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

As exhaustively showed during the conference "Molecular Biology and Cultural Heritage", held in Seville in 2003, molecular biology represents an important source of insight for the development of innovative protocols for the detection and characterization of microbial consortia colonizing historic-artistic manufacts. In particular, fungi and bacteria (frequently associated 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 aerosol of indoor environments, whre the manufacts are exposed or stored, complex microbiai communities may release some molecules with human (visitors, professionals) health damaging properties, that may persist during the time. In order to identify the biological systems on artworks surface andJor dispersed in the aerosol, an integrated morphological-molecular protocol based on microscopy (OM, SEM, CLSM), in vitro culture (colonies isolation) and amplification of DNA target sequences (PCR, sequencing, sequence-comparison) have been applied. Non invasive samplings were performed by sterile swab, adhesive tape or Nylon H+ membrane (Amersham) on work 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 marine invertebrates 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 colonization onto artifacts (Antimicrobial-peptide = BMA). The action of c1eaning represents one of the most important step in restoration projects, such as take out organi c layers (animai glue or other protein mixtures, frequent1y deteriored) stratified onto the manufact surface. Cleaning must be selectively performed, making distinction between different 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 to 37°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 range of temperature ~ 37°C; temperature value represents a limit in the use of these enzymes, since the heating of manufact surface is usually not available. The opportunity to apply BMP molecule on 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 laboratory preliminary assessed; particular1y against Bacillus / Micrococcus and Aspergillus / Penicillium colonies. We focalized the attention on the painting lining process, usually performed by new canvas (natural or synthetic) layers glued by rabbit- skin or others animai adhesives to the verso of degraded paintings; generally, this procedure is performed by using a heat source (iron). This heating-treatment and the presence of organic compounds (glue) can induce microbial colonization. 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.