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The natural durability of the wood is essential for the definition of its use, and this property can be enhanced with the proper chemical treatment of the wood. Thus, the objective of this study was to evaluate the resistance to termites and decay fungi of Jacaranda copaia wood chemically modified through acetylation. Five experimental treatments were assessed: acetylation for 2, 4, 6 and 8 hours and a control (non-acetylated). The acetylation was carried out by immersing wood samples in acetic anhydride at 90 °C. Acetylated and control samples were subjected to the action of xylophagous termites (Nasutitermes sp.) and decaying fungi (Gloeophyllum trabeum and Trametes versicolor). The acetylation process significantly increased the resistance of Jacaranda copaia wood to the attack of the xylophagous organisms. There was no mass loss after exposure to termites of the wood in any of the acetylation treatments, while in the control wood, mass loss was 9.5%. Regarding the decaying fungi, mass loss occurred in all treatments. Acetylation for 6 and 8 hours were the most efficient chemical treatments, increasing the resistance class of the Jacaranda copaia wood to highly resistant. RESUMO A durabilidade natural da madeira é essencial para a definição de seu uso, e essa propriedade pode ser potencializada com o tratamento químico adequado da madeira. Assim, o objetivo deste trabalho foi avaliar a resistência da madeira de Jacaranda copaia modificada quimicamente por acetilação a cupins e fungos apodrecedores. Cinco tratamentos experimentais foram avaliados: acetilação por 2, 4, 6 e 8 horas e um controle (não acetilado). A acetilação foi realizada por imersão das amostras de madeira em anidrido acético a 90°C. Amostras acetiladas e controle foram submetidas à ação de cupins xilófagos (Nasutitermes sp.) e fungos apodrecedores (Gloeophyllum trabeum e Trametes versicolor). O processo de acetilação aumentou significativamente a resistência da madeira de Jacaranda copaia ao ataque dos organismos xilófagos. Não houve perda de massa após exposição aos cupins da madeira em nenhum dos tratamentos de acetilação, enquanto na madeira controle a perda de massa foi de 9,5%. Em relação aos fungos em decomposição, ocorreu perda de massa em todos os tratamentos. Os tratamentos químicos mais eficientes foram os de acetilação por 6 e 8 horas, elevando a classe de resistência da madeira de Jacaranda copaia para altamente resistente.

The application of biocides to control microbial proliferation in stone materials is nowadays a rather common practice. In the Coimbra´s UNESCO World heritage monuments, biocide treatments rely on the application of Biotin T and Preventol R80. However, the application of these formulations often occurs without the complete knowledge of microbial communities’ susceptibility to their application. The aim of this study was to evaluate the efficiency of these compounds and compare them with a commercial version of Ocimum basilicum essential oil, against various fungal species present in these areas. Through the application of in vitro antifungal activity assays, we were able to verify that, in general, Biotin T rather than Preventol R80 was more efficient against all tested fungi. In addition, the commercial version of the Ocimum basilicum essential oil also exhibited good results and might be an alternative option to be taken into consideration in future interventions in these monuments., A aplicação de biocidas para controlar a proliferação microbiana em materiais rochosos é hoje em dia uma prática bastante comum. Nos monumentos do património mundial da UNESCO de Coimbra, os tratamentos à base de biocidas têm consistido na aplicação de Biotin T e Preventol R80. No entanto, a aplicação dessas formulações ocorre muitas vezes sem o conhecimento completo da suscetibilidade das comunidades microbianas à sua aplicação. O objetivo deste estudo foi avaliar a eficiência destes compostos e compará-los com uma versão comercial do óleo essencial de Ocimum basilicum, contra várias espécies de fungos presentes nessas áreas. Por meio da aplicação de ensaios de atividade antifúngica in vitro, pudemos verificar que, em geral, o Biotin T, comparativamente ao Preventol R80, foi mais eficiente contra todos os fungos testados. Adicionalmente, a versão comercial do óleo essencial de Ocimum basilicum também apresentou bons resultados e pode ser uma opção alternativa a ser considerada em futuras intervenções nestes monumentos.

This study is aimed to compare, through laboratory experimentations, the efficiency of UV-C irradiation and an essential-oils-based product as tools to reduce the biofilm identified in a semi-hypogeum room located in the archaeological park of Baia, Italy. During this study, the autotrophic component of the original biofilm, mostly composed of Chlorophyceae and Cyanophycean, was isolated in the laboratory, while simultaneously, the composition of the pigments used for the fresco paintings was examined in situ through X-ray fluorescence. These examinations were necessary for the creation of test samples that were similar to the original surfaces and used for subsequent experiments. The plaster testers were contaminated with artificial biofilm, exposed to UV-C at a distance of 80 cm for a fixed time interval and treated with ESSENZIO©, a product based on oregano and thyme essential oils, to eradicate the biological species. The treatment’s effectiveness was then assessed by employing optical microscopy and spectrometric techniques applied to the areas previously occupied by the biofilm on the different test samples. To obtain an additional parameter to evaluate the treatments efficacy, the concentrations of the photosynthetic pigments were also measured by spectrophotometry. Results showed that biofilms were successfully removed by the irradiation of the surfaces and by the essential-oils-based product at a dilution of 50% in demineralized water with a time of application of 1 h and 30 min; in addition, no visible change of the pigments used on the testers were observed, demonstrating the high efficiency of the treatments against biodeteriogens. The two methods and their different mechanisms of action have provided interesting aspects that suggest a combined strategy to contrast and prevent biological growth in archaeological contexts.

V článku je presentován postup obnovy barokního konventu cisterciáckého kláštera v Plasích založeného na základovém dubovém roštu a pilotách. J. B. Santini navrhl vodní systém pro konzervaci základové konstrukce konventu čistou pramenitou vodou, přiváděnou do jílových bazénů pod klášterem. Tím se udržovala dubová základová konstrukce pod vodní hladinou a byla zajištěna její konzervace. V 19. stol. došlo ke ztrátě znalostí o chování budovy, byly přerušeny všechny vodovody kritické pro stabilitu objektu a uskutečnily se mnohé nevhodné zásahy. Santini pamatoval na tuto možnost a navrhl nouzový režim, který počítal s možností ztráty všech přívodů vody. V nouzovém stavu je stahována okolní voda (splachy z komunikace a polí) do základových bazénů. Tento zdroj vody však neodpovídá požadavkům pro konzervaci základové konstrukce. V nouzovém režimu se stavba nacházela zhruba 70 let do roku 2021, kdy byl částečně obnoven přívod vhodné vody. Článek popisuje obnovu systému, vyhodnocuje její dopad na budovu porovnáním vnitřního mikroklimatu v období před a po opravě a současně ověřuje možnost vysoušení vnitřního vzduchu v konventu pomocí rozstřiku studené vody, jež v minulosti zajišťovala barokní fontánka. Na základě výsledků měření lze konstatovat pozitivní vliv opravy na základovou konstrukci kláštera a zlepšení vnitřního mikroklimatu. Stopovací zkouškou bylo identifikováno vzájemné propojení částí vodního systému. The article presents the process of restoration of the Baroque convent of the Cistercian Monastery in Plasy found on oak raft and piles. J. B. Santini designed a water system for the preservation of the foundation structure of the convent with pure spring water fed into clay basins under the monastery. This kept the oak foundation structure under water and thus ensured its preservation. In the 19th century, knowledge of the behaviour of the building was lost, all water pipes critical to the stability of the building were severed and many inappropriate interventions were made. Santini was mindful of this possibility and designed an emergency scheme that took into account the possibility of losing all water supplies. In the emergency mode, ambient water (runoff from the road and fields) is withdrawn into the foundation basins. However, this water source does not meet the requirements for conservation of the foundation structure. The structure was in emergency mode for approximately 70 years until 2021 when a suitable water supply was partially restored. This paper describes the restoration of the system, evaluates its impact on the building by comparing the indoor microclimate in the pre- and post-repair periods, and at the same time verifies the possibility of drying the indoor air in the convent by means of cold water spraying, which in the past was provided by a baroque fountain. Based on the results of the measurements, it can be concluded that the repair had a positive effect on the foundation structure of the convent and improved the indoor microclimate. A tracing test identified the mutual interconnection of parts of the water system.

