ECIMMEE Project: Marine Rubiscos are the key to understanding carbon fixation in the oceans
The process of taking air (CO2) and turning it into living matter (e.g. plants and algae) is the fundamental building block for life on Earth. Almost all of this conversion is catalyzed by the world’s most abundant enzyme, Rubisco, of which half of this productivity occurs in the oceans across a diverse array of environments and organisms. Marine CO2 fixation influences not only marine ecosystems and biogeochemical cycles, but also has a major effect on global climate. However, research on Rubisco has predominately focused on terrestrial plants at 25°C, and we only have a rudimentary understanding of Rubisco function in marine organisms and environments. This project aims to uncover the diversity of marine Rubiscos across a wide range of microbes including eukaryotic phytoplankton, bacteria and archaea. Our new understanding of Rubisco, coupled with laboratory and field measurements of CO2 fixation by phytoplankton, will enable us to understand the underlying mechanisms that constrain rates of phytoplankton photosynthesis across ocean habitats. In addition, genetic sequences of Rubisco will be used to reconstruct its evolutionary history over 3 billion years to identify how this ancient enzyme has adapted and enabled marine primary producers to thrive in diverse and changing environments.
Jodi Young is a Future of Ice assistant professor within the School of Oceanography at the University of Washington (UW) and a faculty member of the UW astrobiology program. Her research focuses on understanding the underlying mechanisms of photosynthesis in marine microbes. In particular, she investigates how the adaptation and function of enzymes interact with microbe physiology to constrain CO2 fixation rates in widely diverse environments and organisms. Half of Earth’s photosynthesis occurs in the oceans, greatly influencing biogeochemical cycles that form the base of marine ecosystems. Understanding the mechanics and variability of marine photosynthesis will enable more accurate predictions of the response of the marine biosphere to future change. Her research includes exploring photosynthesis in extreme environments, such as within sea ice in the polar oceans. These productive regions are experiencing rapid change and also act as an analog for life on exoplanets. Young received a B.Sc in marine sciences and biotechnology from Murdoch University, Australia (2000) and a D.Phil in Earth sciences from Oxford University (2011). During her D.Phil she studied the adaption of CO2 fixation in phytoplankton over geological timescales. From 2011-2015 she was a postdoctoral researcher at the Department of Geosciences at Princeton University, where she investigated marine photosynthesis in polar environments, taking part in a two-month field study of algal photosynthesis in Antarctica.