Co-occurrence of bacteria and fungi and spatial partitioning during photographic materials biodeterioration

Fungal biodeterioration and preservation of cultural heritage, artwork, and historical artifacts: extremophily and adaptation

SUMMARYFungi are ubiquitous and important biosphere inhabitants, and their abilities to decompose, degrade, and otherwise transform a massive range of organic and inorganic substances, including plant organic matter, rocks, and minerals, underpin their major significance as biodeteriogens in the built environment and of cultural heritage. Fungi are often the most obvious agents of cultural heritage biodeterioration with effects ranging from discoloration, staining, and biofouling to destruction of building components, historical artifacts, and artwork. Sporulation, morphological adaptations, and the explorative penetrative lifestyle of filamentous fungi enable efficient dispersal and colonization of solid substrates, while many species are able to withstand environmental stress factors such as desiccation, ultra-violet radiation, salinity, and potentially toxic organic and inorganic substances. Many can grow under nutrient-limited conditions, and many produce resistant cell forms that can survive through long periods of adverse conditions. The fungal lifestyle and chemoorganotrophic metabolism therefore enable adaptation and success in the frequently encountered extremophilic conditions that are associated with indoor and outdoor cultural heritage. Apart from free-living fungi, lichens are a fungal growth form and ubiquitous pioneer colonizers and biodeteriogens of outdoor materials, especially stone- and mineral-based building components. This article surveys the roles and significance of fungi in the biodeterioration of cultural heritage, with reference to the mechanisms involved and in relation to the range of substances encountered, as well as the methods by which fungal biodeterioration can be assessed and combated, and how certain fungal processes may be utilized in bioprotection.

Bacterial Diversity on Historical Audio-Visual Materials and in the Atmosphere of Czech Depositories

Microbial contamination in cultural heritage storage facilities is undoubtedly still a huge problem and leads to the biodeterioration of historical objects and thus the loss of information for future generations. Most studies focus on fungi that colonize materials, which are the primary agents of biodeterioration. However, bacteria also play crucial roles in this process. Therefore, this study focuses on identifying bacteria that colonize audio-visual materials and those present in the air in the archives of the Czech Republic. For our purposes, the Illumina MiSeq amplicon sequencing method was used. Using this method, 18 bacterial genera with an abundance of higher than 1% were identified on audio-visual materials and in the air. We also evaluated some factors that were assumed to possibly influence the composition of bacterial communities on audio-visual materials, of which locality was shown to be significant. Locality also explained most of the variability in bacterial community structure. Furthermore, an association between genera colonizing materials and genera present in the air was demonstrated, and indicator genera were evaluated for each locality. IMPORTANCE The existing literature on microbial contamination of audio-visual materials has predominantly used culture-based methods to evaluate contamination and has overlooked the potential impact of environmental factors and material composition on microbial communities. Furthermore, previous studies have mainly focused on contamination by microscopic fungi, neglecting other potentially harmful microorganisms. To address these gaps in knowledge, our study is the first to provide a comprehensive analysis of bacterial communities present on historical audio-visual materials. Our statistical analyses demonstrate the critical importance of including air analysis in such studies, as airborne microorganisms can significantly contribute to the contamination of these materials. The insights gained from this study are not only valuable in developing effective preventive measures to mitigate contamination but also valuable in identifying targeted disinfection methods for specific types of microorganisms. Overall, our findings highlight the need for a more holistic approach to understanding microbial contamination in cultural heritage materials.

The first fossil record of the anamorphic genus Zygosporium Mont. from the Oligocene of Csolnok (N Hungary)

Remains of a fungus with unique morphological characters were found on the leaf cuticle of a fossil leaf preserved in Oligocene deposits from Csolnok, Hungary. Vesicular conidiophores with characteristic, darkly pigmented, incurved vesicles were compared with those of the modern representatives of the anamorphic genus Zygosporium. Based on the fossil find, a new fossil-species, Zygosporium oligocenicum G. Worobiec sp. nov., having vesicular conidiophores that arise directly from the mycelium, was described. The fossil Zygosporium oligocenicum presumably preferred warm climate and, similarly to most modern members of the genus, was a saprophyte on fallen, decaying leaves.

