Biopsia con aguja gruesa de timoma en mediastino anterior: creación de ruta de acceso segura mediante hidrodisección / Core Needle Biopsy of an Anterior Mediastinal Thymoma: Creation of a Safe Access Route by Hydrodissection

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Geología, hidrología y protección de las aguas subterráneas del balneario / The geology, the hydrogeology and the protection of its medicinal groundwaters

Se ha estudiado la microbiota autóctona y alóctona del agua mineral del Balneario Villa de Olmedo (Valladolid). El número total de microorganismos en el agua ha sido de 4,5 x 103/mL y el número de bacterias viables heterótrofas menor de 5 ufc/mL. No se han encontrado indicadores fecales ni microorganismos patógenos por lo que estas aguas cumplen con la normativa española de aguas de consumo. La microbiota autóctona está constituida, principalmente, por bacilos Gram negativos de la clase Gammaproteobacteria (68,5%) y, en menor proporción, por cocos Gram positivos (14,3%). La especie más frecuente ha sido Pseudomonas stutzeri (37,2%). Se han detectado bacterias con actividades amonificantes, nitrificantes, proteolíticas y amilolíticas en 100 mL de agua, que contribuyen a la autodepuración del agua

The autochthon and alocthon microbiota of the mineral water of the Villa de Olmedo Spa have been studied. The total number of microorganisms in the water was of 4.5 x103/mL and the number of heterotrophic viable bacteria was lower than 5 cfu/mL. Neither faecal indicators nor pathogenic microorganisms were found; therefore these waters comply with the Spanish regulations on drinking water. The autochthon microbiota mostly belongs to Gram negative bacilli, from the Class Gammaproteobacteria (68.5%) and in smaller percentage to the Gram positive cocci (14.3%). The most frequently found species was Pseudomonas stutzeri. Moreover ammonifying, nitrifiying, proteolytic and amylolytic bacteria have been detected in 100 mL of water, all of them involved in self-purification process of wáter

Phylogenetic diversity of methyl-coenzyme Mreductase (mcrA) gene and methanogenesisfrom trimethylamine in hypersaline environments

Methanogens have been reported in complex microbial communities from hypersaline environments, but little is known about their phylogenetic diversity. In this work, methane concentrations in environmental gas samples were determined while methane production rates were measured in microcosm experiments with competitive and non-competitive substrates. In addition, the phylogenetic diversity of methanogens in microbial mats from two geographical locations was analyzed: the well studied Guerrero Negro hypersaline ecosystem, and a site not previously investigated, namely Laguna San Ignacio, Baja California Sur, Mexico. Methanogenesis in these microbial mats was suspected based on the detection of methane (in the range of 0.00086 to 3.204 %) in environmental gas samples. Microcosm experiments confirmed methane production by the mats and demonstrated that it was promoted only by non-competitive substrates (trimethylamine and methanol), suggesting that methylotrophy is the main characteristic process by which these hypersaline microbial mats produce methane. Phylogenetic analysis of amino acid sequences of the methyl coenzyme-M reductase (mcrA) gene from natural and manipulated samples revealed various methylotrophic methanogens belonging exclusively to the family Methanosarcinaceae. Moderately halophilic microorganisms of the genus Methanohalophilus were predominant (>60 % of mcrA sequences retrieved). Slightly halophilic and marine microorganisms of the genera Methanococcoides and Methanolobus, respectively, were also identified, but in lower abundances (AU)

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Salinity dependence of the distribution of multicellular magnetotactic prokaryotes in a hypersaline lagoon

