The Role of C1-Metabolism in the Estuarine Carbon Cycle: A Microbe to Ecosystem Study

Estuaries, where rivers meet the sea, are dynamic environments that help move and transform carbon in the natural world. However, we still do not fully understand how single carbon (C1) compounds like methane and methanol are cycled in these systems, or the role that microscopic organisms play in controlling these processes. In this project the investigators are determining how microbes in the Neuse River Estuary and Pamlico Sound in North Carolina influence the movement and breakdown of C1 compounds, improving understanding of how estuaries contribute to the broader carbon cycle. In addition, the investigators are providing hands-on research opportunities for graduate, undergraduate, and high school students, training the next generation of environmental microbiologists and biogeochemists. This project investigates the role of one-carbon (C1) metabolism, focusing on methane and methanol, in estuarine carbon cycling within the Neuse River Estuary and Pamlico Sound. The overarching goal is to quantify the stocks and oxidation rates of C1 compounds, identify the microbial communities responsible for their turnover, and characterize the physiological traits that influence methanotroph and methylotroph distributions across estuarine gradients. The investigators hypothesize that methane and methanol, despite low ambient concentrations, act as high-flux currencies within the estuarine carbon cycle, exerting underappreciated influence on microbial food webs. They are integrating spatiotemporally resolved field surveys, laboratory experiments on growth kinetics and metabolic versatility, and the development of a cell-scale reaction-transport model to link microbial physiology with biogeochemical processes. Through this comprehensive approach they are improving predictive models of estuarine responses to environmental change and advance understanding of microbial controls on carbon cycling in estuarine systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.