Bioremediation of organic/heavy metal contaminants by mixed cultures of microorganisms: A review

Although microbial remediation has been widely used in the bioremediation of various contaminants, in practical applications of biological remediation, pure cultures of microorganisms are seriously limited by their adaptability, efficiency, and capacity to handle multiple contaminants. Mixed cultures of microorganisms involve the symbiosis of two or more microorganisms. Such cultures exhibit a collection of the characteristics of each microorganism species or strain, showing enormous potential in the bioremediation of organic or heavy metal pollutants. The present review focuses on the mixed cultures of microorganisms, demonstrating its importance and summarizing the advantages of mixed cultures of microorganisms in bioremediation. Furthermore, the internal and external relations of mixed culture microorganisms were analyzed with respect to their involvement in the removal process to elucidate the underlying mechanisms.

Monitoring the effects of fungi isolated from archival document on model albumen silver prints

Fungi are a common problem in the photographic collection, so the aim of this study focused on isolating and molecular identification of fungi from old albumen prints dating to an archive of Dr. Francis and belonging to the Al-Hagar Family and dating back to 1880-1890. The isolated fungi were identified according to their morphological traits and PCR sequencing. The ability of these isolates to cause deterioration was evaluated on model samples (2 × 2 cm) of albumen silver prints. The effect of these fungi on the morphology and structure of the tested samples were examined by SEM, ATR-FTIR, and chromatic alternations. Four fungal species Aspergillus sydowii, A. flavus, Talaromyces atroroseus, and Penicillium chrysogenum were identified. All isolates were able to grow on the surface of the model Albumen silver print and were capable of causing damage to the binder and able to extend their growth to the paper fibers. A. sydowii, A. flavus, and P. chrysogenum caused hydrolysis and oxidation to the albumen prints, while no significant chemical damage to the albumen was detected for the photographic sample infected with T. atroroseus. All the inoculated samples were significantly affected in terms of color change and the high-light areas have become darker. ATR-FTIR spectra showed the degradation of the protein content in Albumen silver prints inoculated with A. sydowii, A. flavus, and P. chrysogenum.

Microbial Contamination of Photographic and Cinematographic Materials in Archival Funds in the Czech Republic

In this study we investigated the microbial contamination of 126 samples of photographic and cinematographic materials from 10 archival funds in the Czech Republic. Microorganisms were isolated from the light-sensitive layer by swabbing it with a polyurethane sponge. Microbial isolates were identified by MALDI-TOF MS (bacteria) or by phenotype testing and microscopy (fungi). Bacterial contamination was more abundant and more diverse than fungal contamination, and both were significantly associated with archives. The most frequently isolated fungal genera were Cladosporium, Eurotium, Penicillium, Aspergillus and Alternaria. The most frequently isolated bacteria were Gram-positive genera such as Staphylococcus, Micrococcus, Kocuria, Streptococcus and Bacillus. This bacterial and fungal diversity suggests that air is the main vehicle of contamination. We also analysed the impact of the type of material used for the carrier (paper, baryta paper, cellulose acetate and nitrate or glass) or the light-sensitive layer (albumen, gelatine, collodion and other) on the level and diversity of microbial contamination. Carriers such as polyester and cellulose nitrate may have a negative impact on bacterial contamination, while paper and baryta paper may have a partially positive impact on both fungal and bacterial contamination.

Factors Influencing the Fungal Diversity on Audio-Visual Materials

The biodeterioration of audio–visual materials is a huge problem, as it can cause incalculable losses. To preserve these cultural heritage objects for future generations, it is necessary to determine the main agents of biodeterioration. This study focuses on identifying fungi, both from the air and smears from photographs and cinematographic films that differ in the type of carrier and binder, using high-throughput sequencing approaches. The alpha diversity measures of communities present on all types of carriers were compared, and a significant difference between cellulose acetate and baryta paper was observed. Next, the locality, type of carrier, and audio–visual material seem to affect the structure of fungal communities. Additionally, a link between the occurrence of the most abundant classes and species on audio–visual materials and air contamination in the archives was proven. In both cases, the most abundant classes were Agariomycetes, Dothideomycetes, and Eurotiomycetes, and approximately half of the 50 most abundant species detected on the audio–visual materials and in the air were identical.

