Ana Teresa Caldeira

Universidade de Évora | uevora · Department of Chemistry

Mines, like other subterranean environments, have ecological conditions which allow the thriving of microorganisms. Prokaryotes and fungi are common inhabitants of mines, developing a metabolism suitable for growing in such inhospitable environments. The mine of Lousal, Portugal, is an interesting site for the study of microorganisms present in the...

Salt caves are scarce and poorly investigated mainly because they only exist in extremely remote and arid regions, such as the Atacama Desert (Chile). The Cordillera de la Sal (San Pedro de Atacama) is one of the most important rock salt karst areas in the world forming a Mars-like landscape. The detection of microorganisms and biosignatures preser...

Antimicrobial resistance has become a global problem in recent decades. A gradual reduction in drug discoveries has led to the current antimicrobial resistance crisis. Caves and other subsurface environments are underexplored thus far, and they represent indispensable ecological niches that could offer new molecules of interest to medicine and biot...

Aromatic flavoring plants are important ingredients of the Mediterranean diet, one of the healthiest and most sustainable dietary forms, often associated with greater longevity as well as contributing to the reduction of some chronic pathologies with high mortality and morbidity. Their essential oils (EOs) are increasingly used as therapeutic agent...

The network of lava tubes is one of the most unexploited natural wonders of the Galapagos Islands. Here, we provide the first morphological, mineralogical, and biogeochemical assessment of speleothems from volcanic caves of the Galapagos to understand their structure, composition, and origin, as well as to identify organic molecules preserved in sp...

New 2-piperidinium-4-styrylcoumarin derivatives, with large Stokes shifts and high fluorescence quantum yields, as potential fluorescent labels for biomolecules.

Paenibacillus, rod-saped gram-positive endospores forming aerobic or facultative anaerobic bacteria, colonize diverse ecosystems and are involved in the biodegradation of cultural heritage assets. Biodeteriogenic microorganisms can be easily detected/identified by ribonucleic acid- fluorescent in situ hybridization RNA-FISH with specific probes. In...

Important scientific areas, such as cellular biology, medicine, pharmacy, and environmental sciences, are dependent on very sensitive analytical techniques to track and detect biomolecules. In this work, we develop a simple, low-cost and effective synthetic strategy to produce new red-shifted 4-styrylcoumarin derivatives as promising inexpensive fl...

Biocolonization and biodeterioration phenomena in Cultural Heritage is presently considered a relevant issue when planning conservation strategies and preservation measures in museum collections. Artworks such as easel paintings are source of various ecological niches for microbial communities’ growth due to the presence of several organic resource...

Pseudomonas sp. strain L5B5 is an antimicrobial-producing bacterium isolated from an air sample collected in a pyrite mine in Lousal, Portugal. Genomic analyses predicted genes involved in virulence factors. Here, we report the complete genome sequence of this bacterium, which consists of a circular chromosome with a length of 6,811,662 bp.

Microbiome taxa associated with parasitic nematodes is unknown. These invertebrate parasites could act not only as reservoirs and vectors for horizontally transferred virulence factors, but could also provide a potential pool of future emerging pathogens. Trichuris trichiura and Trichuris suis are geohelminths parasitizing the caecum of primates, i...

Microbial biodeterioration is a growing problem in cultural heritage (CH). Many biocides used to control CH biodeterioration have toxic effects and risks of contamination for health and the environment. Essential oils (EOs) due to their antimicrobial potential and low toxicity represent a sustainable and safe alternative in the control of microbial...

Plasma etching is an innovative technique that has been recently applied in the cleaning of soiled archaeological objects. This research investigated the use of low-pressure plasma etching in cleaning microbial contaminations on an oolitic limestone from an UNESCO World Heritage listed monument: the Batalha Monastery in Central Portugal. The cleani...

Protein-based biological materials such as albumin, casein and collagen are found in various cultural heritage (CH) artefacts. This study focuses on the study of protein binders from easel paintings media. Proteins have complex structures which are difficult to identify with non-invasive spectroscopic methods (FT-IR, Raman, UV). Immunoassays such a...

Lava caves differ from karstic caves in their genesis and mineral composition. Subsurface microbiology of lava tube caves in Canary Islands, a volcanic archipelago in the Atlantic Ocean, is largely unknown. We have focused the investigation in a representative lava tube cave, Fuente de la Canaria Cave, in La Palma Island, Spain, which presents diff...

The microbiota present in cultural heritage objects, made by diverse inorganic and organic materials and inserted into particular environment, represents a complex and dynamic ecosystem composed by bacteria, cyanobacteria, fungi, algae and lichens, which can induce decay by biological mechanisms. To control the microbial growth several methods are...

Hypogenic caves represent unique environments for the development of specific microbial communities that need to be studied. Caves with rock art pose an additional challenge due to the fragility of the paintings and engravings and to microbial colonization which may induce chemical, mechanical and aesthetic alterations. Therefore, it is essential t...

