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Our objective, as part of the planned conservation work, was to identify culturable fungi related to the formation of various deterioration symptoms occurring on the Spectatius family marble tomb, the largest monument of the Roman Necropolis in Šempeter, Slovenia. By using fluorescent microscopy, microbial cultivation methods and standard DNA sequencing we were able to identify 21 fungal isolates, 16 being filamentous moulds, primarily dominated by xerophilic Cladosporium spp. (mainly Cladosporium langeronii RN 28) and some Alternaria species; and 5 yeast or yeast like species namely Torula fici, Filobasidium wieringae, Rhodotorula babjevae and Blastobotrys peoriensis. Locations on the tomb, which are well sheltered against rainfall, contained higher concentrations of xerophilic fungi to those, which are completely or partially exposed to rain. The black fungal species of Cladosporium spp. and Alternaria spp. formed the bulk of melanized-greyish patina present on the bottom reliefs and within the cracks of the inner dome of the Spectacius tomb. Moreover, the red coloured yeast R. babjevae caused a thick red pigmentation right under the top roof of the monument’s left side. The obtained results indicated that not only moulds but also yeasts can cause significant biodeterioration. Lastly we isolated indigenous mycoparasitic strains of F. wieringae (RN 37 and RN 38) that could potentially be used in biocontrol formulations applicable in situ for the sustainable preservation of the Spectatius family tomb monument. [ABSTRACT FROM AUTHOR]

Water-based pressure-sensitive adhesives (PSAs) are widely used for different applications due to their cost and convenience. However, their synthesis relies on petroleum-based acrylic monomers, which negatively affects their biodegradability and recyclability. Hybrid acrylic polymers combining acrylic monomers and acrylate-functionalized lactide-based macromonomers could help solve this issue. Recently, we reported on the remarkable biodegradability of these hybrid PSAs in their latex format when using fungal treatments. In this study, we focused on the degradation of dried PSA films, a prevalent application format in commercial settings, by utilizing fungal consortia and solid-state fermentation. Our findings indicated that the type of fungal treatment, carbon source provided, and substrate thickness significantly affected biodegradation rates. The co-culture of Pestalotiopsis microspora and Trametes versicolor demonstrated particularly promising results, achieving degradation rates exceeding 50%, notably, when utilizing wheat bran as a carbon source. Moreover, the renewal of culture media and inoculum further amplified PSA biodegradation. These results underscore the potential of fungal consortia in solid-state cultures to substantially enhance the biodegradation of hybrid acrylic PSA films, offering insights for the design of more sustainable adhesive bio-based products and finally leading to an environmentally responsible end of the PSAs lifecycle. [ABSTRACT FROM AUTHOR]

Biodeterioration is a significant problem in the conservation of stone heritage buildings. In this study, 10 plant essential oils were assessed for their effectiveness in biofilm inhibition on stone heritage building surfaces under laboratory and in situ conditions, and were compared with traditional biocides such as benzalkonium chloride. The plant extracts were tested against algae and mosses. The effect on algae removal was evaluated by measuring the color of the surface before treatment, after 24 h and after 1 month of treatment. The effect on mosses was assessed by measuring the photosynthetic pigment content of mosses after 24 h of treatment. The results showed that the different plant extracts exhibited different levels of antibiotic activity. Benzalkonium chloride, S. aromaticum and C. cassia extracts showed strong antibiotic activity against all algae and mosses tested. T. mongolicus extracts showed antibiotic activity against only some of the algae and mosses, while the application of P. cablin extracts increased chlorophyll b content in the mosses. The other plant extracts were less effective at inhibiting the growth of algae and mosses. GC–MS compositional analysis further indicated that the higher antibiotic activity of S. aromaticum and C. cassia extracts was related to the high content of eugenol and cinnamaldehyde. [ABSTRACT FROM AUTHOR]

The main goal of the current study is to biosynthesize titanium dioxide nanoparticles (TiO2-NPs) using green approach to biocontrol of different fungal strains isolated from historical Description of Egypt book. Nineteen fungal strains were isolated from deteriorated parts and identified by the traditional and molecular methods as Aspergillus flavus (8-isolates), Aspergillus versicolor (2-isolates), Aspergillus ustus (4-isolates), Aspergillus chinensis (2-isolates), Penicillium citrinum (2-isolates), and Penicillium chrysogenum (1-isolate). These fungal strains showed high cellulase, amylase, pectinase, and gelatinase activities which have a significant role in biodeterioration. The biomass filtrate of probiotic strain, Lactobacillus rhamnosus, was used to fabricate TiO2-NPs which characterized by UV-Vis, FT-IR, XRD, TEM, SEM, EDX, DLS, and zeta potential. The obtained data showed the successful formation of spherical and anatase phase NPs with sizes of 3–7 nm and zeta potential values of – 19.9 and – 36.8 mV. The main components of as-formed nanomaterial were Ti and O with weight percentages of 55.91 and 46.25, respectively. The biocompatibility of synthesized TiO2-NPs was investigated toward two normal cell lines, WI38 and HFB4, which reveal the low toxicity at high concentrations (IC50 > 300 μg mL–1). Therefore, concentrations ≤ 300 μg mL–1 were used to biocontrol of isolated fungi. Data showed the promising activity of various concentrations (300, 200, and 100 μg mL–1) of TiO2-NPs to inhibit the growth of fungal strains with varied inhibition zones and dose-dependent manner. This study exhibited the efficacy of probiotic bacterial strains in the synthesis of TiO2-NPs that can be used to preserve historical books from fungal deterioration. [ABSTRACT FROM AUTHOR]

The deterioration of fibre-reinforced sprayed concrete was studied in the Oslofjord subsea tunnel (Norway). At sites with intrusion of saline groundwater resulting in biofilm growth, the concrete exhibited significant concrete deterioration and steel fibre corrosion. Using amplicon sequencing and shotgun metagenomics, the microbial taxa and surveyed potential microbial mechanisms of concrete degradation at two sites over five years were identified. The concrete beneath the biofilm was investigated with polarised light microscopy, scanning electron microscopy and X-ray diffraction. The oxic environment in the tunnel favoured aerobic oxidation processes in nitrogen, sulfur and metal biogeochemical cycling as evidenced by large abundances of metagenome-assembled genomes (MAGs) with potential for oxidation of nitrogen, sulfur, manganese and iron, observed mild acidification of the concrete, and the presence of manganese- and iron oxides. These results suggest that autotrophic microbial populations involved in the cycling of several elements contributed to the corrosion of steel fibres and acidification causing concrete deterioration. [ABSTRACT FROM AUTHOR]

Eco-friendly decontamination treatments on works of art made from organic materials are of growing interest. The high risks to human health and the environment associated with traditional biocides (e.g. ecotoxicity, development of biotic resistance) have made it necessary to search for safer alternatives, also looking at the past but innovating it. The current state of the art is explored here, delving into the literature on the topic from 2000 to today, and outlining trends in terms of the most tested artistic supports and types of published research (in vitro/in vivo). An overview of the characteristics and mechanisms of biodegradation processes on different types of organic products and on the microorganisms mainly involved is thus provided. The main chemical-physical action techniques tested are illustrated and their practical-applicative aspects are discussed on the basis of evidence from case studies. Taking stock of the actual situation, literature consultation highlights that if on the one hand research is advancing rapidly towards the discovery of new ecological and safe solutions, on the other hand these are often biocidal treatments whose protocols have yet to be explored and validated. [ABSTRACT FROM AUTHOR]

Permanent artificial lighting systems in tourist underground environments promote the proliferation of photoautotrophic biofilms, commonly referred to as lampenflora, on damp rock and sediment surfaces. These green-colored biofilms play a key role in the alteration of native community biodiversity and the irreversible deterioration of colonized substrates. Comprehensive chemical or physical treatments to sustainably remove and control lampenflora are still lacking. This study employs an integrated approach to explore the biodiversity, eco-physiology and molecular composition of lampenflora from the Pertosa-Auletta Cave, in Italy. Reflectance analysis showed that photoautotrophic biofilms are able to absorb the totality of the visible spectrum, reflecting only the near-infrared light. This phenomenon results from the production of secondary pigments and the adaptability of these organisms to different metabolic regimes. The biofilm structure mainly comprises filamentous organisms intertwined with the underlying mineral layer, which promote structural alterations of the rock layer due to the biochemical attack of both prokaryotes (mostly represented by Brasilonema angustatum) and eukaryotes (Ephemerum spinulosum and Pseudostichococcus monallantoides), composing the community. Regardless of the corrosion processes, secondary CaCO3 minerals are also found in the biological matrix, which are probably biologically mediated. These findings provide valuable information for the sustainable control of lampenflora. [ABSTRACT FROM AUTHOR]

This work aims discussing the contribution of environmental and technological factors in rock art painting preservation, based on a 3-year experimental program and two archaeological cases from Patagonia (South America). Concerning technological factors, microscopic information of experimental and archaeological contexts indicate that fine-grained pigments have a better preservation potential than coarse-grained ones, likely related to the high binder adsorption capacity of silty and clay size particles, resulting in a strong pigment agglutination and substrate adherence. Mechanical entrapment/translocation of such small particles into the substrate further contributes to preservation. The experiment also evidences that blood-bearing paints present preservation advantages over fat/water-based ones, probably due to clotting and drying processes which agglutinate pigments and seal rock voids, avoiding binder migration. In contrast, experimental gypsum- and, to a lesser extent, charcoal-based paints show a rapid and significant deterioration, particularly in the temperate and humid context. The low archaeological expectancy derived from these results is supported by the scarce and/or ambiguous regional representation of these black pigments in ancient Patagonian paintings. Among natural factors, water-related processes (i.e., rainfall, snow, freezing and water infiltration) play a decisive role in the physicochemical paint degradation, also favoring bioactivity. Raman spectroscopy of neoformed white crystals in experimental paints may evidence, in a short term, a first stage of the profuse biomineralizations archaeologically observed, associated with lichens, fungus, and endolithic organisms. Finally, sheep rubbing and wind abrasion are proposed as the main agents affecting vertical frequencies and integrity of archaeological motifs at the cave and open-air contexts, respectively, whereas differences related to cardinal insolation likely impact in frequencies, motif color and weathering stages at the open-air site too. [ABSTRACT FROM AUTHOR]

The biodeterioration of cultural heritage monuments is a worldwide phenomenon, closely linked to the presence of microorganisms and macroorganisms. Microbial colonization leads to physical, chemical damage and esthetic changes. Synthetic polymers, particularly acrylics, are often used to consolidate and protect monuments and artistic stone surfaces. To increase acrylics performances regarding to durability and antimicrobials' activity, nanoparticles (NPs) were added to polymers. In this study, silver NP was biosynthesized by Malva sylvestris aqueous extract. Furthermore, the in situ method was used for nanocomposite synthesis, which would be simplified the procedure of synthesis. For this, the precursors including the plant aqueous extract, AgNO3 solution and polymer were mixed, and nanocomposite was formed. The morphological characteristics of the obtained nanocomposite were determined using field emission scanning electron microscope (FESEM). The energy-dispersive X-ray (EDX) confirmed AgNPs existence in the composite. Next, the nanocomposite's antibacterial properties were tested on Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Cladosporium cladosporioides, Aspergillus niger, and Alternaria alternata. The antibacterial activity of bioengineered nanocomposite compared to acrylic polymer, alone. The results of antimicrobial experiments have shown that the number of bacterial and fungal cells was decreased by 1 logarithm in the polymer, and by 2 to 4 logarithms in the nanocomposite that the antimicrobial effect of latter was notably increased. This study was based on applying this nanocomposite to improve conservation strategies for stony cultural heritage. Further experiments should be performed to evaluate the efficacy of this nanocomposite on outdoor stony model. [ABSTRACT FROM AUTHOR]

Biodeterioration of monumental complexes is in large part due to the proliferation of various microorganisms that attack the physical–chemical structures of support materials. Various conservation and restoration interventions use commercial biocides of synthetic origin, which exhibit some human and environmental toxicity and sometimes side effects on support materials. The main objective of this work is the assessment of new biocides obtained from endemic Mediterranean plants, to be used in the preservation of cultural heritage with the goal of contributing to the sustainable use of ecosystems and to the development of Mediterranean local communities. The biocidal potential of essential oils (EOs) and solvent extracts (SEs) (ethanol and n-hexane) obtained from four plants were evaluated: Thymus mastichina (Tm), Mentha pulegium (Mp), Foeniculum vulgare (Fv), and Lavandula viridis (Lv). Microorganisms collected at an emblematic site of Portuguese cultural heritage, the ruins of the Roman city of Conímbriga, were used to evaluate the biocidal activity of the EOs and SEs. It can be concluded that (i) SEs did not exhibit fungicidal nor bactericidal activity, except for one fungus specie; (ii) biocidal activity of EOs depends on the microorganism specie. The EOs showed a relative average biocidal activity (when compared to the commercial biocide Biotin T (1% v/v)) of 64%, 32%, 30%, and 25% for Mp, Fv, Lv, and Tm. On carbonate rocks, the application of Fv and Mp EOs up to 3 layers do not promote significant color/tonality changes in the surface of the rock. And the application of three layers of Lv and four layers of Fv, Mp, and Lv OEs only promote the occurrence of blurs or stains (variation of tonality) on rocks that presents very low porosity. It can also be noted that the EO of Mp has the broadest spectrum of activity. The results allow considering the use of Mp, Fv, Lv, and Tm EOs as valid alternatives to commercial biocides, providing a prospective application in the field of green conservation of building heritage. [ABSTRACT FROM AUTHOR]

Archaeological sites and structures suffer from several factors of deterioration. The present survey focuses on the biodeterioration by plants, which is not less important than the rest of the deterioration factors; moreover, in many cases, it leads to their occurrence. Despite the importance of plants in our lives and their aesthetic appearance around stone monuments, they pose a threat to their survival. Therefore, it is necessary to have such a review to detail this topic and understand its severity by identifying the most common and harmful plant species, the co-factors for their existence, and the mechanism of damage. Physical damage through causing cracks, detachment, and loss of structural integrity and chemical damage from root secretions-biological damage by encouraging microorganisms and insects supported by examples of sites that have been damaged by plants. The results will help to apply appropriate methods of prevention and control by mentioning the advantages and disadvantages of each method. [ABSTRACT FROM AUTHOR]

The preservation of cultural heritage, including ancient photographic materials, is of paramount importance in the field of conservation science. In this context, the microbial diversity of 'Skull and Crossbones', a 1983 photograph by Robert Mapplethorpe printed on silver gelatine, was assessed. We employed both culture-dependent and culture-independent methods to characterize microbial communities inhabiting this artwork. Vibrational Raman micro spectroscopy and FT-IR spectroscopy were utilized to assess the chemical degradation condition and characterize the chemical components of the silver gelatin print. The combination of molecular sequencing methods (Sanger and HTS approach) and non-invasive vibrational spectroscopy yielded valuable insights into the microbial communities thriving on photographic material and the chemical degradation of the print. Isolated fungal strains were added to the Fungal Collection at the University of Naples Federico II, and their deteriorative potential was investigated by adding substrates, commonly used in canvas photographs to the culture media. These results establish a link between microbial communities colonizing ancient photographic materials, paper decomposition, and the enzymatic patterns of the retrieved microorganisms. This information is invaluable for understanding and addressing biodeterioration progression on valuable works of art, such as historical photographs, which remain understudied. [ABSTRACT FROM AUTHOR]

This study provided crucial insights into the concentrations of airborne fungi, environmental parameters, and atmospheric pollution in Thailand's ancient stone temples. Airborne fungi were identified based on morphological characteristics. Airborne fungi, meteorological parameters, and atmospheric pollutants concurrently assessed during each sampling event, evaluating indoor/outdoor ratio. Prevalent genera included Penicillium (14.36%), Aspergillus (10.94%), Cladosporium (10.74%), Rhizopus (6.31%), and Fusarium (5.90%), with an average fungi concentration of 4884.46 ± 724.79 CFU/m3. Eighteen fungal species out of the 64 airborne fungi identified were well-known serious pathogenic agents, contributing not only to structural deterioration but also to human health. Significant variations were observed between indoor and outdoor environments and across diverse landscapes, particularly for PM10 (ranging from 43.47 to 121.31 µg/m3) and PM2.5 (ranging from 29.59 to 89.60 µg/m3), with intensive incense burning identified as a prominent source of indoor atmospheric pollution. Historical temples, particularly situated in urban areas, were identified as significant reservoirs of airborne fungi. Correlations between meteorological parameters and pollutants revealed strong associations. Furthermore, principal component analysis (PCA) and cluster analysis elucidated distinct patterns in airborne fungal concentrations and contaminations. This study analyzed environmental factors, pollutants, airborne fungi, and geographical variations from July 2020 to March 2021. Understanding prevalent genera, airborne fungi concentrations, pathogenic species, biodeterioration, and environmental dynamics provided strategies for improving indoor air quality and mitigating airborne fungal contamination in archaeological buildings worldwide. [ABSTRACT FROM AUTHOR]

Wastewater networks are intrinsically attacked by the production of H2S, a highly reactive gas known for its extremely aggressive nature. This study employs a range of techniques, such as XRD, SEM–EDS, TGA, and Raman spectrometry, to investigate the interaction between low concentrations of H2S—averaging 1.3 ppm and various types of Portland cementitious materials (CEM I, CEM II, CEM III, and CEM V). The objective is to discern the chemical alterations contributing to structural deterioration and to provide a mineralogical characterization of the deterioration layers present on these binders. Through a comprehensive examination of the durability of these materials exposed to low concentrations of H2S in a Paris Region sewage system over nearly four years, the findings extend beyond surface-level observations. Despite the absence of visible signs of deterioration, high-precision analytical techniques reveal significant mineralogical transformations within the cementitious matrix. Expansive products such as gypsum, ettringite, and elemental sulfur are identified in mortar samples, underscoring the critical role of precise analysis in comprehending the deterioration process. [ABSTRACT FROM AUTHOR]

Micro- plastics (MPs) pose significant global threats, requiring an environment-friendly mode of decomposition. Microbial-mediated biodegradation and biodeterioration of micro-plastics (MPs) have been widely known for their cost-effectiveness, and environment-friendly techniques for removing MPs. MPs resistance to various biocidal microbes has also been reported by various studies. The biocidal resistance degree of biodegradability and/or microbiological susceptibility of MPs can be determined by defacement, structural deformation, erosion, degree of plasticizer degradation, metabolization, and/or solubilization of MPs. The degradation of microplastics involves microbial organisms like bacteria, mold, yeast, algae, and associated enzymes. Analytical and microbiological techniques monitor microplastic biodegradation, but no microbial organism can eliminate microplastics. MPs can pose environmental risks to aquatic and human life. Micro-plastic biodegradation involves fragmentation, assimilation, and mineralization, influenced by abiotic and biotic factors. Environmental factors and pre-treatment agents can naturally degrade large polymers or induce bio-fragmentation, which may impact their efficiency. A clear understanding of MPs pollution and the microbial degradation process is crucial for mitigating its effects. The study aimed to identify deteriogenic microorganism species that contribute to the biodegradation of micro-plastics (MPs). This knowledge is crucial for designing novel biodeterioration and biodegradation formulations, both lab-scale and industrial, that exhibit MPs-cidal actions, potentially predicting MPs-free aquatic and atmospheric environments. The study emphasizes the urgent need for global cooperation, research advancements, and public involvement to reduce micro-plastic contamination through policy proposals and improved waste management practices. [ABSTRACT FROM AUTHOR]

In the context of bio-deterioration of cultural heritage, the Lavandula angustifolia Mill. plant proves to be of interest for a green approach to the preservation of art manufacts on organic media. Supercritical CO2 fluid extraction (SFE) was utilized to obtain both lavender essential oil (E2LS3) and hydrolate (E2LS3A), while ultrasound assisted maceration in n-hexane:ethanol (99:1, v:v) provided LA2/1 extract. The extracts, all chemically characterized by UHPLC-HRMS and GC–MS analyses, were screened for their antifungal capability towards six fungi isolated from the plywood support of Haim Steinbach's contemporary artwork "Un-color becomes alter ego #2" (1984). To this purpose, disk diffusion method was applied on both mycelium and conidial suspensions to unravel whether the inhibitory activity affects the growth of fungi at different life cycle stages. The micro-atmosphere method was also explored to assess the response of fungal growth in a saturated atmosphere. Data acquired highlighted that SFE-obtained lavender essential oil, whose oxygenated monoterpene part mostly accounting for terpinene-4-ol, borneol, linalool, camphor, and 1,8-cineole, proves to be a dose- and time-dependent inhibitor of fungal growth. It has also been shown that exposure to the oil vapor phase is more effective at very low dose levels. The promising results allow us to hypothesize the use of the essential oil for treating fungal colonization by exposure to its volatile components in a modified atmosphere environment, with no direct contact with the artwork. [ABSTRACT FROM AUTHOR]

Atmospheric nitrogen deposition may affect the biodeterioration process of stone monuments through direct and indirect pathways, but relevant studies are lacking. Therefore, taking the biologically colonized rocks around the Leshan Giant Buddha (World Heritage - Mixed Property) as the research objects, we studied the effects of multiple nitrogen addition levels (0, 9, 18, 36, 72 kg N hm-2 a-1; N0, N1; N2 ; N3; N4) on the bacterial community structure and soil nutrients on the surfaces of stones with four biocolonization types, including naked rock (NR), and lichen (LR), bryophyte (BS) and vascular plant (VS) colonization, to investigate the potential effect of atmospheric nitrogen deposition on the rock weathering of the Leshan Giant Buddha. The results demonstrated that nitrogen addition impacted soil carbon, nitrogen and phosphorus nutrients, as well as bacterial community structure and composition, but the responses to nitrogen input varied among different colonization types. Nitrogen fertilization promoted the accumulation of total organic carbon and total nitrogen in NR and LR, and increased the content of total phosphorus in VS. Bacterial α-diversity decreased with nitrogen addition in NR but increased with nitrogen addition in VS. Nitrogen addition significantly (R > 0.9, p < 0.01) changed the bacterial community composition in the four biocolonization types, and the changes were dominated by species replacement (contributed to 60.98%, 76.32%, 67.27% and 72.14% for bacterial diversity in NR, LR, BS and VS, respectively). Total nitrogen, dissolved organic nitrogen, dissolved organic nitrogen and total phosphorus were the most important ecological factors affecting bacterial community structure in NR, LR, BS and VS, respectively. Nitrogen addition enriched different bacterial taxa in the four biocolonization types. The results of this study provide basic data for the protection of stone monuments and the formulation of sustainable development strategies under a changing climate. [ABSTRACT FROM AUTHOR]

Abstract—The species Amorphotheca resinae is best known among micromycetes that deteriorate aviation fuel. It lives in natural conditions in various biogeocenoses and is known as a component of soil mycobiota. Micromycetes of this type have the ability to obtain the necessary carbon for life from hydrocarbon fuel. This happens through the breakdown of complex hydrocarbons to simpler compounds. The growth of A. resinae in fuel leads to numerous problems associated with the operation of aviation equipment: destruction of nonmetallic materials, increased corrosion of metal elements, and clogging of fuel filters with mycelial biomass. According to some literature sources, not all strains of this species living in natural conditions can absorb petroleum hydrocarbons. According to other data, there is a tendency that the ability to absorb hydrocarbons is becoming characteristic of an increasing number of soil strains of A. resinae. The authors have studied the growth capacity of seven strains of A. resinae isolated from various aviation fuel samples and seven strains isolated from different geographical locations and substrates: soil, air, wood, and rooms. Among the studied strains of A. resinae were both those able to develop due to aviation fuel hydrocarbons and those without this ability. At the same time, visual and quantitative methods for evaluating the growth rate and intensity of the studied fungi strains do not exclude each other and give comparable results. A. resinae strains isolated from fuel samples demonstrated much more active development compared to strains isolated from natural habitats. Five strains of A. resinae isolated from different geographical locations of fuel samples showed almost the same degree of development in the amount of biomass formed during one month. [ABSTRACT FROM AUTHOR]

The article provides an overview of modern ideas about biodegradation and biodeterioration and of polymer materials. The mechanisms of bacteria sedimentation and attachment and the formation of biofilms are described. Schemes of influencing abiotic and biological environmental factors are considered: the impact of polysaccharides and proteins contained in biofilms on a polymer material, implementation of enzymatic biodegradation reactions, as well as the influence of the material composition and its nature on the tendency to biodegradation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Corrosion resistance of structural materials has become one of the most important aspects in the electronics industry. In particular, biodeterioration and biocorrosion lead to operational failures and high economic losses. Biocorrosion of copper and base materials applied for the production of printed circuit boards is studied in this work. The inevitable change in the properties and destruction of textolite and glass textolite that are used in the composition of radioelectronic components and are in contact with copper often results in violations of the performance of devices and equipment. An attempt to explain the role of biofilms of microfungi as the main factor of mycological corrosion of copper in the composition of some electronic-industry products is made in this work. [ABSTRACT FROM AUTHOR]

The processes of biodeterioration of the unique Tomskaya Pisanitsa monument of rock art in Western Siberia have been studied by a complex of biological and mineralogical methods. The species composition of the lithobiotic community (bacteria, fungi, and lichens) is identified using a complex of cultural, morphological, and molecular genetic methods. It is shown that the destruction of the monument is a result of interrelated physical, chemical, and biological processes, accompanied by a change in the properties of the rock and its biological colonization. The structure of microbial communities depends on the local environment and successional processes. The development of biofilms with the dominance of cyanobacteria is observed on the rock zones of increased moisture and the formation of carbonate crusts. The problems of adaptation of the lithobiotic microorganisms to existence at the Tomskaya Pisanitsa rock art monument, as well as their role in the processes of oxalate and carbonate biomineralization, are discussed. The results point to the danger of deterioration of Tomskaya Pisanitsa monument and indicate the need to find new effective ways to protect it, taking into account the accumulated scientific data. [ABSTRACT FROM AUTHOR]

Lingyan Temple is an important part of the World Heritage Mixed Property on Mount Taishan, in which numerous cultural heritage monuments, including exquisite painted arhat statues and inscriptions, display the ancient Chinese Buddhist culture. However, these monuments are suffering aesthetic and structural damage due to rich biofilms. In this study, the microbial communities colonized on historical monuments in different microenvironments were characterized through a combination of culture-dependent techniques and high-throughput sequencing. Microbial diversity was significantly different among the historical sites with different microenvironments. For example, Actinobacteria and Ascomycota were the core phyla in the indoor samples, while they were less abundant in the outdoor samples, and phototrophic microorganisms including Cyanobacteria and green algae were only dominant in the samples near springs. The results suggested that environmental factors such as water and airborne microorganisms may be the main causes influencing microbial distribution. Most of the identified dominant species were common on the historical monuments and could contribute to biodeterioration. This analysis of microbiota will provide further information on the biodeterioration processes and preservation strategies of cultural heritage monuments in Lingyan Temple. [ABSTRACT FROM AUTHOR]

The present study focuses on the development of a fast, non-invasive methodology, appropriate for the detection and characterization of biodeterioration present on the surface of archaeological/historical stone objects and monuments, by exploiting the characteristic fluorescence emission of biological deposits. Fluorescence spectra were collected by use of a portable LED (Light Emitting Diode)-Induced Fluorescence (LED-IF) instrument. Three limestone fragments and one mortar fragment, from different monuments in Greece, presenting various types of biodeterioration on their surface, have been investigated in the laboratory. First, fluorescence emission spectra were acquired with a benchtop laboratory spectrofluorometer in order to select the optimum excitation wavelengths for the fluorophores present in the biological crust. An evaluation of the portable LED-IF instrument was conducted by assessing the performance of its optical components and different LED excitation sources, while an investigation of several experimental parameters on the fluorescence signal was also performed. Furthermore, issues related to the efficiency of detection and identification of biological growth have been studied, such as the effect of sample surface wetting on the fluorescence signal. The results of the present study demonstrate that the LED-IF instrument can be used for a fast and reliable assessment of the presence of biodeterioration on monuments. [ABSTRACT FROM AUTHOR]

In the last decade, biopolymers have been used as organic soil binders in ground improvement and earthen construction material modification. Although biopolymer-treated soils have substantially enhanced mechanical strength, the deformation characteristics under external loads and material durability (e.g. biodeterioration due to microbial activity) have not yet been fully understood, which limits the in situ practical application of the biopolymer-based soil treatment technology. This study investigated the efficiency of combined carrageenan and casein in strengthening a clayey soil with the biodeterioration consideration. Both mechanical tests (e.g. unconfined compressive strength and one-dimensional consolidation) and biological tests (e.g. high throughput sequencing and rating of mould growth) were conducted. Results indicated that the usage of the carrageenan–casein mixture induced a higher soil compressive strength compared with either carrageen or casein, due to the formation of a three-dimensional gel network. In addition, carrageenan–casein mixture and casein decreased the compressibility of the clayey soil, which might be attributed to the casein's peculiarity of self-associating into micelles, leading to minimal interactions with water molecules. Carrageenan, due to its affinity for water, increased the soil compressibility. Under the impact of microbial activity, the biopolymer-treated soils underwent deterioration in both surface appearance (i.e. coloured stains and patches caused by mould growth) and compressive strength. A linear relationship was proposed, in which a reduction in compressive strength by approximately 11% is expected while the rating of mould growth is increased by one in a five-rating system. The current research demonstrates that the soil reinforcement with combined carrageenan and casein is able to improve both soil strength and deformation behaviours. It is also suggested to take into account the biodeterioration considerations in the design and implementation of biopolymer-based soil reinforcement practices. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify and quantify the airborne fungal spore content in the Cathedral of Jaén (South Spain). The evaluation of the microclimatic conditions and their relationship with the presence of airborne fungal spores in different indoor areas was also tested. Airborne fungal spores were recorded during 2019 by using a volumetric sampler. The Choir was the study area with the maximum airborne fungal spore concentrations, representing 55% of the total compared to the minimum representation of 12% sampled in the Museum. Regarding the seasonality, winter records represented only 20% of the total the airborne spore monitoring. Peaks in the daily spore concentrations were mainly recorded in the first half of spring and during the middle of the summer. A total of 29 taxa were identified. Cladosporium and Aspergillus/Penicillium were the potentially biodeteriogen fungal spores that were more frequently recorded in all of the study areas. Of the total airborne fungal spores recorded in the indoor environment, 82.5% belong to biodeteriogen fungi that, under suitable conditions for their germination, could have a negative effect on the preservation of artistic-historical heritage. The installation and correct maintenance of air-conditioning systems and the aeromycological analysis in suspected places would be recommended. [ABSTRACT FROM AUTHOR]

Orobajo Cemetery, a contemporary community cemetery originally located in the floodplains of the Cauca River in Antioquia, Colombia, was exhumed and reinterred in a new site as part of the environmental and cultural protection program associated with the construction of the Ituango Hydroelectric Dam. Bioanthropological, biochemical, and soil sciences methodologies were used throughout the exhumation to recuperate the skeletonized remains of the deceased and evaluate the age and sex of the interred individuals. Individuals of both sexes and every stage of the life cycle were found buried at the cemetery, and their skeletal remains showed bone deterioration and destruction. Thus, the environment in which the deceased were buried was also studied, analyzing the biophysical and biochemical mechanisms of fungal biodeterioration and the chemical composition of the deterioration, as well as the soil of the cemetery. Social context and burial practices were studied to understand their relation to the soil composition in the cemetery. Samples were taken from 31 of the 180 skeletonized remains exhumed at the site. Polarized light microscopy and scanning electron microscopy were used to analyze the samples. The samples showed chemical and physical deterioration as well as fungal biodeterioration with visible loss of minerals, and biodegradation of the organic bone matter, resulting in the destruction of the bone. The study concludes that the high rates of bone deterioration and the resulting fragility of the skeletal remains are due to the burial environment in dry tropical forest soils and the biotic and abiotic agents through which biophysical and biochemical mechanisms produce diagenetic alterations at the microscopic level of the bone. [ABSTRACT FROM AUTHOR]

Polyethylene (PE), a non-biodegradable plastic, is widely used in agriculture as a mulch material, which causes serious plastic pollution when it is discarded. Recent studies have described the biodeterioration of PE by bacteria, but it is difficult for a single bacterial species to effectively degrade PE plastic. We isolated two strains with PE-degrading ability, Bacillus cereus (E1) and Rhodococcus equi (E3), from the soil attached to plastic waste on the south side of Mount Tai, China, using a medium with PE plastic as the only carbon source. By clear zone area analysis, we found that E1 mixed with E3 could improve the degradation of PE plastics. The mixture of E1 and E3 was incubated for 110 days in a medium containing PE and mulch film as the only carbon source, respectively. After 110 days, a decrease in pH and mass was observed. Obvious slits and depressions were observed on the surface of the PE film and the mulch films using scanning electron microscopy. The surface hydrophobicity of both films decreased, and FTIR revealed the formation of new oxidation groups on their surfaces during the degradation process and the destruction of the original CH 2 long chains of PE. Besides, we found that surface of the mulch films contained more viable bacteria than the liquid medium. In conclusion, we identified two PE-degrading strains whose mixture can effectively degrade mulch film than pure PE film. Our results provide a reference for understanding PE plastic degradation pathways and their associated degradation processes., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

UV-C irradiation critically effects the growth of micro-fungi and also deteriorate leather materials. In the present study vegetable tanned and chrome tanned leather were infected with pure cultures of Aspergillus niger and Aspergillus flavus, which were isolated from stored leather materials. UV-C light (λ = 254 nm) was applied on infected leather for 15 and 60 min. The changes in leather qualities were examined through weight, tensile strength, scanning electron microscope, energy dispersive X-ray and Fourier transform infrared spectroscopy study after 15 and 30 days of fungal inoculation. Vegetable tanned leather was more vulnerable in case of fungal attack than chrome tanned leather while A. flavus showed more influence on leather deterioration than A. niger. The results showed that weight loss after 30 days for 15 and 60 min irradiation exposure was 1.3% compared to A. flavus infected leather (3.93%). The tensile strength of vegetable and chrome tanned UV irradiated leather was increased by 44% and 7% respectively. The scanning electron microscopic images exhibit the limited presence of conidiophores in UV-C exposed leather which confirmed the potentiality of irradiation for controlling fungal growth. The infrared spectral analysis of UV-C exposed infected leather samples showed neither shifting of wavenumber nor displacement of any functional groups. Altogether the efficacy of UV-C irradiation against biodeterioration of leather was concluded to be effective. This method can be used to control fungal growth without compromising the leather quality. [ABSTRACT FROM AUTHOR]

In this study, the microbial community (Bacteria, Archaea, and Fungi) of a historical manuscript was investigated by microscopic observation (field emission scanning electron microscopy), culture-dependent methods, and sequencing of amplicons on the Illumina MiSeq platform. Microbial isolates were also assayed for production of hydrolytic enzymes (cellulase, amylase, and protease). Observation of gold-coated paper samples in high-vacuum mode revealed bacterial cells, conidia, and fungal mycelium among the fibers. Eleven bacterial strains, including species of Bacillus, Streptomyces,Corynebacterium, and four fungal strains, including species of Aspergillus and Alternaria, were isolated by culture-dependent methods and identified by 16S rRNA and ITS sequencing, by comparison with the EzBioCloud and MycoBank databases, respectively. Illumina MiSeq sequencing revealed the presence of 20 bacterial genera, including Pseudomonas,Bacillus, Citrococcus, Promicromonospora, Carnobacterium, Arthrobacter, Salinibacterium, and Streptomyces. According to the number of reads, Pseudomonas (58%) was the most abundant genus and P. stutzeri (55.2%) was the most abundant bacterial species. Sequencing results of fungal amplicons indicated 62 genera, including Penicillium, Aspergillus, Alternaria, Mucor, and Chaetomium. Penicillium (58.89%) and Aspergillus (33.02%) were the most abundant genera. P. polonicum (55.45%) and A. ruber (22.55%) were the most abundant species of the fungal community. The results of searching for archaea in the microbial community of the manuscript by culture-dependent and high-throughput amplicon sequencing were negative. The enzymatic activity of microbial isolates indicated a potential risk of biodeterioration. It seems that using a combination of culture-dependent and high-throughput sequencing methods has a significant advantage over using them individually. [ABSTRACT FROM AUTHOR]

Different types of biomineral layers have been identified and characterized on the monuments of rock art in Minusinsk Basin. On the surface of the sandstone (on which images were applied in ancient times), cyanobacterial biofilms and biofouling with the dominance of lichens, mosses, and primary soils have developed, and mineral crusts have formed that are to a greater or lesser extent inhabited by microorganisms. Monospecies cyanobacterial biofilms formed by Gloeocapsopsis magma are a dominant form of biofouling on open rock surfaces exposed to the intense insolation. The most noticeable development of microorganisms was noted on light-colored calcite-bearing crusts with a porous surface. On the contrary, gypsum crusts are poor in organic matter and are almost uninhabited by microorganisms. The formation of gypsum crusts leads to serious damage to the surface layer of the stone and can be one of the main processes leading to the loss of the rock art. [ABSTRACT FROM AUTHOR]

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. Key points: • Rich and abundant microbiomes expose sculptures' vulnerability to deterioration. • Well-preserved sculptures are at risk of deterioration by pigment-producing taxa. • ATP and colourimetry quickly identified the most relevant contaminated areas. [ABSTRACT FROM AUTHOR]

Nossa Senhora da Assunção Cathedral is located in Mariana, the first capital of the state of Minas Gerais, Brazil, and the first seat of the bishopric. Owing to this heritage, the Cathedral has an artistic collection composed of altarpieces with execution attributed to the renowned artists in the eighteenth-century Brazil. These are unique relics that build the religious, artistic, and social culture of the Brazilian city, listed as National Heritage (NH) by the National Institute of Historic and Artistic Heritage (IPHAN). It is, therefore, crucial to preserve these artworks and ensure proper health of the restorers. The assessment of air quality is a vital microbiological parameter to ensure the health of the visitors of the Brazilian Cathedral and to preserve this building of historical relevance. The isolation and identification of cultivable fungal species in the indoor air are essential for treatment against microbial growth to avoid the biodeterioration of the artworks and to prevent possible human infections. Fifteen distinct taxa were identified, and three fungal species of clinical relevance were detected inside the Cathedral: Aspergillus fumigatus, Aspergillus flavus, and Trichophyton rubrum. The values obtained with regard to colony-forming unit (CFU) count, in the air inside the Cathedral, are in accordance with the Brazilian legislation and the World Health Organization (WHO). Majority species of filamentous fungi exhibited potential deterioration risks as producers of extracellular enzymes, acids, and pigments, such as Purpureocillum lilacinum, which presented proteolytic activity and the lowest pH value, and Stachybotrys chartarum, which showed high ICMC values and pigment production. In addition, these fungi populations obtained include pathogenic fungi, with the potential infection in humans, particularly systemic, cutaneous, and opportunistic mycoses. Therefore, appropriate measures for human health, such as the use of appropriate masks by conservators and restorers, are necessary to avoid mild and severe fungal infections. [ABSTRACT FROM AUTHOR]

The growth activity of ten strains of micromycetes isolated from the surfaces of the materials exposed to the tropical climate of the Republic of Cuba is studied on the selective nutrient media: an agarized mineral medium with the addition of microcrystalline cellulose as a single carbon source and an agarized mineral medium without cellulose as a reference. As follows from growth and morphological features, most of the isolated strains are potential destructors and are of interest for further studies of the effect of their growth on the properties of various groups of materials. [ABSTRACT FROM AUTHOR]

In recent years, there has been an exponential growth in the use of digital media for data storage and the creation of museums, libraries and digital archives. In particular, Compact Discs Recordable (CD-R) have become one of the most used tools for archiving documents related to cultural heritage. Many authors have investigated only the CD longevity, but very few studies have focused on their biological deterioration. The aim of this work was to examine the CD-R biodeterioration following two ways: (1) search badly preserved CD-R, showing clear degradation spots and verify that it is fungal deterioration; (2) fungal inoculation tests on blank CD-R to verify their bioreceptivity. The analysis of a badly preserved CD-R showed clear degradation spots, highlighting, after cultural and molecular analysis, the presence on the surface of three different fungi: Chaetomium globosum, Trichoderma atroviride e Coniochaeta sp. For the in vitro inoculation tests we used conidia suspensions of Cladosporium cladosporioides and Penicillium chrysogenum, and we observed the growth for 6 months. At the end of experiment, both fungi colonized the CD-R surface with hyphae and mycelia clearly visible, causing also loss of material and fractal structure presence. For the CD-R use as cultural heritage archiving, the correct storage is an essential phase and, in light of the results obtained, it will be necessary not only to consider the environmental factors (temperature, relative humidity) but also the biological deterioration caused by airborne fungi. Therefore, effort needs to be taken to regularly monitor temperature and relative humidity and it is essential to periodically conduct cleaning of optical media. [ABSTRACT FROM AUTHOR]

The degradation of mortars and plasters can represent a threat for their preservation. That is why a deep understanding of the degradation mechanisms and the identification of degradation patterns is strongly recommended for who is in charge of conservation of archaeological sites and of built heritage in general. Here, it has been described what are the main degrading agents that can be detected on mortars and plasters and how they act to produce degradation. Moreover, an overview of the analyses which can be carried out directly on site and in laboratory as well has been reported. The knowledge that can be achieved by using such methods represents an essential tool to set up a suitable conservation plan. In addition, a more detailed analysis can also have a research purpose, since they can be useful to clarify some mechanisms and interactions that still remain unclear. [ABSTRACT FROM AUTHOR]

The research of the microbiological air quality of a building considered a human historical and cultural heritage site by the United Nations Educational, Scientific, and Cultural Organization is fundamental for preventive conservation action, mainly because it identifies cultivable fungal species around the collections and suggests the appropriate treatment choice. This study investigated the air microbiological parameters inside the Nossa Senhora da Conceição Church and identified the population of airborne fungi. Sixty filamentous fungal isolates were detected with ten distinct taxa. The counts of colony forming units (CFUs) performed at 10 different points were in accordance with Brazilian legislation. In addition, the presence of two fungal species was detected colonizing artworks covered with gold leaves: Cladosporium cladosporioides and Aspergillus versicolor. Air quality monitoring inside the church was in accordance with the required Brazilian legislation standards. The composition of the filamentous fungal community included the presence of human fungal pathogens; for this reason, the use of personal protective equipment was recommended during the restoration work. Thus, characterization of the air microbiological parameters helps to preserve not only the building's collection, but also the health of the faithful, conservators-restorers, tourists, and researchers. [ABSTRACT FROM AUTHOR]

This study addresses the use of Fourier-transform infrared spectroscopy (FTIR) as a characterization tool to evaluate fast-growing pine woods treated by in situ polymerization with three different precursors and then subjected to biodeterioration using a white-rot fungus. The solution treatments consisted of three concentrations of furfuryl alcohol (c.a. 25%, 50%, and 75%), methyl methacrylate, and styrene. The decay assays were performed using a white-rot fungus (Trametes versicolor), and the decayed woods were evaluated at three layers (c.a. bottom, middle, and top surface). Attenuated and shifted bands suggest that the fungus penetrated from the top surface of the untreated pine wood and remained at the middle layer, wherein caused the most severe damages. Regarding the treated woods, the middle and bottom layers remained unchanged in terms of infrared spectra, which suggest that the biodeterioration occurred mostly in the surface in these cases. In general, the FTIR proved to be a rapid and efficient non-destructive technique to analyse those woods studied here. [ABSTRACT FROM AUTHOR]

Fungi cause diverse, serious socio-economic problems, including biodeterioration of valuable products and materials that spawns a biocides industry worth ~$11 billion globally. To help combat environmental fungi that commonly colonise material products, this study tested the hypothesis that combination of an approved fungicide with diverse agents approved by the FDA (Food and Drug Administration) could reveal potent combinatorial activities with promise for fungicidal applications. The strategy to use approved compounds lowers potential development risks for any effective combinations. A high-throughput assay of 1280 FDA-approved compounds was conducted to find those that potentiate the effect of iodopropynyl-butyl-carbamate (IPBC) on the growth of Trichoderma virens; IPBC is one of the two most widely used Biocidal Products Regulations–approved fungicides. From this library, 34 compounds in combination with IPBC strongly inhibited fungal growth. Low-cost compounds that gave the most effective growth inhibition were tested against other environmental fungi that are standard biomarkers for resistance of synthetic materials to fungal colonisation. Trifluoperazine (TFZ) in combination with IPBC enhanced growth inhibition of three of the five test fungi. The antifungal hexetidine (HEX) potentiated IPBC action against two of the test organisms. Testable hypotheses on the mechanisms of these combinatorial actions are discussed. Neither IPBC + TFZ nor IPBC + HEX exhibited a combinatorial effect against mammalian cells. These combinations retained strong fungal growth inhibition properties after incorporation to a polymer matrix (alginate) with potential for fungicide delivery. The study reveals the potential of such approved compounds for novel combinatorial applications in the control of fungal environmental opportunists. Key points: • Search with an approved fungicide to find new fungicidal synergies in drug libraries. • New combinations inhibit growth of key environmental fungi on different matrices. • The approach enables a more rapid response to demand for new biocides. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The Leizhou Peninsula in China is very famous for its unique folk art creation, especially for the stonework, like the basalt sculptures of the Leizhou Stone Dogs, which have a history of more than two thousand years. Since these sculptures are usually exposed outdoors, many of them are suffering from severe damage by lichen and fungi. To protect them from microbial attack, we determined fungal communities in the biofilms colonizing the stone dogs and explored an effective conservation measure. Specifically, the micromorphology analysis of the biofilms on the stone dogs was performed through both on-site and laboratory-based microscopies in order to provide an overview of the fungal community structure. High-throughput sequencing analysis revealed that the predominant fungi in the biofilms belong to the following genera Caloplaca, Chaetomium, Clitopilus, Acanthostigma, Tolypocladium, Aspergillus, and Toxicocladosporium. The energy dispersive X-ray spectrometry (EDS) showed that the basalt is mainly composed of silica (53% by weight), followed by Al2O3 (14.4%), Fe2O3 (10.1%), CaO (8.4%), and MgO (7.4%) that are oxides susceptible to corrosion of biogenic acids. The EDS analysis of the hyphae provided the direct evidence on the leaching of the minerals of the sculptures. To control microbial attack, three kinds of antimicrobial agents were tested for 2 years. As a result, the mixture of biocide and water repellent showed the best effectiveness. Our findings provide an overview of fungi diversity in the biofilms on the stone dogs and help the investigation of fungi-induced biodeterioration and the exploration of specific conservation measure. [ABSTRACT FROM AUTHOR]

The Thannhauser Collection of the Solomon R. Guggenheim Museum, New York, represents an important survey of European avant-garde art production during the late 19th and early 20th centuries. Among the works included in this collection are three paintings by Vincent van Gogh, namely Roadway with Underpass (1887), Landscape with Snow (1888), and Mountains at Saint-Rémy (1889). These examples each exhibit some degree of surface alteration, including fading of specific pigments and, in one case, a non-original, discolored varnish, resulting in obscured color and spatial relationships, as well as being the subject of questions regarding authenticity in the case of the two earlier pictures. Initial examination involved documentation of the brushwork, paint quality, and distribution of colors under magnification. Infrared (IR) and ultraviolet (UV) photography, as well as X-radiography, provided additional information on the surface coatings, the structure of the works, and their supports. Subsequently, an in-depth scientific investigation of the ground and paint layers, with a special focus on fading colors and altered surfaces, was carried out non-invasively with point and macro-X-ray fluorescence (XRF) spectroscopy, visible reflection spectroscopy, and multi-channel visible spectrum four-light imaging, followed by the analysis of cross sections and dispersed pigment samples by means of optical microscopy, transmission Fourier-transform infrared (FTIR) and Raman spectroscopies, and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS), as well as high-performance liquid chromatography with photodiode array detection (HPLC-PDA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Results indicated that both the brushwork and artist's palette of all three paintings are consistent with data previously reported for other Van Gogh works and with pigments described in the artist's letters to his friends and his brother Theo. Most notably, evidence of biodeterioration and paint alteration phenomena was found on Roadway with Underpass, while specific pigments such as eosin red—historically sold as geranium lake—were detected in areas of Landscape with Snow and Mountains at Saint-Rémy that display severe fading. In addition to assisting the development of a suitable plan for the conservation of the 1887 painting, this study traces the progression of Van Gogh's practice over three years critical to his artistic development, discusses the historical context in which each masterpiece was created, identifies the range of materials and techniques used, and addresses authenticity questions by providing a comparison with results of scientific analysis from other similar works. [ABSTRACT FROM AUTHOR]

Principles of a rapid method for monitoring biodeterioration of technical fluids were developed with metalworking fluids as examples. Physicochemical and operation properties of spent metalworking fluids were considered. The loss of the biological resistance of metalworking fluids leads to irreversible changes in the physicochemical and operation properties. A bank of test microorganisms required for validating the rapid method for monitoring biodeterioration was compiled. [ABSTRACT FROM AUTHOR]

Organotin compounds are applied in several industrial reactions and can present antifungal and antibacterial activities. Incorrect handling and storage practices of biodiesel and diesel–biodiesel blends can lead to microbial development, impacting its final quality. Concerning this problem, this work investigated the antimicrobial action of two organotin catalysts used in biodiesel production with four isolated microroorganisms (Bacillus pumilus, Pseudomonas aeruginosa, Pseudallescheria boydii, and Aureobasidium pullulans) and a pool of microorganisms (ASTM E1259 standard practice). Samples of soybean biodiesel with different concentrations of dibutyl tin dilaurate (catalyst 1) and di-n-butyl-oxo-stannane (catalyst 2) were prepared and added of mineral medium. The pool of microorganisms was inoculated and incubated at 30 °C and final biomass was weighted after 14 days. Thereafter, soybean biodiesel with catalyst 2 was used. Fungal biomass was weighted, and plate count was used to assess bacterial growth. Results show that catalysts 1 and 2 presented no inhibitory activity on the pool of microorganisms evaluated. A slight inhibitory activity was observed for B. pumilus and A. pullulans growth, but not for P. boydii, P. aeruginosa, or the pool of microorganisms. All experiment exhibited acidification higher than sterile control. Infrared analysis show less microbiological degradation products in the tin-protected fuel with ASTM inoculum. These results suggest that these tin-based catalysts show no toxic effect on native microbial population and a slight effect on some isolated microbial population in laboratory scale and for the first time shows that these organotin compounds can be employed safely as biodiesel catalyst. [ABSTRACT FROM AUTHOR]

Cultural property preserved in indoor environments is subjected to fungal deterioration which resulted from air biocontamination and can lead to a heavy cultural loss. This study aimed to monitor and assess the biodiversity and concentration of airborne fungi for all areas of the Grand Egyptian Museum—Conservation Center (GEM-CC), such as conservation laboratories, scientific laboratories, corridors, storerooms, and outside in each season during 2013 using the air sampler machine. Results of the quantitative analysis of fungal aerosol demonstrated that the air quality level in GEM-CC was generally acceptable, though some areas showed deviation from the threshold limit value of the GEM-CC (200 CFU m−3). Also, the fungal load in all storerooms was lower than inside the laboratories. Quantitative analysis revealed that 22 fungal species were isolated and identified. The genus Penicillium appeared with high relative distribution (42.6%), followed by Cladosporium and Aspergillus. In vitro study revealed the effectiveness of ethanol with 70% concentration, against the most common airborne fungus: Aspergillus flavus. However, the concentration rose to 95% when applying in vivo. Finally, we suppose that weekly spraying the GEM-CC environment with 95% ethanol is a protective measure for both our valuable artifacts and staff health. [ABSTRACT FROM AUTHOR]

A method based on the use of electromagnetic radiation (EMR) in the radiofrequency band was experimented to eliminate heterotrophic organisms from biofilms encrusting linen canvasses used for paintings. Artificial biofilms were used for exposure to EMR. Biofilms were grown on fragments of canvasses sampled from the backside of a painting. The fragments, after sterilization, were inoculated with several heterotrophic microorganisms previously isolated from other canvasses used for paintings and identified by molecular analyses as the bacteria Bacillus mycoides and Bacillus subtilis, and the microfungi Aspergillus versicolor, Cladosporium cladosporioides, Cladosporium oxysporum and Fusarium oxysporum. The newly formed biofilms resulted to contain the same microorganisms used for the inocula. They were exposed to EMR obtained by an amplitude-modulating radiofrequency sine wave with a train of rectangular pulses with 200 ns repetition time and 10% duty cycle. The exposure protocol consisted of three applications of two hours each, every other day. Denaturing gradient gel electrophoresis analyses carried out on the EMR-treated biofilms showed that all the microorganisms disappeared after the third application. The amplitude of the adopted EMR was not high enough to cause any significant increase in the temperature of the substrates. Therefore, the methodology showed to be non-invasive for the artefacts and its exposure levels not hazardous for operators and the environment compared to other techniques adopted in the field of conservation of cultural heritage. Among the latter techniques, the most common one is based on the use of biocides that, although effective, present problems in all the above-described areas. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The present research was conducted to assess the role of aeromycoflora around world heritage sites of Taxila and its relation with biodeterioration of stone monuments. The aerial mycoflora of six archaeological sites was recorded for one year to monitor the seasonal variations and transportation of fungal spores. Thirty-two fungal species belonging to twenty genera were isolated throughout the whole sampling period. The fungal genera Alternaria, Aspergillus, Cladosporium, Fusarium, Mucor, Helminthosporium, Curvularia and Penicillium were prevalent, whereas at species level Alternaria alternata was dominant followed by Aspergillus niger, Cladosporium herbarum, Penicillium chrysogenum and Fusarium oxysporum. A well-marked qualitative and quantitative seasonal variation in aeromycoflora of selected sites was recorded. Some fungal species showed restricted occurrence to a specific archaeological site of Taxila. The comparative study of aerial and surface mycoflora revealed that dominant aerial fungal species were involved in biodeterioration of monuments. The chemical composition of fungal patinas and biofilm was also carried out, and it was found that calcite, gypsum and calcium oxalate were the main minerals detected by X-ray diffraction technique. The dominant fungal species were also determined for their ability to produce organic acids in broth medium. The fungal species produce a significant amount of citric acid, acetic acid, oxalic acid, fumaric acid and gluconic acid. The different surface alterations of archaeological monuments of Taxila are due to the metabolic activities of fungal species growing on it. The present study is the first investigation about microbial decay of stone monuments of Taxila, and the results of this study will help to make a strategy for prevention of further biodeterioration of these monuments. [ABSTRACT FROM AUTHOR]

This article discusses the concept of biodeterioration of polymeric composite materials. The main criteria for assessing the biostability of materials and a review of methods for their determination are given. The results of experimental studies of the biostability of composites based on epoxy polymers with various compositions and the biostability of several types of fillers by the soil method are presented. Starch was used as an organic filler, and graphite and aluminum powder were used as inorganic fillers. It is shown that a significant decrease in the biostability is determined not only by the presence of starch as a filler in the composite, but also by the composition of the epoxy polymer. [ABSTRACT FROM AUTHOR]