Gymnoascus arxii's potential in deteriorating woollen textiles dyed with natural and synthetic dyes

•Gymnoascus arxii was isolated from contemporary woollen textile.•The fungus was identified by means of classical and molecular techniques.•A woollen textile was dyed with natural and synthetic dyes.•Gymnoascus arxii triggers a quick and severe destruction of dyed woollen textiles.•Readily available nutrients may inhibit living processes of the keratinolytic strain.

So far, very little is known about microbiological deterioration of dyed woollen textiles. In this paper, the influence of the Gymnoascus arxii fungus on woollen textiles dyed with natural and synthetic dyes was studied. What is more, it was analysed whether the enrichment of the culture medium with additional nutrients has any impact on the deterioration of dyed woollen fabrics caused by a strongly keratinolytic strain. The study was carried out by means of a pure culture method over three different time periods, i.e. 1, 2 and 4 weeks. Within a week, the pure Gymnoascus arxii strain led to a severe deterioration in the mechanical strength of the examined woollen textiles, with the raw fabric being the most severely damaged. After the two-week incubation period, only the fabrics coloured in yellow, i.e. the fabric dyed with natural dye weld, and the synthetic yellow textile as well as the textile dyed with natural dye indigo survived, exclusively on the enriched medium. Solely the weld dyed textile withstood the four-week culture on the nutrient-enriched medium. The conducted studies demonstrated a strong influence of Gymnoascus arxii on dyed fabrics leading to their irreversible destruction. It has been also shown that the presence of nutrients in the substrate that are readily available to microorganism may hinder the development of the Gymnoascus arxii strain and thus, prevent textile deterioration.