Antifungal and Reactive Oxygen Species Response of Saccharomyces cerevisiae to Deep Eutectic Solvents for Bacterial Nanocellulose-Based Eutectogel.

Antifungal resistance is an emerging global challenge that requires new antimicrobial materials and mechanistic insights. This study aims to evaluate the antifungal activity and reactive oxygen species (ROS) response of Saccharomyces cerevisiae (TBR1) exposed to imidazole-based deep eutectic solvents (DESs) and ternary DESs (TDESs), including their incorporation into bacterial nanocellulose (BNC) eutectogels. Minimum inhibitory concentration (MIC) results show concentration-dependent inhibition, with DES exhibiting higher antifungal potency than TDES. However, TDES induces significantly greater ROS production, indicating distinct mechanisms of action. Dead cell assay and scanning electron microscopy (SEM) imaging reveal increased cell death and morphological changes without membrane rupture, supporting oxidative stress-driven intracellular damage. Proton nuclear magnetic resonance (1H NMR) metabolite analysis indicates disruption of carbohydrate metabolism and energy homeostasis. Disk diffusion confirms that antifungal activity is primarily driven by imidazole and retained in eutectogel systems, although with reduced diffusion. Herein, DES and TDES act through membrane interaction, metabolic disruption, and ROS-mediated damage, while BNC integration enables sustained antimicrobial delivery for potential biomedical, drug delivery system, and wound dressing applications.