(Georgia Institute of Technology, 2014-05-02)
Cartee, John C.
The structure and diversity of microbial communities associated with the oxygen minimum zone located on the Louisiana Shelf in the northern Gulf of Mexico deadzone was studied through amplicon analysis of the 16S rRNA gene. The oxygen minimum zone located on the Louisiana Shelf is a region of reduced oxygen concentrations, containing dynamic and diverse microbial communities that thrive under microaerophilic and anaerobic conditions. The Gulf of Mexico contains one of the largest zones of coastal hypoxia (region of reduced dissolved oxygen concentrations) which is dominated by complex microbial communities that contribute to marine biogeochemical cycling on a global scale. Here we used next-generation sequencing technology to track the microbial community at a single site over a day-night (diel) cycle. Two varying depths were used to collect seawater samples which were used for amplicon sequencing of the 16S rRNA gene (rDNA). By comparing our genetic data to coupled measurements of oxygen and nutrients, we determined how microbial community composition changes in response to day-night gradients and to environmental variation in oxygen and substrate availability.