Opening: Dr. Clara Chan
Featured: Dr. Dan Buckley
Closing: Dr. Colleen Hansel
Opening Keynote Address
“How Microbes Rust the Earth: insights from fieldwork, cultures, biochemistry, and ‘omics”
Friday, April 13, 2018 (4:00 – 5:00 PM)
Fe(II)-oxidizing microorganisms (FeOM) gain energy by Fe(II) oxidation, in the process fixing carbon, cycling nitrogen, and forming highly reactive Fe(III) oxyhydroxides that strongly bind phosphate, metals, and organic carbon. To unravel the environmental influence of FeOM, we have integrated field studies with culture, ‘omic, and biochemical investigations. I will discuss what we’ve learned about marine FeOM, including mat-formers at the Loihi seamount hydrothermal vents, and new pelagic Zetaproteobacteria isolates from the Chesapeake Bay. I will also present recent work on the genetic and biochemical mechanism of Fe oxidation, as well as (meta)genomic and transcriptomic insights into the lifestyle and biogeochemical impacts of FeOM.
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Dr. Clara Chan
Associate Professor of Geological Sciences
Department of Geological Sciences
University of Delaware
cschan@udel.edu
Clara Chan is an associate professor of Geological Sciences at the University of Delaware, specializing in geomicrobiology. Her work focuses on how microbes make minerals, addressing the molecular mechanisms of biomineralization, as well as the unique composition of biominerals. Dr. Chan earned her B. S. in Geological and Environmental Sciences and M. S. in Civil and Environmental Engineering at Stanford, and Ph. D. in Earth and Planetary Science at Berkeley. She was an NSF Ridge 2000 postdoctoral fellow at WHOI and an NSF CAREER awardee, and is currently a 2017-2018 Distinguished Lecturer for the Mineralogical Society of America.
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Featured Keynote Address
“Unearthing the Microbial Ecology of the Soil Carbon Cycle”
Saturday, April 14, 2018 (11:15 – 12:15 PM)
Soils make up one of the largest active carbon pools on the planet. Although soil carbon cycling is mediated by microbes, the microbes that mediate these cycles remain poorly described. We have developed an approach to High-Throughput- Sequencing enabled Stable Isotope Probing (HTS-SIP) that maps substrate assimilation dynamics across thousands of microbial taxa as they occur in soils. We have rigorously quantified the sensitivity and specificity of this approach and have applied it in a variety of contexts to explore the ecological characteristics of microbes that perform major carbon transformations in soils. We find that microbial isotope assimilation dynamics can be used to identify different ecological groups with distinct life history traits. Furthermore, we find that these ecological traits are more predictive than phylogeny or metabolic potential with respect to defining microbial participation in soil carbon cycling. Isotope probing readily couples HTS-SIP with ‘omic techniques and such combined approaches promise to reveal fundamental new insights on the ecology of soil microbes and their impacts on global carbon cycling.
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Dr. Dan Buckley
Professor of Microbiology and Integrative Plant Science
Soil & Crop Sciences
Cornell University
dhb28@cornell.edu
Daniel H. Buckley is a Professor in Microbiology and Integrative Plant Science at Cornell University. He earned a B.S. in Microbiology (1994) at the University of Rochester and a Ph.D. in Microbiology (2000) at Michigan State University prior to joining the Cornell faculty (2003). His research program investigates the ecology and evolution of soil microbiomes with a focus on the causes and consequences of microbial diversity. He is also a recipient of the National Science Foundation Early Career Development award for excellence in research and education (2005). Dan has taught both introductory and advanced courses in microbiology, microbial diversity, and microbial genomics, has served as Director of the MBL Microbial Diversity Course in Woods Hole, MA (2009-2013), and has been a member of the ‘Brock’s Biology of Microorganisms’ author team since 2012. He currently serves on the editorial boards of Applied and Environmental Microbiology and Environmental Microbiology.
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Closing Keynote Address
“Spectroscopic Windows into Mineral-Carbon Interactions”
Saturday, April 14, 2018 (4:30 – 5:30 PM)
Mineral-carbon interactions play important roles in the nucleation, templation, and preservation of minerals within soils and sediments. We have previously employed synchrotron-based spectroscopic techniques to reveal a dominance of proteinaceous organic carbon (OC) within biominerals and natural marine and cave deposits. This association develops during initial nucleation and is stable during mineral evolution and diagenesis. More recently, we expanded this exploration to pelagic marine sediments where we show that while OC in sediment from the oligotrophic North Atlantic and South Pacific gyres is low (<0.1%), levels remain stable to depths of at least 25 meters and ages of 24 million years. This OC, almost entirely extracellular, has a low carbon to nitrogen ratio (C/N) and is dominated (40-60%) by amide and carboxylic carbon. Extractable proteins are present but account for <<1% of total OC. We posit that this OC consists of small, protein-derived molecules enriched in nitrogen and oxygen. Persistence of this peptide-like carbon indicates that modes of carbon preservation beyond molecular structural recalcitrance and oxygen exposure dictate the accessibility of OM to heterotrophic organisms. We estimate that up to 1.5×10 22 grams of organic carbon are sequestered on million-year time scales in oxic pelagic sediment, exceeding current estimates of total global sediment OC and constituting an important, previously overlooked carbon reservoir.
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Dr. Colleen Hansel
Associate Scientist
Department of Marine Chemistry & Geochemistry
Woods Hole Oceanographic Institution
chansel@whoi.edu
Colleen Hansel is an Associate Scientist in the Department of Marine Chemistry and Geochemistry at the Woods Hole Oceanographic Institution (WHOI). Prior to joining the scientific staff at WHOI, Colleen was an Associate Professor at Harvard University, joint between the Department of Earth and Planetary Sciences and the School of Engineering and Applied Sciences. She obtained a B.S. in Geology at California State University, Sacramento in 1997, M.S. in Environmental Chemistry at the University of Idaho in 1999, and Ph.D. in Biogeochemistry at Stanford University in 2004. Colleen was a postdoctoral investigator in molecular microbial ecology at Stanford from 2004-2006. She was an NSF CAREER Awardee and Kavli Foundation Distinguished Speaker. Most recently, Colleen’s research program is focused on coupled elemental cycles and cryptic processes that control the biogeochemistry and health of various marine ecosystems, ranging from coral reefs to hydrothermal vents to the deep biosphere.
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