Bacterial mineral interactions

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Microorganisms play an important role in catalyzing a wide array of biogeochemical processes that affect the composition of our soil, air and water.  Understanding these phenomena requires a multidisciplinary approach focussed on the contribution of the ubiquitous microorganism (bacteria are everywhere!). The goal of my research program is to bridge the boundary between earth science and microbiology to improve our understanding of fundamental earth system processes and to apply this knowledge to benefit humanity.   Geologists have shown that gold nuggets can grow as they move downstream.  However, as gold containing minerals break down at the earth's surface, these mineral weathering processes produce thiosulphate, a chemical that has the capacity to dissolve gold.  Lithotrophic (rock-eating) bacteria, which also live in these environments, can consume thiosulphate, forming new gold crystals.  I am interested in the role of these lithotrophic bacteria in making gold nuggets.  These biogenic crystals often possess unique chemical properties as well.  My hope is that the biological processes that we are working on can produce chemically important minerals, creating new, environmentally friendly bacteriological nanofactories.   Prior to 2.5 billion years ago, the Earth did not possess a significant amount of oxygen in its' atmosphere.  I am interested in developing a laboratory model to try and determine the geochemical and mineralogical processes that occurred as cyanobacteria (the precursors to plants) created this oxygen, beginning a new era in Earth's history (in which we are now playing a central role).     The history of life on Earth is preserved in a wide range of fossils.  While individual bacteria do not produce significant fossils, they have contributed to the pyritisation (fossilisation) of larger organisms.  I am interested in improving our understanding of these processes so that when we see these fossils, it will tell us more about the history of Earth.  These bacteria are also critical to the bioremediation of metal pollution.  Improving our understanding of how they've worked in the past may help us make them work better for us today.