Study of Biodeterioration Potential of Microorganisms Isolated in the Paintings Storeroom of Mouze Makhsus Museum, Golestan Palace, Tehran

ABSTRACT Paintings are essential components of cultural heritage all over the world. They consist of organic molecules such as oils, waxes, gums, sugars, polysaccharides, and proteins that can support the growth of various microorganisms. In this study, in order to identify the microbial community possibly involved in deterioration of paintings in the storeroom of Mouze Makhsus, culturable bacteria and fungi colonizing the paintings were isolated. The identification of isolated bacteria and fungi was performed through morphological analyses and either PCR amplification and DNA sequencing of 16srRNA gene, for bacteria, and ITS genomic region, for fungi. Based on the obtained 16S rRNA gene sequence of bacteria and ITS region sequence of fungi, a phylogenetic tree was constructed using the Neighbor-Joining method. The study also evaluated, in vitro, the cellulolytic activity of the bacterial and fungal isolates. The results highlighted the diverse array of microbial groups colonizing the sampled paintings. Culture-based analyses revealed 27 isolates of bacteria and fungi. Detected fungi fell in seven genera including Aspergillus, Penicillium, Cladosporium, Alternaria, Curvularia, Chaetomium, and Trametes. The majority of isolated bacteria belong to Bacillus genus, whereas to a lesser extent Staphylococcus, Micrococcus, Paenibacillus, Arthrobacter, Heyndrickxia, Priestia, and Rathayibacter were isolated. Qualitative and quantitative assessment of cellulolytic enzyme production showed that the fungal isolates present important cellulolytic activity, and they are potentially dangerous to the paintings.