An experimental study was conducted to assess the nature and extent of the biodeterioration of the limestone in the Batalha Monastery in Portugal. Stone fragments covered with microbial biofilms and lichenous crusts were investigated using Optical Microscopy (OM), Low Vacuum Scanning Electron Microscopy with Energy Dispersive Spectroscopy (LV-SEM +...

The conservation and preservation of museum collections requires a detailed understanding of their constituent materials which are often natural, synthetic or semi-synthetic polymers. The use of a wide variety of instrumental techniques can give an extraordinary amount of quality information, by delivering complementary data regarding composition a...

The Galapagos Islands (Ecuador) have a unique ecosystem on Earth due to their outstanding biodiversity and geological features. This also extends to their subterranean heritage, such as volcanic caves, with plenty of secondary mineral deposits, including coralloid-type speleothems and moonmilk deposits. In this study, the bacterial communities asso...

Macrophytes are a promising source of bioactive compounds with potential applications in the biocontrol of harmful cyanobacteria blooms. In this study, we investigated the inhibitory effects of extracts from three macrophytes (Nasturtium officinale, Potamogeton natans and Ranunculus aquatilis) on Microcystis aeruginosa. We assessed physiological in...

Many studies have demonstrated the effectiveness of algicidal compounds produced by macrophytes against microalgae. The aim of this study was to assess the algicidal activity of seven Moroccan macrophyte ethyl acetate extracts (MEA) to control harmful algal blooms (HABs). The response and sensitivity of prokaryotic toxic cyanobacteria (Microcystis...

The study performed on the stone materials from the Convent of Christ revealed the presence of a complex microbial ecosystem, emphasizing the determinant role of microorganisms on the biodecay of this built cultural heritage. In this case study, the presence of Rubrobacter sp., Arthrobacter sp., Roseomonas sp., and Marinobacter sp. seems to be resp...

Colour in historic and modern architecture is one of the most important visible characteristics that should be preserved along the times. There are many factors that can induce stone weathering, promoting its discolouration. Among these factors, microorganisms’ action was neglected for many decades, and nowadays there is a lack of association in th...

Coumarins, whether natural products or synthetic, have aroused a growing interest from the scientific community in last decades due to their very significant pharmacological activity and due to their excellent photophysical and spectroscopic properties. The design and synthesis of new efficient organic photosensitizers for DSSC's, considered promis...

Easel paintings are assets with an important historic and cultural value. They usually possess a multi-tiered structure, composed of different layers some of which may present protein binders, making it important to identify these materials for restoration and conservation purposes. We propose the identification of different protein binders by a ne...

Three autochthonous flavouring herbs from Alentejo (Portugal), Calamintha nepeta (syn. Clinopodium nepeta), Origanun virens and Thymus mastichina, were selected to evaluate toxicological, antioxidant, antiproliferative and antimicrobial potential of their essential oils (EOs). C. nepeta and T. mastichina EOs showed a high content of oxygenated mono...

To keep the integrity of our common cultural heritage there is a growing need to understand its deterioration mechanisms, so that aesthetical and structural alterations can be predicted and prevented. This work comprises an important contribution to understand the deterioration mechanisms of four limestone sculptures, stored in an indoor museum env...

Dekkera bruxellensis is the main reason for spoilage in the wine industry. It renders the products unacceptable leading to large economic losses. Fluorescence In Situ Hybridization (FISH) technique has the potential for allowing its specific detection. Nevertheless, some experimental difficulties can be encountered when FISH technique is applied in...

This article reports biocolonization assays carried out on yellow and red ochres and ultramarine blue pigments. These pigments have been most commonly used in traditional limewash of heritage buildings from southern Portugal (Alentejo) and, in the case of the yellow and red ochres, also in historical decorative wall paintings since Roman times. The...

The identification of protein binders used in easel paintings is an important information to understand an artist’s technique and for making informed conservation and restoration decisions. The present work presents a novel fluorescent labelling methodology, using a coumarin derivative chromophore, C392STP (sodium (E/Z -4-(4-(2-(6,7-dimethoxy-couma...

From a screening study of various potential inhibitors for cholinesterases (ChEs), compound (rac)-1 (4-((3-hydroxy-2-oxo-3-phenylindolin-1-yl) methyl) piperidin-1-ium chloride) showed an IC50 of 18 μM for butyrylcholinesterase (BuChE). Herein we present a toxicological and pharmacological evaluation of (rac)-1 to determine its potential for use as...

The photophysical properties of coumarin 392 4-sulfotetrafluorophenyl ester, C392STP (sodium (E/Z)-4-(4-(2-(6,7-dimethoxycoumarin-3-yl)vinyl)-benzoyl)-2,3,5,6-tetrafluoro-benzenesulfonate) an amine reactive coumarine with potential for bioconjungation, have been studied in different solvents. Strong red shifts (31 to 56 nm on going from dioxane to...

