Study of bacterial contamination of some exquisite written works of Astane Qudse Razavi Documentation Center

Biodegradation of organic matter in the elemental cycle is very important, but in the case of the museum and archival works, the degradation called biodeterioration leads to the loss of valuable information that biologists seek to reduce its damages. The purpose of this study was to investigate the bacterial pathology of some of the exquisite manuscripts kept in Astane Quds Razavi Documentation Center in Mashhad. In this study, using classical and molecular methods, bacterial contamination of five exquisite manuscripts was investigated and identified. Sampling was performed using three methods of a direct swab, wet swab in physiological serum and nitrocellulose membrane. Bacterial contamination of the reservoir air was performed using an open plate method. In total, 72 bacterial strains were isolated, 28 of which were identified by molecular method, most of which belonged to the Firmicutes phylum. Bacillus atrophaeus with 38.6% abundance had the highest distribution. Bacterial strains of Staphylococcus hominis and Bacillus altitudinis were isolated only from airborne samples. The microbial community of books and air showed 53% similarity, indicating a possible source of microbial contamination with air origin. The presence of similar bacteria (23.5%) in the buffer room and tank air confirmed this. The results of this study indicate the presence of bacteria in the paper and leather substrates of the studied books, and, on the other hand, identifying bacterial air pollutants helps improve the ventilation of tanks and libraries. Understanding these factors will help in choosing efficient methods of preservation and restoration of written works.