Antioxidant and antimicrobial activity displayed by a fungal endophyte Alternaria alternata isolated from Picrorhiza kurroa from Garhwal Himalayas, India

Harish Chandra^a,1, Pragati Kumari^b, Rajendra Prasad^c, Sateesh Chandra Gupta^d, Saurabh Yadav^e

Department of Medicinal and Aromatic Plant, High Altitude Plant Physiology Research Centre, Hemvati Nandan Bahuguna Garhwal (Central) University, Srinagar Garhwal, Uttarakhand, 246174, India.

Abstract

Picrorhiza kurroa (Kutki) is a medicinal plant of Himalayan region which was exploited for its fungal endophytic association. Endophytic fungi isolated from plants have plant growth promoting attributes and biocontrol activity. We have isolated endophytic fungi to investigate the bioactive compounds which was used for the biocontrol of bacteria of clinical importance. The morphological analysis as well as the molecular characterization using 18s rRNA and phylogenetic analysis, identified the fungus as Alternaria alternata. Investigation using GC-MS of methanolic and ethyl acetate extracts of fungal biomass, led to identification of many bioactive compounds. These chemicals have various medicinal purposes such as antimicrobial activity and antioxidant potential. Our results suggest that these compounds may have clinical importance. The extract from A. alternata was capable of inhibiting B. subtilis and S. aureus. This is the first study conducted about role of secondary metabolites produced by Alternaria alternata isolated from the Picrorhiza kurroa, possessing antibacterial properties and the bioactive compounds may have potential medicinal relevance.

Keywords: Endophytic fungi, Picrorhiza kurooa, Alternaria alternata, Antimicrobial, Antioxidant, Medicinal plants.