de Los Ríos Asunción, Ascaso Carmen, Wierzchos Jacek, Fernández-Valiente Eduardo, Quesada Antonio
Centro de Ciencias Medioambientales, CSIC, 28006 Madrid, Spain.
Appl Environ Microbiol. 2004 Jan;70(1):569-80. doi: 10.1128/AEM.70.1.569-580.2004.
The three-dimensional structures of two types of cyanobacterium-dominated microbial mats from meltwater ponds on the McMurdo Ice Shelf were as determined by using a broad suite of complementary techniques, including optical and fluorescence microscopy, confocal scanning laser microscopy, scanning electron microscopy with back-scattered electron-imaging mode, low-temperature scanning electron microscopy, and microanalyitical X-ray energy dispersive spectroscopy. By using a combination of the different in situ microscopic techniques, the Antarctic microbial mats were found to be structures with vertical stratification of groups of cyanobacteria and mineral sediments, high contents of extracellular polymeric substances, and large void spaces occupied by water. In cyanobacterium-rich layers, heterocystous nostocalean and nonheterocystous oscillatorialean taxa were the most abundant taxa and appeared to be intermixed with fine-size deposits of epicellular silica and calcium carbonate. Most of the cyanobacterial filaments had similar orientations in zones without sediment particles, but thin filaments were tangled among thicker filaments. The combination of the microscopic techniques used showed the relative positions of biological and mineral entities within the microbial mats and enabled some speculation about their interactions.
利用一系列广泛的互补技术，包括光学显微镜和荧光显微镜、共聚焦扫描激光显微镜、采用背散射电子成像模式的扫描电子显微镜、低温扫描电子显微镜以及微分析X射线能量色散光谱，确定了麦克默多冰架上融水池塘中两种以蓝藻为主的微生物垫的三维结构。通过结合不同的原位显微镜技术，发现南极微生物垫具有蓝藻群和矿物沉积物垂直分层的结构、细胞外聚合物含量高以及被水占据的大孔隙空间。在富含蓝藻的层中，具异形胞的念珠藻目和无异形胞的颤藻目分类群是最丰富的分类群，并且似乎与细胞外二氧化硅和碳酸钙的细粒沉积物混合在一起。在没有沉积物颗粒的区域，大多数蓝藻丝具有相似取向，但细丝缠绕在较粗的丝之间。所使用的显微镜技术的结合显示了微生物垫内生物和矿物实体的相对位置，并使得能够对它们之间的相互作用进行一些推测。