Colour is a major argument that drives the decision of an architect in a specific architecture project and one of the most important characteristics and perceptible aspects of natural building stones. “Blue” limestones are building rocks, with different geological ages, typically used in several countries, and are known for their vulnerability to a...

In recent years, the population has become acutely aware of the need to conserve the world's resources. The study of new compounds produced by natural means is important in the search for alternative green solutions that act against biodeteriogenic fungi, which promote biodeterioration of built cultural heritage sites. The present paper reports new...

Amanita ponderosa are wild edible mushrooms that grow in some microclimates of Iberian Peninsula. Gastronomically this species is very relevant, due to not only the traditional consumption by the rural populations but also its commercial value in gourmet markets. Mineral characterisation of edible mushrooms is extremely important for certification...

The Lalibela rock-hewn churches are one of the most important religious pilgrimage sites in Ethiopia. These churches are carved from the scoriaceous basalt rock substrate, which has been exposed to attack by biological agents with significant loss of surface material. Particularly, the widespread growth of lichens and other microorganisms on the ca...

Apesar de comumente aceite a atribuição de uma cronologia paleolítica aos vestígios de pintura descobertos há meio século na Gruta do Escoural, o seu estudo arqueológico nunca fora além de considerações estilístico‑‑formais, dificultadas pela

The identification of microorganisms involved in biodeterioration/biodegradation process is determinant to understand their effects on cultural assets, and furthermore, it is a crucial step to define an efficient strategy to protect monuments and artworks from microbiological recolonisation, in order to promote its preservation. The renaissance mur...

The detection and analysis of metabolically active microorganisms are useful to determine those directly involved in the biodeterioration of cultural heritage (CH). Fluorescence in situ hybridization with oligonucleotide probes targeted at rRNA (RNA-FISH) has demonstrated to be a powerful tool for signaling them. However, more efforts are required...

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, identificatio...

Essential oils (EOs) and aqueous extracts of aerial parts of four aromatic species, Calamintha nepeta, Foeniculum vulgare, Mentha spicata and Thymus mastichina, from southwest of Portugal were characterised chemically and analysed in order to evaluate their antioxidant potential and cholinesterase inhibitory activities. The main components of EOs w...

The detection and analysis of metabolically active microorganisms are useful to determine those directly involved in the biodeterioration of cultural herit-age (CH). Fluorescence insitu hybridization with oligonu-cleotide probes targeted at rRNA (RNA-FISH) has demon-strated to be a powerful tool for signaling them. However, more efforts are require...

Easel paintings have been considered one of the most important art expressions, constituting today outstanding works of art with important historic and cultural value. Unfortunately, due to the presence of several organic materials, these artworks have been affected by microbial contamination that among other factors can be responsible for differen...

Microorganisms play a crucial role in Cultural Heritage’s context by inducing structural and aesthetical damages. Among stone related artworks, Cave Art is primordial in the understanding of the development of art in humans’ societies. Although, they were preserved during millennia, these paintings and engravings are extremely fragile and suffer ch...

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 inve...

The color is a major argument that drives the decision of the architect and the worth of an ornamental stone in a specific architecture project. As limestone and marbles are the more important commercial stones, it is essential to know how the color of each limestone and marble is naturally achieved and how the color can change. Considering that th...

Based on the positive bioassay results of the known oxindole hit compound rac-1-benzyl-3-hydroxy-3-phenylindolin-2-one which showed significant inhibition of butyrylcholinesterase (BuChE) (IC50=7.41 μM), a library of 31 analogues of 3-substituted-3-hydroxyoxindoles was synthesized and screened for both acetylcholinesterase (AChE) and BuChE activity...

A library of isoquinolinone and azepanone derivatives were screened for both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity. The strategy adopted included (a) in vitro biological assays, against eel AChE (EeAChE) and equine serum BuChE (EqBuChE) in order to determine the compounds IC50 and their dose-response activity, conso...

Depuis plus d'un siècle, l'analyse des matières picturles de l'art pariétal du Paléolithique Supérieur en Europe occidentale a permis d'étudier les recettes et techniques des populations préhistoriques. Grâce aux progrès technologiques de ces quarante dernières années, de nombreuses études se sont portées sur les matières colorantes et pigments pré...

The study and preservation of museum collections requires complete knowledge and understanding of constituent materials that can be natural, synthetic, or semi-synthetic polymers. In former times, objects were incorporated in museum collections and classified solely by their appearance. New studies, prompted by severe degradation processes or conse...

Biodeterioração Pintura de cavalete Estratégias de mitigação Biocidas naturais Resumo As pinturas de cavalete têm sido alvo de biodeterioração devido à proliferação de agentes microbi-ológicos, em particular a propagação de estirpes fúngicas, estando estas associadas à formação de biofilmes e desintegração da microestrutura destas obras de arte, at...