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1.
Microbiol Resour Announc ; 13(5): e0050223, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38563744

RESUMEN

T2.26MG-112.2 is a Ciceribacter strain that has been isolated from the deep subsurface of the Iberian Pyrite Belt. We report its draft genome consisting of a chromosome of ≈4.9 Mb and a plasmid of 357 kb. The annotation reveals 4,824 coding sequences, 48 tRNA genes, and 1 rRNA operon.

2.
Brief Bioinform ; 22(6)2021 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-34013348

RESUMEN

NGS long-reads sequencing technologies (or third generation) such as Pacific BioSciences (PacBio) have revolutionized the sequencing field over the last decade improving multiple genomic applications like de novo genome assemblies. However, their error rate, mostly involving insertions and deletions (indels), is currently an important concern that requires special attention to be solved. Multiple algorithms are available to fix these sequencing errors using short reads (such as Illumina), although they require long processing times and some errors may persist. Here, we present Accurate long-Reads Assembly correction Method for Indel errorS (ARAMIS), the first NGS long-reads indels correction pipeline that combines several correction software in just one step using accurate short reads. As a proof OF concept, six organisms were selected based on their different GC content, size and genome complexity, and their PacBio-assembled genomes were corrected thoroughly by this pipeline. We found that the presence of systematic sequencing errors in long-reads PacBio sequences affecting homopolymeric regions, and that the type of indel error introduced during PacBio sequencing are related to the GC content of the organism. The lack of knowledge of this fact leads to the existence of numerous published studies where such errors have been found and should be resolved since they may contain incorrect biological information. ARAMIS yields better results with less computational resources needed than other correction tools and gives the possibility of detecting the nature of the found indel errors found and its distribution along the genome. The source code of ARAMIS is available at https://github.com/genomics-ngsCBMSO/ARAMIS.git.


Asunto(s)
Biología Computacional/métodos , Secuenciación de Nucleótidos de Alto Rendimiento , Mutación INDEL , Programas Informáticos , Algoritmos , Composición de Base , Biología Computacional/normas , Genómica/métodos , Análisis de Secuencia de ADN/métodos , Análisis de Secuencia de ADN/normas , Flujo de Trabajo
3.
Microbiol Resour Announc ; 10(1)2021 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-33414307

RESUMEN

We report the draft genome of Pseudomonas sp. strain T2.31D-1, which was isolated from a drilling core sample obtained 414 m below surface in the Iberian Pyrite Belt. The genome consists of a 4.7-Mb chromosome with 4,428 coding sequences, 1 rRNA operon, 59 tRNA genes, and a 31.8-kb plasmid.

4.
Astron Astrophys ; 6452021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33408420

RESUMEN

CONTEXT: Yebes 40m radio telescope is the main and largest observing instrument at Yebes Observatory and it is devoted to Very Long Baseline Interferometry (VLBI) and single dish observations since 2010. It has been covering frequency bands between 2 GHz and 90 GHz in discontinuous and narrow windows in most of the cases, to match the current needs of the European VLBI Network (EVN) and the Global Millimeter VLBI Array (GMVA). AIMS: Nanocosmos project, a European Union funded synergy grant, opened the possibility to increase the instantaneous frequency coverage to observe many molecular transitions with single tunnings in single dish mode. This reduces the observing time and maximises the output from the telescope. METHODS: We present the technical specifications of the recently installed 31.5 - 50GHz (Q band) and 72 - 90.5 GHz (W band) receivers along with the main characteristics of the telescope at these frequency ranges. We have observed IRC+10216, CRL 2688 and CRL 618, which harbour a rich molecular chemistry, to demonstrate the capabilities of the new instrumentation for spectral observations in single dish mode. RESULTS: The results show the high sensitivity of the telescope in the Q band. The spectrum of IRC+10126 offers a signal to noise ratio never seen before for this source in this band. On the other hand, the spectrum normalised by the continuum flux towards CRL 618 in the W band demonstrates that the 40 m radio telescope produces comparable results to those from the IRAM 30 m radio telescope, although with a smaller sensitivity. The new receivers fulfil one of the main goals of Nanocosmos and open the possibility to study the spectrum of different astrophysical media with unprecedented sensitivity.