The worldwide current practice of the structural design of sewers is based on procedures which usually include the effects caused by chemical and biological deterioration. However, in the last few decades, many sewer pipes have been designed using reinforced concrete which have succinctly considered such deterioration promoters. Indeed, knowledge related to reinforced concrete deterioration processes has become an important issue when forecasting the expected or remaining lifespan of sewers. Within these processes, thickness and strength losses and porosity augments have been found to be the result of the vital activity of sulfur-oxidizing bacteria and some types of fungus. This paper presents a rational methodology that uses biodeterioration measurements to describe how biodeterioration effects can affect the probability of failure during the lifetime of sewers. The probability of failure was obtained using Monte Carlo simulations based on numerical sampling from lognormal and uniform distributions. The concrete and reinforcement strength, geometric properties, H2S concentration in the headspace, and load values were considered as the main sources of uncertainty. The results indicate that the expected service lifespan can vary between 55 and 37 years for low and high H2S concentrations, respectively.

Microbial communities colonising outdoor sculptures form intricate and dynamic ecosystems, which can accelerate the deterioration processes of the artworks and pose challenges to their conservation. In this study, the bacterial and fungal communities colonising the surfaces of five contemporary outdoor sculptures were characterised by high-throughput sequencing. The sculptures, made of marble, granite, Ançã limestone and mortar, are in urban parks and squares in the district of Porto, Portugal. The analysis of the microbial populations revealed great taxonomic diversity and species richness, including in well-preserved sculptures showing few visible traces of contamination. Proteobacteria, namely the genera Pseudomonas and Sphingomonas, were the core taxa common to all the sculptures, while Massilia and Aureobasidium were dominant only in granite. An abundance of pigment-producing microorganisms, such as Deinococcus, Methylobacterium, Rhodotorula and Sporobolomyces, was also found in granite. These are relevant taxonomic groups that can negatively impact stone and mortar artworks. The study was complemented with colourimetric analyses and bioluminescence assays to measure the adenosine triphosphate (ATP) content of samples collected from specific contaminated areas of the sculptures. The characterisation of the microbiomes of sculptures can provide further knowledge on the deterioration risks of this type of artwork in the region and help outline future targeted conservation strategies.

Water affects the susceptibility of stone to alteration by facilitating physical, chemical and biological weathering. Stone properties determine water transport and retention, but it is also expected that biofilms and extracellular polymeric substances could alter the water-stone relationship. A lot of research on this subject has been carried out on soils, but the effect on stones is understudied. For this reason, three sedimentary building stones, Ernzen, Euville and Savonnieres, each with a different pore size distribution, were biofouled with cyanobacteria. Their relationship with the stone material was investigated by optical and electron microscopy, and the effect of cyanobacterial biofilms on water transport and retention was studied. The results showed that the cyanobacteria primarily colonize the building stones on the outer surface and have a limited effect on the water transport properties. They slightly reduced the capillary coefficient and drying rate of the stones, but enhanced the water content in the stone and increased water vapour sorption. They induced (near) hydrophobic conditions, but had no measurable effect on the gas permeability and water vapour diffusion. Moreover, swelling and shrinkage of the biofilms were observed, which could potentially induce physical weathering. It is expected that these changes could influence other forms of weathering, such as freeze-thaw weathering and salt weathering.

Flow cytometry was evaluated for the first time for the microbiological characterisation of samples collected from the surfaces of stone and mortar sculptures. The study was carried out on outdoor sculptures located in the district of Porto (Portugal), from which samples were collected using swabs and poly(2-hydroxyethylmethacrylate) (poly(HEMA)) cryogels as non-invasive sampling methods. The use of poly(HEMA) cryogels was tested as an alternative to swabbing due to the difficulties often encountered in sampling stone surfaces and retrieving microorganisms from swab fibres. The quantification of the microorganisms collected by the two sampling methods and the determination of their cell viability were performed using a combination of the fluorochromes thiazole orange (TO) and propidium iodide (PI). Both methods were effective to collect samples for analysis by flow cytometry, which proved to be a technique of interest and potential use for biodeterioration studies of cultural heritage (CH). Data visualisation of viable and non-viable microbial cells was clearer with cryogels, although higher concentrations of total microorganisms were achieved with swabs. Our results show that swab sampling is a more adequate method, although poly(HEMA) cryogels can be an option to consider for specific microbial viability analyses for biodeterioration evaluation of stone artworks.

This study proposes a method for the chamber disinfection of paper with biocide in the form of fine, volatile droplets using antifungal Rocima GT. This method provides a fungicidal effect, and within a short exposure time, a fungistatic one. At a concentration of 5% Rocima GT solution, the minimum treatment time to ensure the complete disinfection of paper was 15 min. The proposed method of disinfection by a chemical mist was less harmful to paper than disinfection using a swab saturated in a biocide solution. It was noted that when using Rocima GT at insufficient concentrations to inhibit fungal growth completely, Rocima GT can induce, as well as suppress, organic acid produced by Aspergillus niger depending on the concentration.

The aim to evaluate the raw material (agroforestry residues) for particleboard manufacture from the: pseudostem of Musa paradisiaca; the stem and pods of Theobroma cacao; and the sawdust of Ceiba pentandra. The particleboards produced from these cellulosic residues are mixed with cassava starch’s natural adhesive and urea formaldehyde’s synthetic adhesive. The results indicate that lignin, α-cellulose, hemicellulose, and extractives ranged from 6.2–19.0%, 41.4–50.2%, 24.4–31.5%, and 6.8–18.8% respectively and they were significantly different from each other. Additionally, tannins, alkaloids, saponins, flavonoids, phenols, glycosides, and sterols were the phytochemicals present in biomass materials in different quantities. Also, carbon, oxygen, nitrogen, and boron were the elementals significantly present in the manufactured particleboards in the range of 35.3–52.8, 30.2–43.0, 4.2–24.0, and 3.2–9.9 percentage concentration respectively. As for the mechanical properties, it was verified that the cellulose content influenced 96.5% of the variability of the modulus of rupture (MOR) values. Understanding the distribution, functional properties, and impact of biomass organic, phytochemicals and elemental constitutions is an impetus to the improvement of processes with higher retention of these constitutions in the utilization of agroforest residues in the particleboard industry. These chemical compositions of the residues under study contributed largely to the characteristics of the manufactured particleboards.

International audience; Anaerobic digestion, a renewable energy source, is the degradation of organic waste into biogas, mainly composed of CH4 and CO2. The sector is expanding rapidly due to its multiple environmental and economic benefits. This process is implemented industrially in concrete structures that are in direct contact with the biowaste being digested and the gas produced. Both phases can damage concrete through (i) the presence of volatile fatty acids, dissolved CO2, ammonium, and microbial biofilm in the liquid phase, and (ii) high concentrations of CO2 and various concentrations of H2S in the gas phase. In order to develop more sustainable concrete biogas units, long-term, in-situ experiments were carried out in a semi-industrial scale digester to provide new insights into the performance levels and deterioration mechanisms of various low-CO2 binders, including alkali-activated metakaolin (geopolymer), alkali-activated slag (AAS), and supersulfated cements (SSC), in comparison to calcium aluminate cement (CAC) and Portland cement based matrices. In the running conditions explored, carbonation of the cementitious matrices was predominant over other deterioration phenomena in both the digester liquid and the gas phases. Alkali-activated metakaolin and calcium aluminate cement performed better with few degradations observed. Supersulfated cements and alkali-activated slag showed an intermediate behaviour with good performance in the acidic liquid phase but low performance in the CO2-rich gas phase.

Problems in the degradation and biodegradation of cultural heritage objects exposed or stored in public buildings and museums and of construction materials are caused (between others) by the activity of microorganisms. Biodeterioration can be observed not only at the level of the building materials of museum buildings, but also at the level of materials from which art objects are made (natural or artificial) and is determined by factors such as the chemical composition and nature of the composition material, the microclimate characteristics and exposure objects, but also through the manner and frequency of surface cleaning and housekeeping in museums. Based on this, the present study offers, through classical methods, a qualitative and quantitative identification of microorganisms inside a heritage museum building located in a temperate climate country. The purpose of the work was to determine to what extent the bacteriological microflora inside can directly and indirectly contribute to the health quality of the building’s occupants as well as the degradation of its materials and structures. The results emphasize the presence of some fungi and bacteria, among them Alternaria spp., Aspergillus spp., Penicillium spp., Cladosporium spp., and Botrytis spp. All of the analyzed rooms have a high and very high degree of fungal contamination (between 524 and 3674 UFC/m3), which can represent a danger to both human health and the integrity of the exhibitions. This is more pronounced considering that some of species of fungi identified are associated with sick building syndrome, problems in humans due to harmful exposure to viruses, bacteria, and pathogens, which generate possible symptoms such as rhinorrhea, nasal congestion, hoarseness, coughing, sneezing, and irritability for the personnel and visitors.

