Abstract We examined the geochemistry and bacterial and archaeal community structure in the acidic (pH < 2.4) pit lake at Peña de Hierro, near the headwaters of the Río Tinto. The lake has strong vertical gradients in light, O2, pH, conductivity, and dissolved ions. Bacterial and archaeal communities between 0 and 32 m displayed low species richness and evenness. Relatives of iron cycling taxa accounted for 60-90% of the operational taxonomic units (OTUs) throughout the water column. Relatives of heterotrophic, facultative Fe(III)-reducing species made up more than a third of the bacterial and archaeal community in the photic zone. Taxa related to Fe(II) oxidizers Ferrithrix thermotolerans and Acidithix ferrooxidans were also abundant in the photic zone. Below the photic zone, relatives of the lithoautotrophic Fe(II) oxidizers Leptospirillum ferrooxidans and Ferrovum myxofaciens bloomed at different depths within or just below the oxycline. Thermoplasmatales predominated in the deep, microoxic zone of the lake. The microbial population structure of the lake appears to be influenced by the production of oxygen and organic matter by phototrophs in a narrow zone at the lake surface and by strong geochemical gradients present in the water column that create distinct niches for separate Fe(II) oxidizers.

中文翻译：

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伊比利亚黄铁矿带分层酸性坑湖中的微生物种群结构

摘要 我们研究了位于 Río Tinto 源头附近的 Peña de Hierro 酸性 (pH < 2.4) 坑湖中的地球化学以及细菌和古菌群落结构。该湖在光、O2、pH、电导率和溶解离子方面具有很强的垂直梯度。0 到 32 m 之间的细菌和古菌群落显示出较低的物种丰富度和均匀度。铁循环类群的近亲占整个水体操作分类单位 (OTU) 的 60-90%。异养、兼性 Fe(III) 还原物种的近亲占光区细菌和古菌群落的三分之一以上。与 Fe(II) 氧化剂 Ferrithrix thermotolerans 和 Acidithix ferrooxidans 相关的分类群在光区也很丰富。在光区之下，岩性自养型 Fe(II) 氧化剂的近亲氧化亚铁钩端螺旋体和粘液性铁锈菌在氧化层内或刚好在氧化层下方的不同深度开花。Thermoplasmatales 在湖的深部微氧区占主导地位。湖泊的微生物种群结构似乎受到湖面狭窄区域光养生物产生的氧气和有机物的影响，以及水体中存在的强烈地球化学梯度的影响，这些梯度为单独的 Fe(II) 氧化剂创造了不同的生态位.