Please join us Thursday, April 13, 2023 for our Spring Seminar Series with our speaker: Emily Zakem. 

Department of Earth System Science

Seminar Series Spring 2023

12:00-1:20pm 

Thursday, April 13th, 2023

McCullough Building (Room 115) 

Emily Zakem 

Staff Associate | Principal Investigator

Department of Global Ecology 

Carnegie Institution for Science 

"Emergent Biogeography and Function of Marine Microheterotrophs in a Trait-Based Model"

Microorganisms control biological carbon storage in the ocean. How microbial communities will respond and feedback to anthropogenic carbon emissions limits our understanding of global change. Here, we present a trait-based framework that resolves the diversity of microheterotrophs that transform organic carbon into CO2 in the ocean. We also analyze microbial genetic sequencing information along a pole-to-pole transect through the Pacific ocean by aggregating taxonomic guilds at a level that represents function. Our theoretical framework dovetails the established copiotrophic vs oligotrophic delineation of heterotrophic bacteria with variable organic substrate lability to reveal an uninuitive pattern: a transition from a dominance of faster-growing, yet “oligotrophic” types near the surface to slower-growing, yet “copiotrophic” types consuming less labile substrates at depth. This vertical pattern is consistent with observed biogeographies and genome-based proxies for growth optimization of key microheterotrophic guilds. Results provide a framework critically needed to understand how microbially driven carbon cycling will change in a warming ocean.

Biography

Emily Zakem is a Principal Investigator at the Department of Global Ecology at the Carnegie Institution for Science. Previously, she was a Simons Foundation Postdoctoral Fellow in Marine Microbial Ecology at the University of Southern California in Los Angeles. She completed her Ph.D. in Climate Physics and Chemistry in the Department of Earth, Atmospheric and Planetary Sciences at the Massachusetts Institute of Technology. In her research, she aims to improve understanding of the connections between microbial ecosystems, global biogeochemistry, and the climate system. She uses theory and mathematical models to understand how microbial ecology drives carbon, nitrogen, and other elemental cycling.

Website

https://ezakem.scripts.mit.edu/emilyzakem/

https://dge.carnegiescience.edu/labs/zakem-lab