STTR Phase I: Low-Cost, High-Purity Biobased Glucaric Acid

这个小型企业技术转让（STTR）项目的更广泛的影响/商业潜力是开发葡萄糖酸及其中间体葡萄糖醛酸的生物基制造工艺。微生物发酵代表了从可再生资源生产燃料和有价值的化学品的一个有吸引力的选择，葡萄糖是一种可再生的生物质来源资源，可以生产葡萄糖酸。据估计，2016年葡糖酸市场价值5.5亿美元，用途广泛，从洗涤剂到食品成分，防腐蚀抑制剂和除冰应用。该项目将利用C5/C6糖提高微生物的生产效率，从而加快低成本、高纯度葡萄糖酸的生产。实现这些生物工艺的改进将促进生物基葡萄糖酸在各种市场的广泛采用，扩大美国产品的机会。这些应用包括涂料、泡沫和发泡助剂、电解质、凝胶、聚合物和聚合物添加剂。本STTR一期项目拟开展多组学研究，以表征通过发酵生产葡萄糖酸的大肠杆菌菌株的生理特征，并制定菌株工程策略，以实现高产和高产。与起始糖相比，大多数发酵产物高度还原，必须注意保持细胞处于还原状态，这意味着高NADH/NAD比率，以驱动消耗NADH的生物合成反应。相比之下，从糖氧化中提取的产品则带来了截然不同的挑战，而且研究的程度也要小得多。在这里，需要额外的氧气来接受葡萄糖氧化过程中产生的多余电子。众所周知，酿酒葡萄球菌和大肠杆菌是工业应用中最常见的两种生物，它们的电子传递链能力有限，导致高葡萄糖摄取率产生溢出产物。不管发酵设备的氧传递能力如何，这些生物都有一个固有的最大生产速率。在这个项目中，计划是开发具有增加呼吸能力的大肠杆菌菌株，从而提高最大葡萄糖氧化速率。葡萄糖可以通过3个酶促反应步骤产生葡萄糖酸，是一种示例性产品。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 Small Business Technology Transfer(STTR) project is to develop a bio-based manufacturing process for glucaric acid and its intermediate, glucuronic acid. Microbial fermentation represents an attractive option for production of fuels and valuable chemicals from renewable resources, and glucaric acid can be produced from glucose, a renewable biomass-derived resource. The glucaric acid market was estimated at $550M in 2016, and has a plethora of uses ranging from detergents to food ingredients, corrosion inhibitors, and de-icing applications. The proposed project will engineer improved productivity of the microbe using C5/C6 sugars, thus accelerating the production of low-cost, high-purity glucaric acid. Achieving these bioprocess improvements will facilitate widespread adoption of bio-based glucaric acid in a variety of markets, broadening opportunity for US products. These applications include coatings, foams and foaming aids, electrolytes, gels, polymers, and polymer additives.This STTR Phase I project proposes to perform multi-omics studies to characterize the physiology of E. coli strains producing glucaric acid via fermentation, and develop strain engineering strategies to enable high yield and productivity. Most fermentation products are highly reduced compared to the starting sugar, and care must be taken to maintain cells in a reduced state, meaning high NADH/NAD ratio, to drive the NADH-consuming biosynthetic reactions. Products that are derived from sugar oxidation, in contrast, pose a much different challenge, and have been explored to a much lesser extent. Here, additional oxygen is needed to accept the excess electrons generated during glucose oxidation. It is well known that both S. cerevisiae and E. coli, two of the most common organisms for industrial application, are limited in their electron transport chain capacity, resulting in overflow products from high glucose uptake rates. Regardless of the oxygen transfer ability of the fermentation equipment, there is an inherent maximum production rate of these organisms. In this project, the plan is to develop E. coli strains with increased respiration capacity, thus increasing the maximum glucose oxidation rate. Glucaric acid, which can be produced from glucose via 3 enzymatic reaction steps, is an exemplary product.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.