From artefact to microbe and beyond: innovative biomolecular approaches applied to cultural heritage

Cultural heritage is a fundamental part of our identity and the history of a country. Its conservation is essential for preserving the memory of different cultures and requires innovative approaches to identify the deterioration process and its impact on artefacts. This thesis explores the potential of biomolecular and bioinformatics approaches for analyzing parchment and stone materials, focusing on non-invasive (PVC eraser, swabs and nylon membrane) or micro-invasive (fragment from the edges of parchment) sampling methodologies and the use of metabarcoding for the taxonomical identification of parchment (biocodicology) and of artefacts’ microbiome. We employed the MinION device (Oxford Nanopore Technology), one of the last advances in sequencing technology that meets the needs of the field of cultural heritage, easy to use, cheap and portable. Whole Genome Amplification and metagenomic approach with shotgun sequencing, were applied to 15th-century drawings from the Academy of Fine Arts in Vienna whereas the metabarcoding approach was used for: i) parchment from “Frammenti Musicali” and “Graduale D”; ii) stone material, on the frescos in “Tomba degli Scudi” to assess microbial colonization and identify black spots on the fresco. Amplicon sequencing, hence, metabarcoding, was done targeting conserved regions of DNA, Internal Transcribed Spacer (ITS) for fungi, 16S rDNA gene for bacteria and cytochrome b gene (CytB ) for the animal species, and using a custom bioinformatic pipeline, to provide a cost-effective alternative for rapid species identification. The results highlight the advantages and limitations of different sequencing approaches, the utility of Whole Genome Amplification (WGA) to overcome the challenges of minimally invasive sampling techniques and the potential of the MinION (ONT) linked to an ad hoc generated bioinformatic pipeline to provide useful information on the materials and microbiome associated to an artefact such as parchment and stones. They also emphasize the need for standardized protocols to enhance the reproducibility of analyses in cultural heritage studies.