NSF Award
2113742
The broader impact/commercial potential of this I-Corps project is the development of precipitated calcium carbonates (PCCs) using microbial precipitation under ambient conditions. Particulate (micron scale) calcium carbonate has a number of industrial uses in the manufacture of paper, thermoplastics, sealants and adhesives, and paints. Currently, the production of PCCs requires sintering (heating to >1,000°C), which releases an estimated 162 kilotons of carbon dioxide (CO2), a greenhouse gas, into the atmosphere annually. The anthropogenic emission of greenhouse gases represents a significant threat to our planet, with climate impacts that will disrupt societies and damage important ecosystem services. The proposed microbial processes by-passes sintering and sequesters CO2 in the production of PCCs. This technology represents a novel target to reduce CO2 emissions, while carbon capture credits may increase profit margins in a market that is worth $5.6 billion annually. <br/><br/>This I-Corps project is based on the development of a microbial metabolic pathway that uses cellular calcium cations (Ca2+) homeostasis to initiate the precipitation of micron-scale carbonates sourced from atmospheric CO2. By understanding the metabolic pathways and genetic controls that regulate this process, it has been possible to tune the microbial cultures to produce a variety of PCCs, including PCCs that cannot be made using existing technologies. As the carbonates produced in this system are sourced from atmospheric CO2, not only does this represent a green solution to PCC production, but it also has the potential to be a previously unidentified mechanism of carbon-capture. In addition, the proposed technology is unique within current microbially-precipitated calcium carbonate technologies in that mined limestone is not required; nor is bacterial ureolysis utilized. Instead, the source of the carbonates in the PCCs produced using the proposed method is atmospheric CO2 with net carbon capture. By varying the chemical conditions for growth, it may be possible to generate PCCs with a variety of characteristics (particle size, particle shape, surface chemistry, and surface area) that are important in many industrial applications.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
