From Biodeterioration to Creativity: Bioreceptivity of Spruce Pine 87 Glass Batch by Fungi

Abstract

The bioreceptivity, and the consequent biodeterioration of contemporary glass, used by artists worldwide, was studied. The two main objectives were: first, to verify if fungi with some culture media would produce more damages than the same fungi without a nutritional source, and to verify if the two genera of fungi produce the same damage on the same glass. Colourless glass samples with Spruce Pine 87 Batch (SPB-87) composition were inoculated with two distinct fungal species, Penicillium chrysogenum and Aspergillus niger, separately: (i) half with fungal spores (simulating primary bioreceptivity), and (ii) half with fungi in a small portion of culture media (simulating organic matter that can be deposited on exposed glassworks, i.e., secondary bioreceptivity). The alteration of glass surfaces were analysed by Optical Microscopy, SEM-EDS and µ-Raman. The mycelium of Penicillium chrysogenum generated a higher amount of fingerprints, stains and iridescence, whereas Aspergillus niger produced more biopitting and crystals on the glass surface. However, both species damaged the glass to different degrees in 4 and 6 months after the inoculation, producing physico-chemical damage (e.g., iridescence, biopitting), and chemical alterations (e.g., depletion and deposition of elements and crystals). The primary bioreceptivity experiment of glass samples inoculated with Aspergillus niger results in less damage than in the case of secondary bioreceptivity, being almost similar for Penicillium chrysogenum. The new and in-depth understanding of the bioreceptivity and deterioration of post-modern glass art and cultural heritage provided here is of paramount importance for the scientific, conservation and artistic communities – to protect glass cultural materials, or seen by artists as innovative and inspirational ways of creating glass art in the future.