Wierzchos Jacek, Ascaso Carmen, McKay Christopher P
Servei de Microscopia Electrònica, Universitat de Lleida, Lleida, Spain.
Astrobiology. 2006 Jun;6(3):415-22. doi: 10.1089/ast.2006.6.415.
In the driest parts of the Atacama Desert there are no visible life forms on soil or rock surfaces. The soil in this region contains only minute traces of bacteria distributed in patches, and conditions are too dry for cyanobacteria that live under translucent stones. Here we show that halite evaporite rocks from the driest part of the Atacama Desert are colonized by cyanobacteria. This colonization takes place just a few millimeters beneath the rock surface, occupying spaces among salt crystals. Our work reveals that these communities are composed of extremely resistant Chroococcidiopsis morphospecies of cyanobacteria and associated heterotrophic bacteria. This newly discovered endolithic environment is an extremely dry and, at the same time, saline microbial habitat. Photosynthetic microorganisms within dry evaporite rocks could be an important and previously unrecognized target for the search for life within our Solar System.
在阿塔卡马沙漠最干旱的地区，土壤和岩石表面看不到任何生命形式。该地区的土壤仅含有分布在小块区域的微量细菌，而且环境过于干燥，不利于生活在半透明石头下的蓝细菌生存。在此我们表明，来自阿塔卡马沙漠最干旱地区的石盐蒸发岩被蓝细菌定殖。这种定殖发生在岩石表面以下几毫米处，占据盐晶体之间的空间。我们的研究表明，这些群落由极具抗性的蓝细菌色球藻形态种以及相关的异养细菌组成。这个新发现的石内环境是一个极其干燥且同时含盐的微生物栖息地。干燥蒸发岩中的光合微生物可能是在我们太阳系内寻找生命的一个重要且此前未被认识到的目标。
