Diversity and antimicrobial activity of endophytic fungi associated with the alpine plant Saussurea involucrata.

Endophytic fungi are rich in species diversity and may play an important role in the fitness of their host plants. This study investigated the diversity and antimicrobial potential of endophytic fungi obtained from Saussurea involucrata KAR. et KIR. A total of 49 endophytic fungi were isolated from S. involucrata and identified using morphological and molecular techniques. Extracts of fermentation broth from the 49 fungi were tested for antimicrobial activity against pathogenic microorganisms using the agar diffusion method. Forty-eight out of the 49 endophytic fungi were identified and grouped into 14 taxa. Cylindrocarpon sp. was the dominant species isolated from S. involucrata, followed by Phoma sp. and Fusarium sp. Among the 49 endophytic fungi, 9 root isolates having darkly pigmented, septate hyphae were identified as dark septate endophytic (DSE) fungus, and 12 fungi inhibited at least one test microorganism. Moreover, 5 strains showed a broader spectrum of antimicrobial activity and 4 strains displayed strong inhibition (+++) against pathogenic fungi. The results indicate that endophytic fungi isolated from S. involucrata are diverse in species and a potential source of antimicrobial agents.