The Atacama Desert, located in northern Chile, is the driest and oldest Desert on Earth. Research aimed at the understanding of this unique habitat and its diverse microbial ecosystems began only a few years ago, driven mainly by NASA's astrobiology program. A milestone in these efforts was a paper published in 2003, when the Atacama was shown to be a terrestrial analogue site for Mars. From then on, studies have focused on examining every possible niche suitable for microbial life in this extreme environment. Habitats as different as the underside of quartz rocks, fumaroles in the Andes Mountains, the inside of halite evaporates and caves of the coastal range, among others, have shown that life has found ingenious ways to adapt to extreme conditions such as low water availability, high salt concentration and intense UV radiation.
In this seminar, the isolation and characterization of microorganisms from several of these habitats will be described. These include bacteria highly tolerant to UV radiation isolated from soils in the hyperarid region, an ancient photosynthetic Cyanidium eukaryote that forms biofilms in a coastal cave, a novel subaerial Dunaliella species growing on cave spider webs and a Gloeocapsopsis cyanobacteria thriving under quartz rocks that is highly tolerant to desiccation. Some of the molecular and morphological adaptations of the latter microorganism to this stressful condition will be described. Some of the broader philosophical and theological implications will be presented briefly.
PROF. RAFAEL VICUÑA studied Biochemistry at Universidad de Chile in Santiago, where he received his undergraduate degree in 1972. Then he obtained his Masters (1976) and PhD (1978) degrees in Molecular Biology at the Albert Einstein College of Medicine, Nueva York. He is presently full professor at the Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, in Santiago, where he has formerly been Vice-President for Academic Affairs and Dean of his Faculty. He is a member of the Chilean Academy of Sciences, the Latin American Academy of Sciences, the Academy of Sciences for the Developing World (TWAS) and the Pontifical Academy of Sciences. He has published around 100 papers in the fields of enzymology and regulation of gene expression in bacteria and fungi and around 50 papers dealing with either science and religion or science and society.