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

这项小型企业技术转让（STTR）项目的更广泛影响/商业潜力将是开发具有氧化铜矿黄铜矿和金能力的工程细菌。铜储量的大部分是黄铜矿，目前需要冶炼。由于监管限制，美国铜矿采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，这带来了额外的运输和加工成本，同时对冶炼厂来说损失了高达30%的金属总价值。每年出口的铜精矿超过40万吨，这意味着价值损失超过6亿美元。在金矿开采中，生物氧化法在其他黄金回收技术之前被越来越多地使用，提高氧化率将扩大这种做法的使用范围，并显著降低这种做法的资本和操作成本。此外，加强氧化将加速采矿废物流作为生物技术原料的发展。该项目有可能在整个采矿业中进一步推广更经济和可持续的生物湿法冶金技术。这个STTR第一期项目提出了在生物浸出微生物中展示和开发新的氧化活性，扩大生物湿法冶金在金属采矿中的应用。这将允许对重要金属矿物采用更便宜、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。这一建议的知识价值源于过氧化氢的使用，它可以使矿物氧化转化和速度，这是单独使用铁所无法获得的。在生物湿法冶金操作中加入过氧化氢是不可行的，也不符合成本效益，然而，利用生物微生物的基因工程，如氧化亚铁杆菌，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矿化微生物细胞的生产，这些微生物细胞具有前所未有的溶解富含硫化物的矿石的能力，从而扩大了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.