Study of the mechanism of ε-poly-l-lysine as an antifungal on Candida albicans and Saccharomyces cerevisiae

• Published in: Biochimica et biophysica acta. General subjects Vol. 1866; no. 10; p. 130197
• Main Authors: Padilla-Garfias, Francisco, Ríos-Cifuentes, Laura, Sánchez, Norma Silvia, Calahorra, Martha, Peña, Antonio
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2022
• Subjects: acidification; antifungal properties; Antifungals; Antimicrobial; calcium; Candida; Candida albicans; cations; cell viability; fermentation; mechanism of action; membrane potential; minimum inhibitory concentration; peptides; phosphates; plasma membrane; Polycations; reactive oxygen species; Saccharomyces; Saccharomyces cerevisiae; yeasts; ε-poly-l-lysine; Antimicrobial; Antifungals; Saccharomyces; ε-poly-l-lysine; Polycations; Candida
• ISSN: 0304-4165; 1872-8006; 1872-8006
• DOI: 10.1016/j.bbagen.2022.130197

The antimicrobial activity of ε-poly-l-lysine (EPL) has been documented, but its antifungal activity on yeast is not well defined and its mechanism of action has been vaguely explained. Our studies revealed that on both, Candida albicans and Saccharomyces cerevisiae, the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) were 250 μg·mL−1; EPL produced a K+ and Ca2+ efflux, and at higher concentrations also an efflux of material absorbing at 260 nm, small peptides, and phosphate is produced, along with the inhibition of fermentation and extracellular acidification and respiration. Moreover, growth was inhibited, reactive oxygen species (ROS) production increased, and cell viability decreased. The polycation also produced plasma membrane potential hyperpolarization. The effects were dependent both on the cell quantity and polycation concentration, as well as the media used. The plasma membrane disruption was confirmed by TEM and PI staining. [Display omitted] •EPL produced an efflux of ions and intracellular molecules.•The aerobic and anaerobic metabolism of yeasts is affected by EPL.•An inhibition of H+-ATPase and the hyperpolarization of the cells was observed.•EPL induced ROS accumulation also contributing to decrease cell viability.•Important plasma membrane and cell wall damage is caused by this polymer.