Screening for Photolyases and LOV-domains in UV-resistant extremophile bacteria isolated from High-Altitude Andean Lakes in Argentina.

V. H. ALBARRACÍN, G. PATHAK, M. E. FARÍAS, C. BORSARELLI, W. GÄRTNER

Dusseldorf, Alemania

Congreso; 15th INTERNATIONAL CONGRESS IN PHOTOBIOLOGY; 2009

High-Altitude Lakes (HAAL; between 3,000 and 6,000 masl) at the northwest of Argentina in the Puna and Andean regions, are considered extreme environments of biotechnological interest (Fig. 1). These wetlands experience a wide daily range in temperatures (0-40º C), are slight saline to hypersaline, and are subject to low phosphate availability and to high intensity of solar UV-B radiation (Table 1). Microbial communities living in such aquatic ecosystems are tolerant to large fluctuations in environmental factors in addition to steady-state extreme conditions. A collection of 200 extremophile strains from these unique environments contain representatives of Eubacteria, Firmicutes and Actinobacteria, Proteobacteria (gamma, alpha and beta) and Archaea. Amongst the microorganisms isolated and characterized, a widespread UV-B resistance profile was found. Particularly, some isolates were able to survive during 36 h to a high UV-B irradiation (53.3 kJ/m2) while they displayed low CPD accumulation, which suggest a very efficient repair of photo-damage in DNA by photo-dependent mechanisms. We are particularly interested in investigating the enzymes implied in the direct photo-repair of DNA damage such as photolyases, because, so far, no records of these enzymes has been reported in these extremophile bacteria. Blue light-sensitive Light, oxygen, voltage (LOV) protein domains form a subset of the large and diverse Per-ARNT-Sim (PAS) domain superfamily that accomplish light-induced cellular signalling processes across all kingdoms of life. Since the extremophile bacteria found in the HAAL are highly conditioned by light irradiance we think that LOV-domains may play a very important role in regulating activities in DNA repair.2) while they displayed low CPD accumulation, which suggest a very efficient repair of photo-damage in DNA by photo-dependent mechanisms. We are particularly interested in investigating the enzymes implied in the direct photo-repair of DNA damage such as photolyases, because, so far, no records of these enzymes has been reported in these extremophile bacteria. Blue light-sensitive Light, oxygen, voltage (LOV) protein domains form a subset of the large and diverse Per-ARNT-Sim (PAS) domain superfamily that accomplish light-induced cellular signalling processes across all kingdoms of life. Since the extremophile bacteria found in the HAAL are highly conditioned by light irradiance we think that LOV-domains may play a very important role in regulating activities in DNA repair.photolyases, because, so far, no records of these enzymes has been reported in these extremophile bacteria. Blue light-sensitive Light, oxygen, voltage (LOV) protein domains form a subset of the large and diverse Per-ARNT-Sim (PAS) domain superfamily that accomplish light-induced cellular signalling processes across all kingdoms of life. Since the extremophile bacteria found in the HAAL are highly conditioned by light irradiance we think that LOV-domains may play a very important role in regulating activities in DNA repair.Light, oxygen, voltage (LOV) protein domains form a subset of the large and diverse Per-ARNT-Sim (PAS) domain superfamily that accomplish light-induced cellular signalling processes across all kingdoms of life. Since the extremophile bacteria found in the HAAL are highly conditioned by light irradiance we think that LOV-domains may play a very important role in regulating activities in DNA repair. Accordingly, the aim of this work is to screen for photolyases and LOV-domains genes in selected UV-resistant bacteria from HAAL.