Donati Edgardo Rubén, Castro Camila, Urbieta María Sofía
CINDEFI (CCT LA PLATA-CONICET, UNLP), Facultad de Ciencias Exactas (UNLP), 47 y 115, (1900) La Plata, Buenos Aires, Argentina.
World J Microbiol Biotechnol. 2016 Nov;32(11):179. doi: 10.1007/s11274-016-2140-2. Epub 2016 Sep 15.
Biomining is an applied biotechnology for mineral processing and metal extraction from ores and concentrates. This alternative technology for recovering metals involves the hydrometallurgical processes known as bioleaching and biooxidation where the metal is directly solubilized or released from the matrix for further solubilization, respectively. Several commercial applications of biomining can be found around the world to recover mainly copper and gold but also other metals; most of them are operating at temperatures below 40-50 °C using mesophilic and moderate thermophilic microorganisms. Although biomining offers an economically viable and cleaner option, its share of the world´s production of metals has not grown as much as it was expected, mainly considering that due to environmental restrictions in many countries smelting and roasting technologies are being eliminated. The slow rate of biomining processes is for sure the main reason of their poor implementation. In this scenario the use of thermophiles could be advantageous because higher operational temperature would increase the rate of the process and in addition it would eliminate the energy input for cooling the system (bioleaching reactions are exothermic causing a serious temperature increase in bioreactors and inside heaps that adversely affects most of the mesophilic microorganisms) and it would decrease the passivation of mineral surfaces. In the last few years many thermophilic bacteria and archaea have been isolated, characterized, and even used for extracting metals. This paper reviews the current status of biomining using thermophiles, describes the main characteristics of thermophilic biominers and discusses the future for this biotechnology.
生物采矿是一种应用生物技术，用于矿石和精矿的选矿及金属提取。这种回收金属的替代技术涉及湿法冶金过程，即生物浸出和生物氧化，其中金属分别直接溶解或从基质中释放出来以便进一步溶解。世界各地有许多生物采矿的商业应用，主要用于回收铜和金，但也包括其他金属；其中大多数使用嗜温菌和中度嗜热菌在40 - 50℃以下的温度下运行。尽管生物采矿提供了一种经济可行且更清洁的选择，但其在全球金属产量中的占比并未像预期那样大幅增长，主要是因为许多国家的环境限制导致冶炼和焙烧技术正在被淘汰。生物采矿过程的缓慢速度肯定是其应用不佳的主要原因。在这种情况下，使用嗜热菌可能具有优势，因为更高的操作温度会提高过程速率，此外还能消除冷却系统的能量输入（生物浸出反应是放热反应，会导致生物反应器和矿堆内部温度严重升高，对大多数嗜温微生物产生不利影响），并且会减少矿物表面的钝化。在过去几年中，许多嗜热细菌和古菌已被分离、鉴定，甚至用于金属提取。本文综述了利用嗜热菌进行生物采矿的现状，描述了嗜热生物采矿菌的主要特性，并讨论了这种生物技术的未来。
