281 research outputs found

    Halotolerant bacteria in the efflorescences of a deteriorated church

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    7 pages, 6 figures, 3 tables, 18 references.--Proceedings of the 5th International Symposium, celebrado del 5-8, abril, 2000, en Sevilla, España.[EN]: A study on the composition of the efflorescences from the Church of Saint Jerome, Granada, Spain, and their influence on the distribution ofthe bacterial communities was carried out. The composition of the efflorescences varied depending on the location of the sampling point. The colony foming units (cfu) was related with the type of salt, with a clear difference between halite and epsomite/hexahydrite. The most abundant genera were Bacillus and Micrococcus and the abundance of bacilli could be explained by their osmotic adaptation to halophilic environments.[ES]: Se ha determinado la composición de las eflorescencias de la iglesia de San Jerónimo, en Granada, España, y relacionado con la presencia de comunidades específicas de bacterias. Existe una conexión entre el tipo de sales y las comunidades bacterianas; así, la epsomita, la sal más abundante en el templo, origina la selección de comunidades capaces de crecer a concentraciones de hasta,15% de esta sal. Sin embargo, las bacterias que basan su halotolerancia en la halita presentan un crecimiento comparativamente menor y no son significativamente estimuladas por la presencia de epsomita. Los géneros más abundantes son Bacillus y Micrococcus. La abundancia de bacilos se debe a su adaptación osmótica a ambientes salinos.This work was supported by the European Commission, project ENV4-CT98-0705, and the Research Groups RNM-179 and 201 from the Community of Andalusia.Peer reviewe

    Laboratory and in situ assays of digital image analysis based protocols for biodeteriorated rock and mural paintings recording

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    8 pages, 8 figures, 43 references.Rock art paintings, and in general mural paintings, are one of the many elements of cultural heritage complex systems. As the different elements of a system have diverse spatial positions, spatial recording allows understanding their interactions. Thus, a useful approach to mural paintings recording is to understand it as a microcartography issue, managing each element of the system as a cartographic coverage. The approach implemented emphasizes the utilization of data obtained by remote sensing techniques for extracting different kinds of information susceptible of being analysed, classified and plotted in a differentiate way by means of the possibility of reducing redundant data by Principal Component Analysis (PCA) and the elaboration of false-colour images from uncorrelated bands. A laboratory model was prepared in order to simulate biodeterioration of rock art. The samples were photographically recorded thereafter under different lighting conditions, and PCA applied to the resulting images. False-colour images obtained by combining Principal Component bands allowed us to reach results similar to those of an unsupervised classification. The method has been applied to Roman mural paintings from one of the tombs of Carmona Necropolis, obtaining good results.Peer reviewe

    Evolución y análisis filogenético de las comunidades microbianas desarrolladas como respuesta al aumento de los niveles de fenantreno en un suelo contaminado por PAHs

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    Trabajo presentado al citado Congreso que tuvo lugar del 21-24, de septiembre, 2009, en Almería, España.Las comunidades microbianas de los suelos contaminados con hidrocarburos aromáticos poli cíclicos (PAHs) presentan gran biodiversidad. Esta biodiversidad puede relacionarse con la respuesta a niveles elevados de PAHs. En este trabajo se presenta el estudio y la caracterización de las comunidades microbianas de un suelo contaminado principalmente con hidrocarburos aromáticos poli cíclicos (5LO), mediante técnicas basadas en ADN y técnicas de cultivo. Se ha estudiado la evolución de las comunidades como respuesta al aumento de la concentración de fenantreno.Peer reviewe

    Actinobacteria isolated from subterranean and cultural heritage: implications for biotechnology

