Lehman R M, Roberto F F, Earley D, Bruhn D F, Brink S E, O'Connell S P, Delwiche M E, Colwell F S
Idaho National Engineering and Environmental Laboratory, Biotechnologies Department, Idaho Falls, ID 83415-2203, USA.
Appl Environ Microbiol. 2001 May;67(5):2095-106. doi: 10.1128/AEM.67.5.2095-2106.2001.
The bacteria colonizing geologic core sections (attached) were contrasted with those found suspended in the groundwater (unattached) by examining the microbiology of 16 depth-paired core and groundwater samples using a suite of culture-independent and culture-dependent analyses. One hundred twenty-two meters was continuously cored from a buried chalcopyrite ore hosted in a biotite-quartz-monzonite porphyry at the Mineral Park Mine near Kingman, Ariz. Every fourth 1.5-m core was acquired using microbiologically defensible methods, and these core sections were aseptically processed for characterization of the attached bacteria. Groundwater samples containing unattached bacteria were collected from the uncased corehole at depth intervals corresponding to the individual cores using an inflatable straddle packer sampler. The groundwater was acidic (pH 2.8 to 5.0), with low levels of dissolved oxygen and high concentrations of sulfate and metals, including ferrous iron. Total numbers of attached cells were less than 10(5) cells g of core material(-1) while unattached cells numbered about 10(5) cells ml of groundwater(-1). Attached and unattached acidophilic heterotrophs were observed throughout the depth profile. In contrast, acidophilic chemolithotrophs were not found attached to the rock but were commonly observed in the groundwater. Attached communities were composed of low numbers (<40 CFU g(-1)) of neutrophilic heterotrophs that exhibited a high degree of morphologic diversity, while unattached communities contained higher numbers (ca. 10(3) CFU ml(-1)) of neutrophilic heterotrophs of limited diversity. Sulfate-reducing bacteria were restricted to the deepest samples of both core and groundwater. 16S ribosomal DNA sequence analysis of attached, acidophilic isolates indicated that organisms closely related to heterotrophic, acidophilic mesophiles such as Acidiphilium organovorum and, surprisingly, to the moderately thermophilic Alicyclobacillus acidocaldarius were present. The results indicate that viable (but possibly inactive) microorganisms were present in the buried ore and that there was substantial distinction in biomass and physiological capabilities between attached and unattached populations.
通过使用一系列不依赖培养和依赖培养的分析方法，对16对深度匹配的岩芯和地下水样本进行微生物学检测，对比了定殖在地质岩芯部分（附着态）的细菌与地下水中悬浮的细菌（非附着态）。在亚利桑那州金曼附近的矿物公园矿，从赋存于黑云母 - 石英 - 二长斑岩中的埋藏黄铜矿矿石中连续取芯122米。每隔4个1.5米的岩芯采用微生物防护方法获取，这些岩芯段经过无菌处理以表征附着细菌。使用可充气跨孔封隔器采样器，从与各个岩芯对应的深度间隔的裸孔中采集含有非附着细菌的地下水样本。地下水呈酸性（pH值2.8至5.0），溶解氧含量低，硫酸盐和包括亚铁在内的金属浓度高。附着细胞总数少于10⁵个/克岩芯材料，而非附着细胞数量约为10⁵个/毫升地下水。在整个深度剖面中均观察到附着和非附着的嗜酸异养菌。相比之下，嗜酸化能自养菌未在岩石上发现，但在地下水中普遍存在。附着菌群由数量较少（<40 CFU/克⁻¹）的嗜中性异养菌组成，形态多样性高，而非附着菌群含有数量较多（约10³ CFU/毫升⁻¹）但多样性有限的嗜中性异养菌。硫酸盐还原菌仅限于岩芯和地下水的最深样本。对附着的嗜酸分离株进行的16S核糖体DNA序列分析表明，存在与异养嗜酸嗜温菌如食有机嗜酸菌密切相关的生物体，令人惊讶的是，还存在与中度嗜热嗜酸栖热放线菌密切相关的生物体。结果表明，埋藏矿石中存在有活力（但可能无活性）的微生物，并且附着和非附着种群在生物量和生理能力上存在显著差异。