The Microbiome of Leonardo da Vinci's Drawings: A Bio-Archive of Their History

Seven emblematic Leonardo da Vinci’s drawings were investigated through third generation sequencing technology (Nanopore). In addition, SEM analyses were carried out to acquire photographic documentation and to infer the nature of the micro-objects removed from the surface of the drawings. The Nanopore generated microbiomes can be used as a “bio-archive” of the drawings, offering a kind of fingerprint for current and future biological comparisons. This information might help to create a biological catalog of the drawings (cataloging), a microbiome-fingerprint for each single analyzed drawing, as a reference dataset for future studies (monitoring) and last but not least a bio-archive of the history of each single object (added value). Results showed a relatively high contamination with human DNA and a surprising dominance of bacteria over fungi. However, it was possible to identify typical bacteria of the human microbiome, which are mere contaminants introduced by handling of the drawings as well as other microorganisms that seem to have been introduced through vectors, such as insects and their droppings, visible through the SEM analyses. All drawings showed very specific bio-archives, but a core microbiome of bacteria and fungi that are repeatedly found in this type of material as true degraders were identified, such as members of the phyla Proteobacteria, Actinobacteria, and Firmicutes among bacteria, and fungi belonging to the classes Sordariomycetes and Eurotiomycetes. In addition, some similarities were observed that could be influenced by their geographical location (Rome or Turin), indicating the influence of this factor and denoting the importance of environmental and storage conditions on the specific microbiomes.

The microbiomes of a XVIII century mummy from the castle of Krásna Hôrka (Slovakia) and its surrounding environment

This microbiological survey was performed to determine the conservation state of a mummy in the Slovak castle of Krásna Hôrka and its surrounding environment. Culture-dependent identification was coupled with biodegradation assays on keratin, gelatin and cellulose. Next Generation Sequencing (NGS) using Illumina platform was used for a deeper microbial investigation. Three environmental samples were collected: from the glass of the sarcophagus, from the air inside it, and from the air of the chapel where the mummy is located. Seven different samples were taken from mummy's surface: from the left ear, left-hand palm, left-hand nail, left instep, right hand, abdomen and mineral crystals embedded within the skin. Three internal organ samples, from the lung, pleura and stomach, were also included in this study. Together, the culture-dependent and culture-independent analyses revealed that the bacterial communities present had fewer taxa than the fungal ones. The mycobiome showed the largest variability and included Epicoccum nigrum, Penicillium spp., Alternaria spp., Aspergillus spp., Cladosporium spp. and Aureobasidium pullulans; many other Ascomycota and Basidiomycota genera were detected by NGS. The most interesting results came from the skin mineral crystals and the internal organs. The hydrolytic assays revealed those microorganisms which might be considered dangerous 'mummy pathogens'. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

Microbial Life and Death in a Foxing Stain: a Suggested Mechanism of Photographic Prints Defacement

The gelatin-silver halide black and white prints represent an enormous photography heritage with a great value. Unaesthetic phenomena, the foxing stains that are caused by microbial growth on surface, have been described in stamps, drawings, books, and tissues but, until now, scarcely for photographic materials. In this study, a combination of various techniques, including culture-dependent and culture-independent approaches (RNA and DNA analysis), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and μ-Raman spectroscopy supported by X-ray fluorescence analysis (XRF), permitted to describe the microbial contamination dynamics of foxing stains present on the surface of two gelatin-silver halide photographs. The investigation provided also information on the effects of microbial activity on the materials' chemistry of the two prints. The action of microbial community resulted locally in either (a) formation of mixed aluminum-iron-potassium phosphate compounds that could be attributed to the hydrolytic activity of bacteria, (b) leaching of barite,

Microbial communities affecting albumen photography heritage: a methodological survey

This study is one of the few investigations which analyze albumen prints, perhaps the most important photographic heritage of the late 19^th and early 20^th centuries. The chemical composition of photographic samples was assessed using Fourier-transform infrared spectroscopy and X-ray fluorescence. These two non-invasive techniques revealed the complex nature of albumen prints, which are composed of a mixture of proteins, cellulose and salts. Microbial sampling was performed using cellulose nitrate membranes which also permitted the trapped microflora to be observed with a scanning electron microscope. Microbial analysis was performed using the combination of culture-dependent (cultivation in different media, including one 3% NaCl) and culture-independent (bacterial and fungal cloning and sequencing) approaches. The isolated microorganisms were screened for their lipolytic, proteolytic, cellulolytic, catalase and peroxidase activities. The combination of the culture-dependent and -independent techniques together with enzymatic assays revealed a substantial microbial diversity with several deteriogen microorganisms from the genera Bacillus, Kocuria, Streptomyces and Geobacillus and the fungal strains Acrostalagmus luteoalbus, Bjerkandera adusta, Pleurotus pulmonarius and Trichothecium roseum.