Microbial colonization on stone monuments leads to subsequent biodeterioration; determining the microbe diversity, compositions, and metabolic capacities is essential for understanding biodeterioration mechanisms and undertaking heritage management. Here, samples of epilithic biofilm and naturally weathered and exfoliated sandstone particles from different locations at the Beishiku Temple were collected to investigate bacterial and fungal community diversity and structure using a culture-based method. The biodeterioration potential of isolated fungal strains was analyzed in terms of pigmentation, calcite dissolution, organic acids, biomineralization ability, and biocide susceptibility. The results showed that the diversities and communities of bacteria and fungi differed for the different sample types from different locations. The population of culturable microorganisms in biofilm samples was more abundant than that present in the samples exposed to natural weathering. The environmental temperature, relative humidity, and pH were closely related to the variation in and distribution of microbial communities. Fungal biodeterioration tests showed that isolated strains four and five were pigment producers and capable of dissolving carbonates, respectively. Their biomineralization through the precipitation of calcium oxalate and calcite carbonate could be potentially applied as a biotechnology for stone heritage consolidation and the mitigation of weathering for monuments. This study adds to our understanding of culturable microbial communities and the bioprotection potential of fungal biomineralization.

Our cultural heritage consists of manifold cultural ex-pressions and represents a defining feature of our soci-eties that needs to be further inherited to future gen-erations. Even though humankind always fought a daily struggle for survival, at the same time, it seemed to have a spiritual need that went far beyond mere mate-rialistic satisfaction and nowadays manifests in some-times very ancient, yet brilliant artistic works. This fun-damental legacy is endangered by several instances, including biodeterioration. Indeed, microorganisms play a significant role in the decline of all forms of tangible cultural heritage, including movable, immovable and underwater cultural heritage. Microbial colonization, biofilm formation and damaging metabolite production eventually result in critical decay. Thus, efforts to miti-gate the negative impact of damaging microorganisms have been pursued with diverse physical, chemical and biological approaches. Intriguingly, recent advances have unveiled that specific microorganisms and microbi-al-based technologies also have the potential for cultur-al heritage preservation and present unique advantages. This short piece provides a quick overview on the duali-ty of microorganisms in the conservation and restora-tion of cultural heritage.

Conservation of artworks is a fundamental aspect of the immensity of human culture and artistic expression. Two watercolor were examined: Paisaje con casa campesina and El puente, belonging to the collection of the Central Bank of Costa Rica attributed to the national artist Fausto Pacheco Hernández. Particularly, the exclusive approach to explore these artworks is characterized by being a multiple analysis, where non-invasive techniques such as multispectral photography were applied. Based on this technique along with the use of novel computational tools such as RegionsOfInterest and Golden Artists Colors, information about the artist's pictorial palette and creative process was determined. Multiple analysis also allowed identifying areas of interest such as dark spots and other patterns that could be associated with microbial growth. This pioneering study is the starting point to establish indicators that will allow, to evaluate the possible authenticity of these artworks based on the establishment of the artist's pictorial palette, materials used, creative processes and historical context. The application of science to know the characteristics of materials contributes significantly to determining the most efficient way to preserve cultural heritage. La conservación de las obras de arte es un aspecto fundamental de la inmensidad de la cultura humana y la expresión artística. Se analizaron dos obras en acuarela: Paisaje con casa campesina y El puente, pertenecientes a la colección del Banco Central de Costa Rica atribuidas al artista nacional Fausto Pacheco Hernández. Particularmente, el acercamiento exclusivo para estudiar dichas obras de arte está caracterizado por ser un análisis múltiple, donde se aplicaron técnicas no invasivas como la fotografía multiespectral. A partir de dicha técnica y el uso de herramientas computacionales novedosas como RegionsOfInterest y Golden Artists Colors se determinó información sobre la paleta pictórica y el proceso creativo del artista. El análisis múltiple permitió identificar diferentes patrones que podrían estar asociados con el crecimiento microbiano. Este estudio pionero corresponde al punto de partida para establecer indicadores que permitan, en el futuro, valorar la posible autenticidad de las pinturas con base en el establecimiento de la paleta pictórica del artista, los materiales utilizados, los procesos creativos y el contexto histórico. La aplicación de la ciencia para conocer las características de los materiales contribuye significativamente a determinar la manera más eficiente para conservar el patrimonio cultural.

Κατά την εκπόνηση της παρούσας διπλωματικής εργασίας, διεξάχθηκε παραμετρική μελέτη για τον αποτελεσματικό καθαρισμό με λέιζερ λίθινων αντικειμένων με βιολογική επικάθιση. Για το σκοπό αυτό χρησιμοποιήθηκαν θραύσματα ασβεστόλιθου από την ευρύτερη αρχαιολογική περιοχή της Ηπείρου, με παρουσία βιολογικών παραγόντων στην επιφάνεια τους. Εφαρμόστηκαν διαφορετικοί συνδυασμοί παραμέτρων του λέιζερ, ώστε να προσδιοριστεί η βέλτιστη μεθοδολογία καθαρισμού για την αποτελεσματική αφαίρεση της βιοδιάβρωσης από την λίθινη επιφάνεια, χωρίς να επηρεάζεται η ακεραιότητα του λίθινου υποστρώματος. Μια από τις βασικές παραμέτρους καθαρισμού που μελετήθηκαν ήταν το κατάλληλο μήκος κύματος της δέσμης του λέιζερ. Για τον σκοπό αυτό εφαρμόστηκαν μεμονωμένα η υπέρυθρη ακτινοβολία (1064nm), η ορατή ακτινοβολία (532nm), καθώς και ο συνδυασμός των δυο μηκών κύματος σε χωρική και χρονική αλληλοεπικάλυψη. Επίσης διερευνήθηκε ποια ήταν η βέλτιστη τιμή της πυκνότητας ενέργειας του μήκους κύματος, ή η βέλτιστη αναλογία τιμών πυκνοτήτων ενέργειας σε περίπτωση χρήσης του συνδυασμού των δυο μηκών κύματος. Ακόμη μελετήθηκαν ο βέλτιστος αριθμός των παλμών που θα εφαρμοστούν, καθώς και η επίδραση της υγρασίας στον καθαρισμό. Η αξιολόγηση των δοκιμών καθαρισμού με λέιζερ πραγματοποιήθηκε με τη χρήση οπτικής μικροσκοπίας, για την παρατήρηση της μικροδομής των επιφανειών πριν και μετά τον καθαρισμό, καθώς και με τη χρήση φασματοσκοπίας φθορισμού επαγόμενου από LED. Με τη χρήση φασματοσκοπίας συγκρίνονταν φάσματα φθορισμού των λίθινων θραυσμάτων πριν και μετά τον καθαρισμό. Ο δείκτης αναλογίας φθορισμού R που προκύπτει από τα φάσματα φθορισμού, συσχετίζει το φθορισμό του υποκείμενου υποστρώματος με τον φθορισμό των υπερκείμενων φθοροφόρων που περιέχονται στις βιολογικές επικαθίσεις. Έτσι παρέχεται η δυνατότητα για έναν άμεσο ημι-ποσοτικό έλεγχο του καθαρισμού με λέιζερ. Η χρήση του θεμελιώδους μήκους κύματος (1064nm) που εκπέμπεται από ένα Nd:YAG λέιζερ είναι μια καθιερωμένη προσέγγιση στο πεδίο του καθαρισμού αντικειμένων πολιτιστικής κληρονομίας με λέιζερ. Στην παρούσα εργασία αξιοποιείται η προσέγγιση αυτή, προσαρμοσμένη, όμως, στις ανάγκες του εποικισμένου ασβεστολιθικού υποστρώματος, συνδυάζοντάς την με τη δέσμη των 532nm. Η επιλογή του συνδυασμού με το ορατό μήκος κύματος βασίζεται στο γεγονός ότι απορροφάται ισχυρότερα από τις συγκεκριμένες επικαθίσεις. Το προτεινόμενο σχήμα συνεισφέρει στη βελτιστοποίηση της μεθοδολογίας καθαρισμού βιολογικών επικαθίσεων με λέιζερ και στην επίλυση κρίσιμων προβλημάτων που διέπουν κινητά ή ακίνητα μνημεία πολιτιστικής κληρονομίας, εκτεθειμένα σε εξωτερικό περιβάλλον., The main object of this thesis is the investigation of operative parameters for the efficient laser cleaning of stone objects with biological film. For this purpose, fragments of limestone originating from an archaeological site in Epirus with biological presence were chosen, to test and study the laser cleaning parameters and their results. A variety of parameters were studied, in order to determine the most efficient removal of the biofilm, in a way that wouldn’t affect the consistency, morphology and value of the substrate’s material. One of the principal operative parameters studied was the wavelength of the laser beam. In this respect the fundamental (in the IR with wavelength λ=1064nm) and the 2nd harmonic (in the visible wavelength λ=532nm) beams, emitted from a Nd:YAG laser, were investigated. Experiments took place for the use of each beam, as well as their combination in spatial and temporal overlapping. It was also studied the optimal energy density of the operative laser beam, or the optimal ratio of energy density of each beam, in the case of their combined use. Last but not least, the optimal number of pulses was defined, as well as the effect of water application on the surface prior the ablation. To evaluate the results of the laser cleaning tests optical microscopy and LED IF analysis were used. Employing such techniques made possible the observation of the micro-structure of the surface and the comparison of fluorescence spectra of the target areas before and after the cleaning interventions, respectively. The Fluorescence Ratio (R) extracted from the spectra, which describes the relationship between the Fluorescence Intensity of the substrate and the biofilm’s fluorophores, helps to get a better insight into the quality of the cleaning process. In the context of this thesis, the well-established and efficient laser cleaning regime of the fundamental wavelength (1064nm) of a Nd:YAG laser, adapted to the needs of the biodeteriorated limestone, and combined with the visible 532nm wavelength was used. In this way, it contributes to the scientific conversation about the methodology of laser cleaning of biodeteriorated Cultural Heritage and about the problems of outdoor monuments and archeological objects.

