Best Mackenzie B, Kazemi Motlagh Zohreh, McLemore Virginia T, Jones Daniel S
Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA.
Department of Mineral Engineering, New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA.
Appl Environ Microbiol. 2025 Aug 20;91(8):e0043425. doi: 10.1128/aem.00434-25. Epub 2025 Jul 24.
Waste rock and tailings left behind by historic mining operations can contain substantial critical mineral resources. However, over the decades and centuries, since these deposits were emplaced, microbial communities developed that can catalyze rock weathering and elemental cycling, which could have impacted the economic resources but also might be harnessed for future biomining or other metal recovery efforts. Here, we combined microbial cell counting, rRNA gene and transcript sequencing, and whole rock geochemistry to compare the composition and abundance of microbial communities from five inactive mine sites in south-central New Mexico that contain critical minerals. While acidic seeps and adits at the sites contained organisms commonly found in acid rock drainage and bioleaching operations, these organisms were only present at very low abundance in the waste rock and tailings, which were instead dominated by bacteria and archaea that are related to inorganic nitrogen- and organic carbon-oxidizing taxa. Generally, rRNA transcript libraries contain many of the same organisms as rRNA gene libraries, indicating that most of these populations are active. Differences among total and active microbial communities correspond to waste rock geochemistry, including concentrations of sulfur, iron, and other variables such as copper, lead, and rare earth elements. Nevertheless, many of the rRNA gene and transcript sequences in these deposits were from groups without cultured representatives, and these unknown microorganisms are likely important for biogeochemical cycling over the long lifetime of these waste deposits. We also discuss recommendations for microbiological assessment of similar large historic mine waste deposits.
New Mexico has a long history of mining, with hundreds of mining districts across the state, many of which contain inactive operations with historic tailings and waste rock. Because metallurgical processing was in its infancy when most of these mines were active, they contain substantial metal resources in tailings and waste rock that could be used to support domestic demand for critical minerals. We found that microbial communities associated with these deposits do not represent typical bioleaching communities, and instead are dominated by taxa not typically associated with mine waste. However, the deposits did contain rare iron and sulfur-cycling taxa that could catalyze metal mobilization, as well as active populations of novel microorganisms that are likely important for biogeochemical cycling. These microbial communities could represent important resources for bioremediation and other biotechnological applications to recover valuable elements from these and other historic mine wastes.
历史采矿作业留下的废石和尾矿可能含有大量关键矿产资源。然而，自这些矿床形成后的几十年乃至几个世纪里，微生物群落得以发展，它们能够催化岩石风化和元素循环，这可能影响了经济资源，但也可被用于未来的生物采矿或其他金属回收工作。在此，我们结合微生物细胞计数、rRNA基因和转录本测序以及全岩地球化学，来比较新墨西哥州中南部五个含有关键矿产的废弃矿场中微生物群落的组成和丰度。虽然这些矿场的酸性渗流和平硐中含有酸性岩石排水和生物浸出作业中常见的生物，但这些生物在废石和尾矿中的丰度极低，相反，废石和尾矿中主要是与无机氮和有机碳氧化类群相关的细菌和古菌。一般来说，rRNA转录本库包含许多与rRNA基因库相同的生物，这表明这些种群中的大多数都具有活性。总微生物群落和活性微生物群落之间的差异与废石地球化学特征相对应，包括硫、铁的浓度以及铜、铅和稀土元素等其他变量。尽管如此，这些矿床中许多rRNA基因和转录本序列来自没有培养代表的类群，这些未知微生物可能对这些废矿床漫长生命周期内的生物地球化学循环至关重要。我们还讨论了对类似大型历史矿场废矿床进行微生物评估的建议。
新墨西哥州有着悠久的采矿历史，全州有数百个矿区，其中许多都有废弃作业，留有历史尾矿和废石。由于大多数这些矿山活跃时冶金加工尚处于起步阶段，它们的尾矿和废石中含有大量金属资源，可用于满足国内对关键矿产的需求。我们发现，与这些矿床相关的微生物群落并不代表典型的生物浸出群落，相反，它们主要由通常与矿山废弃物无关的类群主导。然而，这些矿床确实含有可催化金属迁移的罕见铁和硫循环类群，以及可能对生物地球化学循环至关重要的新型微生物活性种群。这些微生物群落可能是生物修复和其他生物技术应用的重要资源，用于从这些以及其他历史矿山废弃物中回收有价值的元素。
