Microbial communities adhering to the obverse and reverse sides of an oil painting on canvas: identification and evaluation of their biodegradative potential

Abstract

In this study, we investigated and compared the microbial communities adhering to the obverse and the reverse sides of an oil painting on canvas exhibiting signs of biodeterioration. Samples showing no visible damage were investigated as controls. Air samples were also analysed, in order to investigate the presence of airborne microorganisms suspended in the indoor atmosphere. The diversity of the cultivable microorganisms adhering to the surface was analysed by molecular techniques, such as RAPD analysis and gene sequencing. DGGE fingerprints derived from DNA directly extracted from canvas material in combination with clone libraries and sequencing were used to evaluate the non-cultivable fraction of the microbial communities associated with the material. By using culture-dependent methods, most of the bacterial strains were found to be common airborne, spore-forming microorganisms and belonged to the phyla Actinobacteria and Firmicutes, whereas culture-independent techniques identified sequenced clones affiliated with members of the phyla Actinobacteria and Proteobacteria. The diversity of fungi was shown to be much lower than that observed for bacteria, and only species of Penicillium spp. could be detected by cultivation techniques. The selected strategy revealed a higher microbial diversity on the obverse than on the reverse side of the painting and the near absence of actively growing microorganisms on areas showing no visible damage. Furthermore, enzymatic activity tests revealed that the most widespread activities involved in biodeterioration were esterase and esterase lipase among the isolated bacterial strains, and esterase and N-acetyl-β-glucosaminidase among fungi strains.

The assessment of fungal bioaerosols in the crypt of St. Peter in Perugia (Italy)

“…These airborne particles can be deposited on the works of art, and under favourable conditions of temperature, humidity, light and substrate, they can use the different surfaces not just as a physical support for their growth, but also as a nutrient source. This can cause irreversible structural changes or damage to such protected works of art, with a loss of strength and structure, and also changes from an aesthetic point of view (Lopez-Miras et al, 2013). To avoid irreversible deterioration of such artefacts, and to evaluate the indoor biological risk, it is important to periodically carry out aerobiological monitoring of the biological components of the air of their environment, which provides the characterisation of the air quality from a biological point of view, both quantitatively (e.g., degree of contamination) and qualitatively (e.g., presence of potentially biodeteriogens species or with potential allergenicity) (Gravesen, 1979;Kurup et al, 2000).…”

Fungal bioprospecting and antifungal treatment on a deteriorated Brazilian contemporary painting

“…Micro-organisms may have played a major role in the deterioration of the wooden painting, as the high cellulose content of the artwork promotes its susceptibility to microbial deterioration (Okpalanozie et al 2016). Species from the genus Penicillium are common colonizers of paintings (L opez-Miras et al 2013) where they proliferate due to their cellulolytic activity (Seves et al 1996). However, our results showed that strains of A. flavus had higher I CMC values than P. citrinum.…”

“…Species from the genus Penicillium are common colonizers of paintings (López‐Miras et al . ) where they proliferate due to their cellulolytic activity (Seves et al . ).…”

Changes in soil microbial communities at Jinsha earthen site are associated with earthen site deterioration

“…Previous work demonstrated that some Actinobacteria are potentially harmful to the preservation of cultural relics [18][19][20]. Proteobacteria are commonly the most abundant bacteria in soil [21,22], and…”