Non-conventional yeasts as biocontrol agents against fungal pathogens related to postharvest diseases

There are numerous investigations related to biological control and the use of microorganisms as new control strategies. In this sense, yeasts have been reported to have biocontrol activity and could be interesting candidates for BCA development. The main goal of this study was to evaluate the antagonist effect of four endophytic yeast, Naganishia antarctica YCPUC12, Aureobasidium pullulans YCPUC14, Cryptococcus terrestris YCPUC16 and Filobasidium oeirense YCPUC41 over the growth of Botrytis cinerea MPC40, Monilinia laxa MPC71, Penicillium expansum MPC102 and Geotrichum candidum MPC115.Three experimental approaches were used to evaluate biocontrol effect of yeast. Two in vitro assays (agar plug diffusion and dual-culture) and one in vivo assay. The results obtained here revealed that the four yeast strains evaluated showed inhibitory effect against the phytopathogens tested. Furthermore, it is indicated that the inhibitory effect by the yeasts over the fungi is differential, suggesting that there could be involved more than one antagonist-mechanism on the part of yeasts. Yeasts produce compounds capable of inhibiting the growth of fungi and, depending on the assay, the evaluated antagonist-yeasts have differential biocontrol effect against these pathogens. Their potential as biocontrol agents for postharvest diseases are interesting, and further investigation is needed to verify the effectiveness of these antagonists.