Taxonomic analysis of white gypsum-halite precipitations from Laguna Verde

The Argentine Puna represents a unique environment, characterized by high UV radiation, low oxygen pressure and extreme temperature fluctuations. There we find saline water deposits such as Laguna Verde (Salar de Antofalla, 3300 m.a.s.l.) surrounded by large extensions of white gypsum-halite precipitating crusts. These crusts harbor microbial communities distributed in layers (microbial mats) defined by physicochemical requirements, light and oxygen. These mats colonize both solid and sedimentary surfaces.Metagenomic, physiological and geochemical studies reveal a series of strategies that allow these communities to survive in hypersaline wetlands by performing photosynthesis and serving as CO2 sinks. The goal of this job was to determine the biodiversity associated to these large evaporitics biofilms surrounding the lake. It was observed that the microorganisms are organized in two layers in the salt crust, an upper yellow layer, and a lower green layer. Samples were taken using a cut off sterile 10-ml syringe, were fixed immediately in RNAlater and transported to the laboratory on ice. Total genomic DNA was isolated from each of the layers using the FastDNA ™ SPIN Kit for Soil (MP Biomedical) and it sequenced with Illumina HiSeq. Raw data obtained, was uploaded to the European Bioinformatic Archive (ENA). Once uploaded, it was analyzed using the MGnify Annotation Pipeline developed by Dr. Rob Finn’s Team at EMBL-EBI. This pipeline performed the taxonomic annotation of the raw reads.The taxonomic annotation obtained, showed that the orange layer is dominated by oxygenic photoautotrophic bacteria (Cyanobacteria, ca. 65%) followed by anoxygenic photoautotrophs (Proteobacteria, ca. 10%) from the classes Alphaproteobacteria and Gammaproteobacteria and heterotrophic bacteria (Bacteoridetes, ca. 10%). The green layer is dominated by the phyla Proteobacteria, ca. 50% followed by Bacteroidetes, ca. 30% and Cyanobacteria, ca. 20%. In both layers, the phyla Actinobacteria and Euryarcheota represent at least 1% of the relative abundance.Fil: Marcelino, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Saracho, Hayde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Kurth, Daniel German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina7mo Simposio Argentino de Jóvenes Investigadores en BioinformáticaSan Miguel de TucumánArgentinaArgentine Regional Student GroupUniversidad Nacional de Tucumán. Facultad de Bioquímica Química y Farmaci

Metagenomic insight into precipitation processes in microbial communities from salar de Atacama

The Salar de Atacama is one of the Earth’s largest evaporite basins (ca. 3,000 km2). Within this large area, numerous hypersaline lakes can be found. These lakes are hotspots for microbial diversity, and diverse structures with associated microorganisms have been reported, including microbial mats, microbialites and endoevaporites. In this work, we aim to identify functional differences in the microbiota from these systems, using as models a mat from Brava lake, a microbialite from Chaxas and an endoevaporite from Barros Negros. Metagenomic DNA was extracted from these samples, and sequenced with Illumina technology. The datasets generated allowed to characterize the microbial communities both taxonomically and functionally.The carbonate-rich mats and microbialites are dominated by Proteobacteria, and within this phylum the most abundant classes are Alphaproteobacteria and Gammaproteobacteria. Other important phyla include Bacteroidetes, Cyanobacteria, and Actinobacteria. In the endoevaporites, the phyla are more evenly distributed, being Proteobacteria, Bacteroidetes, and Euryarchaeota similarly abundant, with Cyanobacteria and Actinobacteria also present. At the family level, the mat is the most diverse and the endoevaporite is the least diverse. This is also observed at the function level, with more pathways annotated in Brava. However, the main functional roles present in the three communities are similar, with Cyanobacteria being the main primary producers, involved in photosynthesis and nitrogen fixing, Alphaproteobacteria involved in anoxygenic photosynthesis, and Deltaproteobacteria involved in sulfur cycling. This work starts the exploration of the microbial influence on the formation of different macrostructures harboring microbial ecosystems in extreme environments from the Central Andes region. Certain taxa present only in the more lithified communities, and with metabolic pathways promoting precipitation might be particularly involved in the lithification process.Fil: Marcelino, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Saona Acuña, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Kurth, Daniel German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXVII Congreso Argentino de Microbiología GeneralLos CocosArgentinaSociedad Argentina de Microbiología Genera

Caracterización de inhibidores de acil-CoA carboxilasas de Mycobacterium tuberculosis: un nuevo blanco para el desarrollo de drogas

