INVESTIGADORES
ALVAREZ Hector Manuel
congresos y reuniones científicas
Título:
Genomic and physiological analysis of Vogesella sp. Strain EB isolated in Andean Patagonia
Autor/es:
ARRUA DAY P; ALVAREZ HM
Lugar:
Mar del Plata
Reunión:
Congreso; VIII Congreso Argentino de Microbiologia General (SAMIGE); 2012
Institución organizadora:
Sociedad Argentina de Microbiología General (SAMIGE)
Resumen:
Strain EB is a psychrotropic member of the microbial biodiversity of superficial bodies of water of Andean Patagonia, belonging to the little studied Vogesella genus, and with the ability to produce secondary metabolites. Strain EB was isolated from a sample of an oil-like film collected from the surface of natural aquifers in El Bolsón (Río Negro). For these reasons, the complete genome of strain EB was sequenced and analyzed in this study, as well as its capabilities for producing reserve compounds and secondary metabolites with ecological importance and biotechnological potential. Genome sequencing of strain EB was performed as a service by INDEAR (Rosario, Argentina). A detailed bioinformatic analysis using the available genomic databases of strain EB and related bacteria was performed. Reserve compounds and secondary metabolites production was analyzed by diverse procedures, such as Sudan Black staining, thin layer chromatography, spectrometry and electron microscopy. The complete genome of this Gram-negative bacterium consisted of 3,542,274 bp with 64.26 % of GC content, and 3,440 coding sequences. Genome analysis revealed a complex and extensive biology, containing genes for a facultative anaerobic metabolism, pathways for storage material biosynthesis such as polyhydroxybutyrate (PHB) and cyanophycin, pathways for secondary metabolites production such as indigoidine pigment, and proteins involved in diverse adaptation mechanisms, such as cobalt-zinc-cadmium resistance proteins, copper tolerance proteins, Paraquat-inducible proteins, nitrate and nitrite ammonification proteins, among others. Cells were able to grow at 28 ºC as well as at 10º C in complex media and in mineral salts medium with glucose or glycerol as sole carbon sources. The blue pigment; indigoidine, which was produced only during cultivation at low temperatures, was accumulated in the cellular envelope as suggested microscopy analyses. The pigment, which may protect membranes from oxidative stress, was only produced during cultivation under nitrogen-rich conditions. Cyanophycin-like granules were observed by electron microscopy under such conditions. In contrast, PHB was accumulated by cells during growth on glycerol at 10 ºC under nitrogen-limiting conditions, whereas indigoidine and cyanophycin were not produced in such conditions. The results indicated that the indigenous strain EB is endowed with a diversity of pathways and mechanisms that permit the metabolic adaptation of cells to the extreme conditions of Patagonia. The biosynthesis of indigoidine, PHB and cyanophycin, and the distribution of carbon and nitrogen intermediates to these pathways, seem to be dependent on the nitrogen content in media. Finally, metabolism of strain EB may serve as a biochemical platform for diverse biotechnological products.