La presencia de biofilms subaéreos sobre el patrimonio pétreo supone un motivo de preocupación, con implicaciones tanto a nivel de conservación patrimonial como económicas. La arquitectura típica del noroeste de la Península Ibérica se caracteriza por el amplio uso del granito, una roca muy resistente pero igualmente susceptible al deterioro y a los cambios ambientales experimentados como consecuencia del Cambio Climático. El objetivo de este trabajo es estudiar los efectos del cambio climático en la distribución y actividad deteriorante de los biofilms fotótrofos colonizadores del patrimonio granítico. Para ello, se analizó la colonización típica que habita los monumentos en esta área geográfica, así como los cambios que se espera que experimenten estos organismos en términos de capacidad biodeteriogenica como consecuencia de las variaciones en disponibilidad hídrica, temperatura, concentración de CO2 y radiación UV-B esperados. Los resultados obtenidos predicen una reducción de la biomasa a nivel general, pero una mayor actividad deteriorante de las comunidades resistentes. Así, se espera un aumento en la proporción de cianobacterias frente a la de algas verdes con el aumento de temperatura, con el consiguiente cambio pigmentario y fisiológico asociado. Además, se espera un aumento de la producción de sustancias poliméricas extracelulares en condiciones de sequía, que retienen agua y favorecen procesos de deterioro fisicoquímicos. 2024-05-12

15 páginas.- 6 figuras.- 2 tablas.- 40 referencias, Removing lampenflora, phototrophic organisms developing on rock surfaces in tourist cavities due to the artificial lighting, is a challenge for sustainable and appropriate long-term management of caves. Photosynthetic-based biofilms usually cause rock biodeterioration and an ecological imbalance in cave ecosystems. In this work, a detailed investigation of the effects of the 3 most commonly used lampenflora cleaning operations (NaClO, H2O2 and UVC) was carried out in Pertosa-Auletta Cave (Italy). The application of NaClO showed good disinfection capability over extended periods of time without causing any appreciable rock deterioration. The H2O2 treatment showed to be corrosive for the rock surfaces covered with vermiculation deposits. The chemical alteration of organic and inorganic compounds by H2O2 did not remove biomass, favoring biofilm recovery after three months of treatment. Both NaClO and H2O2 treatments were effective at removing photoautotrophs, although the bacterial phyla Proteobacteria and Bacteroidetes as well as Apicomplexa and Cercozoa among the Eukaryotes, were found to be resistant to these treatments. The UVC treatments did not show any noticeable effect on the biofilms., This work was supported by the Spanish Ministry of Science and Innovation (MCIN) under the research project TUBOLAN PID2019-108672RJ-I00 funded by MCIN/AEI/10.13039/501100011033; the Portuguese Foundation for Science and Technology (FCT) under the MICROCENO project (PTDC/CTA-AMB/0608/2020); the Spanish National Research Council (CSIC) through the intramural project PIE_20214AT021. A.Z.M. was supported by the CEECIND/01147/2017 contract from FCT, and the Ramón y Cajal contract (RYC2019-026885-I) from MCIN. This work was partly funded by University of Salerno (Italy) within the ORSA197159 and ORSA205530 projects.

14 páginas.- 11 figuras.- 45 referencias, The Alcobacenses are one of the most important Portuguese collections of Monastic codices. During a campaign study to further advance our knowledge on this important legacy and its state of conservation, a heavily deteriorated codex (ALC.338) stood out due to the presence of purple stains on the lower margins on virtually all folios. In some of them, the purple stains are accompanied by yellow and brown patches as well. Also noticed was the presence of these purple spots on the white tawed leather covering the codex. The codex was analyzed macro and microscopically, chemically and biologically using state-of-the-art technology such as next-generation sequencing. The biological deterioration associated with the appearance of these purple spots arises from the inside out and reveals significant abundance of the bacterial genus Saccharopolyspora sp., which accounted for 86% of the bacterial genera identified. For the fungal population, the most common genus was Malassezia sp. Visual inspection of the sample confirmed the presence of fungal and bacterial biofilms. Pressing questions, comparison to similar studies and future perspectives are also given., Catarina Pinheiro is under a researcher contract with the HERCULES Laboratory, Évora University (CEECIND/02598/2017) and gratefully acknowledges the FCT/MCTES national support through the UIDB/04449/2020 and UIDP/04449/2020. C.C. acknowledges FCT/MCTES national support through the UIDB/50006/2020 and UIDP/50006/2020. A.Z.M contribution is supported by the Spanish Ministry of Science and Innovation (MCIN) under the Ramón y Cajal contract (RYC2019-026885-I), the CEECIND/01147/2017 research contract from FCT and the intramural project PIE_20214AT021 from the Spanish National Research Council (CSIC). The project under which this work was developed was also funded by FCT through the grant PTDC/ART-HIS/29522/2017.

The degradation of stone materials depends on several interlinked factors. The effects caused by biodeteriogens on mineral-based substrates are now increasingly considered in the field of cultural heritage conservation from different experimental approaches. In this study, biodeteriogenic micro- and macroflora within the gothic building of Santa Maria della Pietà, Squillace, Calabria, have been analyzed using multiple approaches, such as optical microscopy and molecular techniques. All 17 plant species detected are usually widespread in Mediterranean regions and some of these, such as Ailanthus altissima and Ficus carica, showed a very high hazard index, which is potentially dangerous for masonry stability. Fungi, cyanobacteria, and green algae were identified within biofilm compositions in a total of 23 different taxa, showing many similarities with microbial associations commonly found in cave and hypogean environments. All of the 11 fungal taxa detected belong to Ascomycota phylum, with Penicillium as the most represented genus. Photoautotrophic organisms are mostly represented by filamentous genera, with widespread presence of Leptolyngbya as the most abundant genus. The results highlighted how the singular environmental conditions of the study site, combined with the architectural features and the building materials, determined all the degradation phenomena affecting the building’s internal surfaces, compromising over time the structural integrity.

The mycobiome of the cave Church of Sts. Peter and Paul, housing the peculiar fresco painting of “The Bald-headed Jesus”, was analyzed via culture-dependent and -independent methods. Salt efflorescence, colored patinas, and biofilm, as well as biopitting, discolorations, and fruiting bodies of wood-decay fungi were observed on surfaces within the church. Microscopic analyses showed an abundance of fungal structures, i.e., conidiophores, conidia, chlamydospores, and ascospores. The estimated values of the contamination classified all surfaces as the “Danger zone”. A total of 24 fungi from 17 genera were determined as part of the culturable mycobiome, with a dominance of Ascomycota of genera Penicillium. Biodegradative profiles analyzed via plate assays demonstrated positive reactions for 16 isolates: most commonly acid production (8), followed by pigment production and ligninolytic activity (6), protein degradation (5), cellulolytic activity (3) and carbonate dissolution (2). Metabarcoding analysis showed a dominance of Ascomycota in all samples (79.9–99.7%), with high relative abundance documented for Hypoxylonfuscopurpureum on the iconostasis and unclassified Mycosphaerellaceae family within order Capnodiales on fresco and stone, as well as moderate relative abundance for unclassified Dothideomycetes, Botryolepraria lesdainii, Verrucaria sp. and Cladosporium sp. on stone walls. The used set of integrative methods pointed out species of genus Neodevriesia and H.fuscopurpureum as the main deteriogenic agents of fresco and iconostasis surfaces, respectively.

