668 resultados para Archeological heritage
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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The South Carolina Sea Grant Consortium publishes Coastal Heritage, a quarterly publication that covers environmental policy, science, history, and culture.
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Several biosurfactants with antagonistic activity are produced by a variety of microorganisms. Lipopeptides (LPPs) produced by some Bacillus strains, including surfactin, fengycin and iturin are synthesized nonribosomally by mega-peptide synthetase (NRPS) units and they are particularly relevant as antifungal agents. Characterisation, identification and evaluation of the potentials of several bacterial isolates were undertaken in order to establish the production of active lipopeptides against biodeteriogenic fungi from heritage assets. Analysis of the iturin operon revealed four open reading frames (ORFs) with the structural organisation of the peptide synthetases. Therefore, this work adopted a molecular procedure to access antifungal potential of LPP production by Bacillus strains in order to exploit the bioactive compounds synthesis as a green natural approach to be applied in biodegraded cultural heritage context. The results reveal that the bacterial strains with higher antifungal potential exhibit the same morphological and biochemical characteristics, belonging to the genera Bacillus. On the other hand, the higher iturinic genetic expression, for Bacillus sp. 3 and Bacillus sp. 4, is in accordance with the culture antifungal spectra. Accordingly, the adopted methodology combining antifungal screening and molecular data is represent a valuable tool for quick identification of iturin-producing strains, constituting an effective approach for confirming the selection of lipopeptides producer strains.
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The present study is a multidisciplinary approach applied to architectural stone materials of the Convent of Christ in Tomar (Portugal) in order to understand and mitigate the active decay processes. The structure and appearance of the stonework from the Convent of Christ are strongly affected by stains, biofilms and structural degradation. To investigate these phenomena, a multianalytical approach comprising X-ray microdiffraction, scanning electron microscopy, microRaman and microinfrared spectroscopy was applied to the examination of altered outdoor stone areas being detected calcium oxalates, carotenoids and microbial proliferation. The presence of these alteration products seems to be correlated with the microbial activity of bacteria, microalgae, cyanobacteria and filamentous fungi. This work showed that the application of complementary methodologies is an efficient strategy to characterise the stone decay, and constitute a starting point for successful conservation intervention plans that are urgent to ensure the preservation and safeguard of this emblematic monument.
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The damaging of buildings and monuments by biological contamination is a cause of serious concern. Biocides based on chemical toxic compounds have been used to mitigate this problem. However, in the past decade many of the most effective biocides have been banned due to their environmental and health hazards. Therefore, proper remediation actions for microbiologically contaminated historic materials based on environmentally safe solution is of vital importance. Bacillus species are emerging as a promising alternative for built heritage treatment. They produce a great diversity of secondary metabolites with biological activity, well known to possess antagonistic activities against many fungal pathogens. In order to evaluate the antifungal activity of the novel biocides produced in our laboratory by cultures of selected bacterial strains, liquid interaction assays using four biodeteriogenic fungi were achieved, revealing a nearly 100% of inhibitory capacity to fungal proliferation. To confirm their effective safe toxicological properties, in vivo tests using two different biological models were performed. The lyophilized supernatant of the Bacillus culture broth showed no lethality against brine shrimp and also no toxicological effects in Swiss mice through administration of acute dose of 5000 mg/kg by oral gavage. In fact, the bioactive compounds were no lethal at the tested dose unlike Preventol® (commercial biocide) that induced acute toxicity with 10 times minor concentration dose administrated in the same conditions. Therefore, the new bioactive compounds that suppress growth of biodeteriogenic fungi on historical artworks, presenting at the same time no toxicity against other living organisms, constituting an efficient and green safe solution for biodegradation/biodeterioration treatment of Cultural Heritage.