Posted: Monday, October 29, 2012
"Cuatro Cienegas is extraordinarily similar to Mars. As well as the Gale crater where Curiosity is currently located on its exploration of the red planet, this landscape is the home to gypsum formed by fire beneath the seabed," as explained to SINC by Valeria Souza, evolutionary ecologist at the National Autonomous University of Mexico (UNAM).
The researcher states that sulphur components from magma and minerals from the sea (carbonates and molecules with magnesium) are required to form gypsum. In the case of the Cuatro Cienegas Basin, the magma under the seabed was very active. In fact, it allowed for the continent displacement during the Jurassic Period: "Here was where the supercontinent Pangaea opened up some 200 million years ago, pushing the hemisphere north from the equator where it is now."
In the case of Mars, the scientists have not been able to confirm tectonic movement in its crust at any point, but they believe that a large meteorite crashed into its primitive sea. The fact that probing has detected gypsum in the Gale crater indicates that mineral-rich water was present and that sulphur was able to form due to the impact of the meteorite causing the crater.
It is no easy task to find a place on Earth similar to this Martian environment, except in Cuatro Cienegas. For this reason astrobiologists toil in their work to understand how its bacterial communities work. "This oasis in the middle of the Chihuahua desert is a time machine for organisms that, together as a community, have transformed our blue planet yet have survived all extinctions. How they have managed to do this can be revealed by their genes," says Souza.
The team have analyzed the 'metagenomes', the genome of the different bacterial communities that proliferate in these marshes by adapting parallel strategies to overcome survival challenges in a place with so little nutrients.
Green, Red and Blue Springs
The results published in the journal 'Astrobiology' reflect the existence of two communities in different pits. for example. One is 'green' and is formed by cyanobacteria and proteobacteria that have adapted to the lack of nitrogen. Another is 'red' and is made of Pseudomonas and other micro-organisms that live without hardly any phosphorous. There are also blue springs which are generally deeper and lacking in nutrients.
"Understanding the usage and exploitation strategies of phosphorous is necessary in understanding what could happen in extreme scenarios like on other planets where there is a possibly serious limitation to this and other nutrients," explains Luis David Alcaraz, Mexican researcher participating in the study from the Higher Public Health Research center of Valencia, Spain.
This project has enjoyed the support of Mexico's Carlos Slim Foundation and the Technological Innovation Research Project Support Program of UNAM. It has also received the support of the National Science Foundation (NSF) of the USA and NASA, which has been studying Cuatro Cienegas for more than a decade.
The Cuatrocienegas Flora and Fauna Protection Area is a protected area but the scientists and conservation groups are worried that its water is being over exhausted. "The bacterial communities have survived all types of cataclysms here such as the extinction of the dinosaurs or the majority of marine creatures. But, the only thing they are not adapted for is the lack of water," warns Souza.
Agencia SINC, Madrid, Spain
+34 91 425 18 20
Universidad Nacional Autonoma de Mexico (UNAM)
+52 55 5622 9006
Luis David Alcaraz
Universidad Nacional Autonoma de Mexico (UNAM)
Lopez-Lozano NE, Eguiarte LE, Bonilla-Rosso G, Garcia-Oliva F, Martinez-Piedragil C, Rooks C, Souza V. "Bacterial communities and the nitrogen cycle in the gypsum soils of cuatro cienegas basin, coahuila: a Mars analogue". Astrobiology 12(7): 699-709, 2012: http://dx.doi.org/10.1089/ast.2012.0840
Mariana Peimbert, Luis David Alcaraz, German Bonilla-Rosso, Gabriela Olmedo-Alvarez, Felipe Garcia-Oliva, Lorenzo Segovia, Luis E. Eguiarte, Valeria Souza. "Comparative Metagenomics of Two Microbial Mats at Cuatro Cienegas Basin I: Ancient Lessons on How to Cope with an Environment Under Severe Nutrient Stress". Astrobiology 12 (7), 2012: http://dx.doi.org/10.1089/ast.2011.0694
German Bonilla-Rosso, Mariana Peimbert, Luis David Alcaraz, Ismael Hernandez, Luis E. Eguiarte, Gabriela Olmedo-Alvarez, Valeria Souza. "Comparative Metagenomics of Two Microbial Mats at Cuatro Cienegas Basin II: Community Structure and Composition in Oligotrophic Environments". Astrobiology 12 (7), 2012: http://dx.doi.org/10.1089/ast.2011.0724
// end //