María Eugenia Farías

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A total of 88 bacterial strains were isolated from six Andean lakes situated at altitudes ranging from 3,400 to 4,600 m above sea level: L. Aparejos (4,200 m), L. Negra (4,400 m), L. Verde (4,460 m), L. Azul (4,400 m), L. Vilama (4,600 m), and Salina Grande (3,400 m). Salinity ranged from 0.4 to 117 ppm. General diversity was determined by denaturing(More)
High-altitude Andean wetlands are pristine environments with extreme conditions such as high UV radiation, high heavy metal content (mainly arsenic), high salinity, and oligotrophy. In this paper, the UV-B resistance and tolerance to arsenic of phylogenetically characterized bacteria (Actinobacteria [six isolates], Firmicutes [four isolates], and(More)
Acinetobacter johnsonii A2 isolated from the natural community of Laguna Azul (Andean Mountains at 4,560 m above sea level), Serratia marcescens MF42, Pseudomonas sp. strain MF8 isolated from the planktonic community, and Cytophaga sp. strain MF7 isolated from the benthic community from Laguna Pozuelos (Andean Puna at 3,600 m above sea level) were subjected(More)
The North-Western part of Argentina is particularly rich in wetlands located in the Puna in an altitude between 3,600 and 4,600 m above sea level. Most of these high-altitude Andean lakes are inhospitable areas due to extreme habitat conditions such as high contents of toxic elements, particularly arsenic. Exiguobacterium sp. S17, isolated from(More)
In this paper, we report the presence of sedimentary microbial ecosystems in wetlands of the Salar de Atacama. These laminated systems, which bind, trap and precipitate mineral include: microbial mats at Laguna Tebenquiche and Laguna La Brava, gypsum domes at Tebenquiche and carbonate microbialites at La Brava. Microbial diversity and key biogeochemical(More)
High-altitude Andean lakes (HAAL) are a treasure chest for microbiological research in South America. Their indigenous microbial communities are exposed to extremely high UV irradiation and to multiple chemical extremes (Arsenic, high salt content, alkalinity). Microbes are found both, free-living or associated into microbial mats with different degrees of(More)
We describe stromatolites forming at an altitude of 3570 m at the shore of a volcanic lake Socompa, Argentinean Andes. The water at the site of stromatolites formation is alkaline, hypersaline, rich in inorganic nutrients, very rich in arsenic, and warm (20-24°C) due to a hydrothermal input. The stromatolites do not lithify, but form broad, rounded and(More)
Isolation of most ultraviolet B (UV-B)-resistant culturable bacteria that occur in the habitat of Laguna Azul, a high-altitude wetland [4554 m above sea level (asl)] from the Northwestern Argentinean Andes, was carried out by culture-based methods. Water from this environment was exposed to UV-B radiation under laboratory conditions during 36 h, at an(More)
Laguna (L.) Negra and L. Verde are high altitude Andean lakes located at the 4,400 m altitude in the Andean desert (Puna) in the Argentine northwest. Both lakes are exposed to extreme weather conditions but differ in salinity contents (salinity 6.7% for L. Negra and 0.27% for L. Verde). The aim of this work was to isolate ultraviolet B fraction (UV-B)(More)