RESUMEN

The Viking missions showed the martian soil to be lifeless and depleted in organic material and indicated the presence of one or more reactive oxidants. Here we report the presence of Mars-like soils in the extreme arid region of the Atacama Desert. Samples from this region had organic species only at trace levels and extremely low levels of culturable bacteria. Two samples from the extreme arid region were tested for DNA and none was recovered. Incubation experiments, patterned after the Viking labeled-release experiment but with separate biological and nonbiological isomers, show active decomposition of organic species in these soils by nonbiological processes.

Asunto(s)

Bacterias/crecimiento & desarrollo , Clima Desértico , Microbiología del Suelo , Microbiología del Aire , Alanina/química , Alanina/metabolismo , Bacterias/clasificación , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Benceno/análisis , Biodiversidad , Chile , Recuento de Colonia Microbiana , ADN Bacteriano/análisis , ADN Bacteriano/genética , Formiatos/análisis , Formiatos/química , Formiatos/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Genes de ARNr , Glucosa/química , Glucosa/metabolismo , Marte , Compuestos Orgánicos/análisis , Oxidación-Reducción , Fotoquímica , Reacción en Cadena de la Polimerasa , Estereoisomerismo , Temperatura