International audience; Biofilms are the predominant living presence of micro-organisms in the environment, and on the surfaces of cementitious materials. This protective organization gives the microorganisms a certain resilience. But above all, the formation of biofilms on the surface of cementitious materials favours the phenomenon of biodeterioration, which is very prevalent in the field of civil engineering, or in the medical field, in orthodontics and orthopaedic surgery on dental or bone cements. In order to instigate and combat the development of biofilms on cementitious materials, in-depth research studies are being conducted to gain an understanding of the basic mechanisms of biofilm formation and material deterioration. Therefore, analytical techniques have been developed to describe the chemical compositions, structural characteristics and microbial diversity of biofilms formed on cementitious materials. This review article presents the state of the art in terms of technical developments, which provide extensive information on the spatial structure, chemical composition and microbial populations within the biofilm. In addition, it provides a critical analysis of the use and limitations of all these techniques, in order to help the multidisciplinary scientific community to make a judicious and appropriate scientific decision. Finally, new methods, already exploited in other fields of investigation of microbial biofilms, are also discussed. In particular, we have highlighted how the physico-chemical characterization of pH and chemical transport phenomena within a biofilm could help to understand the mechanisms involved in the interactions between biofilms and reactive cementitious materials. Article Structure: The article is organized in 5 parts. A first part introducing the problematics of the subject and the structure of the article. A second part focused on the techniques employed to study the spatial structure and the chemical composition of biofilms formed on cementitious materials. A third part focused on the methods used to quantify and identify the microorganisms in biofilms formed on cementitious materials. The fourth part focuses on approaches not yet used but which would be useful to develop for the study of biofilms formed on cementitious materials. Finally, the last part summarises the key points of the article and provide future directions for the research on biofilms formed on cementitious materials.

Pond apple (Annona glabra L.) belongs to the family of Annonaceae. The seed of A. glabra contains bioactive substance that is toxic to some organisms, however the effectiveness to control wood degrading termites has not yet been scientifically reported. This research analyzes the efficacy of A. glabra seed extract to wood degrading termites. Seed extraction was conducted using n-hexane and ethyl acetate. The paper disc test showed that the extract of A. glabra is toxic to Cryptotermes cynocephalus (dry-wood termites) and Coptotermes curvignathus (subterranean termites). The higher extract concentration (up to 63%) resulted in a higher termite mortality (up to 100%) and lower weight loss of paper sample (less than 1%). Ethyl acetate extract of A. glabra seeds has a better toxicity effect than n-hexane extract against dry wood termites and subterranean termites.

Fungal organisms are considered one of the most relevant stone colonizers, and biodeteriogens. They are ubiquitous heterotrophs, metabolically versatile, ranging from generalist to extremophiles. Limestone, a sedimentary rock characterized by high levels of calcium carbonate, has low compressive strength and hardness and high porosity. These features make it highly susceptible to fungal colonization and an exceptional target for biodeterioration. Understanding the mycobiome composition associated with different biodeterioration scenarios is key for the development of effective guidelines and strategies for preventive conservation and viable maintenance of our cultural heritage. In this work, a thorough analysis of the fungal community composition on the Lemos Pantheon, a limestone-built artwork located in Portugal, was performed using high-throughput sequencing complemented with culture-based methods. The combined results allowed a detailed characterization of the fungal communities of each analyzed spot, revealing highly diverse and dissimilar communities according to the type of biodeterioration observed. In addition, we verified that both cultivation and metagenomics methodologies should be employed synergistically to tackle inherent limitations.

Scientific studies concerning the causes and consequences of the biodeterioration of stone monuments located at high altitudes in permanently cold, mountainous regions are scarce. For that reason, this study aimed to detect and identify the bacteria involved in the deterioration of this type of monument. To achieve this goal, we focused on the most important archeological Inca site in the Ecuadorian Andes: Ingapirca’s Temple of the Sun, built approximately 500 years ago at 3.100 m.a.s.l. We first examined the stone surfaces of the temple by scanning electron microscopy and showed the detrimental impact on the mineral structure of the green andesite mineral used to build the temple, caused by crustose lichen thalli and heterotrophic bacteria. Then, we isolated, characterized, and identified several of these bacteria. Most of them multiplied at a wide range of temperatures, from 4 ◦C to 30 ◦C, and were thus considered eurypsychrophiles. Actinobacteria and Proteobacteria species dominated the culturable fraction of this community. Several isolates produced metabolites that solubilized mineral phosphates at low temperatures; others solubilized iron-containing mineral fractions in the green andesite rock when tested in vitro. To the best of our knowledge, this is the first report related to the biodeterioration of an Inca monument at such an altitude in the Andes range., This project was partially funded by the Catholic University of Cuenca, grant number PICCIITT19-21. The project also received financial support from MNCN-CSIC under a TOP Heritage project, grant number P2018/NMT-4372 of the Community of Madrid, and from the Unidad de Laboratorio y Análisis (Instituto Nacional del Patrimonio Cultural, Quito, Ecuador).

One aspect of heritage science is to examine and, if possible, reduce the chemical and physical interactions between the restoration products and artworks’ constituent materials. This research aims to identify an alternative process to minimize the impact on materials and health risk for users when hypochlorite is used as biocide on stone materials. In this study, we tested a hydrogel comprised of sodium alginate as an inert matrix and hypochlorite ions as biocide agents for the removal of biological patinas from calcarenite Lecce samples. These biofilms resulted formed mainly by filamentous cyanobacteria and green microalgae. We carried out 1H-NMR T2 relaxation measurements to check the hydrogel’s cleaning efficacy on artificially bio-deteriorated samples through a portable NMR equipment. Simultaneously, optical microscopy and colorimetric measurements allowed the establishment of color differences induced by treatments. Our biocide hydrogel proved to be effective in removing microbial colonization from the surface of Lecce stone specimens and from a section of an altar rail in the rupestrian Church of San Pietro Barisano, located in the “Sassi of Matera”.

A.Z.M. was supported by the Ramon y Cajal contract RYC2019-026885 from the Spanish Ministry of Science and Innovation (MCIN). S.G.-P. was supported by the intramural project PIE_20214AT021 from the Spanish National Research Council (CSIC). Publisher Copyright: © 2022 by the authors. The bioreceptivity, and the consequent biodeterioration of contemporary glass, used by artists worldwide, was studied. The two main objectives were: first, to verify if fungi with some culture media would produce more damages than the same fungi without a nutritional source, and to verify if the two genera of fungi produce the same damage on the same glass. Colourless glass samples with Spruce Pine 87 Batch (SPB-87) composition were inoculated with two distinct fungal species, Penicillium chrysogenum and Aspergillus niger, separately: (i) half with fungal spores (simulating primary bioreceptivity), and (ii) half with fungi in a small portion of culture media (simulating organic matter that can be deposited on exposed glassworks, i.e., secondary bioreceptivity). The alteration of glass surfaces were analysed by Optical Microscopy, SEM-EDS and µ-Raman. The mycelium of Penicillium chrysogenum generated a higher amount of fingerprints, stains and iridescence, whereas Aspergillus niger produced more biopitting and crystals on the glass surface. However, both species damaged the glass to different degrees in 4 and 6 months after the inoculation, producing physico-chemical damage (e.g., iridescence, biopitting), and chemical alterations (e.g., depletion and deposition of elements and crystals). The primary bioreceptivity experiment of glass samples inoculated with Aspergillus niger results in less damage than in the case of secondary bioreceptivity, being almost similar for Penicillium chrysogenum. The new and in-depth understanding of the bioreceptivity and deterioration of post-modern glass art and cultural heritage provided here is of paramount importance for the scientific, conservation and artistic communities—to protect glass cultural materials, or seen by artists as innovative and inspirational ways of creating glass art in the future. publishersversion published

Wood modifications are becoming popular as a way to enhance the performance of wood, either to make it more durable, improve the performance of wood, or give it new functionality as a multifunctional or smart material. While wood modifications have been examined since the early 1900s, the topic has become a dominant area of study in wood science over the past decade. This review summarizes recent advances and provides future perspective on a selection of wood modifications, i.e., the methods that are currently commercialized (acetylation, furfurylation, and thermal modification), a rediscovered ancient practice (charring), a family of polymerization modifications that have so far made it to the pilot scale, and examples of novel wood-based functional materials explored at laboratory scale. Wood modifications are becoming popular as a way to enhance the performance of wood, either to make it more durable, improve the performance of wood, or give it new functionality as a multifunctional or smart material. While wood modifications have been examined since the early 1900s, the topic has become a dominant area of study in wood science over the past decade. This review summarizes recent advances and provides future perspective on a selection of wood modifications, i.e., the methods that are currently commercialized (acetylation, furfurylation, and thermal modification), a rediscovered ancient practice (charring), a family of polymerization modifications that have so far made it to the pilot scale, and examples of novel wood-based functional materials explored at laboratory scale.

