Starter Grant: Isolation of Novel Metal-Oxidizing Bacteria at a Deep Subsurface Oxic-Anoxic Interface

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

This postdoctoral starter grant (following completion of a NSF Postdoctoral Fellowship in Microbial Biology) has been awarded to Alexis Templeton, a new assistant professor at CU-Boulder, to culture and characterize novel thermophilic, metal-oxidizing microorganisms that thrive thousands of feet below the surface at Henderson Mine, Colorado. During 2006, deep, ancient, hot and anoxic fluids that issue from boreholes beneath the active molybdenum mine were accessed. The fluids are rich in dissolved metals, such as iron and manganese, which undergo oxidation and sustain microbial communities at the oxic/anoxic interfaces created when the fluids issue into the open tunnels. These subsurface interfaces provide an excellent opportunity to search for forms of microbial life that exhibit a direct dependency upon the local fluid and mineral chemistry. This may be one of the most abundant sources of life on Earth, and yet many fundamental controls on the rates and mechanisms of rock-supported chemosynthesis are unknown. Both the ancient waters and the new mineral products will be used for the cultivation of potentially ubiquitous, diverse and previously unknown thermophilic iron- and manganese-oxidizing microbial organisms. Substantial cultivation efforts will be tightly coupled with geochemical characterization of the local fluid and mineral chemistry using an extensive suite of chemical, spectroscopic and microscopic techniques. Success in culturing efforts using ancient fluids from the deep subsurface should provide significant contributions to our understanding of which microorganisms can survive near the known limits of life, and how they do it. The other major goal of this proposal is to train undergraduate and graduate students with interdisciplinary backgrounds in Biochemistry and Molecular Biology/Chemistry, respectively) in the fundamentals of microbial biology and the direct feedbacks with the geological and geochemical context of a rock-hosted environment.