MODENUTTI Beatriz Estela
Bacterial Community Structure in Patagonian Andean Lakes Abov e and Below Timberline: From Community Composition to Community Function
BASTIDAS NAVARRO, M.,; E. BALSEIRO,; B. MODENUTTI,
Lugar: New York; Año: 2014 vol. 68 p. 528 - 528
Lakes located above the timberline are remote systems with anumber of extreme environmental conditions, becoming physicallyharsh ecosystems, and sensors of global change. We analyzebacterial community composition and community-levelphysiological profiles in mountain lakes located in an altitudegradient in North Patagonian Andes below and above thetimberline, together with dissolved organic carbon (DOC)characterization and consumption. Our results indicated a decreasein 71 % of DOC and 65 % in total dissolved phosphorus (TDP)concentration as well as in bacteria abundances along the altituderange (1,380 to 1,950 m a.s.l.). Dissolved organic matter (DOM)fluorescence analysis revealed a low global variability composedby two humic-like components (allochthonous substances) and asingle protein-like component (autochthonous substances). Lakesbelow the timberline showed the presence of all the threecomponents, while lakes above the timberline the protein-likecompound constituted the main DOC component. Furthermore,bacterial community composition similarity and ordination analysisshowed that altitude and resource concentration (DOC and TDP)were the main variables determining the ordination of groups.Community-level physiological profiles showed a mismatch withbacteria community composition (BCC), indicating the absence of arelationship between genetic and functional diversity in the altitudegradient. However, carbon utilization efficiencies varied accordingto the presence of different compounds in DOM bulk. The obtainedresults suggest that the different bacterial communities in thesemountain lakes seem to have similar metabolic pathways in orderto be able to exploit the available DOC molecules.