Biodeterioration of epoxy resin: a microbial survey through culture‐independent and culture‐dependent approaches

Abstract

During the 20th century, synthetic polymers were greatly used in the field of art. In particular, the epoxy resins were used for both conservation and for creating sculptures. The biodeterioration of these polymers has not been adequately studied. The aim of this investigation was to examine the microflora responsible for the deterioration of an epoxy statue exposed to outdoor conditions. Fungal and bacterial microflora were isolated from the art object, clustered by fluorescence-ITS (internal transcribed spacer), identified by ITS and 16S rRNA sequencing and tested for their lipolytic abilities by three agar assays. Different algal, bacterial, cyanobacterial and fungal clone libraries were constructed. The surrounding airborne microflora was analyzed using culture-dependent and culture-independent approaches. The results indicated the presence, on the statue surface, of an interesting and differentiate microbial community composed of rock-inhabiting members, algal photobionts (Trebouxia spp., Chloroidium ellipsoideum and Chlorella angustoellipsoidea), Cyanobacteria (Leptolyngbya sp., Phormidium sp., Cylindrospermum stagnale, Hassallia byssoidea and Geitlerinema sp.), black yeasts related to the species Friedmanniomyces endolithicus, Pseudotaeniolina globosa, Phaeococcomyces catenatus and Catenulostroma germanicum and several plant-associated fungi. This investigation provides new information on the potential microfloral inhabitants of epoxy resin discovering a new ecological niche, occupied mainly by several members of rock-colonizing microbial species.

Paint-degrading microorganisms

“…The most frequently isolated bacteria present on surfaces coated with epoxy resins belonged to the Firmicutes phylum, especially the genus of Bacillus. γ-Proteobacteria, and particularly Pseudomonas, were also frequently detected [14]. Similar results were obtained by Cappitelli et al [15], who studied surfaces coated with epoxy resins and isolated Gram-positive bacteria of the Bacillus, Brevibacillus, Micrococcus, Staphylococcus and Kocuria genus, as well as Gram-negative bacteria from the genus of Pseudomonas, Agrobacterium and Ochrobacter [15].…”

“…Similar results were obtained by Cappitelli et al [15], who studied surfaces coated with epoxy resins and isolated Gram-positive bacteria of the Bacillus, Brevibacillus, Micrococcus, Staphylococcus and Kocuria genus, as well as Gram-negative bacteria from the genus of Pseudomonas, Agrobacterium and Ochrobacter [15]. In addition, researchers [14] identified several species of black yeast: Friedmanniomyces endolithicus, Pseudotaeniolina globosa, Phaeococcomyces catenatus and Catenulostroma germanicum.…”

“…[13]. Pangallo et al (2015) investigated the biodeterioration of epoxy resins. The most frequently isolated bacteria present on surfaces coated with epoxy resins belonged to the Firmicutes phylum, especially the genus of Bacillus.…”

“…and Cladosporium sp. [9,11,14,15,[32][33][34][35][36] were also frequently found. In addition, Lugauskas et al (2003) identified fungi from the genera of Aureobasidium pullulans, Aspergillus niger, Aspergillus versicolor, Cladosporium cladosporioides, Paecilomyces sulphurellus, Trichoderma viride, Ulocladium atrum as capable of degrading polymer materials [37].…”

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

“…In a recent study (Pangallo et al, 2014) several fungal and bacterial strains were isolated from epoxy resins, which are frequently employed as consolidants of stone materials. The ability of Rhizopus microsporus and Aspergillus fumigatus to grow on an epoxy surface was also shown here for the first time, demonstrating that they have a role in epoxy deterioration.…”