Investigation of the microbiota of historical parchment artifacts: Bacterial and fungal communities and their potential for biodegradation

Written artifacts made from parchment constitute a significant category of the world's documentary heritage. The deterioration of parchment's collagen structure presents a challenge for the conservation of these artifacts. In addition to environmental conditions, the influence of microorganisms is one of the main causes of this deterioration. To better counteract microbial decay, it is necessary to gain an understanding of the microbiota of parchment. The present study was conducted to characterize the microbiota of parchment with a focus on microorganisms that may be involved in decay. Therefore, 12 parchment manuscript fragments showing signs of decay were analyzed by amplicon sequencing. The five most abundant fungal genera were Aspergillus , Alternaria , Plectosphaerella , Wallemia , and Fusarium , while the five most abundant bacterial genera were Bacillus , Skermanella , Streptococcus , Metabacillus , and Cytobacillus . The key organisms that can contribute to the decay of written artifacts are those that can form collagenases. The main genera in this context, Bacillus and Clostridium , were both found within the microbiota of the parchment samples analyzed, with Bacillus being the most prevalent genus. This study underlines the importance of a comprehensive understanding of the microbiota of parchment in order to counteract microbial decay.