Investigating microbial carbon transformations in the ultramafic biosphere and carbon fluxes through serpentine spring portals

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The 2014 IPCC report states with high confidence that “Total anthropogenic GHG emissions have continued to increase over 1970 to 2010 with larger absolute decadal increases toward the end of this period”. One proposed method of climate change mitigation is to sequester the carbon dioxide (CO2) in the ultramafic subsurface. However, the biogeochemical carbon cycling and the deep biosphere in the ultramafic subsurface are poorly understood. For example, this CO2 storage method may result in the production of methane (CH4) another powerful greenhouse gas. Pure research in tracing the carbon substrates, transformations, and products in this ultramafic system is required. My ongoing research program contributes to this need with long-term goals of 1) determining biogeochemical processing of carbon in the deep ultramafic biosphere and 2) determining carbon source and flux through portals that connect the deep biosphere and the atmosphere. Funds are requested to study the microbial processes in the high pH (>11) groundwaters associated with serpentinization - a set of reactions between water and ultramafic rock. My 1st set of research questions ask what do the microbes eat, what do they produce, and how do they survive in the ultramafic subsurface. My 2nd set of research questions ask, how do these systems exchange carbon with the atmosphere and what are the mechanisms that form the CH4 that is released from these systems. Canada will benefit from this research through the production of 10 highly qualified personnel - 2 PhD, 3 MSc, and 5 Undergraduate theses. Canadians will also benefit from the advancement in knowledge into carbon substrates, microbial transformations, and inorganic and organic carbon exchanges with the surface, as well as new biological discoveries in how life survives and thrives in high pH (>11) environments. These results could have a huge impact on how we view carbon transformations between short-term and long-term carbon cycles. For example, the use of carbonate rock as a carbon source by Serpentinomonas, a microbe recently discovered to be adapted to the high pH of serpentinized groundwater. This carbon transformation could have large implications on our understanding of the global carbon cycle, because this organism can move carbon out of the long-term carbon cycle to the short-term carbon cycle. Quantifying the flux of powerful greenhouse gases, CH4 and CO2, in and out of portals between the atmosphere and the deep biosphere must be considered, especially since the deep biosphere may house the majority of biomass on the planet and if CO2 sequestration is deployed in these systems.