Abstract Inactive mines provide a great source of bacterial diversity for studying acidophilic communities and their biotechnological applications, but prospecting of these anthropogenic environments in Colombia has been limited. Conventional microbiological methods were used to isolate acidophilic bacterial strains from effluents emanating from the Colombian gold mine ‘El Zancudo’ (Titiribí, Antioquia). Despite the drainage waters having circumneutral pH, all of the isolated strains were phylogenetically related to the extreme acidophile Acidithiobacillus genus. However, based upon 16S rRNA gene sequences the mesophilic sulfur-oxidizing indigenous strains could not be assigned to a species. Pure cultures were selected by screening in medium with soluble inorganic arsenic (III) and their mineral-oxidative activity was evaluated at 30 °C in Erlenmeyer flasks with arsenopyrite ore under rotary shaking conditions. The indigenous strains were able to catalyze arsenopyrite oxidation in a mixed culture with a pulp density of 10%, maintaining their growth in the presence of >80 mM leached arsenic. This research provides information regarding the isolation of arsenic resistant bacterial communities from neutral effluents from El Zancudo mine and the possibility of the isolated strains to be useful in the biooxidation pretreatment of refractory gold-bearing arsenopyrite ores and concentrates.

中文翻译：

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从哥伦比亚矿井污水中分离出抗砷和毒砂氧化酸性硫杆菌

摘要 非活性矿山为研究嗜酸群落及其生物技术应用提供了细菌多样性的重要来源，但在哥伦比亚对这些人为环境的勘探受到限制。使用常规微生物学方法从哥伦比亚金矿“El Zancudo”（Titiribí，Antioquia）流出的污水中分离嗜酸细菌菌株。尽管排水具有中性 pH 值，但所有分离的菌株在系统发育上都与极端嗜酸菌酸硫杆菌属有关。然而，根据 16S rRNA 基因序列，不能将嗜温硫氧化本地菌株分配给一个物种。通过在含有可溶性无机砷 (III) 的培养基中筛选来选择纯培养物，并在 30 °C 下在带有毒砂矿石的锥形瓶中在旋转振荡条件下评估它们的矿物氧化活性。本地菌株能够在纸浆密度为 10% 的混合培养物中催化毒砂氧化，并在 >80 mM 浸出的砷存在下保持其生长。这项研究提供了有关从 El Zancudo 矿的中性流出物中分离耐砷细菌群落的信息，以及分离的菌株可用于难处理的含金毒砂矿石和精矿的生物氧化预处理的可能性。本地菌株能够在纸浆密度为 10% 的混合培养物中催化毒砂氧化，并在 >80 mM 浸出的砷存在下保持其生长。这项研究提供了有关从 El Zancudo 矿的中性流出物中分离耐砷细菌群落的信息，以及分离的菌株可用于难处理的含金毒砂矿石和精矿的生物氧化预处理的可能性。本地菌株能够在纸浆密度为 10% 的混合培养物中催化毒砂氧化，并在 >80 mM 浸出的砷存在下保持其生长。这项研究提供了有关从 El Zancudo 矿的中性流出物中分离耐砷细菌群落的信息，以及分离的菌株可用于难处理的含金毒砂矿石和精矿的生物氧化预处理的可能性。