Dry biocleaning of artwork: an innovative methodology for Cultural Heritage recovery?

An innovative methodology is proposed, based on applied biotechnology to the recovery of altered stonework: the dry biocleaning, which envisages the use of dehydrated microbial cells without the use of free water or gel-based matrices. This methodology can be particularly useful for the recovery of highly-ornamented stoneworks, which cannot be treated using the conventional cleaning techniques. The experimental plan included initial laboratory tests on Carrara marble samples, inoculated with dehydrated Saccharomyces cerevisiae yeast cells, followed by on-site tests performed on Quattro Fontane (The Four Fountains), a travertine monumental complex in Rome (Italy), on altered highly ornamented areas of about 1,000 cm(2). The mechanism is based on the spontaneous re-hydration process due to the environmental humidity and on the metabolic fermentative activity of the yeast cells. Evaluation by physical-chemical analyses, after 18 hours of the biocleaning, confirmed a better removal of salts and pollutants, compared to both nebulization treatment and control tests (without cells). The new proposed on-site dry biocleaning technique, adopting viable yeast cells, represents a promising method that can be further investigated and optimized for recovering specific altered Cultural Heritage stoneworks.

Automated summary

The innovative methodology proposes the use of dry biocleaning with dehydrated microbial cells for the recovery of altered stonework, showing better removal of salts and pollutants compared to traditional cleaning techniques. The on-site tests demonstrated the effectiveness of the spontaneous re-hydration process and metabolic fermentative activity of yeast cells in the recovery process. Adopting viable yeast cells in the dry biocleaning technique presents a promising method for further investigation and optimization in recovering specific altered Cultural Heritage stoneworks.