Transporter function and kinetics in uncultivated marine microbes

Collaborators: Tom Richards, University of Exeter; Stefano Pagliara, University of Exeter

The gap between our ability to generate sequence information from the ocean and our ability to interpret it continues to grow. Fording this gap requires novel approaches and collaboration among ecologists, molecular cell biologists, and engineers. We propose to employ a high-throughput screening approach to understand the functional characteristics of one group of proteins—membrane transporters—that determine which chemical compounds are being used and consumed by microbes in the ocean. Transport proteins will be reconstituted in both model systems and model lipid bilayers (giant unilamellar vesicles, GUVs). Using a novel microfluidic platform as a tool, we will identify the substrate(s) transported through each protein, determine their relative affinities, and ultimately calculate quantitative kinetic parameters such as half-saturation constants and saturated uptake rates. This will tell us how sensitive, how fast, and how promiscuous transporters from microbes in different parts of the ocean are, giving us new insights into the compounds that comprise the microbial trade market. These data can be fed directly into trait-based models of how microbes interact and compete for resources, opening new avenues for incorporating metagenomic and metatranscriptomic data into biogeochemical models.  


Matthew Kellom