Abstract In this work is evaluated the bioleaching capacity of a bacterium isolated from a mine in Guanajuato, Mexico, namely LR-1. The bacterium oxidized Fe2+ and S2O32− at acidic pH for its energy metabolism. This oxidant activity provided Fe3+ and/or protons that provoke sulfide ore dissolution. Five sulfide ore samples were obtained from different Mexican mines: Remedios, Guerrero, Bolanitos, Aldama, and Ocampo. The Ag, Cr, Cu, Fe, Pb, and Zn contents in the ores was analyzed by atomic absorption. Other physicochemical properties, including pH, electrical conductivity, and oxide-reducing potential, were also measured. Bioleaching was evaluated by metal concentration in the medium due to bacterial growth developed in basal salt medium with 2% (w/v) mineral in acidic conditions at 37 °C. There was an Increase in the percentage release of Ag (18.66% to 29.85%), Cu (60.90% to 73.66%), and Cr (11.71% to 15.04%), with respect to chemical leaching, mainly from the Remedios ore. A phylogenetic analysis of the 16S rRNA gene sequences revealed that bacterium LR-1 belongs to the genus Brevibacillus. There are no known species from this genus related with the leaching processes. This is the first report of an acidophile chemolithoautotrophic iron oxidizing bacterium from the genus Brevibacillus in the metal bioleaching. Therefore, these data contribute to the knowledge of the hydrometallurgical microbiology.

中文翻译：

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使用新型化学自养细菌从硫化矿中提取金属的生物浸出

摘要 在这项工作中，评估了一种从墨西哥瓜纳华托矿山中分离的细菌，即 LR-1 的生物浸出能力。该细菌在酸性 pH 值下氧化 Fe2+ 和 S2O32− 以进行能量代谢。这种氧化活性提供了引起硫化矿溶解的 Fe3+ 和/或质子。五个硫化矿样品来自不同的墨西哥矿山：Remedios、Guerrero、Bolanitos、Aldama 和 Ocampo。通过原子吸收分析矿石中的银、铬、铜、铁、铅和锌含量。还测量了其他物理化学性质，包括 pH 值、电导率和氧化还原电位。生物浸出通过培养基中的金属浓度进行评估，因为细菌在 37 °C 酸性条件下在含有 2% (w/v) 矿物质的基础盐培养基中生长。Ag (18. 66% 至 29.85%)、Cu（60.90% 至 73.66%）和 Cr（11.71% 至 15.04%），化学浸出，主要来自 Remedios 矿石。16S rRNA 基因序列的系统发育分析表明细菌LR-1 属于短杆菌属。该属中没有已知的物种与浸出过程有关。这是来自短杆菌属的嗜酸化学自养铁氧化细菌在金属生物浸出中的首次报道。因此，这些数据有助于了解湿法冶金微生物学。该属中没有已知的物种与浸出过程有关。这是来自短杆菌属的嗜酸化学自养铁氧化细菌在金属生物浸出中的首次报道。因此，这些数据有助于了解湿法冶金微生物学。该属中没有已知的物种与浸出过程有关。这是来自短杆菌属的嗜酸化学自养铁氧化细菌在金属生物浸出中的首次报道。因此，这些数据有助于了解湿法冶金微生物学。