An environmental assessment of biodeterioration in document repositories

Air- and dustborne fungi in repositories of the National Archive of the Republic of Cuba

This study has as objectives to determine the concentration and diversity of the air- and dustborne mycobiota in seven National Archive of the Republic of Cuba repositories, and to assess the potential risk of biodeterioration that isolated taxa may have. In the indoor and outdoor environmental microbiological samplings a SAS biocollector was used and the indoor/outdoor (I/O) ratio was determined for each repository. The settled dust was collected during six months. Sørensen's coefficient of similarity (QS) was calculated to compare the isolated taxa among the three studied niches (indoor air, dust, outdoor air). The biodegradation potential of the isolated taxa was determined by semi-quantitative tests. The concentrations in the air of repositories with natural cross-ventilation ranged from 225.2-750.3 CFU m-3, while in the Map library with air-conditioning the concentration was significantly lower. The I/O ratios ranged from 0.1-1.7 revealing different environmental qualities. The maximum settled dust load was 22.8 mg/m2/day with a top fungal concentration of 6000 CFU g-1. 14 and eleven genera were detected in the air and dust respectively with predominance of the genera Aspergillus, Cladosporium and Penicillium. A QS of 0.8 was obtained between the indoor and the outdoor environments with eleven taxa similar evidencing the incidence of outdoors on the indoor mycobiota. The isolated taxa showed several biodeteriogenic attributes highlighting twelve and 14 taxa from indoor air and dust respectively with positive results for the five tests performed. This demonstrates the potential risk that fungal environmental represent for the preserved documentary heritage.

Biological risk assessment in the History and Historical Documentation Library of the University of Milan

There are billions of books that in recent and in ancient times have been produced by the human race containing evidence of its intellectual and cultural efforts. Even when stored in libraries, not all these books survive over time undamaged, because in the biosphere their materials are potential nutrients. This is the unfortunate case of the History and Historical Documentation Library of the University of Milan, where biological agents have badly affected rare and valuable old books. An entomological monitoring was carried out using sticky traps and collecting insects during inspections. The beetle Gastrallus pubens Fairmaire, rarely identified in European libraries so far, was the main biological agent responsible for the book damage, since several tunnels due to larval activity and holes made by adults were observed. Using the Illumina MiSeq sequencing technology, Proteobacteria, Firmicutes and Actinobacteria were found to be the most abundant phyla. Ascomycota was the dominant phylum among three fungal phyla. As bacteria and fungi spread by the insects are primary indications of the insect presence in the library, in this paper a potential biomarker able to detect the G. pubens presence before visible infestation was searched for among the bacterial and fungal community peculiar in the insect frass and gut, but also found on books and the surfaces of shelves. Symbiotaphrina, an ascomycete fungus described as one of the symbiotic levuliform fungi, present in the anobiid beetles' gut, was the only one found in all samples analyzed and has therefore been proposed as a putative biomarker.

Microbial diversity in biodeteriorated Greek historical documents dating back to the 19th and 20th century: A case study

Paper documents in archives, libraries, and museums often undergo biodeterioration by microorganisms. Fungi and less often bacteria have been described to advance paper staining, so called “foxing” and degradation of paper substrates. In this study, for the first time, the fungal and bacterial diversity in biodeteriorated paper documents of Hellenic General State Archives dating back to the 19th and 20th century has been assessed by culture‐dependent and independent methods. The internally transcribed spacer (ITS) region and 16S rRNA gene were amplified by PCR from fungal and bacterial isolates and amplicons were sequenced. Sequence analysis and phylogeny revealed fungal phylotypes like Penicillium sp., Cladosporium sp., Penicillium citrinum, Alternaria infectoria, Alternaria alternata, Epicoccum nigrum, and Penicillium chrysogenum which are often implicated in paper deterioration. Bacterial phylotypes closely related to known biodeteriogenic bacteria such as Bacillus spp., Micrococcus spp., Kocuria sp. in accordance with previous studies were characterized. Among the fungal phylotypes described in this study are included well‐known allergens such as Penicillium spp., Alternaria spp., and Cladosporium spp. that impose a serious health threat on staff members and scholars. Furthermore, fungal isolates such as Chalastospora gossypii and Trametes ochracea have been identified and implicated in biodeterioration of historical paper manuscripts in this study for the first time. Certain new or less known fungi and bacteria implicated in paper degradation were retrieved, indicating that particular ambient conditions, substrate chemistry, or even location might influence the composition of colonizing microbiota.

