed to influence large-scale geochemical processes. These processes include the biotransformation and mineralization of numerous petroleum constituents. While microbial communities in the Gulf of Mexico are thought to be responsible for the intrinsic bioremediation of crude oil released by the Deepwater Horizon oil spill, much of what has been shown is the enrichment of aerobic, oil-degrading bacteria in deep-seawater habitats. However, relatively little is known about the response of microbial communities in deep-sea sediments, where low oxygen levels may hinder microbial oil degradation. In our study, we examined the hypothesis that increased hydrocarbon exposure in deep-sea sediments results in an altered sediment microbial community structure that reflects the potential for oil biodegradation under low oxygen conditions. We explored this hypothesis using metagenomic analysis and metabolite profiling of deep-sea sediment samples following the Deepwater Horizon oil spill. The presence of aerobic microbial communities and associated functional genes was consistent among all samples, whereas a greater number of Deltaproteobacteria and anaerobic functional genes were found in sediments closest to the Deepwater Horizon blowout site. Metabolite profiling also revealed a greater number of putative oil degradation metabolites in sediments surrounding the blowout zone relative to a background site located 127 km away. Our findings suggest that increased exposure to hydrocarbons enriches for Deltaproteobacteria, which are known to be capable of anaerobic hydrocarbon metabolism. We also provide evidence for an active microbial community metabolizing aromatic hydrocarbons in deep-sea sediments of the Gulf of Mexico.