5.
Protoplasma ; 257(3): 889-900, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31909435

RESUMEN

The study of plants adapted to an extreme environment with a high concentration of iron such as Río Tinto allowed the study of important elements for the development and control of plant growth including their localization, management, and storage. The absorption, transport, and accumulation of iron were studied in different species of dicotyledons (Sarcocornia pruinosa, Salicornia patula, Arthrocnemum macrostachyum, and Halogeton sativus of the Chenopodiaceae family) and monocotyledons (Imperata cylindrica, Cynodon dactylon, and Panicum repens from the Poaceae family), all obtained from the Río Tinto banks in different sample collection campaigns. The results clearly show that phytoferritin is not observed in the chloroplast of monocotyledons, an important difference from what is observed in dicotyledons. The presence of plastids with a high concentration of iron in the sieve tubes of monocotyledons strongly suggests their possible role in the transport and accumulation of iron in these plants.


Asunto(s)
Hierro/uso terapéutico , Hojas de la Planta/química , España
6.
Microbiol Resour Announc ; 8(32)2019 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-31395626

RESUMEN

The draft genome of Brevundimonas sp. strain T2.26MG-97, isolated at a depth of 492.6 m in the subsurface of the Iberian Pyrite Belt, is reported here. It consists of 262 scaffolds with a total genome length of 3.68 Mbp, where 3,549 coding DNA sequences have been annotated.

7.
Artículo en Inglés | MEDLINE | ID: mdl-31186577

RESUMEN

We present a new experimental setup devoted to the study of gas phase molecules and processes using broad band high spectral resolution rotational spectroscopy. A reactor chamber has been equipped with radio receivers similar to those used by radio astronomers to search for molecular emission in space. The whole Q (31.5-50 GHz) and W bands (72-116.5 GHz) are available for rotational spectroscopy observations. The receivers are equipped with 16×2.5 GHz Fast Fourier Transform spectrometers with a spectral resolution of 38.14 kHz allowing the simultaneous observation of the complete Q band and one third of the W band. The whole W band can be observed in three settings in which the Q band is always observed. Species such as CH3CN, OCS, and SO2 are detected, together with many of their isotopologues and vibrationally excited states, in very short observing times. The system permits automatic overnight observations and integration times as long as 2.4×105 seconds have been reached. The chamber is equipped with a radiofrequency source to produce cold plasmas and with four ultraviolet lamps to study photochemical processes. Plasmas of CH4, N2, CH3CN, NH3, O2, and H2, among other species, have been generated and the molecular products easily identified by their rotational spectrum, and mass spectrometry and optical spectroscopy. Finally, the rotational spectrum of the lowest energy conformer of CH3CH2NHCHO (N-Ethylformamide), a molecule previously characterized in microwave rotational spectroscopy, has been measured up to 116.5 GHz allowing the accurate determination of its rotational and distortion constants and its search in space.

8.
Microbiol Resour Announc ; 8(16)2019 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-31000538

RESUMEN

Rhodoplanes sp. strain T2.26MG-98 was isolated from the deep subsurface of the Iberian Pyrite Belt. We report its draft genome, consisting of 214 contigs with a chromosome of ∼5.6 Mb and a 53.7-kb plasmid. The chromosome annotation identified 4,994 coding DNA sequences, 1 rRNA operon, and 57 tRNA genes.

9.
Artículo en Inglés | MEDLINE | ID: mdl-30533741

RESUMEN

Rhizobium sp. strain T2.30D-1.1 was isolated from the deep subsurface of the Iberian Pyrite Belt. We report its draft genome, consisting of 60 contigs with a chromosome of ≈4.6 Mb and a plasmid of 179 kb. The annotation revealed 4,526 coding DNA sequences, 45 tRNA genes, and 1 rRNA operon.

