Biotechnology: Innovative Contributions to the Conservation and Restoration of Cultural Heritage

As exhaustively showed during the conference "Molecular Biology and CulturalHeritage", held in Seville in 2003, molecular biology represents an important source of insight forthe development of innovative protocols for the detection and characterization of microbialconsortia colonizing historic-artistic manufacts. In particular, fungi and bacteria (frequentlyassociated with green algae, cyanobacteria, lichens, etc), wide-spread in biosphere environments,are the main biological systems related to deterioration of cultural asset. Moreover in the aerosolof indoor environments, whre the manufacts are exposed or stored, complex microbiaicommunities may release some molecules with human (visitors, professionals) health damagingproperties, that may persist during the time. In order to identify the biological systems on artworkssurface andJor dispersed in the aerosol, an integrated morphological-molecular protocol based onmicroscopy (OM, SEM, CLSM), in vitro culture (colonies isolation) and amplification of DNAtarget sequences (PCR, sequencing, sequence-comparison) have been applied. Non invasivesamplings were performed by sterile swab, adhesive tape or Nylon H+ membrane (Amersham) onwork of art surfaces, while aerosol sampling by portable AirPort MD8 sampler (Sartorius),equipped with disposable gelatine filters.Recently, in our laboratory, new bioactive molecules (BMs) extracted from marineinvertebrates organisms have been characterized and tested in order to remove protein layers(bio-c1eaning by Proteolytic-peptides = BMP) or to control the bacteria and/or fungi colonizationonto artifacts (Antimicrobial-peptide = BMA).The action of c1eaning represents one of the most important step in restoration projects, suchas take out organi c layers (animai glue or other protein mixtures, frequent1y deteriored) stratifiedonto the manufact surface. Cleaning must be selectively performed, making distinction betweendifferent areas, removing the deposits without acting direct1y to originaI materials ofthe manufact.Particularly interesting is that the Proteolytic-peptides (BMP) start to act from 4°C up to37°C. We tested the BMP molecules on different substrates and temperatures, between 19-26°C.The related commerciaI enzymes, actually used in bio-c1eaning procedures, work at specific rangeof temperature ~ 37°C; temperature value represents a limit in the use of these enzymes, sincethe heating of manufact surface is usually not available. The opportunity to apply BMP moleculeon several substrates, both organic and inorganic (canvas, wooden, ceroplastics, mosaic, frescos),without heating (surface or enzyme solution), improve the efficiency of bio-c1eaning protocols,according to the conservative-restoration procedure.Concerning BMA peptides, their Antimicrobial (biostatic-biocide) activity was in laboratorypreliminary assessed; particular1y against Bacillus / Micrococcus and Aspergillus / Penicilliumcolonies. We focalized the attention on the painting lining process, usually performed by newcanvas (natural or synthetic) layers glued by rabbit- skin or others animai adhesives to the verso ofdegraded paintings; generally, this procedure is performed by using a heat source (iron). Thisheating-treatment and the presence of organic compounds (glue) can induce microbialcolonization.Since these methodologies are totally safe for the operators and environment, are low time-consuming, they can be considered as a sustainable alternative to the traditional procedures.