SBIR Phase I: Microbial conversion of pectin-rich agricultural waste into specialty chemicals

这个小企业创新研究（SBIR）项目的更广泛的影响/商业潜力是开发酵母发酵技术，使富含果胶的农业废物中丰富的糖转化为有用的特种化学品。美国是富含果胶的农业废物的主要生产国，包括柑橘皮（每年500万吨），甜菜（每年3700万吨）和葡萄渣（每年100万吨）。这些果皮和纸浆副产品缺乏价值，然而，本项目中开发的拟议技术将允许从这些废物流中生产价值更高的产品。最初的目标化学产品用作清洁产品中的螯合剂和塑料的前体。其他化学产品也可能使用该平台生产。与石油或其他糖衍生产品相比，这种发酵工艺的实施提供了更低的碳足迹和排放，并在减少浪费和应对气候变化方面产生了影响。当大规模实施时，这些发酵加工厂将与农村农业加工厂位于同一地点，为这些地区增加高科技工作岗位，并通过进入替代市场来降低历史上不稳定的作物收成风险。SBIR第一阶段项目提出改造酵母菌株，使其能够将富含果胶的农业废物中的糖转化为有价值的特种化学品。目前，利用果胶中的主要糖D-半乳糖醛酸的发酵速率限制了这些化学品的生产，包括所提出的第一种产品，其是可生物降解的金属螯合剂。先前的表征已经确定了转运蛋白对果胶糖的摄取是限制性步骤。因此，本提案的第一个目标是确定这类运输工具的特征，以确定费率有所提高的新运输工具。第二个目标是通过蛋白质工程改进最佳转运蛋白。使用这种改进的转运蛋白，最终目标将评估使用生物反应器控制发酵罐条件的发酵过程的细胞能量需求，因为产品合成和运输需要能量。如果成功，该项目将使生产特种化学品从果胶丰富的农业废物。这个奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的知识价值和更广泛的影响审查标准的支持。

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is the development of yeast fermentation technologies that enable conversion of sugars abundant in pectin-rich agricultural waste into useful specialty chemicals. The U.S. is a leading producer of pectin-rich agricultural wastes including citrus peels (5 million tons annually), sugar beets (37 million tons annually), and grape pomace (1 million tons annually). These peel and pulp byproducts lack value, however, the proposed technologies developed in this project will allow for significantly higher valued products to be produced from these waste streams. The initial target chemical product is used as a chelator in cleaning products and a precursor to plastics. Other chemical products potentially may be produced using this platform. Implementation of this fermentation process offers a lower carbon footprint and emissions compared to petroleum or even other sugar-derived products, and has impact in reducing waste and combating climate change. When implemented at scale, these fermentation processing plants will be co-located with rural agricultural processing plants, adding high-tech jobs in these areas, and offering a means to de-risk historically volatile crop harvests by accessing alternative markets.This SBIR Phase I project proposes to engineer yeast strains capable of converting sugars in pectin-rich agricultural wastes into valuable specialty chemicals. Currently, the fermentation rates for utilizing the primary sugar in pectin, D-galacturonic acid, limits production of these chemicals, including the proposed first product, which is a biodegradable metal chelator. Previous characterization has identified that uptake of the pectin sugars by a transporter as the limiting step. Accordingly, the first objective of this proposal is to characterize this class of transporter to identify new transporters with improved rates. The second objective is to improve the best transporter through protein engineering. Using this improved transporter, the final objective will assess the cellular energy requirements for the fermentation process using bioreactors to control fermenter conditions, as product synthesis and transport is energy-demanding. If successful, this project will enable production of specialty chemicals from pectin-rich agricultural waste.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.