10.
Sci Rep ; 7(1): 8775, 2017 08 18.
Artículo en Inglés | MEDLINE | ID: mdl-28821776

RESUMEN

The artificial mineralization of a polyresistant bacterial strain isolated from an acidic, oligotrophic lake was carried out to better understand microbial (i) early mineralization and (ii) potential for further fossilisation. Mineralization was conducted in mineral matrixes commonly found on Mars and Early-Earth, silica and gypsum, for 6 months. Samples were analyzed using microbiological (survival rates), morphological (electron microscopy), biochemical (GC-MS, Microarray immunoassay, Rock-Eval) and spectroscopic (EDX, FTIR, RAMAN spectroscopy) methods. We also investigated the impact of physiological status on mineralization and long-term fossilisation by exposing cells or not to Mars-related stresses (desiccation and radiation). Bacterial populations remained viable after 6 months although the kinetics of mineralization and cell-mineral interactions depended on the nature of minerals. Detection of biosignatures strongly depended on analytical methods, successful with FTIR and EDX but not with RAMAN and immunoassays. Neither influence of stress exposure, nor qualitative and quantitative changes of detected molecules were observed as a function of mineralization time and matrix. Rock-Eval analysis suggests that potential for preservation on geological times may be possible only with moderate diagenetic and metamorphic conditions. The implications of our results for microfossil preservation in the geological record of Earth as well as on Mars are discussed.

11.
Geobiology ; 12(1): 34-47, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24237661

RESUMEN

The Iberian Pyrite Belt (IPB, southwest of Spain), the largest known massive sulfide deposit, fuels a rich chemolithotrophic microbial community in the Río Tinto area. However, the geomicrobiology of its deep subsurface is still unexplored. Herein, we report on the geochemistry and prokaryotic diversity in the subsurface (down to a depth of 166 m) of the Iberian Pyritic belt using an array of geochemical and complementary molecular ecology techniques. Using an antibody microarray, we detected polymeric biomarkers (lipoteichoic acids and peptidoglycan) from Gram-positive bacteria throughout the borehole. DNA microarray hybridization confirmed the presence of members of methane oxidizers, sulfate-reducers, metal and sulfur oxidizers, and methanogenic Euryarchaeota. DNA sequences from denitrifying and hydrogenotrophic bacteria were also identified. FISH hybridization revealed live bacterial clusters associated with microniches on mineral surfaces. These results, together with measures of the geochemical parameters in the borehole, allowed us to create a preliminary scheme of the biogeochemical processes that could be operating in the deep subsurface of the Iberian Pyrite Belt, including microbial metabolisms such as sulfate reduction, methanogenesis and anaerobic methane oxidation.


Asunto(s)
Bacterias/clasificación , Biota , Euryarchaeota/clasificación , Metano/metabolismo , Microbiología del Suelo , Suelo/química , Sulfatos/metabolismo , Bacterias/genética , Bacterias/inmunología , Bacterias/metabolismo , Euryarchaeota/genética , Euryarchaeota/inmunología , Euryarchaeota/metabolismo , Hibridación Fluorescente in Situ , Análisis por Micromatrices , Análisis de Secuencia por Matrices de Oligonucleótidos , Oxidación-Reducción , Análisis por Matrices de Proteínas , España
12.
Environ Sci Technol ; 47(12): 6129-36, 2013 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-23682976

RESUMEN

Here we describe biogeochemical processes that lead to the generation of acid rock drainage (ARD) and rock weathering on the Antarctic landmass and describe why they are important sources of iron into the Antarctic Ocean. During three expeditions, 2009-2011, we examined three sites on the South Shetland Islands in Antarctica. Two of them displayed intensive sulfide mineralization and generated acidic (pH 3.2-4.5), iron-rich drainage waters (up to 1.78 mM Fe), which infiltrated as groundwater (as Fe(2+)) and as superficial runoff (as Fe(3+)) into the sea, the latter with the formation of schwertmannite in the sea-ice. The formation of ARD in the Antarctic was catalyzed by acid mine drainage microorganisms found in cold climates, including Acidithiobacillus ferrivorans and Thiobacillus plumbophilus. The dissolved iron (DFe) flux from rock weathering (nonmineralized control site) was calculated to be 0.45 × 10(9) g DFe yr(-1) for the nowadays 5468 km of ice-free Antarctic rock coastline which is of the same order of magnitude as glacial or aeolian input to the Southern Ocean. Additionally, the two ARD sites alone liberate 0.026 and 0.057 × 10(9) g DFe yr(-1) as point sources to the sea. The increased iron input correlates with increased phytoplankton production close to the source. This might even be enhanced in the future by a global warming scenario, and could be a process counterbalancing global warming.


