Fazilath Uzma and Srinivas Chowdappa*
Fungal Metabolite Research Laboratory, Department of Microbiology and Biotechnology,
Bangalore University, Jnana Bharathi Campus, Bangalore – 560 056, Karnataka, India.
A total of 79 endophytic fungal isolates were obtained from four wild medicinal plants-Tinospora cordifolia (Willd.) Hook.f and Thomson (Menispermaceae), Piper nigrum L., Piper longum L. (Piperaceae) and Zingiber officinale Roscoe (Zingiberaceae)from Western Ghats of Karnataka and screen them for antimicrobial and antioxidant potential.Among them, 16isolates depicting good antimicrobial activityby agar plug method (2.33mm-20.66mm) and agar well diffusion method (2.66mm-21mm)against human pathogens were identified by molecular techniques andsubjected to secondary metabolite extraction. The extracts were tested for their antioxidant potential by DPPH assay, ABTS assay, reducing power assay and total phenolic content. The isolate ABR4 (Fusarium solani) of Tinospora cordifoliashowed remarkable antimicrobial activity against the human pathogens at tested concentrations of 20-100µg/ml. The isolate GKS (Aspergillus terreus) of Zingiber officinale demonstrated excellent antioxidant activity (IC50-3.34) as compared to standard Gallic acid (IC50 – 5.54) which has not been reported previously. The findings of the study indicate that endophytic isolates serve as a potential source of novel bioactive products.
Keywords: Endophytic fungi, medicinal plants, antimicrobial, antioxidant, phenolic content.