Assessing the microbiological contamination along with environmental factors of old books in the 1490-founded Bistrița Monastery, Romania

International audienceMicrobial contamination and damaging effects due to environmental factors (temperature, humidity) of old books is an extremelyimportant issue in the heritage preserving field, being a great threat to this unique cultural and literary treasure. This paperanalysed the indoor environmental conditions, the microbiological characteristics of the air and the condition itself of 27 clericalbooks (from eighteenth to nineteenth centuries), randomly chosen from the library of Bistrița Monastery, Romania. The analysisrevealed that most of the books were contaminated and damaged by moulds and yeasts. The statistical analysis (chi-square test)shows that the incidence of mould species was not coincidental. The most common isolated fungi discovered on old books werePenicillium spp. (40.7%), Cladosporium spp. (33.3%) and Fusarium spp. (29.6%). Fungal contamination was observed in 17books. Microbiota air tests have shown possible contamination by air flow. Often, the measured temperature/humidity values arenot in line with the requirements of the legislation in force, especially during the cold seasons, the average minimum temperaturevarying from 3 to 6 °C to an average maximum temperature of 22–25 °C; the values of relative humidity were between 27 and77%. In terms of storage conditions, the recorded values of temperature and humidity are extremely harmful to the storeddocuments. Therefore, these indoor environmental conditions have to be improved, in order to reduce/eliminate potential sourcesof fungal contamination and to achieve optimal environmental preserving conditions