title: Salt deliquescence drives photosynthesis in the hyperarid Atacama Desert.
abstract: Endolithic cyanobacteria are found in halite nodules in the hyperarid core of the Atacama Desert. Using Pulse Amplitude Modulated Fluorometry, we show here that photosynthetic systems of these cyanobacteria become active when the relative humidity rises above 70% and the salt becomes wet by way of deliquescence. This is the first evidence of active metabolism in the hyperarid core of the Atacama, and supports the view of a microbial community sustained by deliquescence. Our results expand the water activity envelope of life on Earth.
authors.affiliation: Carl Sagan Center at the SETI Institute, 189 Bernardo Ave., Mountain View, CA 94043, USA. adavila@seti.org
authors.forename: Alfonso F
authors.initials: AF
authors.lastname: Davila
authors.forename: Ian
authors.initials: I
authors.lastname: Hawes
authors.forename: Carmen
authors.initials: C
authors.lastname: Ascaso
authors.forename: Jacek
authors.initials: J
authors.lastname: Wierzchos
mesh_terms: D000458:Cyanobacteria / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D003889:Desert Climate; D005470:Fluorometry; D010788:Photosynthesis; D012492:Salts / Q000378:metabolism*; D012988:Soil Microbiology
chemical_list: D012492:Salts