Asunto(s)
Hierro/análisis , Regiones Antárticas , Drenaje , Océanos y Mares , Agua/análisis
13.
Environ Microbiol ; 15(8): 2228-37, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23425574

RESUMEN

Río Tinto (Huelva, southwestern Spain) is an extreme environment with a remarkably constant acidic pH and a high concentration of heavy metals, conditions generated by the metabolic activity of chemolithotrophic microorganisms thriving in the rich complex sulfides of the Iberian Pyrite Belt (IPB). Fungal strains isolated from the Tinto basin were characterized morphologically and phylogenetically. The strain identified as Purpureocillium lilacinum specifically induced the formation of a yellow-ocher precipitate, identified as hydronium-jarosite, an iron sulfate mineral which appears in abundance on the banks of Río Tinto. The biomineral was characterized by X-ray diffraction (XRD) and its formation was observed with high-resolution transmission electron microscopy (TEM) and scanning electron microscopy (SEM) coupled to energy-dispersive X-ray spectroscopy (EDX) microanalysis. Jarosite began to nucleate on the fungal cell wall, associated to the EPS, due to a local increase in the Fe(3+) /Fe(2+) ratio which generated supersaturation. Its formation has been also observed in non-viable cells, although with much less efficiency. The occurrence of P. lilacinum in an ecosystem with high concentrations of ferric iron and sulfates such as Río Tinto suggests that it could participate in the process of jarosite precipitation, helping to shape and control the geochemical properties of this environment.


Asunto(s)
Compuestos Férricos/metabolismo , Hypocreales/metabolismo , Sulfatos/metabolismo , Microbiología del Agua , Ecosistema , Compuestos Férricos/química , Concentración de Iones de Hidrógeno , Hypocreales/aislamiento & purificación , Hypocreales/ultraestructura , Hierro/química , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , España , Sulfatos/química , Sulfuros/química
14.
Adv Appl Microbiol ; 77: 41-70, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22050821

RESUMEN

The recent geomicrobiological characterization of Río Tinto, Iberian Pyrite Belt (IPB), has proven the importance of the iron cycle, not only in generating the extreme conditions of the habitat (low pH, high concentration of toxic heavy metals) but also in maintaining the high level of microbial diversity, both prokaryotic and eukaryotic, detected in the water column and the sediments. The extreme conditions of the Tinto basin are not the product of industrial contamination but the consequence of the presence of an underground bioreactor that obtains its energy from the massive sulfide minerals of the IPB. To test this hypothesis, a drilling project was carried out to intersect ground waters that interact with the mineral ore in order to provide evidence of subsurface microbial activities and the potential resources to support these activities. The oxidants that drive the system appear to come from the rock matrix, contradicting conventional acid mine drainage models. These resources need only groundwater to launch microbial metabolism. There are several similarities between the vast deposits of sulfates and iron oxides on Mars and the main sulfide-containing iron bioleaching products found in the Tinto. Firstly, the short-lived methane detected both in Mars' atmosphere and in the sediments and subsurface of the IPB and secondly, the abundance of iron, common to both. The physicochemical properties of iron make it a source of energy, a shield against radiation and oxidative stress as well as a natural pH controller. These similarities have led to Río Tinto's status as a Mars terrestrial analogue.


Asunto(s)
Sedimentos Geológicos , Marte , Ecología , Ecosistema , Sedimentos Geológicos/microbiología , Concentración de Iones de Hidrógeno , Minerales , España
15.
Water Sci Technol ; 59(6): 1227-36, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19342820

RESUMEN

Water contamination by nitrate is a wideworld extended phenomena. Biological autotrophic denitrification has a real potential to face this problem and presents less drawbacks than the most extended heterotrophic denitrification. Three bench-scale UASB reactors were operated under autotrophic (R1, H2S as electron donor), mixotrophic (R2, H2S plus p-cresol as electron donors) and heterotrophic (R3, p-cresol as electron donor) conditions using nitrate as terminal electron acceptor. 16S rDNA genetic libraries were built up to compare their microbial biodiversity. Six different bacteria phyla and three archaeal classes were observed. Proteobacteria was the main phyla in all reactors standing out the presence of denitrifiers. Microorganisms similar to Thiobacillus denitrificans and Acidovorax sp. performed the autotrophic denitification. These OTUs were displaced by chemoheterotrophic denitrifiers, especially by Limnobacter-like and Ottowia-like OTUs. Other phyla were Bacteroidetes, Chloroflexi, Firmicutes and Actinobacteria that--as well as Archaea members--were implicated in the degradation of organic matter, as substrate added as coming from endogenous sludge decay under autotrophic conditions. Archaea diversity remained low in all the reactors being Methanosaeta concilii the most abundant one.


