Conferences - Seminars

  Tuesday 24 April 2018 12:15 - 13:15 GR A3 32

EESS talk on "A fresh look at microbial methane cycling in lacustrine and marine sediments"

By Dr Mark Lever, professor, Environmental Microbiology, Department of Environmental Systems Science, ETHZ

Methanogenic archaea are among the biochemically and physiologically best studied groups of microorganisms and, by producing the greenhouse gas methane, play an important role in regulating global climate. Research has shown these Archaea to be widespread in anoxic freshwater and marine sediments. Yet, many open questions remain. Genomic analyses on recently discovered archaeal phyla have indicated that more groups of Archaea perform methanogenic metabolism than previously thought. The ecology of methanogens is also not well understood. For unknown reasons, methanogenic communities vary greatly between sedimentary habitats, even ones that utilize the same energy substrates. It is also not known why in certain habitats H2+CO2 and in others acetate is the dominant energy source of methanogens. While methanogenic temperature ranges have been studied in many laboratory cultures, the extent to which these ranges translate to the environment is also unknown. I will present examples of how my group is shedding light on the above unknowns. Detailed quantitative and phylogenetic surveys on methanogens, including members of newly discovered groups, will be presented across a wide range of freshwater and marine sediments varying in dominant methanogenic energy substrate, redox potential, composition of partner organisms, temperature, and energy flux. I will offer a synopsis of potential main drivers of methanogenic community composition and outline important questions for future research.

Short biography:
Mark Lever is an environmental microbiologist with a mixed background in ecology, microbiology, and biogeochemistry resulting from a Masters in ecosystem ecology from Boston University, a PhD in microbial biogeochemistry from the University of North Carolina at Chapel Hill (both USA), and postdoctoral research in geomicrobiology at Aarhus University (DK). His research is driven by his interest in the role of microorganisms (Bacteria and Archaea) in Earth's biogeochemical cycles, in particular the carbon cycle. Through his research, he pursues scientific questions of broad significance concerning the mechanistic (how?) and quantitative (how much?) influence of microorganisms on the short- and long-term fate of organic carbon in aquatic sediments. He studies natural freshwater and marine sediments, from the surface to meters and kilometers below, and perform field and laboratory experiments, covering time scales from current human activity to Earth's ancient past.

Organization EESS - IIE

Contact Prof. Rizlan Bernier-Latmani, EML

Accessibility General public

Admittance Free

This event is internal