9 páginas.- 5 figuras.- 3 tablas.- referencias.-. The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmicb. 2022.982933/full#supplementary-material .- This article is part of the Research Topic Microbial Roles in Caves, The present study reports a sudden fungal outbreak that occurred in the corridor near the entrance of the Catacombs of SS. Marcellino and Pietro in Rome (Italy) observed after 1 year of a restoration treatment that interested the walls of the entrance of the Catacombs and some artifacts placed in situ. The colonization was observed on the vault at the entrance and in correspondence with the restored marble pieces displayed on the left side of the corridor. No growth was observed on the right side where similarly treated marble slabs were placed. Samples taken in correspondence with fungal biofilm were analyzed through the combined use of microscopical, cultural, and molecular tools and showed that the vault and the left side of the corridor entrance were colonized by a complex fungal biofilm consisting mainly of Coniophora sp. and other genera, such as Hypomyces, Purpureocillium, Acremonium, Penicillium, and Alternaria, many of which are well known as responsible of biodeterioration of stone surfaces. Regarding the brown-rot basidiomycete Coniophora, it was able to form very large colonies on the substrata with a diameter of up to 57 cm. Although the direct observation under a light microscope evidenced the presence of abundant brown fungal conidia, several attempts to cultivate the microorganism failed, therefore only through DNA sequencing analyses, it was possible to identify and characterize this fungus. There is very little literature on the genus Coniophora which is reported as one of the causes of wet-rot decay of wood in buildings. A connection with calcium-containing materials such as bricks and mortars was demonstrated, but no data were available about the possible role of this species in the biodeterioration of stones. This study features the first finding of a strain related to the basidiomycetous genus of Coniophora in the order Boletales in association with evident phenomena of biodeterioration., This project was supported thanks to the special funds provided by the University of Messina (approved on 21 February 2022 by the Academic Senatus) (Italy), the Spanish Ministry of Science and Innovation, and project PID2020-114978GB-I00 and project CIACCO DTC TE1 - FASE II - PROGETTI RSI8.

This research is based on the investigation of the possible use of antimicrobial agents such as ethanol and extracts from locally sourced Mitracarpus scaber to prevent biodeterioration of biodiesel. Four castor oil biodiesel samples under various treatment conditions (containing different volumes of antimicrobial agents) and a control (without antimicrobial agents) were monitored for five weeks to check for likely variation in some of the biodeterioration indicating parameters such as acid value (AV), flash point (FP) and cetane number (CN). Results obtained for the control experiment indicated biodeterioration of the biodiesel sample as the presence of microbial activity was noticed from the variation in the AV, FP, and CN. Results obtained also showed that microbial proliferation was mitigated when antimicrobial agents were introduced to the biodiesel samples as seen in the most stable values of acid value, flash point, and cetane number. Of all the samples analyzed, sample A containing the highest percentage of Mitracarpus scaber extract performed best as can be seen from the most stable values of acid value, flash point, and cetane number which are some of the most important biodeterioration indicating parameters of biodiesel, which therefore indicates the introduction of stability in the biodiesel samples.

Introducción y objetivos: Los documentos en papel custodiados en bibliotecas pueden mostrar signos de deterioro causados por la actividad de diferentes hongos. Los principales colorantes fúngico que deterioran estéticamente este sustrato y afectan al patrimonio cultural en soporte celulósico constituyen los pigmentos oscuros o melaninas. El objetivo del presente trabajo es brindar un panorama actualizado del estado de arte de los hongos negros que colonizan papel y las melaninas que sintetizan. M&M: Se realizó una búsqueda bibliográfica sobre los pigmentos oscuros que sintetizan diferentes hongos negros que deterioran papel. Se analizaron 74 trabajos especializados en el tema. Resultados: El conocimiento sobre la diversidad y las características de los pigmentos oscuros que son sintetizados por los hongos negros que deterioran papel es clave para desarrollar estrategias de prevención y remediación para eliminar estos pigmentos de soportes celulósicos con valor patrimonial. Este trabajo presenta información sobre: hongos negros que deterioran papel, tipos de melaninas que pueden sintetizar, estructuras donde se acumulan, y su contribución en el deterioro estético. Conclusiones: Este conocimiento sirve de base para desarrollar nuevas estrategias de restauración que pudieran ser efectivas y sustentables y que aseguren la conservación preventiva de documentos históricos y obras de arte en papel., Background and aims: Paper documents stored in libraries may show signs of deterioration caused by the activity of different fungi. The main fungal dyes that aesthetically deteriorate this substrate and affect the cultural heritage on cellulosic support are dark pigments or melanins. The aim of this work is to provide an updated overview of the state of the art of black fungi that colonize paper and the melanins that they synthesize. M&M: A bibliographic search was carried out on the dark pigments that synthesize different black fungi that deteriorate paper. 74 specialized papers on the subject were analyzed. Results: Knowledge about the diversity and characteristics of the dark pigments that are synthesized by the black fungi that deteriorate paper is key to developing prevention and remediation strategies to eliminate these pigments from cellulosic supports with heritage value. This work presents information on: black fungi that deteriorate paper, types of melanins that can be synthesized, structures where they accumulate, and their contribution to aesthetic deterioration. Conclusions: This knowledge serves as the basis for developing new restoration strategies that could be effective and sustainable and that ensure the preventive conservation of historical documents and works of art on paper., Facultad de Ciencias Naturales y Museo, Instituto de Botánica "Dr. Carlos Spegazzini", Instituto de Fisiología Vegetal

Biodeterioration is an increasingly widespread process of degradation in the context of the conservation of cultural heritage, which involves a combination of physical and chemical damages together with an aesthetic alteration of materials. For biological damage on monuments caused by pathogens, macro- and microorganisms, chemical treatments are generally used, most of the time dangerous for the environment and for the operator. In this context, new eco-friendly products represent necessary tools for the treatment of biologically deteriorated stone surfaces and represent a new challenge in the field of restoration and conservation of materials of cultural interest. A relatively new class of unconventional green solvents are deep eutectic solvents (DESs), which have peculiar chemical-physical characteristics such as being non-toxic, ecological, biodegradable, non-flammable, and stable in the presence of water. Furthermore, many DESs known in the literature have also been shown to have a biocidal action. All these characteristics make DESs very advantageous and safe, and they could be used as biocidal agents for the treatment of biodegraded surfaces of cultural heritage, being non-toxic for the environment and for the operator. So far, they are used in various fields, but they still represent a novel frontier in the cultural heritage sector. The present research aims at testing five different DESs for the first time in cultural heritage. In particular, DESs are applied to a mosaic located in the Ostia Antica Archaeological Park (Rome), and their efficiency is compared with a biocide product currently used in the restoration field, namely, Preventol RI50, through luminescence, bio-luminometry, and spectrocolorimetry analysis. The preliminary results achieved show the different behaviors of each DESs, highlighting the possibility of employing them in the field of cultural heritage. Further studies have been planned, some of which are already underway, to investigate the properties of DESs and indicate any improvements to make them more effective, both as solvents and as biocides, and easy to apply to various types of materials. The results obtained from this first study are very promising for the use of DES as a new green strategy for cleaning and conservation treatments of materials in the field of cultural heritage.

International audience; The biodeterioration of cement-based materials in sewer environments occurs because of the production of sulfuric acid from the biochemical oxidation of H2S by sulfur-oxidizing bacteria (SOB). In the perspective of determining the possible reaction pathways for the sulfur cycle in such conditions, hydrated ce-mentitious binders were exposed to an accelerated laboratory test (BAC test) to reproduce a biochemical attack similar to the one occurring in the sewer networks. Tetrathionate was used as a reduced sulfur source to naturally develop sulfur-oxidizing activities on the surfaces of materials.The transformation of tetrathionate was investigated on materials made from different binders: Portland cement, calcium aluminate cement, calcium sulfoaluminate cement and alkali-activated slag. The pH and the concentration of the different sulfur species were monitored in the leached solutions during 3 months of exposure. The results showed that the formation of different polythionates was independent of the nature of the material. The main parameter controlling the phenomena was the evolution of the pH of the leached solutions. Moreover, tetrathionate disproportionation was detected with the formation of more reduced forms of sulfur compounds (pentathionate, hexathionate and elemental sulfur) along with thiosulfate and sulfate. The experimental findings allowed numerical models to be developed to estimate the amount of sulfur compounds as a function of the pH evolution. In addition, biomass samples were collected from the exposed surface and from the deteriorated layers to identifythe microbial populations. No clear influence of the cementitious materials on the selected populations was detected, confirming the previous results concerning the impact of the materials on the selected reaction pathways for tetrathionate transformation.

