The primary components of "natural gas" are hydrocarbon gasses including methane, ethane, propane and butane. These gasses are emitted at high concentrations from "hydrocarbon seeps", regions of the ocean floor where hydrocarbon gasses and oils percolate out due to the geology, chemistry and hydrology of the underlying sediments and rock layers. Seeps host tremendous microbiological communities that are capable of degrading many of the hydrocarbons and other compounds (such as sulfide and sulfate) found in these habitats. Significant research has focused on determining the fate of methane, sulfate and sulfide, however very little is known about the fate of ethane, butane and propane at seeps. While geochemical evidence points to the existence of microbes that degrade ethane, butane and propane, no microbial species or community has yet been identified or cultured that is capable of consuming these gasses in seep conditions (e.g. with little or no oxygen). This research aims to characterize, quantify and culture microbes capable of anaerobically consuming ethane, butane and propane in deep sea hydrocarbon seeps. To that end, a suite of quantitative molecular biological and geochemical techniques will be used to study the microbial ecology and biogeochemistry of seeps in the Gulf of Mexico. In addition, high-resolution laboratory studies using a novel 'artificial seep' will be used to determine the rates of hydrocarbon degradation, the relationship to sulfate reduction, and the identity and isolation of microbes or microbial assemblages responsible for consuming these gasses.
Despite their critical role in supporting life on Earth, our understanding of microbial physiological and biochemistry is meager. This interdisciplinary research aspires to further our understanding of novel microbial taxa (in particular their physiology and biochemistry), their role in mediating hydrocarbon degradation, and their contribution to global marine carbon cycling. This research will support the development of an educational program designed to teach students about how microbes govern biogeochemical cycles, and support the involvement of disadvantaged high school and college students in marine science and microbiological research. In collaboration with a state aquarium, this research will also contribute to the development of the world''s first hydrocarbon seep exhibit.
