STTR Phase I: Engineering Alternative Oxidation Activity in A. ferrooxidans For Enhanced Biohydrometallurgy Capabilities

这一小型企业技术转让(STTR)项目的更广泛影响/商业潜力将是开发能够氧化铜矿物、黄铜矿和黄金的工程菌。大部分铜储量在黄铜矿中，目前需要冶炼。由于监管限制，美国铜矿业的冶炼能力有限，迫使美国铜制造商将铜精矿运往海外进行冶炼，这产生了额外的运输和加工成本，同时向冶炼厂损失了高达30%的金属总价值。以每年超过40万吨的铜精矿出口量计算，这相当于损失逾6亿美元。在黄金开采中，在利用其他黄金回收技术之前，越来越多地使用生物氧化，提高氧化率将扩大这种做法的用途，并显著降低这种做法的资本和运营成本。此外，加强氧化将加速将采矿废料作为生物技术原料的发展。该项目可能会在整个矿业中进一步发展更经济、更可持续的生物湿法冶金技术。该STTR一期项目建议示范和开发生物浸出微生物中的新氧化活动，扩大生物湿法冶金在金属采矿中的应用。这将允许对重要的金属矿物应用更便宜、低影响的生物湿法冶金方法。目前，生物湿法冶金由于依赖铁作为主要氧化剂而受到限制。这一提议的智力价值来自于过氧化氢的使用，过氧化氢可以实现矿物氧化转化，并提高仅用铁无法获得的氧化速度。在生物湿法冶金操作中添加过氧化氢是不可行的，也不具成本效益，然而，利用生物微生物(如氧化亚铁杆菌)进行基因工程来生产过氧化氢将是一个潜在的改变游戏规则的进步。这一创新将导致生物微生物细胞的产生，具有前所未有的溶解富硫化物矿石的能力，从而扩大采矿行业的生物湿法冶金方法。

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) project will be to develop engineered bacteria with the ability to oxidize the copper mineral chalcopyrite and gold. The majority of copper reserves are in chalcopyrite, which currently requires smelting. The US copper mining industry, due to regulatory restrictions, has a limited smelting capacity forcing US copper manufacturers to ship copper mineral concentrates overseas for smelting, which incurs additional transportation and processing costs while losing up to 30% of the full value of the metal to the smelters. At over 400,000 tons of copper concentrate exported annually, this amounts to over $600M in lost value. In gold mining, biooxidation is increasingly used before other gold recovery techniques are utilized, and increased oxidation rates would expand the use and significantly lower the capital and operating costs of this practice. In addition, enhanced oxidation would accelerate the development of mining waste streams as biotechnology feedstocks. This project potentially furthers more economical and sustainable biohydrometallurgical techniques throughout the mining industry.This STTR Phase I project proposes the demonstration and development of new oxidation activity within bioleaching microbes, expanding the applications of biohydrometallurgy in metal mining. This would permit the application of cheaper, low impact biohydrometallurgical methods for important metal minerals. Currently, biohydrometallurgy is limited by its reliance on ferric iron as the main oxidant. The Intellectual Merit of this proposal stems from the use of hydrogen peroxide, which can enable mineral oxidation conversions and rates that are not obtainable with ferric iron alone. Adding hydrogen peroxide to biohydrometallurgy operations is not feasible or cost effective, however, the genetic engineering of biomining microbes, such as A. ferrooxidans, to produce hydrogen peroxide would be a potentially game changing advance. This innovation will result in the production of biomining microbial cells with an unprecedented ability to dissolve sulfide-rich ores leading to the expansion of biohydrometallurgical approaches in the mining industry.