Biodeterioration Processes Research Articles

Automatic monitoring of the bio[sbnd]colonisation of historical building's facades through convolutional neural networks (CNN)

Built cultural heritage is exposed to various deterioration problems caused by different types of actions. To reduce the need for major interventions, preventive conservation (PC) approaches were proposed, based on data collection, regular monitoring, inspections, and control of environmental factors. Monitoring actions able to depict the evolution of buildings’ deterioration state, have been proposed and implemented in real cases. Considering that digital images (DI) of historical facades are constantly collected by different subjects and for different purposes, they represent the widest existing data source to support PC approaches and develop predictive tools. DI of historical façades can be used to help in the early recognition of different types of deterioration processes, supporting the creation and application of predictive models based on machine learning (ML) methods. This work proposes a method for the automatic detection of biological colonisation of building facades. A convolutional neural network (CNN) has been trained and tested with images representing the microalgae and cyanobacteria growth process on historical bricks’ facades, collected during experimental activities in controlled conditions. The trained model is characterized by an accuracy of 87 % and can recognise bio-colonisation on different types of bricks. The trained model has been applied to a historical building used as a case study. The facades of the case study are constantly monitored by surveillance cameras, and DI of the facades are often collected due to the public function of the building. The study shows that by simply processing these images with the trained network it is possible to detect the first stage of bio-deterioration processes. This work is part of more extensive research for the early detection of different types of building façade damages and can be easily implemented where DI coming from surveillance cameras or other sources are available.

Natural Inhibitory Treatment of Fungi-Induced Deterioration of Carbonate and Cellulosic Ancient Monuments: Isolation, Identification and Simulation of Biogenic Deterioration.

Fungi play a significant role in the deterioration of various types of monuments. Therefore, the protection of ancient monuments from fungal attacks is an important goal that must attract the attention of researchers worldwide. A total of 69 fungal isolates were recovered from 22 deteriorated objects compromising paper, textiles, wood, and stone in the National Museum of Egyptian Civilization (NMEC) storeroom, Cairo, Egypt. The isolates were identified as 12 different species categorized into three different genera, namely, Aspergillus (9 species), Penicillium (2 species) and Trichoderma (1 species). Among them, Aspergillus fumigatus was the most prevalent species. Three essential oils were assessed for antifungal activity and compared with the antifungal effects of five synthetic microcides to identify a natural inhibitory treatment. Thyme oil and sodium azide were found to be the most active growth inhibitors, with minimum inhibitory concentrations (MICs) of 625 and 100 ppm, with inhibition zone diameters of 19.0 ± 0.70 - 23.76 ± 1.15 and 13.30 ± 0.35 - 19.66 ± 0.54 mm, respectively. An in vitro simulation of the biodeterioration process was conducted using spores of the A. fumigatus strain NMEC-PSTW.1 on model cubes made of paper, textile, wood, and stone materials. The changes in the characteristics of the artificially deteriorated materials were analyzed using environmental scanning electron microscopy/energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The results revealed changes in the morphology, physical properties, and chemical composition induced by A. fumigatus NMEC-PSTW.1. Overall, thyme oil is recommended as a natural inhibitor to protect carbonate and cellulosic monuments in NMEC against fungal attack.

Decipherment of text on foxed documents by Hyperspectral Imaging on VSC 6000

Foxing is a process of deterioration that generates spots and browning on ancient paper documents such as books, monographs, postage stamps, certificates, etc. It is believed that metals and bacteria are the primary causes of foxing production. According to scientific studies, physical, chemical, and biological processes degrade paper. Paper is especially prone to biodeterioration processes due to its organic composition and hygroscopic nature; as a result, foxed paper becomes weaker, more fragile, and more acidic than undamaged paper. In circumstances where the text of a book or other document becomes unreadable owing to foxing, measures must be established to make the content readable. In the present study, efforts were made to understand the unreadable text content of books damaged by foxing, and the capabilities of Hyperspectral Image on VSC 6000 employing Near-Infrared Multispectral imaging analysis were presented. It is a method for optimising spectral differences that is non-invasive. First, microbiological flora (fungal and bacterial) from old books were identified, followed by the selection of the mechanism of VSC. The results revealed a correlation between fungal foxing and bacterial foxing, leading to the conclusion that fungus foxing necessitates distinct wavelength ranges between 600 and 800 nm for the decipherment of text, but bacterial foxing allows for decipherment at 645nm. Purchase Article - $10