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    Due to their extraordinary properties, Actinobacteria can thrive in extreme environments, such as limestone caves, lava tubes and stone monuments. They grow forming microbial mats and speleothems on the walls and ceilings of caves, ranging from extensive coatings to small colonies (Riquelme et al. 2015). Their colour includes yellow, tan, orange, grey, pink and white. Recently, we have found abundant yellow and white-coloured bacterial mats coating the cave walls and secondary mineral deposits (speleothems) of lava tubes from La Palma Island, Canary Islands, Spain (Gonzalez-Pimentel et al. 2018) and Mount Etna in Catania (Sicily, Italy). Field Emission Scanning Electron Microscopy (FESEM) of the coloured microbial mats revealed abundant Actinobacteria-like cells, including a variety of filaments and spore structures with smooth surface ornamentation or profuse surface appendages. The DNA-/RNA-based analyses confirmed that these microbial mats are mainly composed of metabolically active Actinobacteria (Gonzalez-Pimentel et al. 2018). It is well known that Actinobacteria, mainly isolated from marine and soil ecosystems, are an important source of bioactive compounds, with Streptomyces ranking first with a huge number of bioactive secondary metabolites (Guo et al. 2015). These compounds, not only produced by Streptomyces but also by Bacillus, are very important to the industrial sector, such as pharmacology, biofuel and food industries, as well as to the conservation of stone cultural heritage, due to their antimicrobial properties (Silva et al. 2017). In the last decades, these sectors have intensified demands for exploring novel eco-friendly bioactive compounds, which stresses the need to investigate new groups of Actinobacteria from underexplored habitats. Yet, Actinobacteria from caves have not been the target of intensive screening for bioactive secondary metabolites. Hence, Actinobacterial-like microbial mats were collected and isolated from lava tubes in La Palma and Mount Etna to investigate their biotechnological potential. The screening of antimicrobial activity was based both on culture-dependent techniques using the agar diffusion assay and on metagenomics. Our study has showed that the strain Streptomyces sp. MZ0467C isolated from La Palma lava tube has antimicrobial activity against Microbacterium, Rhodococcus, Arthrobacter, Kocuria, Sphingomonas and Paenibacillus due to its ingenious adaptations and metabolic strategies to survive under extreme environmental conditions. This demonstrates that Actinobacteria from subterranean environments are promising sources of antibacterial compounds with interest for cultural heritage conservation

    Biodeterioration of Roman tombs: The role of pigmented actinobacteria

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    Etruscan and Roman necropolises are cemeteries with different types of burial practices, which are remarkable for their magnificent mural paintings. The conservation of these paintings is difficult, mainly derived from environmental factors and the opening of the tombs to public visits. One of the most complex phenomena observed on these sites is biodeterioration. The Circular Mausoleum tomb (Roman Necropolis of Carmona, Seville, Spain) is characterized by a heavy colonization of phototrophic microorganisms on the walls and ceiling. In addition, some areas near the ceiling exhibited an important number of violet stains of unknown origin. Previously, Agarossi (1994) found similar violet stains, attributed to streptomycetes, in two Etruscan tombs. However, no data on the species involved or the chemical structure of the pigments were reported. Here we show that the violet stains observed in the Circular Mausoleum are produced by a strain of the actinobacterium Streptomyces isolated from the mortar walls, and able to synthesize the same violet pigment in the laboratory. Streptomyces parvus MC05 was identified after whole genome study by means of Next Generation Sequencing methods. Pairwise comparisons carried out for genomes of the type strain of S. parvus DSM40348T and the MC05 strain were performed using Jspecies service. While results observed for ANIb, ANIm and Tetra indexes indicated that both strains belong to the same species, the S. parvus MC05 strain differs from the DSM20348T type strain in genome size and secondary metabolites production. AntiSMASH analysis implemented for both strains showed that the S. parvus MC05, isolated from the tomb, presents the capacity of synthesize bioactive compounds which were absents in the type strain. HPLC-MS of the culture extracts from S. parvus MC05 showed the production of three main granaticin derivatives (dihydrogranaticin A, granaticin A and granaticin B) in addition to minor products of other granaticin analogues. Granaticin pigments exhibited antibacterial activity, which justified the low number of clones of Gram positive bacteria found in the whole microbial community study. Gram negative bacteria were not affected (Dominguez-Moñino et al. 2017). To conclude, the origin of the violet stains in the walls of the Circular Mausoleum is the presence of S. parvus MC05, a member of the complex microbial community thriving on the tomb. In growing periods (rainy season) the bacterium excretes the soluble violet granaticins, compounds with a benzoisochromanequinone structure, which diffuses to the mortar and surrounding substrata in wetting periods

    Agromyces italicus sp. nov., Agromyces humatus sp. nov. and Agromyces lapidis sp. nov., isolated from Roman catacombs

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    A polyphasic study was carried out to clarify the taxonomic positions of three Gram-positive isolates from the Catacombs of Domitilla, Rome (Italy). 16S rRNA gene sequence comparisons placed these strains within the genus Agromyces. The morphological and chemotaxonomic characteristics of these isolates were consistent wiih the description of the genus Agromyces. The three isolates could be readily distinguished from one another and from representatives of all Agromyces species with validly published names by a broad range of phenotypic characteristics and DNA-DNA relatedness studies. Therefore, these isolates are proposed to represent three novel species of the genus Agromyces, Agromyces italicus sp. nov. (type strain CD1T=HKI 0325T=DSM 16388T=NCIMB 14011T), Agromyces humatus sp. nov. (type strain CD5T=HKI 0327T=DSM 16389T=NCIMB 14012T) and Agromyces lapidis sp. nov. (type strain CD55T =HKI 0324T=DSM 16390T=NCIMB 14013T). © 2005 IUMS.V. J. and L. L. are grateful to fellowships from the Spanish Ministry of Education and Science (MEC) I3P programme and J. M. G. to an MEC contract from the ‘Ramo´n y Cajal’ programme. This study was supported by project CATS (EVK4-CT2000-00028) and MEC project BTE2002-04492-C02-01.Peer Reviewe

