Research Seminar, David Malcolm: Observing Bacterial Community Shifts with Metagenomics

Abstract: Globally, blue carbon ecosystems (such as tidal wetlands, seagrass meadows, and estuaries) are widely recognized as efficient sites of atmospheric carbon sequestration, storing carbon in organic-rich soils¹. Within these environments, bacterial metabolism is a significant component of carbon flow, contributing to an estimated 95% of blue carbon formation². Though the estimation of carbon fluxes into and out of blue carbon microbial communities has seen extensive research since 2009 when the term was coined, far less effort has been made to characterize the ecological network of these microbial communities. Working as part of the larger Ecocosm project to study sustained estuarine microbial communities in lab conditions, this study aims to utilize metagenomic methods to taxonomically identify the members of the microbial community of the Neuse River Estuary (Coastal North Carolina) and observe trends in community dynamics as the community is subjected to different experimental lighting conditions. Though analysis of the data is still ongoing, preliminary results have offered interesting abundance trends in significant marine taxonomic groups, as well as a set of 166 metagenome-assembled genomes (MAGs) from which metabolic capabilities can be elucidated. Soon we aim to incorporate data from the second running of the Ecocosm experimental method, contributing an additional set of taxonomic abundance data and potential MAGs. Through the incorporation of these data, we aim to not only replicate the trends observed in our Ecocosm I run, but also compare the two runs on a seasonal basis, comparing the summer (Ecocosm I) and winter (Ecocosm II) communities.