Papers by Cristina Dorador
Revista Chilena De Historia Natural, Mar 1, 2013
RESUMEN El lago Chungará, es el más austral y de mayor altura de los lagos altoandinos, está ubic... more RESUMEN El lago Chungará, es el más austral y de mayor altura de los lagos altoandinos, está ubicado a 4.520 m de altitud en el altiplano chileno (18º14'S, 69º09'O); es un lago polimíctico-frío, con origen tectónico-volcánico y 34 m de profundidad máxima. Presenta ...
Poster in 33 Congreso Chileno De Microbiologia 29 11 02 12 2011 Olmue Chile, 2011
Poster in 4 Congress of European Microbiologists Fems 2011 26 30 06 2011 Genf Switzerland, 2011
Gayana (Concepción), 2015
Advanced Materials Research, 2013
Revista chilena de …, 2007
Rapel reservoir is an eutrophic system in Chile that has undergone a series of anthropogenic impa... more Rapel reservoir is an eutrophic system in Chile that has undergone a series of anthropogenic impacts in recent decades. To provide a better understanding of the processes occurring in the reservoir, we examined bacterial composition from surface ...
Journal of Geophysical Research-Part G-BioGeo, 2011
Journal of Geophysical Research-Part G-BioGeo, 2011
Research in Microbiology
Microorganisms are used to aid the extraction of valuable metals from low-grade sulfide ores in m... more Microorganisms are used to aid the extraction of valuable metals from low-grade sulfide ores in mines worldwide, but relatively little is known about this process in cold environments. This study comprises a preliminary analysis of the bacterial diversity of the polyextremophilic acid River Aroma located in the Chilean Altiplano, and revealed that Betaproteobacteria was the most dominant bacterial group (Gallionella-like and Thiobacillus-like). Taxa characteristic of leaching environments, such Acidithiobacillus and Leptospirillum, were detected at low abundances. Also, bacteria not associated with extremely acidic, metal-rich environments were found. After enrichment in iron- and sulfur-oxidizing media, we isolated and identified a novel psychrotolerant Acidithiobacillus ferrivorans strain ACH. This strain can grow using ferrous iron, sulfur, thiosulfate, tetrathionate and pyrite, as energy sources. Optimal growth was observed in the presence of pyrite, where cultures reached a cel...
Research in Microbiology, 2014
Microorganisms are used to aid the extraction of valuable metals from low-grade sulfide ores in m... more Microorganisms are used to aid the extraction of valuable metals from low-grade sulfide ores in mines worldwide, but relatively little is known about this process in cold environments. This study comprises a preliminary analysis of the bacterial diversity of the polyextremophilic acid River Aroma located in the Chilean Altiplano, and revealed that Betaproteobacteria was the most dominant bacterial group (Gallionellalike and Thiobacillus-like). Taxa characteristic of leaching environments, such Acidithiobacillus and Leptospirillum, were detected at low abundances. Also, bacteria not associated with extremely acidic, metal-rich environments were found. After enrichment in iron-and sulfuroxidizing media, we isolated and identified a novel psychrotolerant Acidithiobacillus ferrivorans strain ACH. This strain can grow using ferrous iron, sulfur, thiosulfate, tetrathionate and pyrite, as energy sources. Optimal growth was observed in the presence of pyrite, where cultures reached a cell number of 6.5$10 7 cells mL À1 . Planktonic cells grown with pyrite showed the presence of extracellular polymeric substances (10 C and 28 C), and a high density of cells attached to pyrite grains were observed at 10 C by electron microscopy. The attachment of cells to pyrite coupons and the presence of capsular polysaccharides were visualized by using epifluorescence microscopy, through nucleic acid and lectin staining with Syto ® 9 and TRITC-Con A, respectively. Interestingly, we observed high cell adhesion including the formation of microcolonies within 21 days of incubation at 4 C, which was correlated with a clear induction of capsular polysaccharides production. Our data suggests that attachment to pyrite is not temperature-dependent in At. ferrivorans ACH. The results of this study highlight the potential of this novel psychrotolerant strain in oxidation and attachment to minerals under low-temperature conditions.
Fundamental and Applied Limnology / Archiv für Hydrobiologie, 2013
Journal of Geophysical Research, 2009
1] The High Lakes Project is a multidisciplinary astrobiological investigation studying high-alti... more 1] The High Lakes Project is a multidisciplinary astrobiological investigation studying high-altitude lakes between 4200 m and 6000 m elevation in the Central Andes of Bolivia and Chile. Its primary objective is to understand the impact of increased environmental stress on the modification of lake habitability potential during rapid climate change as an analogy to early Mars. Their unique geophysical environment and mostly uncharted ecosystems have added new objectives to the project, including the assessment of the impact of low-ozone/high solar irradiance in nonpolar aquatic environments, the documentation of poorly known ecosystems, and the quantification of the impact of climate change on lake environment and ecosystem. Data from 2003 to 2007 show that UV flux is 165% that of sea level with maximum averaged UVB reaching 4 W/m 2 . Short UV wavelengths (260-270 nm) were recorded and peaked at 14.6 mW/m 2 . High solar irradiance occurs in an atmosphere permanently depleted in ozone falling below ozone hole definition for 33-36 days and between 30 and 35% depletion the rest of the year. The impact of strong UVB and UV erythemally weighted daily dose on life is compounded by broad daily temperature variations with sudden and sharp fluctuations. Lake habitat chemistry is highly dynamical with notable changes in yearly ion concentrations and pH resulting from low and variable yearly precipitation. The year-round combination of environmental variables define these lakes as end-members. In such an environment, they host ecosystems that include a significant fraction of previously undescribed species of zooplankton, cyanobacterial, and bacterial populations.
Revista Chilena De Historia Natural, 2005
Journal of Geophysical Research, 2010
Revista Chilena De Historia Natural, 2003
El lago Chungará, es el más austral y de mayor altura de los lagos altoandinos, está ubicado a 4.... more El lago Chungará, es el más austral y de mayor altura de los lagos altoandinos, está ubicado a 4.520 m de altitud en el altiplano chileno (18º14' S, 69º09' O); es un lago polimíctico-frío, con origen tectónico-volcánico y 34 m de profundidad máxima. Presenta variaciones reducidas de temperatura entre profundidades y estaciones del año (4 a 11 ºC), el promedio de temperatura anual se ha incrementado en 1,2 ºC entre los períodos 1986-1987 y 1998-1999. Entre los mismos períodos se observó una disminución significativa en el volumen del lago (-6,58 %) y consecuentemente en la profundidad máxima. Conjuntamente la salinidad aumentó significativamente con valores máximos de 1.464 µmhos y 2.650 µmhos para cada período. Estos cambios pueden ser las causas de la modificación en composición y abundancia del fitoplancton, asociadas, además, a la disminución significativa de la clorofila a (P < 0,0054).
Uploads
Papers by Cristina Dorador