Scopulariopsis sp. and Fusarium sp. in the Documentary Heritage: Evaluation of Their Biodeterioration Ability and Antifungal Effect of Two Essential Oils

Fungi produce pigments and acids, generating particular local conditions which modify the physicochemical properties of materials. The aims of this work are (i) to investigate bioadhesion, foxing production and biofilm formation by Scopulariopsis sp. and Fusarium sp. isolated from document collections under laboratory conditions; (ii) to verify attack on cellulose fibres and (iii) to study the possibility of reducing fungal growth using natural products. Biofilm formation and extracellular polymeric substance (EPS) production by fungi were demonstrated in laboratory assays and by scanning electron microscopy (SEM) observations. The biocidal activity of two essential oils of Origanum vulgare L. and Thymus vulgaris L. was evaluated using the microatmosphere method. SEM observations showed that these strains were able to attach to paper and form biofilms, causing damage on them, which demonstrates the biodeterioration ability of these microorganisms. Scopulariopsis sp. and Fusarium sp. isolated from paper books showed the formation of fox-like reddish-brown colour spots, attack to the paper structure and pigment production on aged paper samples. The strains tested produced a decrease in the pH of one unit. This would substantiate the effect of the strains in paper biodeterioration. The microatmosphere method showed that volatile compounds of the essential oils have antifungal activity.

Airborne microorganisms cultivable on naturally ventilated document repositories of the National Archive of Cuba

The quality of the indoor air can provide very useful information for the artwork conservation. The aim of the study was to evaluate the microbial concentration inside six document repositories of the National Archive of the Republic of Cuba in two months of 1 year. The repositories are large, high, and have a natural cross-ventilation system. The microbial sampling was done in July 2010 (summer or rainy month) and February 2011 (winter or dry month) using the SAS Super 100 biocollector at 100 L/min. An appropriate selective culture media were used to isolate fungi and bacteria. A high total microbial concentration on the north side of the building in two studied months was observed. The fungal concentrations were significantly higher in July 2010 in all repositories, while the bacterial concentrations were significantly higher mostly in February 2011 only in repositories located on the first and second floor of the building. Eight fungal genera in the indoor air of all environments were isolated. Regardless of the side of the analyzed building, Penicillium, Aspergillus, and Cladosporium were the predominant genera. Aspergillus flavus and Aspergillus niger were the species isolated in almost all of the analyzed repositories in the studied months. Gram-positive bacteria prevailed among bacterial groups isolated from indoor air repositories, and some percentages corresponded to the genera Bacillus and Streptomyces. In Cuba, the temperature and relative humidity are high during the whole year but the natural ventilation plays an important role in retarding microbial growth on materials.

A combined approach to assess the microbial contamination of the archimedes palimpsest

A combined approach, using molecular and microscopic techniques, was used to identify the microbiota associated with the Archimedes Palimpsest, an unusual parchment manuscript. SEM analyses revealed the microbial damage to the collagen fibers and the presence of characteristic cell chains typical of filamentous bacteria and fungal spores. Molecular analysis confirmed a homogeneous bacterial community colonizing the manuscript. The phyla Proteobacteria and Actinobacteria were associated with this ancient parchment; the sequences were most related to uncultured clones detected in the human skin microbiome and in ephitelium, and to cultivated species of the genera Acinetobacter and Nocardiopsis. Nevertheless, a great variation was observed among the different sampled areas indicating fungal diversity. Blumeria spp. dominated in the healthy areas of the parchment while degraded areas showed disparate fungal communities, with dominant members of the genera Mucor and Cladosporium. In addition, the quantification of the β-actin gene by real-time PCR analyses (qPCR) revealed a higher fungal abundance on degraded areas than on the healthy ones.