Search for new surface active compounds of microbial origin in view of the development of biorestorarion techniques

Abstract: The research presented here lies within the biotechnology sector of the field of Preservation and Restoration of Cultural Heritage. This work aims to contribute to the search for new molecules of microbial origin for biorestoration, in order to offer an effective alternative, or a suitable support to traditional methods, both chemical and mechanical, in those cases where these are not effective, or require the use of potentially harmful products. In particular, the research is focused on novel Surface Active Compounds (SACs) of microbial origin. These non-toxic and environmentally safe biopolymers exhibit a surface activity, and have physico-chemical properties suitable for removing undesirable surface deposits from artistic surface. The work presented is divided into three different phases: - preliminary screening of bacterial strains, belonging to the ENEA-Lilith Strain Collection, to identify manufacturers of SACs, followed by optimization of the production of SACs by the selected strain, Pedobacter sp. (MCC-Z), and the development of the purification procedure of SACs products; - study of the emulsifying properties and antimicrobial characteristics of the SAC; - testing of the cleaning capability of the new product, called Bio-Z, on artificial specimens and then on real specimens, via cleaning tests conducted on the frescoes of Casina Farnese, situated within the archaeological site of the Palatine Hill in Rome. Although the completion of a new bio-cleaning procedure using Bio-Z still requires further refinement, the characteristics of the bio-product which have so far been identified, i.e. an effective surfactant capacity, stability not only over time, but also to changes in pH, temperature and salinity, effective emulsifying, antimicrobial activity, lack of toxicity, biodegradability, provide the foundations for designing Bio-Z as a new product for biorestoration.