Assessing the microbiological risk to stored sixteenth century parchment manuscripts: a holistic approach based on molecular and environmental studies

Minimally Invasive Vacuum-Aided Extraction Technique for the Lipid Analysis of Historic Parchment

Parchment is an ancient writing support formed from dehaired animal skins. Its manufacture comprises a series of liming and scraping steps before being stretched and dried under tension. Historical parchment represents a valuable source of cultural heritage which, until now, has limited investigations to noninvasive analyses to infer ink composition, degradation, or physical changes over time. We highlight the prospect of the molecular and isotope compositions of animal lipids from parchment as an untapped record of its production and the animal's diet and environment. We report a minimally invasive, total lipid extraction aided by a vacuum for historical parchments. The quantitative and qualitative compositions of lipid extracts obtained using this method are compared with those obtained using invasive sampling for nine sacrificial membranes dated 1765-1825 CE. This extraction method is then applied to membranes from the Chancery Parliament Rolls (1814-1820 CE) held by The National Archives, UK to obtain lipids and derive taxonomic and dietary information using their stable carbon isotope compositions. This novel vacuum-aided extraction allows, for the first time, animal lipids to be obtained from parchment minimally invasively, paving the way for dietary and paleoclimate studies using this well-dated and common material.

Current Insights in Fungal Importance-A Comprehensive Review

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).

The Green Patina and Chromatic Alterations on Surfaces of Gypsum Plaster Casts by Lucio Fontana: Multidisciplinary Investigations in a Case Study of Contemporary Art

Literature reports on Lucio Fontana’s work have focused on the study of the pictorial surface of his paintings. Consequently, to the best of our knowledge, this paper presents the first scientific investigation of gypsum objects made by this artist. These are the gypsum plaster casts made for the construction of the fifth door of the Milan Cathedral, Italy, which were discovered after 60 years, and which showed a green patina and chromatic discolorations. With the aim of understanding the microbiological or chemical nature of the stains, the surfaces of the tiles were investigated by microbiological analysis and analytical techniques including observations by optical, fluorescence and electron microscopy and spectroscopy. The investigated samples showed that the amount of microbiological cells in the stained area was negligible. Chemical analyses allowed the identification of compounds responsible for the chromatic alterations.

Corrigendum: Application of a Medical Diode Laser (810 nm) for Disinfecting Small Microbiologically Contaminated Spots on Degraded Collagenous Materials for Improved Biosafety in Objects of Exceptional Historical Value From the Auschwitz-Birkenau State Museum and Protection of Human Health

[This corrects the article DOI: 10.3389/fmicb.2020.596852.].

The Bad and the Good-Microorganisms in Cultural Heritage Environments-An Update on Biodeterioration and Biotreatment Approaches

Cultural heritage objects constitute a very diverse environment, inhabited by various bacteria and fungi. The impact of these microorganisms on the degradation of artworks is undeniable, but at the same time, some of them may be applied for the efficient biotreatment of cultural heritage assets. Interventions with microorganisms have been proven to be useful in restoration of artworks, when classical chemical and mechanical methods fail or produce poor or short-term effects. The path to understanding the impact of microbes on historical objects relies mostly on multidisciplinary approaches, combining novel meta-omic technologies with classical cultivation experiments, and physico-chemical characterization of artworks. In particular, the development of metabolomic- and metatranscriptomic-based analyses associated with metagenomic studies may significantly increase our understanding of the microbial processes occurring on different materials and under various environmental conditions. Moreover, the progress in environmental microbiology and biotechnology may enable more effective application of microorganisms in the biotreatment of historical objects, creating an alternative to highly invasive chemical and mechanical methods.

An In Vitro Evaluation of the Biocidal Effect of Oregano and Cloves’ Volatile Compounds against Microorganisms Colonizing an Oil Painting—A Pioneer Study

In this study, the biocidal activity of two plant derivatives (oregano and cloves’ essential oils—EOs) was evaluated, as a potential innovative and eco-friendly cleaning method for canvas paintings. The object of the study was the oil painting on canvas entitled “Studio di nudo” (Giovanni Maria Mossa, 1921), showing stains caused by microorganisms. The research focused on: (1) isolation and identification of microorganisms associated with discolorations on the obverse and reverse sides of the canvas; (2) evaluation of biocidal activity of selected EOs against fungal and bacterial collections. The phylogenetic identification was conducted with both cultivation and molecular methods. The canvas was mainly colonized by Penicillium, Aspergillus, and Cephaloteca fungal genera and by bacteria of the Bacillus genus. To evaluate the biocidal effect of the EOs’ volatile components only, an antibiogram assay (agar disc diffusion method) and a customized assay (named the contactless test) were conducted. Tested EOs showed antimicrobial activity on fungi and bacteria. However, compared to cloves, oregano EO exhibited a better inhibition activity both in contact and contactless tests. The work is pioneering for the use of EOs’ volatile compounds against oil painting biodeteriogens, and gives insights into possible extended, innovative and eco-friendly cleaning methods for painting control procedures.

