Mechanisms employed by Debaryomyces hansenii in biological control of anthracnose disease on papaya fruit

The mechanisms of action associated with the biocontrol capacity of Debaryomyces hansenii against Colletotrichum gloeosporioides, causal agent of anthracnose in papaya, were studied by means of in vitro and in situ assays. In vitro the yeast exhibited a variety of different antagonistic mechanisms against the phytopathogenic fungus including: volatile organic compounds (VOCs) production, β-1, 3 glucanase and protease activity, inhibition of spore germination, and the competition for saccharose, glucose, fructose and total carbohydrates. Results in situ indicated that disease incidence and lesion diameter of anthracnose on papaya var. Maradol fruit was significantly reduced with a higher concentration of D. hansenii. Our study indicates that D. hansenii is an excellent agent of control to anthracnose disease on papaya var. Maradol fruit.