Effects of Chitosan on Candida albicans: Conditions for Its Antifungal Activity

Figure 13

Postulated action mechanism of low to medium concentrations of chitosan. (1) Chitosan, because of its positively charged amino groups binds to the surface of the cells; (2) this produces the displacement of the K⁺ attached to the surface, disrupting the equilibrium between the electric plasma membrane difference and the relative internal/external concentrations of the cation; (3) this loss of equilibrium results in the efflux of K⁺; (4) the efflux of positively charged potassium ions results in an hyperpolarization of the plasma membrane; (5) the hyperpolarization of the plasma membrane greatly increases the uptake of Ca²⁺ and the efflux of negatively charged small molecules, and (6) metabolic functions as fermentation and respiration are also affected.