Antimicrobial Activity of Endophytic Fungi from Xylaria Species

Abstract

In this present study the isolated endophytic fungi were cultured on PDB and MEB, than the mycelia was separated by filtration after 9 days. It also discusses the antibacterial and antifungal activity of Xylaria species on a group of bacterial and fungal organisms by agar well diffusion method, broth microdilution method and spectrophotometric method.

Against E. coli XF-8 PDB, XF-8 MEB, XF-15 PDB & XF-15 MEB was effective than streptomycin. Against B. megaterium almost all extracts were equally effective. XF-15 PDB was more effective against P. aeruginosa. XF-8 PDB showed pronounced effect against S. aureus as compared with control & other extracts. However in case of fungal culture C. albicans XF-15 PDB has more efficient response. From the result it may concluded that culture grown on PDB show more antimicrobial activity than fungal cultures grown on MEB.

The MIC values obtained from TTC method against B. megaterium was XF-8 PDB, XF-15 PDB >2µg/ml, XF-8 MEB >2.5µg/ml, XF-15 MEB >1µg/ml. MIC value against E. coli was XF-8 PDB, XF-15 PDB & XF-15 MEB >2µg/ml, whereas XF-8 MEB has MIC >1µg/ml. In case of P. aeruginosa the MIC value was XF -8 PDB, XF-15 PDB, XF-15 MEB >1µg/ml & that of XF-8 MEB >1.5µg/ml. MIC value against S. aureus was XF-8 MEB, XF-15 PDB & XF-15 MEB >2µg/ml whereas XF-8 PDB has MIC >1.5µg/ml. The MIC value against C. albicans varied from XF-8 PDB >4 µg/ml, XF-8 MEB >3 µg/ml, XF-15 PDB>6 µg/ml., XF-15 MEB >5µg/ml.

From all these results it is observe that the crude extract of Xylaria species XF-8 & XF-15 showed significant antimicrobial activity against the bacterial cultures E. coli, B. megaterium. S. aureu, P. aeruginosa and also fungal cultures like C. albicans, Aspergillus fumigatus. The instrumental analysis like TLC indicated the presence of amino group in the extracts. Preliminary phytochemical investigation of fungal extracts shows the presence of bioactive metabolite including alkaloids, amino acid, carbohydrates, flavonoids and steroids & terpenoids. Further studies may be carried out to determine the nature of pure compound responsible for antimicrobial activity.