Aktywność biologiczna i toksyczność nanocząstek srebra pozyskanych na drodze mikrobiologicznej przy udziale grzyba strzępkowego Gloeophyllum striatum

Abstract

Silver nanoparticles (AgNPs) are among the most widely commercialized nanomaterials due to their versatile properties and strong antimicrobial activity, making them valuable in electronics, textiles, cosmetics, and biomedicine. The increasing demand for AgNPs highlights the need for synthesis methods that are cost-effective, rapid, and environmentally sustainable. Biological synthesis, particularly using filamentous fungi, offers an attractive alternative to conventional methods due to their ease of cultivation, high biomass production, and ability to produce metabolites influencing nanoparticle properties. This doctoral dissertation focused on the microbiological synthesis of silver nanoparticles using the brown-rot wood fungus Gloeophyllum striatum DSM 9592 under various process conditions, followed by evaluation of their antimicrobial, cytotoxic, ecotoxic, and synergistic activity with antibiotics. The results confirmed that G. striatum can efficiently synthesize silver nanoparticles, and that synthesis conditions, such as temperature and shaking, significantly affect their physicochemical and biological properties. The synthesized nanoparticles demonstrated antimicrobial activity against tested microorganisms, with fungi showing greater sensitivity than bacteria. The most sensitive organisms included the yeast Malassezia furfur and the bacterium Pseudomonas aeruginosa. Toxicity assessments revealed variable cytotoxic and ecotoxic effects depending on synthesis conditions. Nanoparticles synthesized at 4°C exhibited the lowest cytotoxicity while maintaining antimicrobial effectiveness. Ecotoxicity studies showed the highest sensitivity in the freshwater crustacean Daphnia magna and the lowest in tested crop plants. Overall, nanoparticles synthesized at 4°C without shaking showed the most favorable balance between antimicrobial activity and low toxicity. Additionally, these nanoparticles exhibited synergistic effects with antibiotics, enabling dose reduction. The findings demonstrate that optimization of fungal biosynthesis conditions enables the production of effective antimicrobial nanomaterials with reduced toxic potential.