Microbiological contamination in the selected premises of the Jagiellonian University Museum

This study was aimed to assess the seasonal variability of microbial aerosol concentrations in the Jagiellonian University Museum and the fungal contamination of the selected exhibits shown or stored in the JUM. The air contamination analysis was conducted four times per year by air collision method. The concentrations of mesophilic bacteria, mold fungi, actinomycetes and staphylococci were examined in the magazine of exhibits in the attic, at the Olszewski Hall (exposure), in the wooden frames magazine in the basement and the Museum cafe. External background was the Professors’ Garden. In the study sites air temperature was measured during each sampling. The surface contamination of the Museum exhibits was examined by the collection of swabs. Seasonal differences in the concentration of the analyzed microorganisms were observed: the concentration of all microbial groups - except fungi - was the highest in summer, when the temperature in all tested sites was the highest. On the other hand, the highest concentrations of fungi in the tested premises were observed in autumn and spring. The smallest levels of mesophilic bacteria and staphylococci were observed in winter, while the smallest amounts of actinomycetes were found in spring and autumn. The smallest concentrations of fungi in all examined sites occurred in spring. The concentrations of the analyzed microorganisms did not exceed the limit values, except in one case - i.e. actinomycetes in the Museum cafe in summer. The surfaces of the exhibits were colonized by fungal strains that can be potentially dangerous to human health or cause biodeterioration, but only one object (the Wyspiański painting) was damaged by a harmful strain of Penicillium italicum. Other objects showed no losses due to microbial degradation, which proves effective conservation and lack of optimum conditions for fungal colonization. We also found a relationship between the concentration of microbial aerosol and the conditions in the studied sites, and therefore the season of the year. Also the type and utility character of the premises determined the bioaerosol concentrations. However, the observed concentrations of airborne microorganisms do not pose a direct threat to the Museum employees or its visitors.