Candidatus Magnetoglobus multicellularis is an unusual magnetotactic multicellular microorganism composed of a highly organized assemblage of gram-negative bacterial cells. In this work, the salinity dependence of Ca. M. multicellularis and its abundance in the hypersaline Araruama Lagoon, Brazil were studied. Viability experiments showed that Ca. M. multicellularis died in salinities >55 per-mille and <40 per-mille. Low salinities were also observed to modify the cellular assemblage. In microcosms prepared with different salinities, the microorganism grew better at intermediate salinities whereas in high or low salinities, the size of the population did not increase over time. The concentrations of Ca. M. multicellularis in the lagoon were related to salinity; sites with lower and higher salinities than the lagoon average contained less Ca. M. multicellularis. These results demonstrate the influence of salinity on the survival and distribution of Ca. M. multicellularis in the environment. In sediments, the abundance of Ca. M. multicellularis ranged from 0 to 103 microorganisms/ml, which represented 0.001% of the counts of total bacteria. The ability of Ca. M. multicellularis to accumulate iron and sulfur in high numbers of magnetosomes (up to 905 per microorganism) suggests that its impact on the sequestration of these elements (0.1% for biogenic bacterial iron) is not proportional to its abundance in the lagoon (AU)

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Communities of green sulfur bacteria in marine and saline habitats analyzed by gene sequences of 16S rRNA and Fenna-Matthews-Olson protein / Comunidades de bacterias verdes del azufre en hábitats marinos o salinos analizados mediante las secuencias de genes rRNA 16S y de la proteína Fenna-Matthews-Olson

Communities of green sulfur bacteria were studied in selected marine and saline habitats on the basis of gene sequences of 16S rRNA and the Fenna- Matthews-Olson (FMO) protein. The availability of group-specific primers for both 16S rDNA and the fmoA gene, which is unique to green sulfur bacteria, has, for the first time, made it possible to analyze environmental communities of these bacteria by culture-independent methods using two independent genetic markers. Sequence results obtained with fmoA genes and with 16S rDNA were largely congruent to each other. All of the 16S rDNA and fmoA sequences from habitats of the Baltic Sea, the Mediterranean Sea, Sippewissett Salt Marsh (Massachusetts, USA), and Bad Water (Death Valley, California, USA) were found within salt-dependent phylogenetic lines of green sulfur bacteria established by pure culture studies. This strongly supports the existence of phylogenetic lineages of green sulfur bacteria specifically adapted to marine and saline environments and the exclusive occurrence of these bacteria in marine and saline habitats. The great majority of clone sequences belonged to different clusters of the Prosthecochloris genus and probably represent different species. Evidence for the occurrence of two new species of Prosthecochloris was also obtained. Different habitats were dominated by representatives from the Prosthecochloris group and different clusters or species of this genus were found either exclusively or as the clearly dominant green sulfur bacterium at different habitats (AU)

Se han estudiado las comunidades de bacterias verdes del azufre en hábitats marinos o salinos seleccionadas a partir de las secuencias de genes del rRNA 16S y de la proteína Fenna-Matthews-Olson (FMO). La disponibilidad de cebadores específicos de grupo para el rDNA 16S y para el gen fmoA, que es exclusivo de las bacterias verdes del azufre, ha permitido por primera vez analizar las comunidades naturales de estas bacterias por métodos que no requieren cultivo usando dos marcadores genéticos independientes. Los resultados de la secuencia obtenidos con los genes fmoA y con rDNA 16S concordaban entre sí. Todas las secuencias de rDNA 16S y fmoA procedentes de hábitats del mar Báltico, del Mediterráneo, de las salinas de Sippewissett (Massachusetts, EE UU) y de Bad Water (Death Valley, California, EE UU) se encuentran en las líneas filogenéticas dependientes de sal de las bacterias verdes del azufre establecidas mediante estudios de cultivo puro. Esta constatación respalda la existencia de linajes filogenéticos de bacterias verdes del azufre adaptadas específicamente a medios marinos o salinos y a su distribución exclusiva en tales ambientes. La gran mayoría de secuencias clónicas pertenece a agrupaciones genéticas (clusters) del género Prosthecochloris y probablemente representan especies diferentes. Se han conseguido pruebas de la presencia de dos nuevas especies de Prosthecochloris. En diversos hábitats dominaban representantes del grupo Prosthecochloris y varias agrupaciones genéticas o especies de ese género eran exclusivos de esos hábitats o bien eran las bacterias verdes del azufre claramente dominantes en ellos (AU)

Microorganismos halófitos: potencial biotecnológico e interés farmacéutico / Biotechnological potential and pharmaceutical interest of Halophilic Microorganisms

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