The objective of the study was to evaluate the biodeterioration of the archaeological collections of the Tumbas Reales de Si-pán museum warehouses in Lambayeque. The surface of 24 textiles and 30 bones with physical alterations in four warehou-ses was sown and planted on agar, at 30° C in aerobiosis for up to 10 days. 100 % of textiles presented alterations in texture, coloration, and integrity and 45.8 % at the edges. Bacteria were quantified with an average of 4.9 x 104 CFUm-2 in textiles and 1.4x105 CFUm-2 in bones. Fungi were quantified with an average of 7.1x103 CFUm-2 in textiles and 5.2x103 CFUm-2 in bones. The genera Bacillus, Micrococcus, Staphylococcus, Streptococcus and Streptomyces were identified in textiles and bones. In textiles, the genera Aspergillus, Alternaria, Cladosporium, Chrysosporium, Geotrichum, Gliocladium, Penicillium, Rhizopus, and Scopulariopsis were identified. In skeletons Aspergillus, Alternaria, Curvularia, Cercospora, Cladosporium, among others.

In this work, poly(vinyl)alcohol-borax (PVA-borax) hydrogels containing active ingredients with antimicrobial effects were designed and tested over two biodeteriorated stones of different nature and composition. The polymer network was reinforced with a filler of ZnAl layered double hydroxide (LDH) supporting sodium alginate (SA) chains (LDH@SA) and the active role has been assigned to three ingredients: silver nanoparticles (AgNPs), silver nanoparticles-silver chloride (Ag/AgCl) and thyme essential oil (EO), used either separately or mixed together within the same hydrogel. For better comparison, a final test was performed by preparing hydrogels containing a common antimicrobial agent such as methylisothiazolinone (MIT). The effects of the treatments have been investigated through staining techniques (periodic acid staining PAS, triphenyl-tetrazolium chloride TTC) and colony forming unit assays (CFUs) performed on media specific for bacteria, fungi and algae. The data collected consented to identify the most efficient cleaning systems in the hydrogel prepared with AgNPs and in that with thyme EO, leading the way for a new approach in the field of bioremediation.

Cultural heritage sites such as historical or sacred areas provide suitable habitats for plants and play an important role in nature conservation, particularly in human-modified contexts such as urban environments. However, such sites also provide opportunities for the spread of invasive species, whose impact on monuments has been raising growing concerns. The aim of this study was to investigate the patterns of distribution and spread of invasive plants in heritage areas, taking the city of Rome as an example. We focused on woody species as they pose the greatest threat to the conservation of monuments, owing to the detrimental effects of their root system. We analysed changes in the diversity and traits of native and non-native flora growing on the walls of 26 ancient sites that have been surveyed repeatedly since the 1940s. We found that the diversity of the native flora has steadily decreased, while there has been an increase in non-native, larger and more damaging species. The introduced species that have expanded most are ornamental wind- or bird-dispersed trees, which represent a major management problem as their propagules can reach the upper sections of the monuments, where they become more difficult to control. The most widespread and damaging of such species is Ailanthus altissima, which has recently been included among the invasive species of European Union concern (EU Regulation 2019/1262). Our findings show that plant invasion is an emerging challenge for the conservation of heritage sites and needs to be prioritized for management to prevent future expansion.

Microbial cells that produce biofilms, or patinas, on historic buildings are affected by climatic changes, mainly temperature, rainfall and air pollution, all of which will alter over future decades. This review considers the colonization of stone buildings by microorganisms and the effects that the resultant biofilms have on the degradation of the structure. Conservation scientists require a knowledge of the potential effects of microorganisms, and the subsequent growth of higher organisms such as vascular plants, in order to formulate effective control strategies. The vulnerability of various structural materials (“bioreceptivity”) and the ways in which the environmental factors of temperature, precipitation, wind-driven rain and air pollution influence microbial colonization are discussed. The photosynthetic microorganisms, algae and cyanobacteria, are acknowledged to be the primary colonizers of stone surfaces and many cyanobacterial species are able to survive climate extremes; hence special attention is paid to this group of organisms. Since cyanobacteria require only light and water to grow, can live endolithically and are able to survive most types of stress, they may become even more important as agents of stone cultural property degradation in the future.

La especie Tricorynus herbarius (Coleoptera: Ptinidae), conocida como el “escarabajo de los libros”, causa deterioro en bibliotecas de numerosos países de América. Dada la falta de información existente acerca de las características biológicas de la especie y, teniendo en cuenta su existencia en distintos espacios de guarda de la Universidad Nacional de La Plata (Buenos Aires, Argentina), se realizó un primer estudio para conocer aspectos de su biología tales como el tiempo de vida por estado y estadio de desarrollo en condiciones controladas, preferencias alimenticias y observaciones de comportamiento, fundamentales al momento de diseñar estrategias apropiadas de conservación preventiva y/o curativa de las poblaciones que se consideren perjudiciales para materiales de valor patrimonial., Tricorynus herbarius (Coleoptera: Ptinidae) is known as the “book beetle”, which causes deterioration in libraries in many countries of America. Given the lack of existing information about the biological characteristics of the species and, taking into account its existence in different storage areas of the National University of La Plata (Buenos Aires, Argentina), a first study was carried out to know aspects of its biology such as life time by state and stage of development under controlled conditions, food preferences and behavioral observations, essential when designing appropriate preventive or curative conservation strategies for populations that are considered detrimental to heritage value materials., Facultad de Ciencias Naturales y Museo

Preah Vihear temple is one of the most significant representatives of the ancient Angkorian temples listed as United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Sites. The surfaces of this Angkor sandstone monument are covered with deteriorated materials, broadly called "sediments" here, resulting from a long time of weathering of the sandstone. The sediments might adversely affect the ancient sandstone substratum of this cultural heritage, and the potential risk from them is essential information for current strategies and on-going protection and management. The extracted DNA from the sediment samples of this temple was used for Illumina high-throughput sequencing analysis, resulting in approximately 12 Gb of metagenomic dataset. The results of this shotgun metagenomic analysis provided a thorough information of the phylogenetic groups presented in the microbiome of the sediment samples, indicating that potential metabolic activities, involving different geomicrobiological cycles, may occur in this microbiome. The phylogenetic result revealed that the majority of metagenomic reads were affiliated with Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes at the phylum level. The metabolic reconstruction results indicated that the important geomicrobiological cycling processes include carbon sequestration, and nitrogen and sulfur transformation as the potentially active ones in the sediments of the sampling sites. Specifically, the dissimilatory nitrate reduction to ammonium (DNRA) and the newly discovered complete ammonia oxidation (comammox) were retrieved from this metagenomic dataset. Furthermore, the genetic information on the presence of acid-producing processes by sulfur- and ammonia-oxidizing bacteria and archaea in this metagenomic dataset suggested that the microbial flora in these samples has the potential to participate in the degradation of sandstone cultural heritage by producing acids. N-15 isotope amendment and incubation analysis results confirmed the presence of active denitrification, but not anammox activity at this temple. These results are important for our knowledge on the microbial community composition and microbial biodeterioration processes affecting this sandstone cultural heritage and will aid in the protection and management of the ancient Preah Vihear temple.Key Points• Microbiota on Preah Viher temple was analyzed using NGS.• Nitrate-N transformation by DNRA, comammox, and denitrifcation was detected.• N-15 isotope analysis confirmed the active denitrifcation, but not Anammox.• Accumulation of nitrate is a result of less active removal by denitrification.

