In vitro potential of endophytic fungus Aspergillus terrus (JAS-2) associated with Achyranthus aspera and study on its culture conditions

Abstract

The present study explores the efficacy of an endophytic fungus from symbiotic plant Achyranthus aspera, an herb of medicinal importance. Considering limitation of secreted fungal metabolites in terms of biologically active molecules; an endeavour was made to increase the amount of secreted active product. Enhanced secretion of active compound was observed by optimizing different parameter of culture conditions. The fungal culture was isolated from stem of Achyranthus aspera and taxonomically identified as Aspergillus terreus. While analysing it's different in vitro potential, culture metabolites showed antibacterial, antifungal and anti-oxidant activity. In order to increase the yield of compound, culture was optimized for different parameters such as carbon and nitrogen sources and extracting solvent. All the optimization was performed based on % inhibition of bacterial growth when challenged with 10 μg/μl metabolite concentration. Among different media used, potato dextrose broth (PDB) and sabouraud's dextrose broth (SDB) proven to be better media for growth of fungus as well as metabolites production. 1% yeast extract and 4% dextrose resulted in higher cell inhibition. Ethyl acetate served as good extracting solvent.