title: Comparative metagenomics of two microbial mats at Cuatro Ciénegas Basin I: ancient lessons on how to cope with an environment under severe nutrient stress.
abstract: The Cuatro Ciénegas Basin (CCB) is an oasis in the desert of Mexico characterized by low phosphorus availability and by its great diversity of microbial mats. We compared the metagenomes of two aquatic microbial mats from the CCB with different nutrient limitations. We observed that the red mat was P-limited and dominated by Pseudomonas, while the green mat was N-limited and had higher species richness, with Proteobacteria and Cyanobacteria as the most abundant phyla. From their gene content, we deduced that both mats were very metabolically diverse despite their use of different strategies to cope with their respective environments. The red mat was found to be mostly heterotrophic, while the green mat was more autotrophic. The red mat had a higher number of transporters in general, including transporters of cellobiose and osmoprotectants. We suggest that generalists with plastic genomes dominate the red mat, while specialists with minimal genomes dominate the green mat. Nutrient limitation was a common scenario on the early planet; despite this, biogeochemical cycles were performed, and as a result the planet changed. The metagenomes of microbial mats from the CCB show the different strategies a community can use to cope with oligotrophy and persist.
authors.affiliation: Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México , México D.F., México.
authors.forename: Mariana
authors.initials: M
authors.lastname: Peimbert
authors.forename: Luis David
authors.initials: LD
authors.lastname: Alcaraz
authors.forename: Germán
authors.initials: G
authors.lastname: Bonilla-Rosso
authors.forename: Gabriela
authors.initials: G
authors.lastname: Olmedo-Alvarez
authors.forename: Felipe
authors.initials: F
authors.lastname: García-Oliva
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Segovia
authors.forename: Luis E
authors.initials: LE
authors.lastname: Eguiarte
authors.forename: Valeria
authors.initials: V
authors.lastname: Souza
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D000458:Cyanobacteria / Q000235:genetics; D004777:Environment; D004783:Environmental Microbiology; D005798:Genes, Bacterial / Q000235:genetics; D005819:Genetic Markers; D054892:Metagenome / Q000235:genetics; D056186:Metagenomics / Q000379:methods*; D008800:Mexico; D025341:Principal Component Analysis; D020560:Proteobacteria / Q000235:genetics; D011549:Pseudomonas / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013312:Stress, Physiological / Q000235:genetics*
chemical_list: D005819:Genetic Markers