Stones of historical monuments exposed to the open air deteriorate over the course of time depending on physical, chemical, and biological factors acting in co-association. Among the biological factors, microorganisms play a key role in the deterioration process of stones. Detecting the level of microbial activity on stones is an essential step in diagnostic and monitoring studies of stone biodeterioration, and aids in controlling the performance of treatments applied to the stones. Therefore, this study aimed to develop a practical and rapid method for the determination of microbial activity on historical stones and use this method on the Mount Nemrut monuments (MNMs) (Adiyaman, Turkey). For that purpose, the fluorescein diacetate (FDA) hydrolysis method, frequently employed for soil environments, was adapted for the estimation and assessment of total microbial activity to understand whether microorganisms posed a potential risk for the biodeterioration of the limestones and sandstones of the MNMs. The traditional plate count method was also applied simultaneously to the same stone samples to compare and assist in the interpretation of the results of the FDA hydrolysis method, which relies on the quantitative determination of bacterial and fungal colonies in nutrient agar and malt extract agar medium, respectively. The results of the FDA hydrolysis and plate count methods showed consistency. The total microbial activity determined by the FDA hydrolysis method was low for both types of stone samples. In addition, the plate count method showed low bacterial and fungal counts on all of the samples. This revealed that microbial activity did not play an important role in the stone deterioration process on the MNMs, although different lichen species were frequently observed on both the sandstones and the limestones. Hence, further investigation must be undertaken for determination of their long-term behavior and effects on the stones of the MNMs. On the other hand, the results of the FDA hydrolysis and plate count methods showed correlation. Lower bacterial counts were observed when lower enzymatic activity was observed in the stone samples, and likewise, higher bacterial counts were observed when higher enzymatic activity was observed. Consequently, the application of the FDA hydrolysis method was determined to be reliable for the estimation of total microbial activity on historical stones. The method had obvious advantages in terms of its rapid measurement rate and sensitivity, even on small samples.

Despite the growing attention to Underwater Cultural Heritage (UCH) in Europe and worldwide, the efforts in wholly enjoying underwater archaeological assets and sites are still remarkable; hence, the need for innovative research and solutions that are suitable for raising knowledge on the subject. In this way, this paper wants to be a review for highlighting all of the developments, potentials, and results achieved in the last decade to reach a good protection of UCHs related to the study of stone materials, degradation processes, and the new methods for protection/consolidation directly in situ. The present work is focused on the analysis of the main results obtained from several studies conducted to date, providing additional guidelines for operators in the UCH sector (i.e., restorers, archaeologists, conservation scientists, geologists, etc.). Such guidelines will be a very useful key factor in enhancing knowledge, management, protection, and promotion of underwater sites. In particular, the purpose of this paper is to provide an analysis of the state of the art on both consolidated techniques for studying materials coming from seawater and innovations in the field of protection and consolidation of UCH against biofouling, the main cause of damage in underwater environments.

The importance of urban forests is undeniable when considering their benefits to the environment, such as improving air quality, landscapes and breaking its monotony. However, trees are subject to failures that can cause personal and economic damage. Therefore, it is necessary to know the health conditions of the trees to define their most adequate management. Some tools are used to detect plant health conditions, such as visual analysis, tomography, and drilling resistance. In addition, some formulas based on the cavity and trunk diameter relation or the remaining trunk wall dimension are also used to infer the strength loss of a tree and its consequent risk of falling. However, these formulas have limitations, such as assuming only cavities that are always centered and not considering areas with decay. Therefore, this research evaluates whether ultrasonic tomographic imaging allows us to improve the reach of the equations proposed in the literature to infer the strength loss of trees due to the presence of cavities and decays. The results showed that ultrasonic tomographic imaging allowed the equations to be closer to real conditions of the tree trunk, such as the inclusion of wood strength reduction from decay and the displacement of internal cavities in calculating the reduction in the second moment of area.

The architectural remains as well as sculptures, mosaics, and other artifacts in the archaeological sites are mostly made of stone and susceptible to biodeterioration by microorganisms. Bacterial communities are known to have the most effective role in biological deterioration in stones. The ancient city of Anazarbos (Anavarza), chosen as the study area, is the 1st Degree Archaeological Site in the vicinity of Dilekkaya Village, Kozan District, about 70 km north of Adana. The microbiological, chemical, mineralogical, and microstructural properties of stone samples taken from different places were studied in this research. Samples were taken from i) where no deterioration occurred, ii) where different forms of deterioration were observed, iii) archaeological deposits, iii) archaeological deposits that came from deteriorated stone samples area. Spectroscopic, thermal, and microscopic techniques applied included: X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy-Energy Dispersive System (SEM-EDS), Thermogravimetric Analysis/Differential Thermal Analysis (TG/DTA). The bacterial biodiversity was analyzed by the application of Illumina-based next-generation sequencing methods. Results show intense biological colonisations with clay minerals on limestone surfaces. A patina of clay minerals was observed on newly excavated stone surfaces, while biological colonisations have not yet intensified. The metabarcoding analysis showed 15 bacterial phyla. The Proteobacteria and Actinobacteria were the most abundant phyla in both stones and archaeological deposits samples. Human activity (intensive agriculture, animal husbandry), accumulation of rainwater in excavated areas adversely affects stones, which leads to acceleration of biological deterioration in stones. Thus, all features of the site require multi-faceted studies prior to unearthing of archaeological remains.

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 this work, probes designed in silico were analyzed to calculate hybridization efficiency and specificity by varying the formamide concentration in the hybridization. The Pab489 probe showed excellent in silico performance with high theoretical maximum efficiency hybridization (99.99%) and specificity and was selected for experimental assays with target Paenibacillus sp. and non-target biodeteriogenic microorganisms. Results assessed by epifluorescence microscopy and flow cytometry revealed that, regardless of the formamide concentration, it was possible to observe that the Pab489-Cy3 probe had a similar signal intensity to the EUB338-Cy3 probe (positive control), so the presence of formamide, a highly toxic and carcinogenic compound used to aid the hybridization process, is not necessary. The designed probe used in FISH assays allows specific in situ identification of Paenibacillus spp. in microbial communities in a culture-independent way. This approach can be employed for screening Paenibacillus spp., showing great potential for future application in biodeterioration of heritage assets, in the search for Paenibacillus strains that produce compounds with biotechnological or medical potential.

Polyvinyl chloride (PVC) is a petroleum-based plastic used in various applications, polluting the environment because of its recalcitrance, large content of additives, and the presence of halogen. In our case study, a new, two-stage biodegradation technology that combined composting process used for PVC pretreatment with a subsequent PVC attack by newly-isolated fungal and bacterial strains under SSF conditions was used for biodegradation of commercial PVC films. The novelty consisted in a combined effect of the two biodegradation processes and the use for augmentation of microbial strains isolated from plastic-polluted environments. First, the ability of the newly-isolated strains to deteriorate PVC was tested in individual, liquid-medium- and SSF cultures. Higher mass-reductions of PVC films were obtained in the former cultures, probably due to a better mass transfer in liquid phase. Using the two-stage biodegradation technology the highest cumulative mass-reductions of 29.3 and 33.2% of PVC films were obtained after 110 days with Trichoderma hamatum and Bacillus amyloliquefaciens applied in the second stage in the SSF culture, respectively. However, FTIR analysis showed that the mass-reductions obtained represented removal of significant amounts of additives but the PVC polymer chain was not degraded.

In this study, we explored the biodiversity and abundance of culturable fungi in four samples associated with different biodeterioration outlines collected from the Lemos Pantheon, a limestone-built artwork in Portugal. We compared the results from prolonged standard freezing with those previously obtained from fresh samples to analyze differences in the obtained community and assess the effectiveness of the standard freezing incubation protocol in uncovering a different segment of culturable fungal diversity. Our results showed a slight decrease in culturable diversity, but over 70% of the obtained isolates were not present in the previously studied fresh samples. We also identified a high number of potential new species with this procedure. Moreover, the use of a wide variety of selective culture media positively influenced the diversity of the cultivable fungi obtained in this study. These findings highlight the importance of developing new protocols under varying conditions to accurately characterize the culturable fraction in a given sample. The identification and study of these communities and their possible contribution to the biodeterioration process is crucial knowledge for formulating effective conservation and restoration plans to prevent further damage to valuable cultural heritage assets.

Biodeterioration in building façades represents an important economic loss related to maintaining a functional protective coating system. Research papers with long-time studies on paint performance exposed to field conditions are scarce. Fungi, cyanobacteria, and algae are frequently present in biofilms formed in outdoor locations. Among these, defacement caused by fungi is known for the broad damage spectrum produced. Therefore, it is important to extend the service life of the protective coatings systems. To reach this goal, studies that consider the action of both biotic and abiotic factors acting simultaneously for prolonged periods are necessary. The present research work presents the assessment carried out on acrylic outdoor paint with a nano-additive exposed to long term field conditions. Paint with 1% by weight of ZnO particles with nano-sized crystallites (nano additive) was exposed to natural weathering. Samples with north and south orientation were evaluated by long-term field studies during a period of four years. The incorporation of the nano additive proved to extend service life. In the paints facing north, the ZnO particles were more efficient for the biodeterioration control., Centro de Investigación y Desarrollo en Tecnología de Pinturas