STTR Phase I: Using mining waste as a feedstock for the production of chemicals from CO2 with genetically engineered Acidithiobacillus ferrooxidans

这项小型企业技术转让项目的更广泛影响/商业潜力是开发利用硫化物采矿废物流作为从二氧化碳中生产化学品的新能源的技术。硫化物采矿废物作为采矿作业的副产品不断产生，具有严重的、永久性的环境风险。采矿废物中的硫化物矿物也是多种微生物群落的可行能源，这些微生物从这些矿物的氧化中获得能量。这种生物氧化从岩石中释放出大量的能量。一吨硫化物采矿废料释放的能量大约相当于一桶石油。大约95%的铜矿石是在富含硫化物的矿床中发现的，每年约有2000万公吨，占采矿废物的15%（相当于数百万桶石油）。从基因工程微生物中，有人建议利用这种能量从二氧化碳中产生化学物质。因此，硫化物废物流代表了从二氧化碳中可持续生产化学品的一种新的高能量原料。这项技术将提高采矿的可持续性，并提供一种非农业、非光合作用和经济上具有吸引力的碳中性化学品途径。这个STTR第一阶段项目提议展示转基因氧化亚铁的发展，以利用采矿过程废物流作为生物技术应用的原料。在传统的铜冶炼过程中产生的易获得的富硫废液每公吨含有约40%的葡萄糖能量，美国每年产生约2000万吨。这些能源密集型废液目前被填埋，它们的环境氧化可能导致酸性矿山排水。为了利用这一机会，合理地设计这种物种从大气中的二氧化碳中生产异丁酸的能力已经被开发出来。本提案的具体目标是：1)开发模型反应堆系统，以表征使用实际矿山尾矿原料的性能和操作；2)通过进一步的代谢工程提高氧化亚铁杆菌的生物生产力；3)对这种新型生物过程进行复杂的技术经济分析。此外，还将获得一家采矿公司的承诺，使其能够使用尾矿原料供应和一个地点来建造和经营一个试验规模的工厂。完成这些目标将为未来的后续第二阶段提案做好准备，以扩大我们的技术，进一步表征实际工艺流的性能，并证明大规模工艺的可行性。

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) project is the development of technology for use of sulfide mining waste streams as a novel energy source for the production of chemicals from CO2. Sulfide mining wastes pose a serious, perpetual environmental risk, and are continuously generated as by-products of mining operations. The sulfide minerals in mining waste also are viable energy source for a diverse community of microbes that derive their energy from the oxidation of these minerals. This biological oxidation releases significant amounts of energy from the rock. The energy released from one ton of sulfide mining waste is approximately equivalent to one barrel of oil. Approximately 95% of copper ores are found in sulfide-rich ore deposits and at about 20 million metric tons annually, constitute ~15% of mining waste (representing millions of barrels of oil). From genetically engineered microbes, it is proposed to use this energy to generate chemicals from CO2. As such, sulfide waste streams represent a new high energy feedstock for the sustainable production of chemicals from CO2. This technology will improve the sustainability of mining and provide a non-agricultural, non-photosynthetic and economically attractive route to carbon-neutral chemicals. This STTR Phase I project proposes to demonstrate the development of genetically modified A. ferrooxidans for the utilization of mining process waste streams as a feedstock for biotechnology applications. Readily available sulfur-rich waste streams produced during the traditional smelting processing of copper contain about 40% per metric ton of the energy of glucose, and about 20 million metric tons are produced annually in the U.S. These energy intensive waste streams are currently landfilled, and their environmental oxidation can lead to acid mine drainage. To leverage this opportunity, the ability to rationally engineer this species to produce isobutyric acid from atmospheric CO2 has been developed. The specific aims of this proposal are: 1) develop model reactor systems to characterize performance and operations using actual mine tailing feedstocks; 2) improve biological productivity through further metabolic engineering of A. ferrooxidans; and 3) develop a sophisticated techno-economic analysis of the novel bioprocess. In addition, a commitment from a mining company for access to a tailing feedstock supply and a site to construct and operate a pilot-scale plant will be secured. Accomplishing these goals will prepare for a future follow-on Phase II proposal to scale-up our technology, further characterize performance on actual process streams, and demonstrate large-scale process feasibility.