Nanoplastics as a substrate for fungal growth Lecanicillium coprophilum (Cordycipitaceae, Hypocreales)

Abstract

Anthropogenic pollution of the environment by plastic waste represents one of the most serious environmental problems. Nanoplastics, particles smaller than 1000 nm, pose a particular danger, as their small size and high specific surface area result in high bioavailability and toxicity for a wide range of aquatic organisms. Fungi are promising candidates for cleaning contaminated ecosystems due to their metabolic capabilities for breaking down complex molecules. In this study, for the first time, we experimentally investigated the ability of the micromycete, Lecanicillium coprophilum, to use nanoparticles of synthetic polymers–polyvinyl chloride (PVC), polystyrene (PS), and polymethyl methacrylate (PMMA)–as a growth substrate. Fluorescence microscopy and measurements of polymer concentrations in the medium proved that this fungus can not only adsorb nanoplastics on the surface of its hyphae but also metabolize them. Non-parametric analysis of variance (Kruskal-Wallis test) revealed statistically significant differences in mycelial biomass accumulation in media containing different plastics at 10°C. PS was the most favorable substrate for the growth of L. coprophilum. The median mycelial biomass values demonstrated a consistent ranking of polymers by favorability: PS > PMMA > PVC, which remained across different cultivation temperatures. This paper also discusses the enzymatic activity of L. coprophilum and the potential contribution of enzymes, particularly lipases, to the biodegradation of nanoplastics by this fungal species.