UV-Resistant Actinobacteria from High-Altitude Andean Lakes: Isolation, Characterization and Antagonistic Activities

RASUK, MARÍA CECILIA; FERRER, GABRIELA MÓNICA; KURTH, DANIEL; PORTERO, LUCIANO RAÚL; FARÍAS, MARÍA EUGENIA; ALBARRACÍN, VIRGINIA HELENA

PHOTOCHEMISTRY AND PHOTOBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2017 vol. 93 p. 865 - 880

0031-8655

Polyextremophiles are present in a wide variety of extreme environments in which they must overcome various hostile conditions simultaneously such as high UVB radiation, extreme pHs and temperatures, elevated salt and heavy-metal concentration, low-oxygen pressure and scarce nutrients. High-altitude Andean lakes (HAALs; between 2000 and 4000 m) are one example of these kinds of ecosystems suffering from the highest total solar and UVB radiation on Earth where an abundant and diverse polyextremophilic microbiota was reported. In this work, we performed the first extensive isolation of UV-resistant actinobacteria from soils, water, sediments and modern stromatolites at HAALs. Based on the 16S rRNA sequence, the strains were identified as members of the genera Streptomyces, Micrococcus, Nesterenkonia, Rhodococcus, Microbacterium, Kocuria, Arthrobacter, Micromonospora, Blastococcus, Citrococcus and Brevibacterium. Most isolates displayed resistance to multiple environmental stress factors confirming their polyextremophilic nature and were able to produce effective antimicrobial compounds. HAALs constitute a largely unexplored repository of UV-resistant actinobacteria, with high potential for the biodiscovery of novel natural products.