Abstract

ISOLATION OF ENDOPHYTIC FUNGI FROM LEAVES OF AZADIRACHTA INDICA AND PRELIMINARY SCREENING FOR ANTIMICROBIAL ACTIVITY

Pranay Jain* and Tarun Kumar

Abstract

Endophytes are microorganisms that reside asymptomatically in thetissues of higher plants and promising source of novel organic naturalmetabolites exhibiting a variety of biological activities. The Objectiveof present study was to isolate endophytic fungal strains from theleaves of Azadirachta indica and screen the isolated strains forantibacterial and antifungal metabolites production. The leaves weresterilized, inoculated in the potato dextrose agar medium and incubatedat 28±2˚C for 7days. A total of 4 strains TK1, TK2, TK3, and TK4were isolated and used for further studies. The strains were cultivatedon potato dextrose broth in 500 ml Erlenmeyer flask containing 200 mlmedium and incubated in BOD shaking incubator for 10-12 days at28±2°C with periodic shaking at 150 rpm. Resulting broth wasseparated from the mycelium and extracted 2-3 times with ethyl acetateto obtain crude extracts. Agar well diffusion method was used to evaluate the antimicrobialpotential of the fungal isolates. Out of these four strains TK3 identified as Aspergillus sp.showed antimicrobial activity against five Gram positive bacteria (Streptococcus pyogenes,Streptococcus mutans, Staphylococcus aureus, Bacillus subtilis, and Bacillus megaterium),two Gram negative bacteria (Escherichia coli and Pseudomonas fluorescens) and five fungalpathogens (Candida tropicalis, Candida glabrata, Candida albicans, Alternaria solani andFusarium graminearum). Zone of growth inhibition against test pathogens ranged between16-36 mm. The results showed the ability of the isolated fungal strain TK3 capable ofproducing antimicrobial compounds and helped in justifying the traditional use ofAzadirachta indica against human pathogenic bacteria.

Keywords: Asymptomatic, Antifungal, Antibacterial, Endophytes, Azadirachta indica.