Jones Daniel S, Kohl Courtney, Grettenberger Christen, Larson Lance N, Burgos William D, Macaladya Jennifer L
Appl Environ Microbiol. 2015 Feb;81(4):1242-50. doi: 10.1128/AEM.02919-14.
A legacy of coal mining in the Appalachians has provided a unique opportunity to study the ecological niches of iron-oxidizing microorganisms. Mine-impacted, anoxic groundwater with high dissolved-metal concentrations emerges at springs and seeps associated with iron oxide mounds and deposits. These deposits are colonized by iron-oxidizing microorganisms that in some cases efficiently remove most of the dissolved iron at low pH, making subsequent treatment of the polluted stream water less expensive. We used full-cycle rRNA methods to describe the composition of sediment communities at two geochemically similar acidic discharges, Upper and Lower Red Eyes in Somerset County, PA, USA. The dominant microorganisms at both discharges were acidophilic Gallionella-like organisms, “Ferrovum” spp., and Acidithiobacillus spp. Archaea and Leptospirillum spp. accounted for less than 2% of cells. The distribution of microorganisms at the two sites could be best explained by a combination of iron(II) concentration and pH. Populations of the Gallionella-like organisms were restricted to locations with pH>3 and iron(II) concentration of >4 mM, while Acidithiobacillus spp. were restricted to pH<3 and iron(II) concentration of <4 mM. Ferrovum spp. were present at low levels in most samples but dominated sediment communities at pH<3 and iron(II) concentration of >4 mM. Our findings offer a predictive framework that could prove useful for describing the distribution of microorganisms in acid mine drainage, based on readily accessible geochemical parameters.
阿巴拉契亚地区的煤炭开采遗留问题为研究铁氧化微生物的生态位提供了独特的机会。受采矿影响的缺氧地下水，其溶解金属浓度很高，会在与氧化铁丘和沉积物相关的泉眼和渗流处涌出。这些沉积物被铁氧化微生物定殖，在某些情况下，这些微生物能在低pH值条件下有效地去除大部分溶解铁，从而降低后续处理受污染溪水的成本。我们使用全周期rRNA方法来描述美国宾夕法尼亚州萨默塞特县两个地球化学性质相似的酸性排放点——上红眼和下红眼——沉积物群落的组成。两个排放点的优势微生物都是嗜酸的类嘉利翁氏菌、“铁原体”属和嗜酸氧化硫杆菌属。古菌和钩端螺旋菌属占细胞总数不到2%。两个地点微生物的分布情况可以通过结合二价铁浓度和pH值来最好地解释。类嘉利翁氏菌种群局限于pH>3且二价铁浓度>4 mM的位置，而嗜酸氧化硫杆菌属则局限于pH<3且二价铁浓度<4 mM的位置。铁原体属在大多数样本中含量较低，但在pH<3且二价铁浓度>4 mM的沉积物群落中占主导地位。我们的研究结果提供了一个预测框架，基于易于获取的地球化学参数，该框架可能有助于描述酸性矿山排水中微生物的分布。
