This study aimed to obtain basic information on the indoor environmental hygiene of non-disinfected libraries used for paper records preservation in the Nara Repository of National Archives, Korea. Microorganisms were investigated in dust samples collected from bookshelves of five libraries using the swab method. Bacterial concentration ranged from 6 CFU/m2 up to 1,730 CFU/m2 . A total of 11 bacterial species belonging to five genera were identified, with Bacillus being the predominant genus. Some bacterial species forming colonies with pigmentation on TSA media were also present. No bacterial species capable of producing cellulases were found. However, one species that could have harmful effects on human health was discovered. For fungi, concentration ranged between 6 CFU/m2 to 1,660 CFU/m2, and a total of six fungal species belonging to five genera were found. Some fungal species forming pigmented colonies on PDA media were also present. Additionally, three species that could have harmful effects on human health were identified. This study’s data suggests that microbial contamination in the dust is relatively low, but the dust in the bookshelves of non-disinfected libraries at the Nara Repository requires management. This is the first report conducted on microorganisms in the dust of bookshelves at the National Archives in Korea.

Fungi are organisms that must be monitored and controlled in order to preserve valuable paper records. They reduce the quality of paper records by degradation and/or discoloration. As an effort to understand fungal contamination in the National Archives of Korea, the concentration of fungi in the indoor air of the unsterilized record rooms has been reported. However, what species are present in the facilities is not much known. In the present study, we examined the fungi isolated from the National Archives of Korea and found among them that there are fungal species which are newly documented in Korea. They were identified based on morphological properties and nucleotide sequences analysis of the polymerase chain reaction-amplified the internal transcribed spacer region of rDNA, calmodulin gene, and beta-tubulin gene. We report Cladosporium parahalotolerans, Cladosporium subuliforme, Ochroconis mirabilis, Penicillium angulare, and Penicillium fundyense as new instances of fungal species in Korea. Among these five species, P. angulare is known to able to produce cellulase and O. mirabilis as an opportunistic pathogen of human and animals.