I-Corps: Microbially-derived, Precipitated Calcium Carbonates for Industrial Applications

该I-Corps项目更广泛的影响/商业潜力是在环境条件下使用微生物沉淀法开发沉淀碳酸钙。微粒（微米级）碳酸钙在造纸、热塑性塑料、密封剂和粘合剂以及油漆的制造中具有许多工业用途。目前，生产PCCs需要烧结（加热至1，000 °C），每年向大气中释放约162千吨二氧化碳（CO2），这是一种温室气体。人为排放的温室气体对我们的地球构成了重大威胁，其气候影响将扰乱社会并破坏重要的生态系统服务。拟议的微生物工艺绕过了烧结，并在生产PCCs时封存了CO2。 这项技术代表了减少二氧化碳排放的新目标，而碳捕获信用额可能会增加每年价值56亿美元的市场的利润率。该I-Corps项目基于微生物代谢途径的开发，该途径使用细胞钙离子（Ca 2+）稳态来启动来自大气CO2的微米级碳酸盐的沉淀。通过了解调节这一过程的代谢途径和遗传控制，有可能调整微生物培养物以产生各种PCC，包括使用现有技术无法制造的PCC。由于在该系统中产生的碳酸盐来源于大气CO2，这不仅代表PCC生产的绿色解决方案，而且还具有成为先前未识别的碳捕获机制的潜力。此外，所提出的技术在目前的微生物沉淀碳酸钙技术中是独特的，因为不需要开采石灰石;也不利用细菌脲解。相反，使用所提出的方法生产的PCC中的碳酸盐的来源是具有净碳捕获的大气CO2。通过改变生长的化学条件，有可能产生具有多种特性（颗粒大小、颗粒形状、表面化学和表面积）的PCC，这些特性在许多工业应用中非常重要。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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. 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.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.