Metagenomics and metatranscriptomics-based investigation of Lake Michigan bacterioplankton

Lake Michigan is one of the largest freshwater lakes in the world, and second largest of the Great Lakes by volume. Over the last two decades, the lake has witnessed dramatic ecological changes due to the proliferation of the invasive dreissenid mussels. These changes include a reduction in annual primary production that has significant implications for the microbial food web dynamics. The impact of these changes on the labile dissolved organic matter pool (DOM) available for bacterial consumption, and the relative importance of terrestrially derived DOM (t-DOM) for bacterial metabolism across Lake Michigan in the post-mussel period is poorly understood. In this project, we investigated the bacterioplankton dynamics in coastal and offshore regions of southern Lake Michigan using metagenomics and metatranscriptomics. In addition, we evaluated short-term bacterioplankton response to a pulse of terrestrially derived dissolved organic matter (leaf litter leachate) in mesocosms set up using nearshore and offshore lake-water.