Seminar: Andrew D. Steen – Dept. of Earth and Planetary Sciences, Univ. of Tennessee, Knoxville

UNC-CH’s Department of Marine Sciences is proud to host a seminar by Andrew D. Steen, Ph.D. This event is scheduled for Wednesday, March 20th, at 3:35pm in room G201 on the ground floor of Murray Hall at the University of North Carolina at Chapel Hill. This seminar will also be broadcast live to both UNC’s Institute of Marine Sciences room 222 and online via Zoom.

Presenter Affiliation: Assistant Professor; Marine Sediment, Carbon, Microorganisms, and Aquatic Ecosystems, Department of Earth and Planetary Sciences, University of Tennessee at Knoxville

Title:  Microbe-organic matter interactions in White Oak River sediments: New techniques and persistent problems

Abstract: Subsurface sediments contain large communities of barely-active microorganisms, many of which are heterotrophs, which subsist extraordinarily using a poorly-understood mix of organic substrates. In this talk, I’ll discuss investigations of microbe-organic matter interactions in sediments of the White Oak River. Enzyme assays indicate that subsurface microorganisms there use extracellular enzymes to access complex organic carbon, even though one could raise a reasonable argument that that shouldn’t be possible. I’ll also discuss some of the challenges involved in metagenomic approaches to trying to understand how microorganisms in those sediments get their dinner. Briefly, 60-80% of putative genes in sediments of the White Oak River and other environmental samples lack reliable annotation, so metagenomics inevitably provide a limited window into the function of those communities. Finally, I’ll describe work toward the development of new, machine-learning-based techniques to avoid (or at least to mitigate) those challenges.