Antioxidant Activities of Fungal Endophytes Isolated from Strawberry Fragaria x ananassa Fruit

Fragaria x ananassa (strawberry) fruit is one of the most common products of Baguio City and La Trinidad, Benguet, Philippines. In this study, strawberry fruits were sampled for its fungal endophytes. These organisms live within the living tissues of plants without causing any immediate and apparent negative effects. The antioxidant activities of fungal endophytes isolated and identified from strawberry fruits were evaluated. Fungal isolates were identified using ITSrDNA. Seven species of endophytes were successfully identified. These species were Sporidiobolus sp., Rhodotorula sp., Pilidium concavum, Corynespora cassiicola, Neodeightonia subglobosa, Aspergillus awamori, and Aspergillus sp. Antioxidant activities of these microorganisms were evaluated using ABTS decolorization assay and DPPH radical scavenging assay. Results showed that two species had antioxidant activities comparable to ascorbic acid. These isolates were Aspergillus awamori DT11 and Corynespora cassiicola DT13. Possibly, these fungal endophytes contribute to the total antioxidant system of the plant. Also, these fungal endophytes may also be contributors to the nutritive value of the strawberry fruits.