Uncovering the microbial diversity of Czech Republic archives: A study of metabolically active airborne microbes

Despite the diligent efforts of libraries, archives, and similar institutions to preserve cultural monuments, biodeterioration continues to pose a significant threat to these objects. One of the main sources of microorganisms responsible for the biodeterioration process is the presence of airborne microorganisms. Therefore, this research aims to monitor and compare outcomes of both culture-dependent (utilising various cultivation strategies) and culture-independent approaches (RNA-based sequencing) to identifying metabolically active airborne microorganisms in archives in the Czech Republic. Through this study, several species that have the potential to pose risks to both cultural heritage objects and the health of institution employees were found. Additionally, the efficacy of different cultivation media was demonstrated to be varied across archive rooms, highlighting the necessity of employing multiple cultivation media for comprehensive analyses. Of noteworthy importance, the resuscitating-promoting factor (Rpf) proved to be a pivotal tool, increasing bacterial culturability by up to 30% when synergistically employed Reasoner's 2A agar (R2A) and R2A + Rpf media. Next, the study emphasises the importance of integrating both culture-dependent and culture-independent approaches. The overlap between genera identified by the culture-dependent approach and those identified also by the culture-independent approach varied from 33% to surpassing 94%, with the maximum alignment exceeding 94% in only one case. Our results highlight the importance of actively monitoring and assessing levels of microbial air contamination in archives to prevent further deterioration of cultural heritage objects and to promote improved conditions for employees in archives and similar institutions.

Effects of simulated atmospheric nitrogen deposition on the bacterial community structure and diversity of four distinct biocolonization types on stone monuments: a case study of the Leshan Giant Buddha, a world heritage site

AbstractAtmospheric 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.

Biomineral deposits and coatings on stone monuments as biodeterioration fingerprints

Biominerals deposition processes, also called biomineralisation, are intimately related to biodeterioration on stone surfaces. They include complex processes not always completely well understood. The study of biominerals implies the identification of organisms, their molecular mechanisms, and organism/rock/atmosphere interactions. Sampling restrictions of monument stones difficult the biominerals study and the in situ demonstrating of biodeterioration processes. Multidisciplinary works are required to understand the whole process. Thus, studies in heritage buildings have taken advantage of previous knowledge acquired thanks to laboratory experiments, investigations carried out on rock outcrops and within caves from some years ago. With the extrapolation of such knowledge to heritage buildings and the advances in laboratory techniques, there has been a huge increase of knowledge regarding biomineralisation and biodeterioration processes in stone monuments during the last 20 years. These advances have opened new debates about the implications on conservation interventions, and the organism's role in stone conservation and decay. This is a review of the existing studies of biominerals formation, biodeterioration on laboratory experiments, rocks, caves, and their application to building stones of monuments.

Decay resistance and weathering properties of thermally-modified amazon woods – Parkia pendula (Willd.) and Simarouba amara (Aubl.)

ABSTRACT Thermal modification is a technique that can be used to increase the resistance of wood to the biodeterioration processes. In this context, the objective of this study was to evaluate the durability of Parkia pendula (angelim-saia) and Simarouba amara (marupá) woods thermally modified in rotting field tests and by the action of natural weathering. The tests were carried out in the Brazilian Amazon region, in the Mato Grosso State. The thermal modification of the wood was set with four treatments: control (T1); electric-oven treatment, 180°C for 3 h (T2); combination of autoclave and electric-oven, 125°C for 3 h, and 180°C for 3 h respectively (T3), and immersion in vegetable oil, 180°C for 3 h (T4). The samples were partially buried for the field rotting assays, and the mass loss and deterioration index were seasonally evaluated after the experiment was installed. These analyses were performed on the same samples which has been exposed to rotting essays. The action of natural weathering was assessed through the CIELAB* colour system. T4 was the most efficient for increasing the resistance to biological deterioration, under the tested conditions. T2 and T3 treatments conferred higher colorimetric stability for both types of woods after natural weathering, under the tested conditions.

