COG3 Seminar: Jeffrey Marlow (Harvard University)

Jeffrey Marlow (Harvard University)
Friday, November 3, 2017 - 10:00am to 11:00am

“Methane & Microbial Communities: Uncovering New Habitats and Harnessing a Mysterious Metabolism”

Methane metabolisms represent intriguing, challenging targets for researchers studying a wide range of processes, from global carbon flux to engineered, biofuel producing pathways. This talk will spotlight two key aspects of methane metabolism and the techniques used to investigate them in an environmental context.

1) At marine methane seeps, consortia of anaerobic methanotrophic archaea and sulfate reducing bacteria consume vast quantities of methane through tightly coupled metabolisms that facilitate the precipitation of carbonate rock. We show that methanotrophic activity within these rocks continues at a geologically diverse set of actively seeping sites and can be resuscitated in samples from inactive sites - a strategy that signifies an important methane sink but presents long-term challenges due to self-entombment. Carbonate rock samples from a newly discovered seep site have produced the highest rates of methane oxidation measured to date, necessitating a broader review of global methane fluxes and reservoirs.

2) Activity-based analyses at a much smaller scale have revealed several novel post-translational modifications on the keystone anaerobic methane-relevant enzyme, methyl coenzyme M reductase (Mcr). Through changes to the energetic landscape and genetic context, we are working to understand precisely what these modifications could mean and how they modulate metabolic activity in responsive, transcription-independent ways that may represent a novel dimension of functional diversity.

About this Seminar

The Chemical Oceanography, Geology, Geochemistry, and Geobiology Seminar [COG3] is a student-run seminar series. Topics include chemical oceanography, geology, geochemistry, and geobiology. The seminars take place on Fridays from 10-11am in Building E25, Room 119, unless otherwise noted (term-time only).