Akademik Veri Yönetim Sistemi
Journal of Cultural Heritage, cilt.79, ss.94-106, 2026 (SCI-Expanded, AHCI, Scopus)
One of the major challenges in preservation and long-term sustainability of historical manuscripts (HMs) is their vulnerability to biodegradation caused by bacterial enzymatic activity. Among these, cellulolytic bacteria pose a significant threat, as they degrade the cellulose-based components that form the structural backbone of paper materials through the action of cellulases. However, the diversity and abundance of total and cellulolytic bacteria on damaged HMs remain poorly understood due to the lack of standardized sampling, culture media, and identification methods. This study aims to address this knowledge gap by revealing these bacterial communities using various identification approaches and evaluating the methodological factors affecting their detection and isolation. Samples were collected from ten deteriorated HMs from the Süleymaniye Manuscript Library. Two sampling techniques (nitrocellulose membrane filter and swab) were compared in combination with two culture media (R2A and TSA). The bacterial communities were analyzed using denaturing gradient gel electrophoresis (DGGE). In addition, culturable isolates were screened for cellulolytic activity and identified by molecular technique. DGGE analysis produced no results with individual sampling methods, whereas combining samples and performing nested polymerase chain reaction yielded successful outcomes. DGGE and culture findings indicated that bacterial communities were specific to each HM, with every sample hosting a distinct microbiota. The culture-independent detection of opportunistic pathogenic Escherichia coli and Finegoldia magna on HMs suggests potential risks not only to integrity of the manuscript but also to human health. Moreover, HMs may act as a potential reservoir of pathogenic microorganisms. The presence of Cutibacterium acnes , a member of the skin microbiota not previously reported in HMs, as above bacteria, likely reflects contamination during examination or restoration. The culture findings showed that the sampling method significantly affected both bacterial abundance and diversity. The nitrocellulose membrane method was found to be particularly effective for the isolation of cellulolytic bacteria, whereas the swab method yielded a higher total bacterial abundance. The culture medium had minimal influence on cellulolytic bacterial variation. Bacillus spp. were the most commonly detected cellulolytic bacteria. For the first time in HM samples, DGGE analysis revealed bacteria from several previously undetected genera, including Cupriavidus, Escherichia, Lawsonella, Parapusillimonas, Pusillimonas , and Salinimicrobium , while culture-dependent methods indicated additional taxa such as Arthrobacter bussei, Oceanobacillus profundus, Heyndrickxia sporothermodurans, Peribacillus huizhouensis, Peribacillus frigoritolerans , and Niallia circulans . Combined culture-dependent and independent analyses revealed the phyla Bacillota and Pseudomonadota as dominant on HMs, underscoring the need for integrated methods for accurate bacterial composition. As a result, this study provides new insights into the influence of methodological variables on total and cellulolytic bacterial community analysis in historical materials and emphasizes the importance of standardized and complementary approaches in biodegradation and conservation research.