Ascaso C, Wierzchos J
Centro de Ciencias Medioambientales, CSIC, Madrid.
Microbiologia. 1994 Mar-Jun;10(1-2):103-110.
The advances that have been made on the effect of lichens on rock substrate have been numerous. The first techniques used in order to know the type of biodeterioration produced by lichen thalli, were observations by light microscopy. The microchemical techniques that followed this, such as X-Ray Diffraction and Infrared Spectroscopy, provided knowledge of the mineral composition of the substrate which is in contact with the lichen thalli. This zone is known as interface. More recently, the Scanning Electron-Microscope has allowed observations of the relationship between the hyphae of the lower part of the thallus and the topography of the superficial part of the rock. In the current work, new applications of Scanning Electron Microscopy are presented. The backscattered electron image permits observation of the penetration of living thalli elements in the rock. With this technique, it is possible to follow the fissures underneath the lichen thalli and see at a cellular level the biological elements. This technique is an important step in understanding the biodeterioration produced by lichens. It allows clarification of such aspects as the ability of embedded minerals detached from the rock among the hyphae and also the possibility of investigating organic and inorganic compounds mixed with hyphae and algae. This technique, moreover, is promising for use in future investigations of biodeterioration where the cellular morphology of the different organisms are interesting, taking into account treatments with biocides.
在地衣对岩石基质的影响方面已经取得了许多进展。为了了解地衣叶状体产生的生物劣化类型，最初使用的技术是光学显微镜观察。随后的微化学技术，如X射线衍射和红外光谱，提供了与地衣叶状体接触的基质矿物成分的知识。这个区域被称为界面。最近，扫描电子显微镜使得人们能够观察叶状体下部的菌丝与岩石表面形貌之间的关系。在当前的工作中，展示了扫描电子显微镜的新应用。背散射电子图像可以观察活的叶状体元素在岩石中的渗透情况。通过这项技术，可以追踪地衣叶状体下方的裂缝，并在细胞水平上观察生物元素。这项技术是理解地衣产生的生物劣化的重要一步。它有助于阐明诸如从岩石中分离出来并嵌入菌丝中的矿物质的能力，以及研究与菌丝和藻类混合的有机和无机化合物的可能性等方面。此外，考虑到使用杀生物剂的处理方法，这项技术在未来对不同生物体细胞形态感兴趣的生物劣化研究中很有前景。
