PROIMI   05436
PLANTA PILOTO DE PROCESOS INDUSTRIALES MICROBIOLOGICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Large linear plasmids in Micrococcus strains isolated from Argentinean high altitude wetlands.
Autor/es:
DIB, JR; WAGENKNECHT, M; FARIAS, M.E.; MEINHARDT F.
Lugar:
Bochum, Alemania
Reunión:
Conferencia; Annual Conference of the Association for General and Applied Microbiology (VAAM); 2009
Institución organizadora:
the Association for General and Applied Microbiology
Resumen:
High altitude wetlands are pristine and extreme environments in the northwest of Argentina. Three strains belonging to the genus Micrococcus, isolated from such environments, were found to harbour  large linear plasmids (93 - 114 kb). Though for a number of Actinobacteria, including members of  the  genera Arthrobacter, Streptomyces, Mycobacterium and Rhodococcus, linear plasmids were found to exist, these are novel elements for Micrococcus spp. Three giant plasmids, pA1 (114 kb), pH5 (114 kb) and pV7 (93 kb) were separated and isolated by PFGE and electroelution, and were subsequently tested for sensitivity to Exonuclease III and λ-exonuclease, which hydrolyze dsDNA in 3´-5´ and 5´-3´ direction, respectively. Exonuclease III completely degraded the plasmids, whereas λ-exonuclease did not, indicating that the 5´ ends are protected, presumably by covalently attached terminal proteins. Uniform restriction patterns were obtained for pA1 and pH5; whereas pV7 was different. Consistently, by making use of a cloned pA1 fragment as the probe, Southern analysis revealed identical hybridization patterns for pA1 and pH5. Since Micrococcus strains harboring either pA1 or pH5 were isolated from different locations, these plasmids may play a role in the adaptation to extreme environmental conditions in Argentinean high altitude wetlands. Julián R. Dib thanks DAAD for financial support.