Asunto(s)
Fenómenos Bioquímicos , Nitrógeno/aislamiento & purificación , Nitrógeno/metabolismo , Aguas del Alcantarillado/microbiología , Procesos Autotróficos , Biomasa , Procesos Heterotróficos , Filogenia
16.
Syst Appl Microbiol ; 30(8): 601-14, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17950555

RESUMEN

The prokaryotic diversity of macroscopic filaments located at the water surface in an extreme acidic environment, Río Tinto (SW, Spain), has been analysed through denaturing gradient gel electrophoresis (DGGE), cloning of 16S rRNA genes and fluorescence in situ hybridization (FISH). The dominant species present in the macrofilaments were Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans and Acidiphilium spp., which represented the three main bacterial genera found in the water column of the river. However, our results also showed the presence of other microorganisms not previously detected in the Río Tinto. Within the Gammaproteobacteria class, sequences closely related to the iron-oxidizing bacteria WJ2 and DSM 2392 were found, as well as sequences related to the non-acidophilic genera Aeromonas and Acinetobacter. In addition, two other new phylotypes related to Gram-positive species from the genera Desulfosporosinus, Clostridium and Mycobacterium were identified. The presence of these anaerobic microorganisms strongly suggests that the filaments could originate in the deeper parts of the river as a typical acid streamer attached to the rocks or the sediments and be pulled up towards the surface when they reach certain buoyancy.


Asunto(s)
Bacterias/clasificación , Bacterias/aislamiento & purificación , Biodiversidad , Ríos/microbiología , Bacterias/genética , Dermatoglifia del ADN , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , ADN Ribosómico/química , ADN Ribosómico/genética , Electroforesis en Gel de Poliacrilamida , Genes de ARNr , Hibridación Fluorescente in Situ , Datos de Secuencia Molecular , Desnaturalización de Ácido Nucleico , Filogenia , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido Nucleico , España
17.
Biol Trace Elem Res ; 115(1): 67-86, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17406075

RESUMEN

Two species of perennial Phyllanthus (Euphorbiaceae) (Phyllanthus orbicularis and Phyllanthus discolor, both endemic to ultramafic areas of Cuba, and their natural hybrid, Phyllanthus xpallidus) were selected for metal localization microanalysis. Different plant tissues were analyzed by X-ray fluorescence, inductively coupled plasma-atomic emission spectroscopy, and scanning electron microscopy coupled with an energy-dispersive X-ray probe. All of the studied taxa are nickel (Ni) hyperaccumulators and significant concentrations of this element were found in different leaf and stem tissues. The highest Ni content was found in the laticifer tubes, whereas leaf epidermis Ni content resulted to be much more relevant in terms of total metal storage. Calcium and magnesium were found more evenly distributed in leaf and stem tissues.


Asunto(s)
Euphorbiaceae/metabolismo , Níquel/metabolismo , Suelo , Álcalis , Cuba , Euphorbiaceae/ultraestructura , Concentración de Iones de Hidrógeno , Microscopía Electrónica de Rastreo
18.
Water Sci Technol ; 54(2): 11-7, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16939078

RESUMEN

Denitrification is applied in the tertiary treatment of wastewater to reduce N-pollutants. Fluorescence in situ hybridisation (FISH), CARD (catalyzed reporter deposition)-FISH, cloning, and scanning electron microscopy (SEM) were applied to follow the evolution of the microbial composition and structure of granular sludge in autotrophic denitrifying bioreactors fed with nitrate and thiosulfate. With this goal, FISH oligonucleotide probes for the autotrophic denitrifiers, Thiobacillus denitrificans and Thiomicrospira denitrificans, were designed and their utility tested. CARD-FISH and cloning data showed that bacterial diversity changed with bioreactor operation time. After 110 days of operation, the abundance of Thiobacillus denitrificans cells increased considerably: from 1 to 35% of total DAPI-stained cells and from no isolated clones to 30% of the total positives clones. This fact strongly suggests that this microorganism played a dominant role in the autotrophic denitrification. The Archaeal diversity remained almost unchanged and it was mainly represented by Methanosaeta soehngenii. Scanning electron microscopy results indicated a considerable loss in the integrity of the sludge granules during the operation, with risk of sludge buoyancy.


