SMB Events and Seminars
SMB Faculty Seminar speaker Dr. Harold Drake: Darwin's Invertebrates: A Transient Anoxic Microbial Oasis
Dr. Harold Drake
Chair, Department of Ecological Microbiology
University of Bayreuth, Germany
Hosted by Dr. John Alderete
"Darwin's Invertebrates: A Transient Anoxic Microbial Oasis"
Although their subsurface lifestyle make earthworms an unseen feature of the terrestrial biosphere, Charles Darwin was fascinated by the capacity of these invertebrates to alter terrestrial habitats and documented their unique bioengineering skills in his final publication. However, Darwin was not aware that the impact of earthworms is due in part to their effect on the activities of ingested soil microbes during gut passage. Anoxia and a tidal wave of nutrients in the alimentary canal trigger explosive levels of anaerobic activities, leading to the in vivo emission of molecular hydrogen and the greenhouse gases nitrous oxide and methane by the earthworm. The complex fermentation-driven food web in this model gut ecosystem includes diverse facultative aerobes and obligate anaerobes, and hydrogen-producing fermentations in the gut have the potential to drive both methanogenesis and acetogenesis. These collective findings illustrate that the alimentary canal of the earthworm (a) constitutes a mobile and dynamic anoxic micro-compartment that has novel impact on the soil microbiome and (b) augments the production of greenhouse gases and the cycling of elements in the terrestrial biosphere. Functional parallels to other greenhouse-gas-emitting ecosystems will be presented.
Biosketch of Speaker
H. L. Drake is Chair of the Department of Ecological Microbiology at the University of Bayreuth in Germany and is Editor-in-Chief of the journal Applied and Environmental Microbiology. His work is focused on (a) the physiology and ecology of anaerobes, (b) invertebrate microbiology, and (c) the intermediary ecosystem metabolism of environments that emit the greenhouse gases methane and nitrous oxide.