Screening of new isolates fungal strains for polygalacturonase production in submerged fermentation

Résumé

Thirty–two fungi isolate belonging to the genera Aspergillus, Fusarium and Mucor were isolated from fungal contaminated fruits (Green beans, grape, cucumber, plantain, banana and oranges). Nine pectinolytic fungi were selected based on the screening of the isolates on solid agar using pectin as the single carbon source. The selected strains belong species: Fusarium compactum, Aspergillus flavus, Aspergillus tamarii, Aspergillus sclerotioniger, Aspergillus parasiticus, Aspergillus terreus, Mucor piriformis, Aspergillus piperis and Aspergillus niger. The selected isolate were used for polygalacturonase production in submerged fermentation using different substrates derivated from fruits, pure citrus pectin, mango peels, watermelon peels, plantain peels and banana peels. The polygalacturonase yield ranged from 0.0212 - 5.8850 U/ml in which Aspergillus tamari produced the highest level of enzyme by cultivation on medium containing pure citrus pectin. The studies confirm that some selected fungal species isolated from contaminated fruits can be used for polygalacturonase production.