Investigating biogeochemical controlled redox gradients in terrestrial and aquatic ecosystems

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The development of biogeochemical gradients is often dependent on a microorganism’s ability to physically alter and interact with its chemical surroundings. In many cases the activity of microorganism will directly impact the chemical conditions in both surface and subsurface water environments controlling the fate of nutrients and contaminants alike. However we face several daunting challenges when defining the bioremediation strategy of choice. Often the application is not straightforward since in many cases the anthropogenic disturbance has altered the local landscape creating problems when defining the remedial end goal. Questions arise such as what are the baselines or reference systems that can be used and hopefully applied to support a remedial action of choice. What indices can be used to study the long term and short-term controls on the mobility, cycling, and bioavailability of toxic metals and organic contaminants? For example, studies in our lab have shown that mineral dissolution in the presence of bacteria can lead to specific pathways of metal release and will control the fate of these elements dependent on the metals solubility and how the bacteria utilize this aspect during its metabolism. Our research has observed this in both laboratory and applied industrial applications. This research program will continue to focus on the interactions between mineral systems/sediments and bacteria with an emphasis on elucidating mechanistic chemical pathways used by reducing and oxidizing forms of bacteria at the sediment water interface. This research will be hypothesis driven and use novel microbial and analytical techniques in both laboratory and field based programs to address these research questions. The information will be applied to support comprehensive models for biogeochemical cycling in natural and anthropogenic stressed environmental ecosystems. In addition research within this program will support the development new environmental tracers to track. Maintaining sustainable freshwater resources are directly tied to Canada’s continued socio-economic success (i.e. agriculture, industry, people, and tourism). This research program will enhance our understanding of how bacteria control metal release in natural ecosystems as well as those impacted by mining sector and anthropogenic inputs.