Isolation of epiphytic yeasts from Eugenia dysenterica DC. fruits and evaluation of their antimicrobial activity against phytopathogenic fungi

Resumo

Plants commonly interact with microorganisms that may influence their physiology and performance. Epiphytic yeasts are microorganisms that can be found in the phylosphere, in significantly larger numbers in fruits than in other plant tissues due to their higher nutritional content. The present study aimed to contribute to knowledge of epiphytic yeasts associated with Eugenia dysenterica DC. fruits and to evaluate their antimicrobial activity against phytopathogens. E. dysenterica fruits were collected, washed in saline solution, and sonicated. Each fruit solution was plated in three Petri dishes with NYDA medium. Yeast identification was performed through morphological and physiological criteria, and richness evaluation was performed using the Jackknife 1 estimator. All isolated yeasts were tested for diffusible substances against three phytopathogenic fungi. Only four of 42 isolates were inhibited sporulation of Aspergillus parasiticus, but none was able to inhibit or diminish mycelium growth of any tested phytopathogen. The present study contributes to the characterization of the E. dysenterica microbiome, presenting the first report of in vitro A. parasiticus sporulation inhibition by epiphytic yeasts and suggesting their promising use in biological control of this phytopathogen.