I-Corps: Catalytic Artificial Self-Assemblies for the Biocatalytic Production of Small Molecules

这个i-Corps项目的更广泛的影响/商业潜力是开发一类合成电池，可以取代传统的生物催化工艺用于化学生产。目前，实现小分子生物催化的方法主要有两种：全细胞催化和无细胞催化，这两种方法各有优势和挑战。由于毒素的积累，全细胞催化在生产指标上受到限制。相比之下，无细胞系统可以支持更高的生产指标，但会受到酶降解的影响，这使得制造复杂化学品变得困难，在经济上也是不可行的。这项拟议的技术为缓解这些挑战提供了一条中间路线，并可用于生产目前由传统生物催化手段制造的小分子，如食品添加剂和香料、药物前体和生物燃料。例如，拟议的技术可以用来从被认为是下一代生物燃料的木质纤维素中生产异丁醇。木质纤维素是最大的天然可获得原料，不是从食品来源提取的，消除了人们对生物燃料与粮食生产竞争的担忧。与传统的乙醇生物燃料相比，异丁醇可以在更高的浓度下与汽油混合，并直接用于现有的石油基础设施。由于糖化木质纤维素的耐受性比微生物更好，拟议的技术有望实现95%的异丁醇产量，并将温室气体排放减少70%，这是传统方法无法实现的。这项I-Corps项目基于胶体材料的开发，称为催化人工自组装(CASA)，这是用于生物催化生产小分子的合成细胞。建议的技术使用复杂的凝聚原细胞，并使用低成本的商业可获得的聚合物来制备和稳定。简化的复杂凝聚原细胞已被证明在其接近自然的环境中保存酶，同时仍提供无细胞系统的灵活性。复杂凝聚微滴乳液的原细胞将酶反应速度提高高达25倍，并提供酶的长期稳定性(~4个月)以及细胞无法获得的加工灵活性。除了显示改进的反应指标外，CASA对环境扰动具有很强的抵抗力，并克服了有关整个细胞系统中的细胞毒性和无细胞系统中的酶稳定性的关键挑战。这可能允许更灵活和经济的生物反应器设计和这些工艺的扩大，其中建议的平台可以用作独立方法或集成到现有工业管道中，以降低化学品生产的成本。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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 a class of synthetic cells that can replace conventional biocatalytic processes for chemical production. Currently, biocatalysis of small molecules is implemented by two main methods: whole-cell catalysis and cell-free catalysis, both of which have their advantages and challenges. Whole-cell catalysis is limited in production metrics by the accumulation of toxins. In contrast, cell-free systems can support higher production metrics but suffer from enzyme degradation, which makes the manufacturing of complex chemicals difficult and economically unfeasible. The proposed technology provides an intermediate route to alleviate these challenges, and may be used to produce small molecules currently manufactured from conventional biocatalytic means, such as food additives and fragrances, drug precursors, and biofuels. For example, the proposed technology may be used to produce isobutanol from lignocellulose, which is considered the next generation of biofuels. Lignocellulose is the largest naturally available feedstock and is not derived from food sources, eliminating concerns about biofuel competition with food production. Compared with conventional ethanol biofuels, isobutanol may be blended with gasoline at higher concentrations and used directly in the existing petroleum infrastructure. The proposed technology is expected to achieve a 95% isobutanol yield from saccharified lignocellulose concentrations due to its improved tolerance compared to microbes, and lower greenhouse gas emissions by 70%, which cannot be achieved by conventional methods.This I-Corps project is based on the development of colloidal materials, called catalytic artificial self-assemblies (CASA), which are synthetic cells for the biocatalytic production of small molecules. The proposed technology uses complex coacervate protocells prepared and stabilized using low-cost, commercially available polymers. Simplified complex coacervate protocells have been shown to preserve enzymes in their near-native environments while still providing the flexibility of cell-free systems. Protocells of complex coacervate microdroplet emulsions improve enzymatic reaction rates by up to 25-fold and provide long-term stability (~4 months) to enzymes as well as processing flexibility not accessible in cells. In addition to showing improved reaction metrics, CASA is robust to environmental perturbations and overcomes key challenges concerning cell toxicity in whole cell systems, and enzyme stability in cell-free systems. This may allow a more flexible and economical bioreactor design and scaling up of these processes where the proposed platform may be used as a standalone method or integrated into existing industrial pipelines to reduce the cost of chemical production.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.