State Key Laboratory of Biogeology and Environmental Geology and Institute of Earth Sciences, China University of Geosciences, Beijing, China.
PLoS One. 2013;8(1):e53350. doi: 10.1371/journal.pone.0053350. Epub 2013 Jan 9.
The Rehai and Ruidian geothermal fields, located in Tengchong County, Yunnan Province, China, host a variety of geochemically distinct hot springs. In this study, we report a comprehensive, cultivation-independent census of microbial communities in 37 samples collected from these geothermal fields, encompassing sites ranging in temperature from 55.1 to 93.6°C, in pH from 2.5 to 9.4, and in mineralogy from silicates in Rehai to carbonates in Ruidian. Richness was low in all samples, with 21-123 species-level OTUs detected. The bacterial phylum Aquificae or archaeal phylum Crenarchaeota were dominant in Rehai samples, yet the dominant taxa within those phyla depended on temperature, pH, and geochemistry. Rehai springs with low pH (2.5-2.6), high temperature (85.1-89.1°C), and high sulfur contents favored the crenarchaeal order Sulfolobales, whereas those with low pH (2.6-4.8) and cooler temperature (55.1-64.5°C) favored the Aquificae genus Hydrogenobaculum. Rehai springs with neutral-alkaline pH (7.2-9.4) and high temperature (>80°C) with high concentrations of silica and salt ions (Na, K, and Cl) favored the Aquificae genus Hydrogenobacter and crenarchaeal orders Desulfurococcales and Thermoproteales. Desulfurococcales and Thermoproteales became predominant in springs with pH much higher than the optimum and even the maximum pH known for these orders. Ruidian water samples harbored a single Aquificae genus Hydrogenobacter, whereas microbial communities in Ruidian sediment samples were more diverse at the phylum level and distinctly different from those in Rehai and Ruidian water samples, with a higher abundance of uncultivated lineages, close relatives of the ammonia-oxidizing archaeon "Candidatus Nitrosocaldus yellowstonii", and candidate division O1aA90 and OP1. These differences between Ruidian sediments and Rehai samples were likely caused by temperature, pH, and sediment mineralogy. The results of this study significantly expand the current understanding of the microbiology in Tengchong hot springs and provide a basis for comparison with other geothermal systems around the world.
位于中国云南省腾冲县的热海和瑞滇地热田拥有多种地球化学性质不同的温泉。本研究对这两个地热田中 37 个样本的微生物群落进行了全面的、无需培养的普查，这些样本的温度范围从 55.1°C 到 93.6°C，pH 值范围从 2.5 到 9.4，矿物学范围从热海的硅酸盐到瑞滇的碳酸盐。所有样本的丰富度都较低，检测到的种水平 OTUs 为 21-123 种。热海样本中优势的细菌门为泉古菌门或古菌门泉古菌纲，然而，这些门内的优势类群取决于温度、pH 值和地球化学性质。低 pH 值（2.5-2.6）、高温（85.1-89.1°C）和高硫含量的热海温泉有利于古菌目 Sulfolobales，而 pH 值较低（2.6-4.8）且温度较低（55.1-64.5°C）的热海温泉有利于泉古菌属 Hydrogenobaculum。中性-碱性 pH 值（7.2-9.4）、高温（>80°C）、高浓度二氧化硅和盐离子（Na、K 和 Cl）的热海温泉有利于泉古菌属 Hydrogenobacter 和古菌目 Desulfurococcales 和 Thermoproteales。Desulfurococcales 和 Thermoproteales 在 pH 值远高于这些目最佳和最大 pH 值的温泉中占优势。瑞滇水样中仅存在一个泉古菌属 Hydrogenobacter，而瑞滇沉积物样品中的微生物群落的多样性在门水平上更高，与热海和瑞滇水样明显不同，含有更多未培养的类群，与氨氧化古菌“Candidatus Nitrosocaldus yellowstonii”的近缘关系，以及候选分类群 O1aA90 和 OP1。瑞滇沉积物与热海样本之间的这些差异可能是由温度、pH 值和沉积物矿物学引起的。本研究的结果极大地扩展了对腾冲温泉微生物学的现有认识，并为与世界各地其他地热系统进行比较提供了基础。
