Wicaltin, a New Protein Toxin Secreted by the Yeast Williopsis californica and Its Broad-Spectrum Antimycotic Potential

Wicaltin, a New Protein Toxin Secreted by the Yeast Williopsis californica and Its Broad-Spectrum Antimycotic Potential

The yeast Williopsis californica was shown to secrete a unique broad-spectrum killer toxin (Wicaltin) with antifungal activity against 14 yeast genera, including yeast-like and mycelial forms of the human pathogens Candida albicans and Sporothrix schenkii. Agar diffusion bioassays indicated that its activity was more pronounced than the antifungal potential of frequently used antimycotics; 0.07 pmol Wicaltin showed the same toxicity as 0.2 pmol miconazole and 29 pmol clotrimazole. Since the toxin's primary target would appear to be the yeast cell wall, Wicaltin may be attractive in combatting clinically relevant yeast and fungal infections.