Quantifying the biogeochemical consequences of viruses in marine food webs

Pasulka Alexis L, Studio City CA

Investigators

Abstract

Over the past decade, marine viruses (bacteriophage and eukaryotic viruses) have become increasingly recognized as juggernauts in ocean food webs, influencing microbial community structure, shaping the trajectory of carbon and nutrient flows, and serving as agents of gene transfer. While the collective impact of viral activity in the ocean has become more apparent over the last decade, our current understanding of the biogeochemical impact of marine viruses is limited by our ability to measure exchanges of energy between viruses and their environment. This research aims to develop techniques to examine virus-host interactions at the resolution of individual viral particles. These single-cell resolution approaches will provide the unprecedented ability to fill critical gaps in our understanding of the biogeochemical impact of viruses in ocean ecosystems. In addition, research results will be shared broadly and used to increase diversity in the ocean sciences. Through the implementation of interactive microbial-focused lesson plans into both a formal (high-school biology classroom) and informal (aquarium/science center) setting, the investigator aims to increase the number of students from under-represented groups that successfully transition from high school to college with an interest in science. By integrating marine viruses into food web studies, we can better understand how interactions with their microbial hosts influence ecosystem structure, biogeochemical cycling, and potential responses of ecosystems to future climate changes. The application of fluorescence-based activity assays and single-cell stable isotope analysis to marine viruses will open new doors to studying these microscopic entities in our oceans. More specifically, the use of a fluorescence-based click chemistry approach to study marine viruses would provide a relatively inexpensive and fast way of determining the fraction of free virioplankton that are actively involved in cell lysis over a defined set of conditions and time period. Furthermore, the development of nanoscale secondary ion mass spectrometry (nanoSIMS) techniques for studying marine viruses will allow us to track C and N exchange between viruses and host microorganisms and ultimately enable the direct quantification of the proportion of active virioplankton involved in the recycling of new primary production vs. those targeting marine heterotrophs. Technological and methodological advancements are key to the success of oceanographic research as they enhance our understanding of organisms and processes in ocean ecosystems. By developing new tools to study marine viruses, we can continue to make progress in our ability to link small-scale processes (e.g., single-cell level microbial interactions) with large-scale biogeochemical cycles and climate.