ALBARRACIN Virginia Helena
Culture-dependent and independent methods revealed dominance of halophilic Euryarchaeota at High-Altitude Andean Lakes
MALDONADO, MJ; ALBARRACÍN, VH; LARA, JA; FERRERO, MA; FARÍAS, ME
AQUATIC MICROBIAL ECOLOGY
The hypersaline and extreme environments of the so-called High Altitude Andean Lakes (HAAL) in the dry central region of the Andes are considered pristine ecosystems of biotechnological interest. By using culture-dependent and -independent methods, this study aims to describe the phylogenetic affiliation and ecological importance of archaea thriving at extreme, hypersaline lakes and salt flats in Argentinean and Chilean Puna. To this purpose, water and sediment samples were collected from fourteen lakes and salt flats, locally called Laguna and Salar. Denaturing Gradient Gel Electrophoresis (DGGE) indicated that representatives of the Euryarchaeota phylum dominated the microbial community in all the samples. Most of the DGGE bands were assigned to the Halobacteriaceae family, while the rest corresponded to Methanocaldococcaceae, Methanobacteriaceae, Methanococcaceae, Methanosarcinaceae and Methanothermaceae. In addition, isolation procedures yielded single colonies of 53 pure isolates belonging to the following genera: Haloarcula, Halomicrobium, Halopiger, Halorubrum, Natrialba, Natrinema, Natronorubrum and Natronococcus. All strains proved to be poly-extremophils, with high tolerance to NaCl, UV-B radiation and high arsenic concentration.