Centro GeoBioTec UA

Porto, Portugal

Centro GeoBioTec UA

Porto, Portugal
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Garcia-Sanchez A.M.,CSIC - Institute of Natural Resources and Agriculture Biology of Seville | Miller A.Z.,CSIC - Institute of Natural Resources and Agriculture Biology of Seville | Jurado V.,CSIC - Institute of Natural Resources and Agriculture Biology of Seville | Dionisio A.,University of Lisbon | And 5 more authors.
The Conservation of Subterranean Cultural Heritage - Selected papers from International Workshop on Conservation of Subterranean Cultural Heritage, CSCH 2014 | Year: 2014

Subsurface engineering environments, such as mines, tunnels and water galleries, may have cultural significance, in addition to their inherent geological characteristics. The 16th century Paranhos spring water tunnel located in Porto city (NW Portugal) was excavated throughout the granitic bedrock to supply water for the public fountains for more than five centuries. Nowadays, due to groundwater quality degradation and high deterioration level of the granite tunnel, the water is no longer used for public purposes. This subsurface granite heritage represents a favourable habitat for a wide variety of microorganisms, which participate in the formation processes of secondary minerals and dissolution of rock components. Due to the large number of anthropogenic contamination sources and urban surface activities along the course of the Paranhos spring water tunnel, such as garages, petrol stations and in situ sanitation and sewer network, this subterranean environment shows high vulnerability to contamination. In fact, previous hydrogeochemical studies showed a nitrate and sulfate-enriched composition for the groundwater probably resulting from urban drainage, sewer leakage and agricultural activities. In this study, we identify and characterize the bacterial communities in biogenic ferromanganese deposits coating the weathered subsurface granite in order to understand the relationship between their presence and the potential contamination sources. Molecular biology techniques of enrichment and isolation cultures, field emission scanning electron microscopy, transmission electron microscopy and micro-Raman spectroscopy were conducted. Thirty-five different bacterial strains were isolated, most of them belonging to Bacillus, Pseudomonas and Ensifer genera. The presence of Pseudomonas spp. is usually associated with contaminated environments, which is consistent with the contaminated sources described before. Moreover, micro-Raman analysis pointed out the presence of copper phthalocyanine, a blue pigment commonly used in the manufacture of enamels, printing inks, and automotive finishes. Its presence is consistent with the existence of garages and petrol stations on the surface of the Paranhos spring water tunnel. Electron microscopy observations of isolates and enrichment cultures for Mn- and Fe- oxidizing bacteria revealed the presence of Mn- and Fe-rich precipitates upon bacterial cells, which suggests that these bacteria induce the precipitation of Fe and Mn oxides. We were thus able to isolate bacteria probably involved in the formation of the black ferromanganese oxides coating the Paranhos granite surfaces. This clearly demonstrates that the interest in the geomicrobiology of man-made subterranean environments lies not only in the fact that some of them can provide useful information for general and applied microbiology but also for representing geomining sites of particular geological and cultural relevance that needs conservation and maintenance interventions. © 2014 Taylor & Francis Group, London, UK.

Miller A.Z.,University of Lisbon | Dionisio A.,University of Lisbon | Sequeira Braga M.A.,University of Minho | Hernandez-Marine M.,University of Barcelona | And 11 more authors.
Chemical Geology | Year: 2012

This paper reports the results of a study of biogenic Mn oxide minerals coating in a subsurface granite environment.This subterranean environment corresponds to galleries of a 16th century spring water tunnel dug throughout the granite bedrock located in Porto city (NW Portugal). Several techniques (XRD, FTIR, Raman, ICP-MS, TEM-EDS, FESEM-EDS, STEM-EDS and STXM-NEXAFS) were used to assess the mechanisms involved in the formation of manganese oxides, specifically birnessite and todorokite. These manganese oxides presented peculiar shapes, nano-dimensions, low degree of crystallinity, and high levels of some trace elements such as P, Ca, C, Al, Si, Ba and Zn. They were associated with large amounts of extracellular polymeric substances exuded by filamentous bacterial communities, which serve as nuclei for preferential precipitation of manganese oxides on the extracellular sheaths. Scientific assessment revealed that biological activity played a major role in the development of these manganese oxides. © 2012 Elsevier B.V.

Miller A.Z.,University of Lisbon | Hernandez-Marine M.,University of Barcelona | Jurado V.,Institute Recursos Naturales y Agrobiologia IRNAS | Dionisio A.,University of Lisbon | And 7 more authors.
Environmental Microbiology Reports | Year: 2012

In the last few years, geomicrobiologists have focused their researches on the nature and origin of enigmatic reticulated filaments reported in modern and fossil samples from limestone caves and basalt lava tubes. Researchers have posed questions on these filaments concerning their nature, origin, chemistry, morphology, mode of formation and growth. A tentative microbial origin has been elusive since these filaments are found as hollow tubular sheaths and could not be affiliated to any known microorganism. We describe the presence of similar structures in a 16th century granite tunnel in Porto, Northwest Portugal. The reticulated filaments we identify exhibit fine geometry surface ornamentation formed by cross-linked Mn-rich nanofibres, surrounded by a large amount of extracellular polymeric substances. Within these Mn-rich filaments we report for the first time the occurrence of microbial cells. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

Marques J.E.,University of Porto | Marques J.M.,University of Lisbon | Chamine H.I.,Polytechnic Institute of Porto | Chamine H.I.,University of Porto | And 12 more authors.
Geosciences Journal | Year: 2013

Mountains are often considered as the world's water towers. This paper presents a critical review on the research concerning the integrated assessment of groundwater resources of the mountain hydrogeologic system of Serra da Estrela Natural Park (central Portugal). The study area is the Zêzere river basin upstream of Manteigas village located at the Serra da Estrela Mountain in Central Portugal. It provides the source of strategic water resources for the Portuguese mainland, including normal groundwaters, thermomineral waters and surface waters. An integrated approach has been used to formulate a conceptual model for this complex mountain hydrogeological system by integrating the geological, morphotectonic, hydroclimatic, unsaturated soil zone, hydrogeological, hydrogeophysical, hydrogeochemical and isotopic data. This model has been useful to: i) evaluate the water resources; ii) provide the basis for a sustainable management of water resources, iii) design measures for groundwater exploitation and contamination control; and iv) set up land-use policies. © 2013 The Association of Korean Geoscience Societies and Springer-Verlag Berlin Heidelberg.

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