Innovative approaches to accurately assess the effectiveness of biocide-based treatments to fight biodeterioration of Cultural Heritage monuments

The development of diagnostic methods to accurately assess the effects of treatments on lithobiont colonization remains a challenge for the conservation of Cultural Heritage monuments. In this study, we tested the efficacy of biocide-based treatments on microbial colonization of a dolostone quarry, in the short and long-term, using a dual analytical strategy. We applied a metabarcoding approach to characterize fungal and bacterial communities over time, integrated with microscopy techniques to analyze the interactions of microorganisms with the substrate and evaluate the effectiveness. These communities were dominated by the bacterial phyla Actinobacteriota, Proteobacteria and Cyanobacteria, and the fungal order Verrucariales, which include taxa previously reported as biodeteriogenic agents and observed here associated with biodeterioration processes. Following the treatments, changes over time in the abundance profiles depend on taxa. While Cyanobacteriales, Cytophagales and Verrucariales decreased in abundance, other groups, such as Solirubrobacteriales, Thermomicrobiales and Pleosporales increased. These patterns could be related not only to the specific effects of the biocide on the different taxa, but also to different recolonization abilities of those organisms. The different susceptibility to treatments could be associated with the inherent cellular properties of different taxa, but differences in biocide penetration to endolithic microhabitats could be involved. Our results demonstrate the importance of both removing epilithic colonization and applying biocides to act against endolithic forms. Recolonization processes could also explain some of the taxon-dependent responses, especially in the long-term. Taxa showing resistance, and those benefiting from nutrient accumulation in the form of cellular debris following treatments, may have an advantage in colonizing treated areas, pointing to the need for long-term monitoring of a wide range of taxa. This study highlights the potential utility of combining metabarcoding and microscopy to analyze the effects of treatments and design appropriate strategies to combat biodeterioration and establish preventive conservation protocols.

Exploring Differences in Culturable Fungal Diversity Using Standard Freezing Incubation-A Case Study in the Limestones of Lemos Pantheon (Portugal).

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.

Community structures and biodeterioration processes of epilithic biofilms imply the significance of micro-environments

Epilithic biofilms colonising outdoor stone monuments can intensify the deterioration processes of the stone materials and pose great challenges to their protection. In this study, biodiversity and community structures of the epilithic biofilms colonising the surfaces of five outdoor stone dog sculptures were characterised by high-throughput sequencing. Although they are exposed to the same envrionment in a small yard, the analysis of their biofilm populations revealed high biodiversity and species richness as well as great differences in community compostions. Interestingly, populations responsible for pigment production (e.g., Pseudomonas, Deinococcus, Sphingomonas and Leptolyngbya) and for nitrogen (e.g., Pseudomonas, Bacillus, and Beijerinckia) and sulfur cycling (e.g., Acidiphilium) were the core common taxa in the epilithic biofilms, suggesting the potential biodeterioration processes. Furthermore, significant positive corrolections of metal elements rich in stone with biofilm communities showed that epilithic biofilms could take in minerals of stone. Importantly, geochemical properties of soluble ions (higher concentration of SO42− than NO3−) and slightly acidic micro-environments on the surfaces suggest corrosion of biogenic sulfuric acids as a main mechanism of biodeterioration of the sculptures. Interestingly, relative abundacne of Acidiphilium showed a positive correlation with acidic micro-environments and SO42− concentrations, implying they could be an indicator of sulfuric acid corrosion. Together, our findings support that micro-environments are inportant to community assembly of epilithic biofilms and the biodeterioration processes involved.

Impact of fungi on historical monument with reference to Mahadev temple Bastar of Chhatisgarh

Materials of built heritage are at risk of bio-deterioration caused by diverse populations of microorganisms living in biofilms. The microbial metabolites of these biofilms are responsible for the deterioration of the underlying substratum and may lead to physical weakening and discoloration of stone. Fungal ability in production of pigments and organic acids have crucial role in discoloration and degradation of different types of stone in cultural heritage objects. Additionally, stone objects may support novel communities of microorganism that are active in bio-deterioration process this investigation focused on mycological analyses of microbial biofilm from Mahadev temple, Bastar of Chhattisgarh state which is made of sand stone and which were heavily colonized by fungi. The eight fungal species on sand stone were isolated. Aspergillus sp. was common in stone structure. The identified micro fungi cause discoloration as well as mechanical exfoliation of building stone material that was analyzed through mechanical hyphae penetration and production of dark pigments and organic acids.

