TY - JOUR
T1 - A microbial oasis in the hypersaline atacama subsurface discovered by a life detector chip
T2 - Implications for the search for life on mars
AU - Parro, Victor
AU - De Diego-Castilla, Graciela
AU - Moreno-Paz, Mercedes
AU - Blanco, Yolanda
AU - Cruz-Gil, Patricia
AU - Rodríguez-Manfredi, José Antonio
AU - Fernández-Remolar, David
AU - Gómez, Felipe
AU - Gómez, Manuel J.
AU - Rivas, Luis A.
AU - Demergasso, Cecilia
AU - Echeverría, Alex
AU - Urtuvia, Viviana N.
AU - Ruiz-Bermejo, Marta
AU - García-Villadangos, Miriam
AU - Postigo, Marina
AU - Sánchez-Román, Mónica
AU - Chong-Díaz, Guillermo
AU - Gómez-Elvira, Javier
PY - 2011/12/1
Y1 - 2011/12/1
N2 - The Atacama Desert has long been considered a good Mars analogue for testing instrumentation for planetary exploration, but very few data (if any) have been reported about the geomicrobiology of its salt-rich subsurface. We performed a Mars analogue drilling campaign next to the Salar Grande (Atacama, Chile) in July 2009, and several cores and powder samples from up to 5m deep were analyzed in situ with LDChip300 (a Life Detector Chip containing 300 antibodies). Here, we show the discovery of a hypersaline subsurface microbial habitat associated with halite-, nitrate-, and perchlorate-containing salts at 2m deep. LDChip300 detected bacteria, archaea, and other biological material (DNA, exopolysaccharides, some peptides) from the analysis of less than 0.5g of ground core sample. The results were supported by oligonucleotide microarray hybridization in the field and finally confirmed by molecular phylogenetic analysis and direct visualization of microbial cells bound to halite crystals in the laboratory. Geochemical analyses revealed a habitat with abundant hygroscopic salts like halite (up to 260g kg -1) and perchlorate (41.13μg g -1 maximum), which allow deliquescence events at low relative humidity. Thin liquid water films would permit microbes to proliferate by using detected organic acids like acetate (19.14μg g -1) or formate (76.06μg g -1) as electron donors, and sulfate (15875μg g -1), nitrate (13490μg g -1), or perchlorate as acceptors. Our results correlate with the discovery of similar hygroscopic salts and possible deliquescence processes on Mars, and open new search strategies for subsurface martian biota. The performance demonstrated by our LDChip300 validates this technology for planetary exploration, particularly for the search for life on Mars.
AB - The Atacama Desert has long been considered a good Mars analogue for testing instrumentation for planetary exploration, but very few data (if any) have been reported about the geomicrobiology of its salt-rich subsurface. We performed a Mars analogue drilling campaign next to the Salar Grande (Atacama, Chile) in July 2009, and several cores and powder samples from up to 5m deep were analyzed in situ with LDChip300 (a Life Detector Chip containing 300 antibodies). Here, we show the discovery of a hypersaline subsurface microbial habitat associated with halite-, nitrate-, and perchlorate-containing salts at 2m deep. LDChip300 detected bacteria, archaea, and other biological material (DNA, exopolysaccharides, some peptides) from the analysis of less than 0.5g of ground core sample. The results were supported by oligonucleotide microarray hybridization in the field and finally confirmed by molecular phylogenetic analysis and direct visualization of microbial cells bound to halite crystals in the laboratory. Geochemical analyses revealed a habitat with abundant hygroscopic salts like halite (up to 260g kg -1) and perchlorate (41.13μg g -1 maximum), which allow deliquescence events at low relative humidity. Thin liquid water films would permit microbes to proliferate by using detected organic acids like acetate (19.14μg g -1) or formate (76.06μg g -1) as electron donors, and sulfate (15875μg g -1), nitrate (13490μg g -1), or perchlorate as acceptors. Our results correlate with the discovery of similar hygroscopic salts and possible deliquescence processes on Mars, and open new search strategies for subsurface martian biota. The performance demonstrated by our LDChip300 validates this technology for planetary exploration, particularly for the search for life on Mars.
KW - Atacama Desert
KW - Biopolymers
KW - Biosensor
KW - In situ measurement
KW - Life detection
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U2 - 10.1089/ast.2011.0654
DO - 10.1089/ast.2011.0654
M3 - Article
C2 - 22149750
AN - SCOPUS:80054859485
VL - 11
SP - 969
EP - 996
JO - Astrobiology
JF - Astrobiology
SN - 1531-1074
IS - 10
ER -