Antimicrobial and antioxidant properties of fungal endophytes associated with Piper mullesua Buch.-Ham. Ex D. Don.

Endophytes are microscopic organisms that live inside plants without causing disease. Among them, endophytic fungi are important biological resources known to produce pharmaceutically important metabolites. Several important bioactive metabolites of endophytic fungal origin have been identified and are being considered for large scale production. Their types and quantity vary from plant to plant; thus, they need to be investigated from new plant sources. Piper mullesua is a vital medicinal plant frequently used by indigenous populations of Arunachal Pradesh, India but not been examined so far. This investigation aims to identify fungal endophytes from the roots of P. mullesua and assess their antimicrobial and antioxidant activities. Total 5 endophytic fungi identified as Colletotrichum gloeosporioides (OR136407), Fusarium oxysporum (OR136409), Fusarium solani (OR136405), Gliocladiopsis tenuis (OR136407) and Penicillium crustosum (PP706771) were isolated from P. mullesua roots. Crude extract of P. crustosum and G. tenuis exhibited significant antimicrobial and antioxidant activities compared to others. P. crustosum was reported to produce a considerably higher zone ofinhibition against pathogenic bacteria Enterococcus faecalis, Escherichia coli, Proteus vulgaris and Staphylococcus aureus with notably higher antioxidant activity than G. tenuis. The antioxidant activity index (AAI) and ferric reducing antioxidant power value were found to be 4.5 ± 0.01 and 936.68 ± 9.9 for P. crustosum and 1.02 ± 0.0 and 263.93 ± 10.9 for G. tenuis respectively. This is the first report on the antimicrobial and antioxidative properties of G. tenuis, highlighting the potential of endophytes as sources of pharmaceutically important metabolites. Bio-prospecting of fungal endophytes, thus, is an important task that may lead to new drug discovery.