Application of a Medical Diode Laser (810 nm) for Disinfecting Small Microbiologically Contaminated Spots on Degraded Collagenous Materials for Improved Biosafety in Objects of Exceptional Historical Value From the Auschwitz-Birkenau State Museum and Protection of Human Health

The research aim was to optimize the operating parameters of a diode laser irradiation for the effective disinfection of degraded collagenous materials. Historical leather shoes stored at the Auschwitz-Birkenau State Museum in Oświęcim (Poland) were the main study objects. Surfaces of contaminated small spots occurring on the degraded materials were sampled with moistened swabs and microbiologically examined using the molecular techniques MALDI-TOF MS, 16S rRNA, and NGS sequencing. The surfaces were colonized by bacteria with 10⁶ CFU/100 cm² and 10⁴ CFU/100 cm² by fungi, on average. Microorganisms of the genera Bacillus and Penicillium were predominant. The effectiveness of the laser treatment was assessed for the new and degraded collagenous materials against isolated environmental strains using four variants of exposure time and number of repetitions. 0.3 W/CW 2 × 2 min variant was the most effective and also did not noticeably change the color of the treated samples. The variant caused a reduction in the numbers of microorganisms by 96–100%. After 1 month, four types of leather were subjected to comprehensive physico-chemical analyses. SEM and FTIR techniques confirmed that laser irradiation in the selected optimal variant did not affect the surface morphology and collagen structure, while XPS technique enabled detection of subtle changes in non-historical protective coatings on the surfaces of tested degraded historical materials.

Decoding the biological information contained in two ancient Slavonic parchment codices: an added historical value

This study provides an example in the emerging field of biocodicology showing how metagenomics can help answer relevant questions that may contribute to a better understanding of the history of ancient manuscripts. To this end, two Slavonic codices dating from the 11th century were investigated through shotgun metagenomics. Endogenous DNA enabled to infer the animal origin of the skins used in the manufacture of the two codices, while nucleic sequences recovered from viruses were investigated for the first time in this material, opening up new possibilities in the field of biocodicology. In addition, the microbiomes colonizing the surface of the parchments served to determine their conservation status and their latent risk of deterioration. The saline environment provided by the parchments selected halophilic and halotolerant microorganisms, which are known to be responsible for the biodegradation of parchment. Species of Nocardiopsis, Gracilibacillus and Saccharopolyspora, but also members of the Aspergillaceae family were detected in this study, all possessing enzymatic capabilities for the biodeterioration of this material. Finally, a relative abundance of microorganisms originating from the human skin microbiome were identified, most probably related to the intensive manipulation of the manuscripts throughout the centuries, which should be taken with caution as they can be potential pathogens.

Application of Microbial Cleaning Technology for Removal of Surface Contamination

Microbial cleaning takes advantage of naturally-occurring microbes to remove a wide variety of contaminants from various surfaces. The method is based on the affinity of microbes for hydrocarbons that are digested, producing harmless carbon dioxide, water, and soluble fatty acids. The microbes are nonpathogenic and are safe to handle and dispose. The process is environmentally-friendly and is less expensive than solvent cleaning, but it is not applicable to high precision cleaning applications. Typical applications include parts washing; oil and grease removal from concrete and other floor surfaces, and from drains and grease traps; cleaning and disinfection in healthcare facilities; cleaning of historical artworks and structures; and household and institutional cleaning applications.

Melding the Old with the New: Trends in Methods Used to Identify, Monitor, and Control Microorganisms on Cultural Heritage Materials

Microbial activity has an important impact on the maintenance of cultural heritage materials, owing to the key role of microorganisms in many deterioration processes. In order to minimize such deleterious effects, there is a need to fine-tune methods that detect and characterize microorganisms. Trends in microbiology indicate that this need can be met by incorporating modern techniques. All of the methods considered in this review paper are employed in the identification, surveillance, and control of microorganisms, and they have two points in common: They are currently used in microbial ecology (only literature from 2009 to 2015 is included), and they are often applied in the cultural heritage sector. More than 75 peer-reviewed journal articles addressing three different approaches were considered: molecular, sensory and morphological, and biocontrol methods. The goal of this review is to highlight the usefulness of the traditional as well as the modern methods. The general theme in the literature cited suggests using an integrated approach.

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,

Evaluation of a Parchment Document, the 13th Century Incorporation Charter for the City of Krakow, Poland, for Microbial Hazards

The literature of environmental microbiology broadly discusses issues associated with microbial hazards in archives, but these publications are mainly devoted to paper documents. There are few articles on historical parchment documents, which used to be very important for the development of literature and the art of writing. These studies present a broad spectrum of methods for the assessment of biodeterioration hazards of the parchment document in question. They are based on both conventional microbiological methods and advanced techniques of molecular biology. Here, a qualitative analysis was conducted, based on genetic identification of bacteria and fungi present on the document as well as denaturing gradient gel electrophoresis profiling and examining the destructive potential of isolated microbes. Moreover, the study involved a quantitative and qualitative microbiological assessment of the indoor air in the room where the parchment was kept. The microbes with the highest destructive potential that were isolated from the investigated item were Bacillus cereus and Acinetobacter lwoffii bacteria and Penicillium chrysogenum,Chaetomium globosum, and Trichoderma longibrachiatum fungi. The presence of the B. cereuss train was particularly interesting since, under appropriate conditions, it leads to complete parchment degradation within several days.

Microbiological Analysis of Surfaces of Leonardo Da Vinci's Atlantic Codex: Biodeterioration Risk

Following the discovery of discoloration on some pages of the Atlantic Codex (AC) of Leonardo da Vinci kept in the Biblioteca Ambrosiana in Milan, some investigations have been carried out to verify the presence of microorganisms, such as bacteria and fungi. To verify the presence of microorganisms a noninvasive method of sampling has been used that was efficient and allowed us to highlight the microbial facies of the material that was examined using conventional microbiological techniques. The microclimatic conditions in the storage room as well as the water content of the volume were also assessed. The combined observations allowed the conclusion that the discoloration of suspected biological origin on some pages of AC is not related to the presence or current attack of microbial agents.

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.