A Multidisciplinary Approach in Examining the Susceptibility to Microbial Attack of Polyacrylic and Polyurethane Resins Used in Art Restoration

The synthetic polymers used to protect artworks from deterioration process can be colonized by the fungi and bacteria responsible for the biodeterioration process. In this study, the susceptibility of synthetic polyacrylics and polyurethane resins to microorganisms (Aspergillus niger ATCC 9642, Aureobasidium pullulans ATCC 15233, Chaetomium globosum ATCC 6205, Cladosporium cladosporioides ATCC 16022, Alternaria alternata BC01, Penicillium citrinum LS1 and Pseudomonas aeruginosa ATCC 9027) was investigated. The microbial attack was simulated alone and with a biocide and the related growth was observed up to 21 days for bacteria and 28 days for fungi. The polyacrylic and polyurethane resins were subjected to microbial attack, regardless of the biocide treatment, with a fungal growth from 60% to the complete coverage of the plate surface. Penicillium citrinum showed the greatest adaptation ability and was found in all the examined resins. P. aeruginosa was visible in all the different resins, regardless of the presence of biocide. An environmental scanning electron microscope (ESEM) revealed the presence of fungal conidia and hyphae in the inoculated resins and the Fourier transform IR spectroscopy (FTIR-ATR) indicated chemical transformations in the IR spectra, particularly the hydrolysis of esters, with some differences between the polyacrylic and polyurethane resins, which were probably due to their different chemical features. Overall, our data stress that the chemical, physical and biological deterioration caused by microorganisms capable of degrading synthetic polymers is still a problem in art restoration and that new strategies must be considered to counteract this phenomenon.

Circumfusicillium cavernae gen. et sp. nov. (Bionectriaceae, Hypocreales) Isolated from a Hypogean Roman Cryptoporticus.

Stone monuments and relics are prone to biodeterioration processes prompted by microbial proliferation and activity. Among the distinct microbes capable of stone colonization, fungi are known to strongly contribute to stone biodeterioration. During the ongoing efforts aiming to study fungi thriving in dolomitic limestone walls of the Coimbra’s hypogean Roman cryptoporticus (Portugal), two unknown Bionectriaceae isolates were retrieved. The aim of this work was to depict the molecular and phenotypic characteristics of these microorganisms. The phylogenetic analyses revealed that the studied strains could not be assigned to any of the currently known Bionectriaceae genera. Moreover, the isolates exhibited distinctive and peculiar characteristics, such as the packing of conidia by surrounding hyphal segments and the formation of rope-like microsclerotia with a textura globose. Taking into account all the data obtained, a novel genus and species, Circumfusicillium cavernae gen. et sp. nov. in Bionectriaceae (Hypocreales), is proposed here.

Influence of nanoscale defects on the improvement of photocatalytic activity of Ag/ZnO

