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Paper-based works of art and documents of cultural importance kept in museums and libraries can show notorious signs of deterioration, including foxing stains, caused by fungal colonization. Some of the main chromophore agents of fungal origin that deteriorate paper and therefore affect paper cultural heritage both aesthetically and structurally are the group of pigments called melanins. Thus, knowledge of the diversity and features of fungal melanins and of the melanization pathways of fungi growing on paper is key to removing these pigments from paper-based works of cultural importance. This review provides an approach about the current knowledge of melanins synthesized by paper-colonizing fungi, their localization in the fungal structures, and their role in the deterioration of paper. This knowledge might contribute to developing new, effective, and sustainable strategies of restoration and conservation of historical documents and works of art based on paper.

Oštećenja knjižnične građe nastala kao posljedica poplave nisu uobičajena oštećenja s kojima se konzervatori i restauratori susreću u svakodnevnim okolnostima, s obzirom na to da do močenja knjižničnog gradiva dolazi relativno rijetko. U ovom članku opisan je slučaj poplave Gradske knjižnice „Juraj Šižgorić“ u Šibeniku, primjenjivane tehnike sušenja stradale knjižnične građe te njihov učinak, kao i sanacija prostorija oštećenih poplavom. Svrha ovoga rada je, analizom stanja Gradske knjižnice prije, tijekom i nakon poplave, utvrditi uzrok i spriječiti njezino ponavljanje. Uzrok poplave tražen je analizom odstupanja od IFLA-inih načela o skrbi i rukovanju knjižničnom građom, analiziranjem povijesti Gradske knjižnice „Juraj Šižgorić“, kao i proučavanjem raznovrsnih slučajeva stradavanja knjižničnog gradiva djelovanjem vode. Na temelju analizom prikupljenih podataka predložene su mjere zaštite., Regardless of how library materials get wet – during a flood caused by a burst water pipe, extinguishing a fire using water, leaky roof or any other way – water is one of the greatest enemies of documents and books kept in archives and libraries around the world. Damage to library materials caused by floods, from the perspective of conservation and restoration, stands out from the usual damage caused by standard conditions. The consequences of this type of damage can be more extreme, and result in a complete destruction of library materials. In 2015, a flash flood at the Juraj Šižgorić City Library in Šibenik resulted in extensive damage to a large quantity of library materials that needed to be saved, adequately taken care of, and processed in the shortest possible timeframe. Situations in which large quantities of materials are suddenly damaged require the employment of a large number of people, a large space sufficient for the processing of damaged materials, and considerable funds. In this case, during a heavy rainstorm, the entire basement, with the audiovisual department, gallery, newspaper library and book depository, was flooded, and a significant amount of library materials was lost, as well as some priority items from the Rara collection. Based on the data collected, protection measures were proposed that need to be carried out in accordance with IFLA principles for the care and handling of library materials as prevention for possible similar situations in the future.

A non-destructive and non-invasive method for quantitative characterization of parchment deterioration, based on spectral measurements, is proposed. Deterioration due to both natural aging (ancient parchments) and artificial aging (achieved by means of controlled UV irradiation and temperature treatment) was investigated. The effect of aging on parchment native fluorescence was correlated with its deterioration condition. Aging causes fluorescence intensity drop, spectral shift of the main peak, and an overall change in the fluorescence spectral features. Digital color imaging analysis based on visible reflectance from the parchment surface was also applied, and the correspondent color components (RGB) were successively correlated with the state of parchment deterioration/aging. The fluorescence and color imaging data were validated by analysis of historical parchments, aged between 50 and 2000 years and covering a large variety of states of deterioration. The samples were independently assessed by traditional microscopy methods. We conclude that the proposed optical method qualifies well as a non-destructive tool for rapid assessment of the stage of parchment deterioration.

International audience; AMDES (aminopropylmethyldiethoxysilane) was used to investigate the physicochemical and chemical events related to the introduction of aminoalkylalkoxysilanes in cellulosic materials. Using 29Si CP-MAS and 1H NMR to study the reactivity and structural modification of AMDES in the paper it was shown that polymerization occurs in situ. The distribution of the active compound on the surface of the fibers and throughout the fibers’ thickness was visualized by SEM-EDS. A relation between moisture content, fiber swelling, and uptake of AMDES was found. To better represent old and brittle documents, the paper was predegraded by oxidation with sodium hypochlorite. XRD confirmed the advanced destruction of the amorphous areas of cellulose. Adding AMDES in the oxidized paper resulted in improved mechanical properties, a roughly unmodified degree of polymerization of cellulose, but a slight increase in the yellowing, probably due to several possible reaction products such as imines, amine, amides, and Maillard reactions products. The deacidification efficacy was established and the strengthening effect was shown to arise from the interaction of AMDES with the cellulose fibers.

In 2006, after a visual inspection of the Leonardo da Vinci’s Atlantic Codex by a scholar, active molds were reported to have been present on Codex pages showing areas of staining. In the present paper, molecular methods were used to assess the current microbiological risk to stained pages of the manuscript. Bacterial and fungal communities were sampled by a non-invasive technique employing nitrocellulose membranes. Denaturing gradient gel electrophoresis of 16 S rRNA gene and internal transcribed space regions were carried out to study the structure of the bacterial and fungal communities and band patterns were analyzed by the multivariate technique of principal component analysis. Any relationship between the presence of an active microbial community and staining was excluded. The presence of potential biodeteriogens was evaluated by constructing bacterial and fungal clone libraries, analyzing them by an operational taxonomic unit (OTU) approach. Among the bacteria, some OTUs were associated with species found on floors in clean room while others were identified with human skin contamination. Some fungal OTU representatives were potential biodeteriogens that, under proper thermo-hygrometric conditions, could grow. The retrieval of these potential biodeteriogens and microorganisms related to human skin suggests the need for a continuous and rigorous monitoring of the environmental conditions, and the need to improve handling procedures.

Paper, like all other cultural heritage materials, degrades over time, but conservation slows down the rate of its deterioration. There is a long history of cooperation between microbiologists and conservators of libraries and archival materials, but current approaches addressing paper deterioration need urgent reassessment to take full advantage of modern microbiological methodologies. The present article discusses what we believe are the current priority research areas in assessing microbial risk to paper heritage, and reports studies on a 13th century Italian manuscript and on Leonardo da Vinci's Atlantic Codex which illustrate the problems and challenges encountered when dealing with microbial investigations of paper artworks. The potential of using a more advanced microbiological approach is highlighted.