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Please join us Thursday, January 26, 2023 for our Winter Seminar Series with our guest speaker: Magdalena Osburn. A special thanks to Professor Paula Welander for bringing this speaker to us for this seminar.
DEPARTMENT OF EARTH SYSTEM SCIENCE
SEMINAR SERIES WINTER 2023
12:00 - 1:20pm
Thursday, January 26, 2023
Mccullough Building (Room 115)
Magdalena Rose Osburn, Ph.D
Associate Professor, Curriculum Chair, and Seminar Coordinator from Northwestern University
“Journey to the center of the Earth: habitability and geobiology of two distinct subsurface realms”
The subsurface contains a vast biosphere, permeating the land beneath continents wherever temperature and porosity limits permit. While the numerical magnitude of this biosphere has come into focus over the last decades, the life strategies and metabolisms employed by microbes to inhabit subterranean environments and how they might vary with depth remain obscure. Here I present recent work from my group from two subsurface locations, both aimed at understanding microbial life strategies, but applying very different methods. The first study targets environments within a basaltic lava cave system using a lipid biomarker and compound-specific carbon isotope approach. We find evidence for active carbon fixation, despite abundant surface-derived organic carbon, occurring in microbial taxa commonly considered heterotrophic. The second portion of my talk describes some of our work within the deep subsurface, specifically the Deep Mine Microbial Observatory, hosted in the former Homestake gold mine. Establishment of this observatory allowed us to produce a four-year record of subsurface geochemistry and microbial diversity. We combine thermodynamic modeling of metabolisms, metagenomic sequencing, and in situ cultivation to better understand the behavior and potential of intraterrestrial microbes with depth in the crust. Combined these two study areas illustrate the heterogeneity of subsurface habitats and demonstrates widespread potential for life independent from surficial biomes.
Magdalena Osburn is an isotope organic geobiologist interested in understanding how microbes interface with the Earth and how we can trace signatures of biological activity in modern and ancient environments. Her lab uses a diverse suite of tools to answer these questions including analysis of lipid biomarkers, organic isotopes, microbial cultivation, and DNA sequencing all stemming and grounded in detailed characterization of field sites. The lab focuses on “extreme” microbially dominated environments such as deep mines, limestone and basaltic caves, hypersaline lakes, hot springs, and Greenland.
She is an associate professor at Northwestern University.
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