This study presents the advances in the field of ZnO/Ag catalysts from the synthesis of hierarchical ZnO nanowires (NWs) decorated with Ag nanoparticles, prepared by a facile solvothermal method at 120°C. It evaluates the photocatalytic efficiency from studying the time reaction of Ag/Zn concentration ratio and the presence of cetyltrimethylammonium bromide (CTAB) as an organic dispersant. X-ray diffraction, scanning electron microscopy, and analytical/high-resolution transmission electron microscopy results confirmed the presence of homogeneous cylindrical ZnO nanowires and quasi-spherical Ag crystals. ZnO NWs exhibited hexagonal wurtzite structure and cubic FCC symmetry in Ag nanoparticles (NPS). Two types of nanostructures, including homogeneous cylindrical ZnO NWs in the absence of Ag and simultaneous presence of ZnO NWs and Ag NPs, formed depending on experimental conditions. The photocatalytic activity was evaluated by studying methylene blue (MB) degradation time under UV light excitation. Diffuse reflectance UV–Vis spectrophotometry (UV–Vis DRS) allowed identifying the ZnO absorption band at ~393 nm. Crystal size varied depending on the reaction time and the addition of CTAB. Synthesis time increased bandgap values, getting better photocatalytic performance in samples synthesized in intermediate times (6 h), higher Ag + /Zn 2+ molar ratio (0.2/1.0), and CTAB. According to HRTEM observations, the presence of silver nanocrystals with high content of defects (twinning, stacking faults) could play an essential role in the photocatalytic response. In this context, the specific synthesis conditions of Ag/ZnO might be more appropriate for their use in organic dyes degradation in water and the potential use in protective treatments against materials biodeterioration processes. • Ag/ZnO nanostructures were synthesized by solvothermal method using CTAB at 120°C. • Wurtzite (ZnO) and face-centered-cubic (Ag) crystalline phases have been identified. • The presence of defects in Ag NPs could be identified and related to PCA enhanced. • The photocatalytic behavior can be improved by incorporating Ag NPs on NWs of ZnO. • The PCA of Ag/ZnO depends upon the crystallinity, surface area, and morphology.

Black Fungi and Stone Heritage Conservation: Ecological and Metabolic Assays for Evaluating Colonization Potential and Responses to Traditional Biocides

Identifying species involved in biodeterioration processes is helpful, however further effort is needed to assess their ecological requirements and actual activity. Black fungi (BF) represent one of the most underestimated threats to stone cultural heritage in the Mediterranean basin; they are difficult to kill or remove due to their ability to grow inside the rock and cope with several stresses. Despite this, little is known about BF and factors favoring their growth on stone surfaces. Eighteen BF species were here investigated for temperature and salt tolerance, and metabolic traits by plate assays. The relation between some highly damaged monuments and their BF settlers was assessed using X-ray diffraction analysis, mercury intrusion porosimetry, and SEM. The sensitiveness to four commonly used traditional biocides was also tested. All strains were able to grow within the range of 5–25 °C and in the presence of 3.5% NaCl. Instrumental analyses were fundamental in discovering the relation between halophilic strains and weathered marble sculptures. The acid, cellulase, esterase, and protease production recorded proved BF’s potential to produce a chemical action on carbonate stones and likely affect other materials/historical artefacts. Besides, the use of carboxymethylcellulose and Tween 20 should be evaluated in restoration practice to prevent tertiary bioreceptivity. Agar diffusion tests helped identify the most resistant species to biocides, opening the perspective of its use as reference organisms in material testing procedures.

Identification of Microorganisms Dwelling on the 19th Century Lanna Mural Paintings from Northern Thailand Using Culture-Dependent and -Independent Approaches.

Simple SummaryIn this study, we compared microbial communities in Lanna mural paintings in temples with different numbers of visitors using culture-dependent and culture independent approaches. The results showed that microorganisms could damage the colors that are used on murals. The process of degradation involved the production of organic acids and formation of the calcium crystal. Furthermore, we found that the site with higher number of visitors is associated with microbial contamination from humans while the site with lower number of visitors had higher saprotroph population. Further research into these microorganisms, their activities and functional roles may provide crucial information to aid the preservation of mural paintings.Lanna painting is a unique type of painting in many temples in the Northern Thai region. Similar to most mural paintings, they usually decay over time partly due to the activity of microbes. This study aimed to investigate the microorganisms from two Lanna masterpiece paintings in two temples that differ in the numbers of visitors using both culture-dependent and -independent approaches. The microorganisms isolated from the murals were also tested for the biodeterioration activities including discoloration, acid production and calcium precipitation. Most microorganisms extracted from the paintings were able to discolor the paints, but only fungi were able to discolor, produce acids and precipitate calcium. The microorganism communities, diversity and functional prediction were also investigated using the culture-independent method. The diversity of microorganisms and functional prediction were different between the two temples. Gammaproteobacteria was the predominant group of bacteria in both temples. However, the fungal communities were different between the two temples as Aspergillus was the most abundant genus in the site with higher number of visitors [Buak Krok Luang temple (BK)]. Conversely, mural paintings at Tha Kham temple (TK) were dominated by the Neodevriesia genera. We noticed that a high number of visitors (Buak Krok Luang) was correlated with microbial contamination from humans while the microbial community at Tha Kham temple had a higher proportion of saprotrophs. These results could be applied to formulate a strategy to mitigate the amount of tourists as well as manage microorganism to slow down the biodeterioration process.

