3.5 Billion Years of Microbial Community Interactions

Speaker: John Stoltz, Center for Environmental Research and Education at Duquesne University

Life has existed on Earth for over 3.5 billion years. We know this through the preserved remains of microorganisms, as microfossils and microbialites such as microbially induced sedimentary structures (MISS) and stromatolites. Over half of the elements in the periodic table have some biological role, many with complex biogeochemical cycles that are microbially mediated. The global microbiome encompasses a wide range of environments including deep in the Earth’s crust, with an estimated population of ~1030 cells and more than a trillion species. Deep sequencing projects have revealed hitherto unknown phyla and “microbial dark matter.” The discoveries of conductive pili and cable bacteria have shown that microbes can transfer electrons to and from external sources (a process known as electrotrophy), sometimes over significant distances. This talk focuses on John Stolz’s research on metal munching microbes and the microbial communities of living stromatolites from the Bahamas and Shark Bay, Australia. Stolz will discuss how the intimate interactions of microbes with their environment that started way back in the Archean has helped forge the world we know today.