FUNGI INVOLVED IN BIODETERIORATION OF DOCUMENTS IN PAPER AND EFFECT ON SUBSTRATE.

S. BORREGO; P.BATTISTONI.; P. GUIAMET; I.VIVAR

ACTA MICROSCOPICA

Special Issue from extended papers presented at XIV CIASEM 2017

Año: 2018 vol. 27 p. 37 - 44

0798-4545

Fungi damage valuable documents mechanically, chemically and aesthetically because they form hyphae, excrete pigmentsand organic acids, generating particular local conditions that modify the physical-chemical properties of the differentdocumentary supports. The aims of this research were to determine the fungal genera associated with the paper documentsbiodeterioration and to demonstrate the biofilm formation and the damages. Sampling was done from documents with signsof biodeterioration using sterile cotton swabs. After serial dilutions from the samples, plates with Extract Malt Agar wereinoculated and incubated at 30 °C for 7 days. Additional little fragments of the damage zone from each analyzed documentwere observed using stereomicroscopy, environmental scanning electron microscopy (ESEM) and scanning electronmicroscopy (SEM). To evaluate the biodeterioration potential risk the strains were grown on cellulose, the acids productionand pigments secretion were evaluated too. The genera Aspergillus, Cladosporium, Fusarium and Scopulariopsis werepredominant. Isolated strains excreted acids into the culture medium; most of them grew well on cellulose and a fewexcreted pigments. The formation of a mature biofilm and the production of extracellular polymeric substances by fungi, aswell as a dense biofouling mainly formed by dust mites, were evidenced by the SEM and ESEM observations. Also theobservations showed that these strains were able to attach to paper fibre causing damage on them. The observation underoptical microscopy of dead insect found inside the book showed fungal adhesion on the insect body and SEM support thatthis adhesion was formed by Aspergillus sp.