New records of fungi in oleic ecosystems through analyzing olive oil, paste, and pomace from an olive oil production area in northern Italy

Aims: This study analyzed the fungal diversity in oleic ecosystems adopting a culture-based approach. Methods and results: In all, 66 yeasts and 10 filamentous fungi were isolated from samples of olive oil, paste, and pomace collected in a small area of olive oil production in northern Italy. Twenty-three and 7 taxa of yeasts and filamentous fungi were identified with molecular method, respectively. Most yeasts belonged to species commonly occurring in oleic. Conversely, other isolates belonged to species rarely or never found in olive oil and by-products. Filamentous fungal species were recorded for the first time on olive oil. The isolates were tested for β-glucosidase and esterase/lipase activity to evaluate their potential effects on the chemical and sensory properties of olive oil. Significant variations of these activities were observed among isolates. Conclusions: Olive oil and its by-products can harbor significant variability among fungal species having enzymatic activities with potential impact on olive oil quality. The presence of basidiomycetous yeasts and filamentous fungi in stored oil requires further investigation.