ALBARRACIN Virginia Helena
capítulos de libros
Extreme Microbiology at Laguna Socompa: A High-Altitude Andean Lake (3570 m a.s.l.) in Salta, Argentina
Microbial Ecosystems in Central Andes Extreme Environments
Lugar: Cham; Año: 2020; p. 205 - 220
UV irradiation and the effect on microbial diversity and ecological impact wasstudied in Laguna Socompa. It is considered a hypersaline and moderate alkalinelake and is located at 3570 m a.s.l. at the base of the active Socompa volcano. Themicrobialites thriving on its shore are the highest on Earth (Farías et al. 2013),which exhibit an atypical microbial community with abundant representatives ofDeinococcus?Thermus, Rhodobacteraceae, Desulfobacterales, and Spirochaetes.Their metagenome showed a high proportion of sequences depicting less than 80%identity to the best hit in the NCBI database, an indication of novel distant lineages(Farías et al. 2013). Several bacterial and archaeal strains from Socompa stromatolites were isolated, physiologically characterized, and subjected to genome pyrosequencing (Farías et al. 2011b; Ordoñez et al. 2013; Gorriti et al. 2014; Albarracínet al. 2016). Screening of the genomes of these strains, i.e., Exiguobacterium sp.S17, Sphingomonas sp. S17, Nesterenkonia sp. Act20, and Salinivibrio spp., yieldedgenes putatively encoding essential traits for survival under multiple extreme environmental conditions, e.g., high levels of UV radiation, elevated salinity, and thepresence of poisonous arsenic concentrations (Farías et al. 2011b; Belfiore et al.2013; Ordoñez et al. 2013, 2015; Gorriti et al. 2014; Albarracín et al. 2016).Additionally, a new species of Salinivibrio was recently proposed in this microbialecosystem: Salinivibrio socompensis (Galisteo et al. 2019).Thus, the study of microbes associated with Socompa stromatolites and theirenvironment opens a window to the past by providing a modern analog to theirPrecambrian counterparts. On the other hand, they serve as models for furtherunderstanding of adaptation and the function of proteins under extremely harsh conditions, which offers a biotechnological interest.In this chapter, we compare the microbial diversity of the different microbialniches found in Laguna Socompa (3570 m), i.e., lake water, sediments, stromatolites, and soil surrounding the lake.