Microbial Diversity on the Surface of Historical Monuments in Lingyan Temple, Jinan, China.

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.

A more accurate definition of water characteristics in stone materials for an improved understanding and effective protection of cultural heritage from biodeterioration

The water associated with cultural heritage materials is the most important factor before initiation microbial colonization and subsequent biodeterioration processes to occur. Since moisture or water in such materials is the key to life, a more refined characterization of water is needed to advance the basic understanding of the fundamental mechanisms, especially for the accurate assessment of bio-susceptibility or bio-receptibility of different materials. Water can be categorized to free, gravitational, capillary, and hygroscopic to account for the physical states and sorption strength with the materials. Material porosity or water-holding capacity are fundamental criteria used in characterization of various types of materials on a common ground and basis, but pore connectivity has been largely ignored and must be addressed to establish the methods for assessment and also its relationship to bio-colonization and biodeterioration. When a threshold value of water in the relevant physical categories is available, microbial life can colonize and establish colonies as biofilms on materials surfaces to carry out the biochemical reactions leading to biodeterioration, from appearance of discoloration to physical damage of the materials. Microbial destruction of inorganic materials is mainly carried out by the biochemical reactions through carbon, nitrogen and sulfur cycles. Among material porosity characteristics, available water and microorganisms, mobility and movement of soluble salts under wet and dry cycles have significant impact on the durability of materials. Uptake of soluble salts and supersaturated salts in water into materials can result in crystallization and mineral formation under evaporation condition to initiate the internal stress and cracks, which eventually result in surface delamination and damage. From an architecture design point of view, it is clear that management of water is a basic and important strategy to prevent development of microbial issues in the long-term protection of cultural heritage.

Silver-Derived Antimicrobial Coatings for the Prevention of Microbial Biofilms in Metal Pipes

Biodeterioration is one of the most important processes in metal pipeline corrosion, and it can be due to physical, chemical, and biological factors. Coatings rich in silver have been used to inhibit this undesirable phenomenon. In this study, the antimicrobial properties of several silver-containing products used as a coating in pipelines were determined on a pilot scale in order to evaluate the ability of silver to inhibit biofilm formation. The results showed that the coating with silver zeolite at a concentration of 2000 mg L–1 inhibited the formation of a microbial biofilm and prevented the biodeterioration process. Therefore, from our study, it can be concluded that silver zeolite shows greater protection capacity than other silver preparations and presents advantages in relation to other silver coatings that are currently available

Detection DETEKSI DAN IDENTIFIKASI KAPANG PADA PROSES BIODETERIORASI ARSIP FOTO MEMORY OF THE WORLD (MOW) RESTORASI CANDI BOROBUDUR

ABSTRACT 
 This study aims to identify the genus of mold in the biodeterioration process of the photo archive of Memory of the World (MoW) restoration of Borobudur Temple and the potential for the enzymatic activity of these molds. The type of research method chosen is descriptive qualitative. Starting with survey sampling and sampling. Inoculation of fungi using the streak method on PDA medium. Mold identification based on macroscopic and microscopic observations of fungi. The results of characterization were then identified using the matching profile method using the mold identification reference book. The identification results resulted in six genera of contaminant molds in the biodeterioration of the MoW photo archive of the Borobudur Temple restoration. The genera identified included: Acremonium (69.66 %%), Penicillium (14.59%), Aspergillus (3.36%), Culvularia (2.24%) Fusarium (1.12%), and Pleurostomophora (1.12%) and some sterile mycelia. The types of biodeterioration in the photo collection include mold growth, discolored spots, peeling off layers, and damage to the substrate in the photo. Based on literature search, all mold genera found as the cause of biodeterioration has the potential to have proteinase, gelatinase, and cellulase enzymes.
 Keywords: Biodeterioration; Mold; Photograph; Memory of the World; Borobudur Temple