Biogeochemistry and the Subsurface Biosphere
Our laboratory undertakes a number of studies of natural and built environments using genomic tools to describe microbial community functions, and geochemistry approaches to measure their consequences.
Serpentinites represent a vector for the transport of reducing and deeply sourced carbon from the mantle into the biosphere. Our ongoing work is tracking the composition and source of carbon-bearing compounds in marine and terrestrial serpentinizing environments, and the ways in which microbial populations impact the flux of these compounds. Recently, we have also examined sulfur biogeochemistry in serpentinites, as the transport of sulfur (and paleo-seawater) during the weather of oceanic crust and its' accretion onto the contents represents a mechanism connection marine and terrestrial environments.
Biology meets Subduction
An international team of researchers, using seed funding from the Deep Carbon Observatory has studied the flux of volatiles (H2O, CO2, etc) from above subduction zones. Work in Central America showed that a substantial proportion of carbon previously assumed to be buried in the deep Earth was actual "trapped" in the forearc region. Ongoing work is investigating the links between volatiles and the deep biosphere in Central and South America.
Evolutionary Ecology in Extreme Environments
Extreme environments challenge microbial physiology by shaping adaptations to cope with variations in energy flow, nutrient acquisition, cell survival, and biomolecular repair. We investigate microbial adaptations to environmental extremes (pH, pressure, temperature) by studying naturally occurring extreme environments. We study how microbial interactions within these communities, including horizontal gene transfer shaping genome composition and evolution.