La pared celular de M. tuberculosis posee numerosos l¡pidos de estructura compleja que no solo son necesarios para la viabilidad y patogenicidad del microorganismo, sino que son capaces de modular la respuesta inmune del huesped. Entre estos, unos de los mas caracteristicos son los acidos micolicos. Algunas de las drogas antituberculosas mas usadas afectan justamente estas vias biosinteticas. Sin embargo, se conoce muy poco acerca de las vias involucradas en la biosintesis de los precursores de estos lipidos complejos. Nuestra hipotesis de trabajo es que los alfa-carboxi acil-CoAs utilizados para la biosintesis de los acidos grasos de membrana y de la pared celular son producidos por los complejos acil-CoA carboxilasas (ACCasas) presentes en M. tuberculosis. Estas enzimas, cuya estructura es diferente a la de la acetil-CoA carboxilasa de humanos, son un blanco atractivo para el diseño de nuevos agentes anti-micobacterianos especificos. En nuestro laboratorio se han caracterizado dos complejos ACCasa a nivel bioquimico y estructural. La obtencion de las estructuras cristalograficas de las subunidades carboxiltransferasas de estos complejos permitio la busqueda in silico de inhibidores, resultando en la identificacion varios compuestos capaces de inhibir la actividad enzimatica in vitro. Uno de estos compuestos tambien fue capaz de inhibir, a concentraciones micromolares, el crecimiento de diferentes especies de micobacterias, incluyendo cepas mutirresistentes de M. tuberculosis. Nuestros resultados sugieren que su accion antimicobacteriana se debe a la inhibicion de una ACCasa especifica. Por un lado se observo que en presencia del inhibidor disminuye la incorporacion de 1-[14C-acetato], y tambien la biosintesis de acidos grasos y micolicos. Ademas la actividad acetil-CoA carboxilasa es menor en extractos de cultivos tratados con el inhibidor, mientras que la actividad acido graso sintasa no se encuentra afectada. En conjunto, estos datos confirman que los complejos ACCasa podrian proveer una herramienta para el diseño de nuevos compuestos antimicobacterianos especificos.Fil: Kurth, Daniel German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Gago, Gabriela Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Gramajo, Hugo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaIV Congreso Argentino de Microbiología GeneralCiudad Autónoma de Buenos AiresArgentinaSociedad Argentina de Microbiología Genera

Systematic Roughness Variation to Model the Influence of Skewness on Wall Bounded Flows

In recent years, the research on roughness has focused on various roughness features, rather than the roughness height only, in order to improve the understanding of roughness effects on wall bounded flows. A special focus is placed on the skewness of the roughness height profile. The skew-ness measures whether the height profile is dominated by negative or positive roughness elements. Surfaces with both features can be found on worn blades: On the leading edge, roughness is caused by the impact of particles resulting in a negative skewness. Rough surfaces around the trailing edge, however, develop due to depositions leading to a positive skewness. In this paper, rough surfaces taken from a compressor blade of an aero engine are systematically varied to investigate the isolated effect of skew-ness on aerodynamic losses. By direct numerical simulations of a periodic flow channel. The results show that the skewness has a major influence on loss generation. Based on these results, an existing model which essentially uses the shape-and-density parameter, is extended by a skewness factor. The modified correlation predicts the influence of the rough surfaces investigated well

High-Up: A Remote Reservoir of Microbial Extremophiles in Central Andean Wetlands

The Central Andes region displays unexplored ecosystems of shallow lakes and salt flats at mean altitudes of 3700 m. Being isolated and hostile, these so-called “High-Altitude Andean Lakes” (HAAL) are pristine and have been exposed to little human influence. HAAL proved to be a rich source of microbes showing interesting adaptations to life in extreme settings (poly-extremophiles) such as alkalinity, high concentrations of arsenic and dissolved salts, intense dryness, large daily ambient thermal amplitude, and extreme solar radiation levels. This work reviews HAAL microbiodiversity, taking into account different microbial niches, such as plankton, benthos, microbial mats and microbialites. The modern stromatolites and other microbialites discovered recently at HAAL are highlighted, as they provide unique modern—though quite imperfect—analogs of environments proxy for an earlier time in Earth's history (volcanic setting and profuse hydrothermal activity, low atmospheric O2 pressure, thin ozone layer and high UV exposure). Likewise, we stress the importance of HAAL microbes as model poly-extremophiles in the study of the molecular mechanisms underlying their resistance ability against UV and toxic or deleterious chemicals using genome mining and functional genomics. In future research directions, it will be necessary to exploit the full potential of HAAL poly-extremophiles in terms of their biotechnological applications. Current projects heading this way have yielded detailed molecular information and functional proof on novel extremoenzymes: i.e., DNA repair enzymes and arsenic efflux pumps for which medical and bioremediation applications, respectively, are envisaged. But still, much effort is required to unravel novel functions for this and other molecules that dwell in a unique biological treasure despite its being hidden high up, in the remote Andes.Fil: Albarracín, Virginia Helena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Kurth, Daniel German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Ordoñez, Omar Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Belfiore, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Luccini, Eduardo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Química e Ingeniería-Rosario; ArgentinaFil: Salum, Graciela Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Piacentini, Ruben Dario Narciso. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentin