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Cyanobacteria (blue-green algae) are a highly adaptable and widely-distributed group of prokaryotic organisms, which grow and survive in various terrestrial and aquatic habitats. As epiliths or epilithobionts, many cyanobacteria successfully colonize and grow on exposed surfaces of lithic (stone-built) temples, monuments and buildings, where they encounter frequent desiccation (water-deficit stress) and other abiotic stresses. They comprise major and dominant component of sub-aerial biofilms or crusts on exposed lithic surfaces, and are implicated in unaesthetic discoloration and biodeterioration of temples, monuments and heritage structures. The present study focuses on the occurrence and accumulation of intracellular free proline, a proteinogenic amino acid involved in desiccation/drought tolerance in a wide range of organisms, in cyanobacteriadominated crusts/biofilms (cyanobacterial crusts) sampled from 11 lithic temples located in the Garhwal region of Uttarakhand. The analysis of species composition of the crusts/biofilms showed high cyanobacterial species richness comprising, in total, 22 species of 17 different genera. Proline, in the range 11- 27 µg/g crust biomass, occurred in all the cyanobacterial crust samples when estimated following their hydration for 24 hours. When the hydrated crusts were subjected to desiccation (water-deficit stress) for 24 hours, there was 48% to 77 % increase in intracellular proline content. This study provides insights in to the physiological response of crust-forming epilithic cyanobacteria to desiccation stress, which they face during their growth and survival on exposed lithic surfaces, as well as in to their eco-physiological adaptation. [ABSTRACT FROM AUTHOR]

Colonization and growth of cyanobacteria on exposed surfaces of stone-made temples and monuments result in their biodeterioration in form of both aesthetic and structural damage. This study investigates the epilithic cyanobacterial colonization of exteriors of 11 different ancient stone temples, showing varying degree of deterioration, located in Garhwal region of Uttarakhand. Cyanobacteria-dominated biofilms/ crusts occurring on the exteriors of the temples were sampled and analyzed. The intensity of cyanobacterial colonization of temples, as assessed by quantifying the chlorophyll a (Chl a) content of biomass of phototrophic biofilms/crusts developed on wall surfaces of temples, ranged from 6.8 µg Chl a cm-2 to 14.5 µg Chl a cm-2. A total of 22 epilithic cyanobacterial species (17 genera) representing unicellular, colonial and filamentous (heterocystous and non-heterocystous) forms were isolated from epilithic biofilms/crusts and identified. The results showed that epilithic cyanobacteria dwelling on investigated temples have ample diversity.Among the recorded taxa, the commonly occurring and widely distributed taxa with percentage occurrence of 50% and above comprised Asterocapsa sp., Gloeocapsaatrata, Gloeocapsa sp., Phormidium sp. and Scytonema ocellatum. [ABSTRACT FROM AUTHOR]

With an impressive ability to survive in harsh environments, black fungi are an ecological group of melanized fungi that are widely recognized as a major contributor to the biodeterioration of stone cultural heritage materials. As part of the ongoing efforts to study the fungal diversity thriving in a deteriorated limestone funerary art piece at the Lemos Pantheon, a national monument located in Águeda, Portugal, two isolates of an unknown microcolonial black fungus were retrieved. These isolates were thoroughly studied through a comprehensive analysis based on a multi-locus phylogeny of a combined dataset of ITS rDNA, LSU, and rpb2, along with morphological, physiological, and ecological characteristics. Based on the data obtained from this integrative analysis, we propose a new genus, Saxispiralis gen. nov., and a new species, Saxispiralis lemnorum sp. nov., in the recently described Aeminiaceae family (order Mycosphaerellales). Prior to this discovery, this family only had one known genus and species, Aeminium ludgeri, also isolated from deteriorated limestone. Additionally, considering the isolation source of the fungus and to better understand its potential contribution to the overall stone monument biodeterioration, its in vitro biodeteriorative potential was also evaluated. This work represents a significant contribution to the understanding of the fungal diversity involved in the biodeterioration of limestone heritage. [ABSTRACT FROM AUTHOR]

Environmental control strategies are commonly practised to limit biodeterioration issues threatening indoor cultural heritage objects, while they are still poorly exploited for the conservation of outdoor stone heritage surfaces, including rock art. In this study, we evaluated the environmental factors driving the diversity and abundance of lithobiontic communities in the Rock Engravings National Park of Naquane (UNESCO WHS n. 94, Italy). The survey considered 23 rocks that had been cleaned in the last three (3YC) or twelve (12YC) years or more than 40 years ago (NRC). A cyanobacteria-dominated biofilm and lichens (37 taxa) were the most widespread and abundant lithobiontic components, prevailing on 3YC–12YC and NRC rocks, respectively. On the latter, a turnover of xerophytic and meso-hygrophytic lichen communities was observed. On 3YC–12YC rocks lichen colonization, if present, was limited to nitrophytic species, including common epiphytes from surrounding trees and a small number of meso-hygrophytic species, with a prevalence of asexual reproductive strategies. Multivariate analyses including environmental parameters (canonical correspondence analyses) indicated that tree cover and the presence of bare or vegetated ground upstream of the rocks, probably prolonging wetness and providing nutrients by water transport, are the factors mostly related to the microbial and lichen recolonization of 3YC–12YC surfaces. On this basis, an experiment on preventive conservation was conducted, consisting of a new cleaning of a strongly recolonized 3YC surface combined with the building of a small wall to protect part of the rock from prolonged water fluxes. The fluorimetric and colorimetric monitoring of the rock surface, carried out 40 months after this new cleaning intervention, displayed recolonization on the unprotected area only, indicating the potential of preventive conservation strategies in outdoor environments. [ABSTRACT FROM AUTHOR]

Heritage buildings clad with natural rock endure over time destruction caused by weathering mechanisms, pollution from urban areas, biodeterioration due to organisms, microorganisms, and also the anthropic factor. On the surface of the limestone samples taken from the ornamental natural rock with which the outside of Markovits-Mathéser house, Oradea, Romania, is clad, two species of fungi were inoculated in the laboratory: Aspergillus spp. and Cladosporium spp. Wollastonite was then applied, and from the imaging analysis (SEM), the inhibition of fungi by it is clearly observed (48 h after its application), which was also confirmed using the image segmentation method. It was also noted that the hydrophilicity of the aqueous suspension of wollastonite resulted in the absorption of water in the substrate, which in turn resulted in the drying out and surface breakage of the specimens. X-ray diffraction analysis showed the presence of the two phases (calcite and quartz) as in the starting sample, and also an additional phase assigned to wollastonite in the later phase of the experiment. An amorphous component, due to the applied gel composition, was also reported. This research highlights the fact that there are good premises for aqueous suspension of wollastonite to have a biocidal character for Aspegillus spp. and Cladosporium spp., when applied on natural stone used in the construction of heritage buildings located in temperate climates; due to its easy application, green and ecofriendly properties, and also low cost of acquisition and application. [ABSTRACT FROM AUTHOR]

Microbiologically influenced corrosion (MIC) is a phenomenon of increasing concern that affects various materials and sectors of society. MIC describes the effects, often negative, that a material can experience due to the presence of microorganisms. Unfortunately, although several research groups and industrial actors worldwide have already addressed MIC, discussions are fragmented, while information sharing and willingness to reach out to other disciplines are limited. A truly interdisciplinary approach, which would be logical for this material/biology/chemistry-related challenge, is rarely taken. In this review, we highlight critical non-biological aspects of MIC that can sometimes be overlooked by microbiologists working on MIC but are highly relevant for an overall understanding of this phenomenon. Here, we identify gaps, methods, and approaches to help solve MIC-related challenges, with an emphasis on the MIC of metals. We also discuss the application of existing tools and approaches for managing MIC and propose ideas to promote an improved understanding of MIC. Furthermore, we highlight areas where the insights and expertise of microbiologists are needed to help progress this field. [ABSTRACT FROM AUTHOR]

The preservation of natural stone heritage is still a major challenge for the scientific community. This topic assumes a greater importance since it impacts economic and socio-cultural values. Recent research has indicated that water action and microorganism activity are among the major contributors to the deterioration of this material. Despite the emergence of new protective solutions in the market, some constraints still need to be overcome. This study aims to contribute to unveiling the effectiveness of innovative commercial coatings on the preservation of natural stone frequently used in built heritage. Four different commercial coatings are assessed regarding their compatibility with the substrata and effectiveness against UV radiation, water action, and microbial development under accelerated ageing. The protective solutions are tested on five different Portuguese lithotypes, including carbonate and silicate-based stones. Colour change is measured to assess compatibility, while profilometric change of the stones' surface and antimicrobial potential are evaluated to determine their effectiveness. Our research demonstrates that the solution that exhibits the greatest compatibility and effectiveness potential is composed of modified silanes and siloxanes derivatives. [ABSTRACT FROM AUTHOR]

Bioweathering crusts are widely distributed on the limestone sculptures of the Longmen Grottoes, a UNESCO World Heritage Site. However, information on microbial communities in this archaeological site is missing. To fill this gap, we identified bacterial communities involved in the formation of bioweathering crusts. The composition analysis showed that Cyanobacteria, Acidobacteria, Chloroflexi, Actinobacteria, Firmicutes, and Planctomycetota are the major components of the bacterial communities in the crusts. Cyanobacteria might be one of the major contributors to the formation of the crusts. A culture-based analysis indicated the presence of bacterial isolates (e.g., Enterobacter sp. and Bacillus sp.) with a potential role in bioprotection. Moreover, five types of biogenic organic acids were detected in the crusts, implying a consequence of organic acid corrosion. Scanning electron microscopy analysis further confirmed microbial penetration into the stone monuments with a biomechanical attack. Our reports provide a microbiological reference for heritage conservators to treat bioweathering crust. [ABSTRACT FROM AUTHOR]

Environmental factors and climate are the primary factors influencing the microbial colonization and deterioration of cultural heritage in outdoor environments. Hence, it is imperative to investigate seasonal variations in microbial communities and the biodeterioration they cause. This study investigated the surfaces of sandstone sculptures at Wat Umong Suan Phutthatham, Chiang Mai, Thailand, during wet and dry seasons using culture-dependent and culture-independent approaches. The fungi isolated from the sandstone sculptures were assessed for biodeterioration attributes including drought tolerance, acid production, calcium crystal formation, and calcium precipitation. The results show that most of the fungal isolates exhibited significant potential for biodeterioration activities. Furthermore, a culture-independent approach was employed to investigate the fungal communities and assess their diversity, interrelationship, and predicted function. The fungal diversity and the communities varied seasonally. The functional prediction indicated that pathotroph–saprotroph fungi comprised the main fungal guild in the dry season, and pathotroph–saprotroph–symbiotroph fungi comprised the dominant guild in the wet season. Remarkably, a network analysis revealed numerous positive correlations among fungal taxa within each season, suggesting a potential synergy that promotes the biodeterioration of sandstone. These findings offer valuable insights into seasonal variations in fungal communities and their impacts on the biodeterioration of sandstone sculptures. This information can be utilized for monitoring, management, and maintenance strategies aimed at preserving this valuable cultural heritage. [ABSTRACT FROM AUTHOR]

In this work, some micro-samples belonging to the open-air rock art site of Cueva de la Vieja (Alpera, Albacete, Spain) were analysed. These samples were collected after and before a desalination treatment was carried out, with the aim of removing a whitish layer of concretion that affected the painted panel. The diagnostic study was performed to study the conservation state of the panel, and to then confirm the effectiveness of the treatment. Micro energy dispersive X-ray fluorescence spectrometry, Raman spectroscopy, and X-ray diffraction were employed for the characterization of the degradation product as well as that of the mineral substrate and pigments. The micro-samples analysis demonstrated that the painted layer was settled on a dolomitic limestone with silicon aggregates and aluminosilicates as well as iron oxides. The whitish crust was composed by sulfate compounds such as gypsum (CaSO4·2H2O) with a minor amount of epsomite (MgSO4·7H2O). An extensive phenomenon of biological activity has been demonstrated since then in almost all of the samples that have been analysed, and the presence of calcium oxalates monohydrate (CaC2O4·H2O) and dehydrate (CaC2O4·2H2O) were found. The presence of both calcium oxalates probably favoured the conservation of the pictographs. In addition, some carotenoids pigments, scytonemin (C36H20N2O4), and astaxanthin (C40H52O4) were characterized both by Raman spectroscopy and by X-ray diffraction. Hematite was found as a pigment voluntarily used for the painting of the panels used in a mixture with hydroxyapatite and amorphous carbon. The results of the analyses of the samples taken after the cleaning treatment confirmed a substantial decrease in sulphate formation on the panel surface. [ABSTRACT FROM AUTHOR]

Abstract Purpose Maritime cultural relics from the Nanhai No. 1 shipwreck were immersed in a buffer to maintain stability. To better monitor the changes in the composition of microorganisms in the buffer and, thus, prevent the damage to artifacts caused by harmful microorganisms. Methods In September and November 2019, we conducted high-throughput sequencing of water samples from four types of maritime cultural relics (ironware, porcelain, axe, and hull wood) to reveal the composition and changes in microbial communities. In addition, we isolated culturable microorganisms and conducted biocide sensitivity tests and lignin and cellulose degradation tests. Results Visible microbial colonization was observed in the water samples collected from the buffer solutions of ironware, porcelain, axe, and hull wood of the Nanhai No. 1 shipwreck; additionally, apparent differences in the composition of microorganisms in the water samples collected from different cultural relics and different collection times of the same cultural relics were noted. Few species of bacteria and fungi from the microbial community observed in the maritime cultural relics were cultured, and it was noted that various biocides had certain inhibitory effects on them. Some dominant strains had lignin and cellulose degradation abilities and could only grow under specific environmental conditions. Conclusion We found apparent differences in the composition of microorganisms obtained from different cultural relics and different collection times of the same cultural relics. This study can provide data support for better protection of maritime cultural relics obtained from the Nanhai No. 1 shipwreck and provide a theoretical basis for the biological protection of other maritime cultural relics.

[Ar] النشاط الحيوى وضد الفطرى للتريكوديرما فى التراث الثقافى للصور الجدارية فى مقبرة مصرية قديمة لقد تم عزل أجناس فطر التريكوديرما Trichoderma sppمن أسطح الصور الجدارية بمقبرة «نفر-باو-بتاح». لقد تعرضت هذه المقبرة سابقاً فيىعام 2007 لهجوم ميكروبى مُتمثل فى A. niger و A. flavus وAlternaria alternataفى عام 2019 تم عزل فطر الاسبرجلس نيجر فقط، بالاضافة إلى عزل أنواع من فطر التريكوديرما والتى لم يتم عزلها من قبل خلال عام 2007. لقد تم تحديد ثلاثة أجناس من فطر التريكوديرما وفقًا لتأثيرها الحيوى على A.nigerو A flavusو A. alternataومن خلال تسلسلها فىGenBank إلى Trichoderma harzianum و T. hamatumوT. aureoviride.. ولقد تم تحليل اللوحات الجدارية فى حجرة الدفن بتقنية تحليل EDX الذى أظهر أن الطبقة الأرضية تتكون من الكوارتز والكالسيت والجبس، بينما أظهر تحليل المواد الملونة إستخدام الألوان المُتمثلة فى الأخضر المصرى والأزرق المصري والهيماتيت. ولقد أثبت تحليل الرامان أن الوسيط اللوني المُستخدم كان بمثابة وسيط صفار البيض. لقد تم قياس المواد الملونة باستخدام جهاز السبيكتروفتوميتر مرتين: الأولى خلال عام 2007م والثانية بعد نمو Trichoderma خلال عام 2019. ولقد أظهرت النتائج أن عملية التمثيل الغذائي خارج الخلية لفطر التريكوديرما اثر على اللون الأزرق المصري والأخضر المصري وتجدر الإشارة إلى أن نتائج التحليل قد أظهرت قدرة فطر التريكوديرما على تثبيط نمو A.niger وA.flavus وAlternaria alternata ، والتى تم العثور عليها سابقًا خلال عام 2007م. ولقد تم تحديد العوامل القياسية لتعزيز نمو فطر التريكوديرما،حيث أظهرت النتائج أن 5٪ من NaCl: NaNO3 (1: 1) كان بمثابة أفضل تركيز للنشاط المضاد للفطريات لجميع أنواع Trichoderma عند درجة الحرارة الواقعة بين 30و 35 درجة مئوية في وسط حمضي. تجدر الإشارة إلى أن عملية الحفظ الحيوي للتراث الثقافى مازالت قليلة الاستخدام فى نطاق الشرق الأوسط، وهى تعتبر منهجية علمية وتقنية علاج صديقة للبيئة، وذلك مع الأخذ فى الإعتبار للمخاطر التى تُسبب التغير اللوني، بالإضافة إلى كونها تقنية سهلة التطبيق، حيث يُمكن تطبيقها في نطاق الحيز المكاني والبيئات المفتوحة أو في نطاق المتاحف. [En] Trichoderma spp. was isolated from the mural paintings’ surfaces of the tomb of Nefer-Bau-Betah. This tomb was previously deteriorated in 2007 by Aspergillus niger, A. flavus, and Alternaria alternata but in 2019, the tomb was deteriorated by only A.niger, and Trichoderma species that had not been isolated before in 2007. Three species of Trichoderma were identified according to their bioactivity effect on these microorganisms and by their sequences in the GenBank to Trichoderma harzianum, T. hamatum, and T. aureoviride. Furthermore, mural paintings in the burial chamber were characterized by EDX analysis which indicated that the ground layer consisted of Quartz, Calcite and Gypsum, while the pigments were characterized as Egyptian green, Egyptian blue, and hematite (Fe2O3). The binding media was egg yolk according to the spectrum of Raman spectroscopy. The pigments were assayed by the spectrophotometer but it caused a little effect in the color change of the pigment inside the tomb especially the blue and green Egyptian pigments, while it caused less effect in the color change of red hematite pigment. The optimization factors for increasing the bioactivity of the Trichoderma spp. were 5% of sodium nitrate and sodium chlorine that crystallize in the tomb, where the average temperature is between 30:35°C in acidic pH (pH=5.5). These conditions helped Trichoderma species to grow and work as antifungal factors in the tomb A. niger, A. flavus, and Alternaria alternata. Trichoderma spp < /em>. can be used as a new methodology for controlling the deterioration of cultural heritage. It is an eco-friendly methodology, risk-free when controlling the color change, and easy to apply anywhere in vivo or vitro in cultural heritage found in open air or in the museums.

One of the most significant monuments of the Roman Danube Limes is Trajan’s Bridge, built in the period from 103 to 105 AD. The remains of the pillars on the Serbian bank of the Danube were partially restored four decades ago. Today, the pillar that is closest to the river, which has not undergone conservation, is subject to different types of deterioration. During the comparison between the present condition of the pillar and those recorded in photos over the last six decades, we can estimate that its level of material loss has not overly changed. However, the difference in biological growth is visible. The primary aim of this study was to record the degree of infestation and endangerment of the monument and check for possible risks of mortar deterioration where mortar is in direct contact with severely infested bricks. Moreover, a characterisation of the biodeteriogens was performed. Special emphasis was given to fungi as the main agents of deterioration. A precise assessment of the level of risk they pose to this monument was made as a basis for the formulation and implementation of appropriate conservation treatments. Severe macrofouling by epilithic lichenised fungi and mosses was documented. Even areas where pillars lack visible infestation, thriving microbial communities characterized by the presence of various fungal structures, as well as structures of trichal Cyanobacteria, and Chlorophyta were recorded. Similarities between communities documented on brick, mortar, and stone surfaces, estimated via Sørensen’s quotient of similarity, were high, with the highest similarity documented between mortar and stone.

Abstract 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.

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.

Thermo-mechanical densification modifies wood to produce a more dense and resistant lignocellulosic material and may degrade extractives that contribute to the increased susceptibility of wood to attack by xylophagous organisms. This study evaluated the efficiency of tannin extracts of Acacia mearnsii in the treatment of thermo-mechanical densified pine wood in relation to physical, mechanical, and biological resistance (Cryptotermes brevis) properties. Pinus elliottii samples were pretreated with oxalic acid in a Parr reactor, then treated by diffusion in tannin solutions at concentrations 5, 10, and 15%, and finally hot pressed. The apparent density of the modified wood was 87.8% greater than that of the in natura wood (control) with tannins at 15%. The mechanical strength increased, especially the parallel compressive strength, which had an average increase of 169% for the wood with tannins at 10 and 15%, compared with the in natura wood. There was an increase in termite mortality and a reduction in damage for the modified wood treated with 15% tannins, obtaining the best results in mechanical and biological resistance and for the physical parameters. Thermal densification pine wood and preserved with tannin extractives proved to be a potential alternative as a high performance material.

The present research investigated bio-based construction material based on hemp shives and gypsum. Low-density material was developed with densities of 200, 300, and 400 kg/m3. Simple yet robust production technology was used. For the first time, a binder for biocomposites obtained from phosphogypsum was used and properties were compared to commercial gypsum. CO2 negative building material was developed with up to 92 kg CO2 ekv./m3 entrapped. Both physical and mechanical properties were studied. Thermal conductivity was in the range from 0.058 to 0.101 W/(m·K) and compressive strength from 0.10 to 0.57 MPa. Biodeterioration test results showed that the pH of 5.60–6.55 for biocomposites promoted a rapid mold growth. Mold growth was slightly lower for composites with higher gypsum content, while phosphogypsum induced more rapid mold growth. Cladosporium, Rhizopus, Chaetomium, and other molds were observed on samples even at an early stage of testing giving a serious concern about only limited application in dry conditions for such gypsum-based biocomposite.

Introduction: Biodeterioration is a big challenge for the preservation of cultural heritage objects and for the community’s safety, fostering the search for novel methods effective in removing microbial biofilms and subsequent biodeterioration. In this context, nanoparticles (NPs) are considered an interesting alternative, based on their unique physico-chemical and biological properties.Methods: The present study aimed to evaluate the antimicrobial efficiency of Ag, Au, Cu, and ZnO NPs against a significant number of filamentous fungi and bacterial strains isolated from wooden and stone cultural heritage objects from different Romanian regions, as well as from museum collections, with the final goal to establish their potential to develop novel preservation strategies, which have high efficiency and low ecotoxicity.Results: Six types of nanoparticles (NPs) based on Ag, Au, Cu, and ZnO were synthesized and characterized for their physico-chemical properties, ecotoxicity, and efficacy against 75 filamentous fungi and 17 bacterial strains isolated from wooden and stone cultural heritage objects (15th–19th century). The results showed that all synthetized NPs are homogeneous, demonstrating a good stabilizing coating, and have spherical or triangular shapes, with sizes between 9 and 25 nm. The highest antifungal efficiency has been recorded for Ag NPs, followed by Cu NPs and ZnO NPs, with the most susceptible strains being Aspergillus montevidensis, Penicillium commune, Penicillium corylophilum, Bacillus megaterium, and B. cereus. The Cu NPs and ZnO NPs decreased the capacity of microbial strains to adhere to the inert substratum. The influence of the tested NPs against enzyme/organic acid production varied depending on the NP types and by species.Conclusion: The obtained results are promising for the development of efficient and economical alternative solutions for heritage preservation, showing high antimicrobial activity against the prevalent fungal and bacterial strains involved in the biodeterioration of Romanian heritage objects.

Simple Summary: The main challenge in libraries, archives, and museums is the fungal deterioration of historical manuscripts (paper and leather), and an eco-friendly approach can be used to reduce or stop biodeterioration. Therefore, the current study examines the green synthesis of titanium oxide nanoparticles (TiO2-NPs) using a green method to inhibit the growth of fungal strains isolated from deteriorated historical manuscripts. Fifteen fungal strains were involved in the deterioration of historical manuscripts dating back to the 16th century that were identified by traditional and molecular identification. In addition, their potential in biodeterioration was investigated by hydrolytic enzymatic activities. TiO2-NPs were synthesized using a probiotic bacterial extract as a safe method and characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), and Fourier-transform infrared (FT-IR). The safe concentration of synthesized TiO2-NPs that was used as a coating agent for leather to inhibit fungal growth was detected via the investigation of in vitro cytotoxicity against two normal cell lines (skin and lung). The experimental study showed that the leather without NP treatment and inoculated with the most potent fungal strain exhibited high deterioration compared with those coated with NPs and inoculated with fungal strain. The main hypothesis of the present research is investigating the efficacy of titanium oxide nanoparticles (TiO2-NPs) to prevent the growth of fungal strains when applied on leather under an experimental study. Therefore, fifteen fungal strains were isolated from a deteriorated historical manuscript (papers and leathers) and identified by traditional methods and ITS sequence analysis, including Aspergillus chevalieri (one isolate), A. nidulans (two strains), A. flavus (four strains), A. cristatus (one strain), A. niger (one strain), Paecilomyces fulvus (two strains), Penicillium expansum (two strains), and P. citrinum (two strains). The enzymes cellulase, amylase, pectinase, and gelatinase, which play a crucial role in biodegradation, were highly active in these fungal strains. TiO2-NPs were formed using the cell-free filtrate of the probiotic bacterial strain, Lactobacillus plantarum, and characterized. Data showed that the TiO2-NPs were successfully formed with a spherical shape and anatase phase with sizes of 2–8 nm. Moreover, the EDX analysis revealed that the Ti and O ions occupied the main component with weight percentages of 41.66 and 31.76%, respectively. The in vitro cytotoxicity of TiO2-NPs toward two normal cell lines, WI38 and HFB4, showed a low toxicity effect against normal cells (IC50 = 114.1 ± 8.1µg mL−1 for Wi38, and 237.5 ± 3.5µg mL−1 for HFB4). Therefore, concentrations of 100 μg mL−1 were used to load on prepared leather samples before inoculation with fungal strain P. expansum AL1. The experimental study revealed that the loaded TiO2-NPs have the efficacy to inhibit fungal growth with percentages of 73.2 ± 2.5%, 84.2 ± 1.8%, and 88.8 ± 0.6% after 7, 14, and 21 days, respectively. Also, the analyses including SEM, FTIR-ART, color change, and mechanical properties for leather inoculated with fungal strain AL1 in the absence of NPs showed high damage aspects compared to those inoculated with fungal strains in the presence of TiO2-NPs. [ABSTRACT FROM AUTHOR]

Controlling biodeterioration is a worldwide necessity for the preservation of cultural heritage. Biocides are the most effective compounds used for heritage protection of stone; however, their specific efficacy, performance over time, interference with cultural heritage materials, and potential hazards are still unclear. In this work, we test and evaluate a large number of biocides to address the degradation of stone cultural relics by mosses. The quantitative and qualitative evaluations of biocide efficiency were performed by chlorophyll fluorescence (ChlaF) measurements and confocal microscopy. Surprisingly, traditional herbicides (glyphosate, glufosinate-ammonium) and metal oxide nanoparticles (CuO, ZnO) with antibacterial effects do not affect mosses. However, some plant hormones and essential oils showed good effects at all stages of moss growth. Meanwhile, biocides were also tested on artificial simulated rocks to see if they change their properties. It turns out that biocides containing copper ions can cause chromaticity changes on the rock surfaces. In the end, a total of six efficient and safe biocides were obtained, which will play a good role in biological control for cultural heritage protection. [ABSTRACT FROM AUTHOR]

Introduction: Microorganisms, including the pioneer microorganisms that play a role in the early colonization of rock, are extremely important biological factors in rock deterioration. The interaction of microorganisms with limestone leads to biodeterioration, accelerates soil formation, and plays an important role in the restoration of degraded ecosystems that cannot be ignored. However, the process of microbial colonization of sterile limestone in the early stages of ecological succession is unclear, as are the factors that affect the colonization. Acid erosion (both organic and inorganic), nutrient availability, and water availability are thought to be key factors affecting the colonization of lithobiontic microorganisms. Methods: In this study, organic acid (Oa), inorganic acid (Ia), inorganic acid + nutrient solution (Ia + Nut), nutrient solution (Nut), and rain shade (RS) treatments were applied to sterilized limestone, and the interaction between microorganisms and limestone was investigated using high-throughput sequencing techniques to assess the microorganisms on the limestone after 60 days of natural placement. Results: The results were as follows: (1) The abundance of fungi was higher than that of bacteria in the early colonization of limestone, and the dominant bacterial phyla were Proteobacteria, Bacteroidota, and Actinobacteriota, while the dominant fungal phyla were Ascomycota, Basidiomycota, and Chytridiomycota. (2) Acid erosion and nutrient availability shaped different microbial communities in different ways, with bacteria being more sensitive to the environmental stresses than fungi, and the higher the acidity (Ia and Oa)/nutrient concentration, the greater the differences in microbial communities compared to the control (based on principal coordinate analysis). (3) Fungal communities were highly resistant to environmental stress and competitive, while bacterial communities were highly resilient to environmental stress and stable. Discussion: In conclusion, our results indicate that limestone exhibits high bioreceptivity and can be rapidly colonized by microorganisms within 60 days in its natural environment, and both nutrient availability and acid erosion of limestone are important determinants of early microbial colonization. [ABSTRACT FROM AUTHOR]

Besides plants and animals, the Fungi kingdom describes several species characterized by various forms and applications. They can be found in all habitats and play an essential role in the excellent functioning of the ecosystem, for example, as decomposers of plant material for the cycling of carbon and nutrients or as symbionts of plants. Furthermore, fungi have been used in many sectors for centuries, from producing food, beverages, and medications. Recently, they have gained significant recognition for protecting the environment, agriculture, and several industrial applications. The current article intends to review the beneficial roles of fungi used for a vast range of applications, such as the production of several enzymes and pigments, applications regarding food and pharmaceutical industries, the environment, and research domains, as well as the negative impacts of fungi (secondary metabolites production, etiological agents of diseases in plants, animals, and humans, as well as deteriogenic agents). [ABSTRACT FROM AUTHOR]

Nowadays, sustainable and biodegradable bioplastics are gaining significant attention due to resource depletion and plastic pollution. An increasing number of environmentally friendly plastics are being introduced to the market with the aim of addressing these concerns. However, many final products still contain additives or mix non-biodegradable polymers to ensure minimum performance, which often undermines their ecological footprint. Moreover, there is a lack of knowledge about all stages of biodegradation and their accuracy in classifying products as biodegradable. Therefore, this review provides an overview of biodegradable polymers, elucidating the steps and mechanisms of polymer biodegradation. We also caution readers about the growing marketing practice of "greenwashing" where companies or organizations adopt green marketing strategies to label products with more environmental benefits than they have. Furthermore, we present the main standards for evaluating biodegradation, tools, and tests capable of measuring the biodegradation process. Finally, we suggest strategies and perspectives involving concepts of recycling and the circularity of polymers to make them more environmentally friendly and sustainable. After all, "throwing away" plastics should not be an option because there is no outside when there is only one planet. [ABSTRACT FROM AUTHOR]

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. [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]

Copyright of Revista de Arqueologia is the property of Revista de Arqueologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study explores the application of natural biocides (oregano essential oil and eugenol, directly applied in solutions or encapsulated within silica nanocapsules) for safeguarding stone cultural heritage from biodeterioration, using green algae (Chlorococcum sp.) and cyanobacteria (Leptolyngbya sp.) as common pioneer biodeteriogens. Core-shell nanocontainers were built for a controlled release of microbicidal agents, a safe application of chemicals and a prolonged efficacy. The qualitative and quantitative evaluations of biocide efficiency at different doses were periodically performed in vitro, after six scheduled intervals of time (until 100 days). The release kinetics of composite biocide-embedding silica nanocapsules were characterized by the UV-Vis spectroscopy technique. Data showed both promising potential and some limitations. The comparative tests of different biocidal systems shed light on their variable efficacy against microorganisms, highlighting how encapsulation influences the release dynamics and the overall effectiveness. Both the essential oils showed a potential efficacy in protective antifouling coatings for stone artifacts. Ensuring compatibility with materials, understanding their differences in biocidal activity and their release rates becomes essential in tailoring gel, microemulsion or coating products for direct on-site application.

Abstract 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. Graphical Abstract

ABSTRACT 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.

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.

Cyanobacteria or blue algae are ubiquitously present in both fresh and brackish water environments. They also grow in conditions of high humidity, colonizing stones or monuments and fountain surfaces, and creating thick biofilms able to induce biodeterioration in the constituent materials of artefacts. As well as several photoautotrophic organisms, cyanobacteria belong to the microorganisms identified as primary colonizers, playing an important role in stone artwork deterioration. In this study, an analysis was made of the biofilm collected from the stone fountain of the Two Dragons in Palermo (Italy), revealing the presence of cyanobacterial colonies by optical microscopy, due to their peculiar auto-fluorescence. Furthermore, molecular investigations by qPCR (quantitative Polymerase Chain Reaction) were utilized to gather quantitative information, and phylogenetics analysis was used to confirm the Thioredox- in reductase (TrxR) gene as a suitable molecular marker. The results highlight the presence of cyanobacteria as the main taxa, whose growth is induced by microclimatic and environmental conditions, and by the physical characteristics of the stone surface. Identification of microbial populations living on stone artworks is the starting point for successful control and conservation strategies, which can help to define the correct protocols to block cellular activity and to find appropriate methods for removing biofilm, as well as counteracting possible recolonization.

Two tombs of the Southern Tang Dynasty (Qinling Tomb and Shunling Tomb), the most important cultural heritages in China, were built for emperors 1000 years ago and decorated with murals and stone sculptures. After their excavation in the 1950s, it was found that drastic fluctuations in the environment within the tombs had caused multiple diseases, such as salt efflorescence, powdering, and biodeterioration, which led to irreversible damage to the murals. This research comprised long-term (yearly) environmental monitoring and short-term (monthly) investigation into the distribution of salt crystallization and microbial growth within the two tombs. The objective was to unveil the relationship between the temporal and spatial distributions of the mural diseases and environmental characteristics while proposing a promising environmental regulation strategy for relic conservation. The results showed a gradual reduction in temperature fluctuation from the entrance to the back chamber and a distinct vertical stratification in relative humidity. The relative humidity in the upper areas of the tombs reached 100% during summer, while it averaged around 40–50% in the lower areas during winter. Consequently, significant condensation was observed on the ceiling in summer, whereas salt crystallization occurred on the murals in the lower space in winter. The distribution of these diseases was influenced by the airflow exchange between the interior and exterior. Furthermore, the structural disparities between the two tombs contributed to higher relative humidity and greater microorganism coverage in the Shunling Tomb compared to the Qinling Tomb. From the abovementioned findings, we suggest that microclimate control is essential for mitigating mural deterioration and should be paid more attention in the future.

A large percentage of the world’s tangible cultural heritage is made from stone; thus, it deteriorates due to physical, chemical, and/or biological factors. The current study explored the microbial community inhabiting two prehistoric sites with high cultural value in the Memphis necropolis of Egypt (Djoser and Lahun Pyramids) using amplicon-based metabarcoding and culture-dependent isolation methods. Samples were examined by epifluorescent microscopy for biological signs before environmental DNA extraction and in vitro cultivation. The metabarcoding analysis identified 644 bacterial species (452 genera) using the 16S rRNA and 204 fungal species (146 genera) using ITS. In comparison with the isolation approach, an additional 28 bacterial species (13 genera) and 34 fungal species (20 genera) were identified. A total of 19 bacterial and 16 fungal species were exclusively culture-dependent, while 92 bacterial and 122 fungal species were culture-independent. The most abundant stone-inhabiting bacteria in the current study were Blastococcus aggregatus, Blastococcus saxobsidens, and Blastococcus sp., among others. The most abundant rock-inhabiting fungi were Knufia karalitana and Pseudotaeniolina globosa, besides abundant unknown Sporormiaceae species. Based on previous reports, microorganisms associated with biodeterioration were detected on color-altered sites at both pyramids. These microorganisms are potentially dangerous as physical and chemical deterioration factors and require proper conservation plans from a microbiological perspective.

Bryophyte colonization on selected monuments of Champaner Pavagadh UNESCO World Heritage site was investigated. A total of seventeen bryophytes including nine liverworts, six mosses and two hornworts, causing degradation of the monuments, were recorded. The geological substrate was studied by a thin section of substratum and Powder X-Ray Diffraction analysis. Microscopic images of the thin section of geological substrate of the samples showed the presence of quartz, ferruginous materials, calcareous materials, orthoclase and plagioclase feldspar minerals. The XRD analysis spectra revealed the presence of different minerals such as aluminosilicate, calcite, muscovite, hematite, magnetite, orthoclase and plagioclase feldspar. The geological investigation showed that selected monuments are composed of the most calcareous materials. Hence, calcium uptake by Asterella wallichiana (Lehm. & Lindenb.) Grolle and Hyophila involuta (Hook.) A.Jaeger from the substratum was studied using a flame photometer. Maximum calcium uptake (i.e., 52 µg/mg) was obtained for plant samples of Asterella wallichiana compared to Hyophila involuta (i.e., 36 µg/mg). Bryophyte colonization on monuments was initiated by humus formation, followed by the protonema stage, mature gametophyte and rhizoids penetration into crevices as well as porous surfaces, forming cracks and degrading structures. This deterioration mechanism due to bryophyte colonization is explained by pictorial representation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Biological degradation of documentary heritage is a serious issue faced by libraries, museums and archives as it can lead to paper becoming brittle, fragile and discoloured, resulting in a loss of information. This study investigates the impact of didecyldimethylammonium bromide (DDAB) on the properties of pure or inked paper and the growth of different types of fungi. Three fungi species known for their ability to cause paper biodete-rioration in libraries and museums, Aspergillus clavatus Desm, Penicil-lium paneum Frisvald and Ulocladium chartarum Preuss, were selected for the DDAB salt antifungal activity test. The study measured the pH and degree of polymerization (DP), monitored colour changes and conducted scanning electron microscopy analyses (SEM) to confirm that DDAB can be used as a biocide for fungi on pure or inked paper. The study also investigated the antifungal effect of DDAB on paper treated with different types of ink, including black (iron-gall ink) and brown (copper ink). Didecyldi-methylammonium bromide (DDAB) can be used as a biocide for cleaning and preserving paper documents, with active concentrations of 0.7 and 1%. [ABSTRACT FROM AUTHOR]

This study aims to describe a new simple and efficient method of extracting DNA from filamentous fungi isolated from historical earthen walls. This method involves growing the mycelium on overlapping cellophane discs on solid medium and the disruption of the fungal cell wall by a combined action of liquid nitrogen and a lytic enzyme. The extraction is performed with the PureLink ™ Genomic DNA Mini Kit protocol from Pure Genomic. The full procedure can be completed in two hours. The new genomic DNA extraction protocol provided good quality and quantity of fungal DNA, from fungal mycelium, with an average yield of 27 ng/µL of DNA per sample. Purified DNA samples yielded 25 ng of DNA ready for sequencing. PCR amplifications of the DNA extracted using the new method were more successful than those extracted using the CTAB method. Thus this new extraction protocol is demonstrated to be an effective method for the identification of a wide range of filamentous fungal species that affect the integrity of buildings with earthen architecture. [ABSTRACT FROM AUTHOR]

Fungi play a critical role in the deterioration of ancient papyri due to their organic and hygroscopic nature. Fourteen fungal species belonging to five genera—Aspergillus, Cladosporium, Penicillium, Talaromyces, and Ulocladium—were isolated and identified from 20 Egyptian papyrus artifacts located at the Grand Egyptian Museum—Conservation Center (GEM‐CC). The biodeterioration mechanism was evaluated by two analyses: cellulase enzyme activity and acid production assay. The isolated fungus P. lanosum showed potent biodeterioration power as it exhibited the highest enzymatic activity and could produce acid as well. Four different analyses were performed to assess the entity of the biodeterioration phenomenon: scanning electron microscopy, Fourier transform infrared spectroscopy, colorimetry, and pH measurements. The analyses demonstrated considerable changes in surface morphology, chemical structure (mainly represented by oxidation and hydrolysis of infected papyrus samples), darkness of the papyrus samples (ΔE 3.84–7.33), and pH (which dropped to 5.2 in the case of A. niger‐infected sample. This article builds a preliminary perception for monitoring the biodeterioration of archaeological papyri and a trial for in vitro treatment to prevent further degradation, which may lead to loss of our valuable artifacts over a prolonged period. [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]

Indian sandalwood (Santalum album L.) is a semi-parasitic tree, well known for its valuable sandalwood oil extracted from heartwood and roots. Extensive loss of heartwood as a result of its decay is observed in living trees and this has inspired the current study, to investigate the health of sandalwood in Marayur sandalwood forest reserves. Located in Kerala, India, the majority of the trees in Marayur are facing high mortality with the loss of heartwood. The current study evaluated the health status and heartwood-rot disease severity of each tree, which revealed that only 16.67 % of the total trees were healthy and 1.5 % of them were dead. Statistical analysis revealed increasing girth class of trees has a significant positive association with increased disease severity at a 0.05 level of significance. Laboratory analysis confirmed the presence of the major wood-rotters Allophoma tropica , Xylaria berteroi , Diaporthe sp. Fomes sp. Ganoderma appalanatum , and Trametes sp. and that they are collectively responsible for the heart rot. A durability assessment revealed sandalwood is highly resistant (durability class I) to white-rot fungi (viz. Trametes hirsutus and T. [ Coriolus ] versicolor) and moderately resistant (durability class II) to brown-rot fungi (Oligoporous placenta and Fomitopsis meliae). Study Implications : This study highlights the health status and heart-rot disease severity of sandalwood trees in Marayur Forest Reserves. Of the total trees surveyed, about 1.5% mortality was observed and only 17% of the trees were devoid of any heart-rot symptoms. Allophoma tropica , Ganoderma applanatum , Xylaria berteroi isolate SR52, Diaporthe sp. Fomes sp. G. appalanatum , and Trametes sp. are typical species collectively responsible for the heart rot and this was found to be the case in our study. These findings will sensitize forest managers to the loss of valuable sandalwood and death of the trees due to the heart rot, thereby enabling them to take appropriate preventive measures. Also, the natural durability of sandalwood against brown- and white-rot fungi is reported for the first time, indicating that sandalwood falls in the resistance class I (highly resistant) against white-rot fungi (Trametes hirsutus and T. (Coriolus) versicolor) and resistance class II (resistant) against brown-rot fungi (Oligoporous placenta and Fomitopsis meliae). [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]

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. [ABSTRACT FROM AUTHOR]

Purpose: Maritime cultural relics from the Nanhai No. 1 shipwreck were immersed in a buffer to maintain stability. To better monitor the changes in the composition of microorganisms in the buffer and, thus, prevent the damage to artifacts caused by harmful microorganisms. Methods: In September and November 2019, we conducted high-throughput sequencing of water samples from four types of maritime cultural relics (ironware, porcelain, axe, and hull wood) to reveal the composition and changes in microbial communities. In addition, we isolated culturable microorganisms and conducted biocide sensitivity tests and lignin and cellulose degradation tests. Results: Visible microbial colonization was observed in the water samples collected from the buffer solutions of ironware, porcelain, axe, and hull wood of the Nanhai No. 1 shipwreck; additionally, apparent differences in the composition of microorganisms in the water samples collected from different cultural relics and different collection times of the same cultural relics were noted. Few species of bacteria and fungi from the microbial community observed in the maritime cultural relics were cultured, and it was noted that various biocides had certain inhibitory effects on them. Some dominant strains had lignin and cellulose degradation abilities and could only grow under specific environmental conditions. Conclusion: We found apparent differences in the composition of microorganisms obtained from different cultural relics and different collection times of the same cultural relics. This study can provide data support for better protection of maritime cultural relics obtained from the Nanhai No. 1 shipwreck and provide a theoretical basis for the biological protection of other maritime cultural relics. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai University / Shanghai Daxue Xuebao is the property of Journal of Shanghai University (Natural Sciences) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)