Microbial colonisation of chasmoendolithic habitats in the hyper-arid zone of the Atacama Desert
[ 摘要 ]
Efforts in searching for microbial life in the driest part of AtacamaDesert, Chile, revealed a small number of lithic habitats that can beconsidered as environmental refuges for life. In this study, we describe forthe first time chasmoendolithic colonisation of fissures and cracks ofrhyolite-gypsum and calcite rocks collected in the hyper-arid zone of thedesert. The use of high-throughput sequencing revealed that the Atacama rockcommunities comprised a few dominant phylotypes and a number of lessabundant taxa representing the majority of the total community diversity.The chasmoendolithic communities were dominated by Chroococcidiopsis species cyanobacteriaand supported a number of heterotrophic bacterial lineages. Micro-climatedata and geomorphic analysis of the mineral substrates suggested higherwater availability in the calcite rocks in the form of enhanced waterretention in the complex network of cracks and fissures of these rocks aswell as increased occurrence of liquid water in the form of dewfall. Thesecharacteristics were associated with a diverse community of phototrophic andheterotrophic bacteria in the calcite chasmoendolithic ecosystem. This studyis another example of the diversity of adaptive strategies at the limit forlife and illustrates that rock colonisation is controlled by a complex setof factors.
[ 发布日期 ] 2013-04-12
[ 发文字号 ] 996390|doi:10.5194/bg-10-2439-2013