Asunto(s)
Nitritos/química , Piscirickettsiaceae/aislamiento & purificación , Aguas del Alcantarillado/química , Aguas del Alcantarillado/microbiología , Thiobacillus/aislamiento & purificación , Secuencia de Bases , Clonación Molecular , Cartilla de ADN , Hibridación Fluorescente in Situ , Microscopía Electrónica de Rastreo , Piscirickettsiaceae/genética , Piscirickettsiaceae/ultraestructura , ARN Ribosómico 16S/genética , Thiobacillus/genética , Thiobacillus/ultraestructura
19.
New Phytol ; 165(3): 781-9, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15720689

RESUMEN

* The analysis of metal distribution in Imperata cylindrica, a perennial grass isolated from the banks of Tinto River (Iberian Pyritic Belt), an extreme acidic environment with high content in metals, has shown a remarkable accumulation of iron. This property has been used to study iron speciation and its distribution among different tissues and structures of the plant. * Mossbauer (MS) and X-ray diffraction (XRD) were used to determine the iron species, scanning electron microscopy (SEM) to locate iron biominerals among plant tissue structures, and energy-dispersive X-ray microanalysis (EDAX), X-ray fluorescence (TXRF) and inductively coupled plasma emission spectroscopy (ICP-MS) to confirm their elemental composition. * The MS spectral analysis indicated that iron accumulated in this plant mainly as jarosite and ferritin. The presence of jarosite was confirmed by XRD and the distribution of both minerals in structures of different tissues was ascertained by SEM-EDAX analysis. * The convergent results obtained by complementary techniques suggest a complex iron management system in I. cylindrica, probably as a consequence of the environmental conditions of its habitat.


Asunto(s)
Hierro/metabolismo , Minerales/metabolismo , Poaceae/metabolismo , Transporte Biológico Activo , Ecosistema , Hierro/química , Minerales/química , Hojas de la Planta/metabolismo , Hojas de la Planta/ultraestructura , Raíces de Plantas/metabolismo , Raíces de Plantas/ultraestructura , Poaceae/química
20.
Can J Microbiol ; 50(11): 923-34, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15644909

RESUMEN

The characterization of the microbial ecology of the Tinto River, an extreme habitat with an extremely low pH and a high concentration of heavy metals, revealed an unexpected level of microbial richness. A variety of microbial eukaryotes was isolated, among them several fungal strains that were identified and their physiological characteristics studied. Ninety strains of yeast were isolated from the Tinto River. Fifty-two percent of them were capable of growth in vitro using medium amended with river water. They belong to 6 genera of basidiomycetes (Rhodotorula, Cryptococcus, Tremella, Holtermannia, Leucosporidium, and Mrakia) and 2 of ascomycetes (Candida and Williopsis). In addition, 349 strains of hyphomycetes belonging to 17 genera (most of them ascomycetes) were isolated and studied. Forty-four percent of the isolated filamentous fungi (154 strains) were capable of growing in vitro using medium amended with Tinto River water. Of this percentage, 19% (29 strains) belonged to the genus Penicillium (16 species) and 66% (102 strains) were included in the genera Scytalidium, Bahusakala, Phoma, and Heteroconium or showed dark sterile mycelia, which probably are of dematiaceous hyphomycetes. In addition, we characterized strains of the ascomycete genera Lecythophora and Acremonium and of the zygomycete genus Mortierella, all of them capable of growing in medium amended with river water. Statistical correlation of biological and physicochemical variables suggested a positive relationship between the dematiaceous hyphomycetes and the most extreme physicochemical conditions found in the Tinto River. Principal components analysis confirmed this relationship and also showed that the Acremonium and Lecythophora groups had environmental preferences similar to those of dematiaceous fungi. The spatial positions of the sampling sites were grouped in 2 main clusters: (i) sampling sites in the mine zone in which most of the dematiaceous, Acremonium, and Lecythophora strains were isolated and (ii) sites that were not in the mine zone and sampling station 5 from which were isolated mainly strains of fungi that were not capable of growing in the medium amended with river water and species of the Penicillium genus.


Asunto(s)
Ecosistema , Hongos/clasificación , Metales Pesados , Ríos/microbiología , Contaminación Química del Agua , Medios de Cultivo , Hongos/crecimiento & desarrollo , Hongos/aislamiento & purificación , Concentración de Iones de Hidrógeno , Metales , Minería , Ríos/química , España
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