EESS talk on "Genetic elements in Microorganisms with an Ancient Metabolic Pathway"

Microbial communities regulate most of Earth’s methane cycling, yet the genetic mechanisms behind the processes remain poorly understood. In this talk, I will present the discovery of giant extrachromosomal elements termed “Borgs”, which likely expand the metabolic capacity of their methane-oxidizing archaeal hosts. I will further provide evidence that Borgs may in fact represent giant archaeal viruses. I will then describe our project on pristine peatlands in Sweden, presenting genome-resolved community profiles and mobile genetic elements with a focus on methane-cycling consortia across depth gradients. Finally, I will discuss genetic elements within Borgs and within the genomes of key methanogens, specifically rapidly evolving tandem repeats, which we propose are overlooked but important regulators of microbial methane cycling. Together, these findings identify previously unrecognized genetic drivers within the anaerobic one-carbon cycle with potential consequences for ecosystem-scale methane fluxes.  

Marie C. Schölmerich joined ETH Zürich in August 2023 as a Tenure Track Assistant Professor of Environmental Microbiology at the Institute of Biogeochemistry and Pollutant Dynamics within the Department of Environmental Sciences. Born in Berlin, Germany, in 1989, she received her B.Sc. in Biochemistry from Leipzig University, Germany, in 2011, and her M.Sc. in Molecular Biosciences in 2013, and Ph.D. in Biology in 2018 from Frankfurt University, Germany. She was a junior group leader at Hamburg University, Germany, from 2018 – 2020 and later went on to become a Postdoctoral Fellow at UC Berkeley, CA, USA, a position she held from 2021 to 2023.