β-(1 → 3)-Glucanolytic yeasts from Brazilian grape microbiota: production and characterization of β-glucanolytic enzymes by Aureobasidium pullulans 1WA1 cultivated on fungal Mycelium.

A total of 95 yeast strains were isolated from the microbiota of different grapes collected at vineyards in southern Brazil. The yeasts were screened for β-(1 → 3)-glucanases using a newly developed zymogram method that relies upon the appearance of clearance zones around growing colonies cultured on agar–botryosphaeran medium and also by submerged fermentation on nutrient medium containing botryosphaeran, a (1 → 3),(1 → 6)-β-d-glucan. Among 14 β-(1 → 3)-glucanase-positive yeasts identified, four strains produced the highest β-glucanolytic activities and were evaluated for enzyme production on cellobiose, botryosphaeran, and mycelial biomass from Botryosphaeria rhodina (MAMB-05).