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

I-Corps项目更广泛的影响/商业潜力是在环境条件下利用微生物沉淀开发沉淀碳酸钙（PCCs）。颗粒（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有许多工业用途。目前，PCCs的生产需要烧结（加热到1000°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星球构成了重大威胁，其气候影响将扰乱社会，破坏重要的生态系统服务。提出的微生物过程绕过烧结和封存二氧化碳在生产PCCs。这项技术代表了一个减少二氧化碳排放的新目标，而碳捕获信用额度可能会增加这个每年价值56亿美元的市场的利润率。这个I-Corps项目是基于微生物代谢途径的发展，该途径利用细胞钙离子（Ca2+）稳态来启动来自大气二氧化碳的微米尺度碳酸盐的沉淀。通过了解调节这一过程的代谢途径和遗传控制，已经有可能调整微生物培养以产生各种PCCs，包括使用现有技术无法制造的PCCs。由于在该系统中产生的碳酸盐来源于大气中的二氧化碳，这不仅代表了PCC生产的绿色解决方案，而且也有可能成为一种以前未被发现的碳捕获机制。此外，拟议的技术在目前的微生物沉淀碳酸钙技术中是独一无二的，因为不需要开采石灰石；也没有利用细菌解尿。相反，使用提议的方法生产的PCCs中碳酸盐的来源是大气中的二氧化碳和净碳捕获。通过改变生长的化学条件，可以生成具有多种特性（粒度、颗粒形状、表面化学和表面积）的PCCs，这些特性在许多工业应用中都很重要。该奖项反映了美国国家科学基金会的法定使命，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.