    Phyllobacterium catacumbae sp. nov., a member of the order 'Rhizobiales' isolated from Roman catacombs

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    Two strains were isolated from tuff, a volcanic rock that forms the walls of the Roman Catacombs of Saint Callixtus in Rome, Italy. A polyphasic approach using nutritional and physiological tests, reactions to antibiotics, fatty acid profiles, DNA base ratios, DNA-DNA reassociation and 16S rRNA gene sequence comparisons showed that the two isolates belong to a novel species within the genus Phyllobacterium. The species Phyllobacterium catacumbae sp. nov. is proposed. The type strain is CSC19T (=CECT 5680T=LMG 22520T).V. J. and L. L. received fellowships from the Spanish Ministry of Education and Science (MEC), I3P programme and J. M. G. is supported by an MEC contract from the ‘Ramón y Cajal’ program. This study was supported by EC project EVK4-CT2000-00028 and MEC project BTE2002-04492-C02-01.Peer Reviewe

    Deterioration of an Etruscan tomb by bacteria from the order Rhizobiales

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    7 páginas, 4 figuras, 29 referencias.The Etruscan civilisation originated in the Villanovan Iron Age in the ninth century BC and was absorbed by Rome in the first century BC. Etruscan tombs, many of which are subterranean, are one of the best representations of this culture. The principal importance of these tombs, however, lies in the wall paintings and in the tradition of rich burial, which was unique in the Mediterranean Basin, with the exception of Egypt. Relatively little information is available concerning the biodeterioration of Etruscan tombs, which is caused by a colonisation that covers the paintings with white, circular to irregular aggregates of bacteria or biofilms that tend to connect each other. Thus, these colonisations sometimes cover extensive surfaces. Here we show that the colonisation of paintings in Tomba del Colle is primarily due to bacteria of the order Rhizobiales (Alphaproteobacteria), which were likely influenced by the neighbouring rhizosphere community and the availability of nutrients from root exudates.This work was funded through the projects CGL2010-17183, 201030E011 and Consolider 2007-00058. M.D.H. was supported by a JAE Research Fellowship from CSIC, and S.C. was supported by a Juan de la Cierva contract.Peer reviewe

    Survival of Atlantic bluefin tuna (Thunnus thynnus) larvae hatched at different salinity and pH conditions

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    In this study, we assessed the effect of environmental salinity and pH as independent factors on larval survival of Atlantic bluefin tuna (ABFT –Thunnus thynnus) together with their whole-body Na+/K+-ATPase and v-type H+-ATPase activities. Fertilized eggs of ABFT were obtained from a spontaneous spawning of broodstock in the farming facilities at El Gorguel (Cartagena, SE Spain) and were transferred to facilities of the Spanish Institute of Oceanography (IEO) in Mazarrón (SE Spain). In a first experiment, eggs (200 fertilized eggs L-1 per treatment, in 3 replicates) were exposed to different salinities treatments and constant pH 8.0 (control) until hatch was completed (50 h post- fertilization, hpf, at 23 ºC): 27, 30, 33, 36, 37, 38 (control), 39, 40, 43, 46 and 49 ppt. In a second experiment eggs (200 fertilized eggs L-1, in 3 replicates) were exposed to seawater salinity (SW: 38 ppt) and four reduced pH treatments until hatch was completed (50 hpf at 23 ºC): 8.0 (control), 7.7, 7.5 and 7.3. An inverse „„U-shaped‟‟ relationship was observed between environmental salinity and number of hatched larvae. An opposite pattern was observed for both Na+/K+-ATPase and H+-ATPase activities in hatched larvae, increasing both activities in groups exposed to extreme salinities. Thus, larval survival was higher at intermediate salinities and lower at the extreme salinities tested. These results suggest higher survival rates with lower active pumps activities. No significant differences in larval survival were observed with pH treatment, but lower H+-ATPase activity was detected at control environmental pH (pH 8.0). Survival results are discussed in terms of osmoregulatory cost adapting to a salinity and pH predicted for the near future scenarios.Versión del edito

    Caracterización de un mutante de S. clavuligerus NRRL 3585 capaz de metabolizar glucosa y expresión del gen glk de S. coelicolor en S. clavuligerus

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    Comunicación presentada al citado congreso, celebrado del 19-23, junio, 1988, Barcelona, España.Peer reviewe
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