Molecular detection and antimicrobial activity of Endophytic fungi isolated from a medical plant Rosmarinus officinalis

Abstract

Endophytes are tiny organisms present in living tissues of distinct plants and have been extensively studied for their endophytic microbial complement. Roots of Rosmarinus officinalis were subjected to the isolation of endophytic fungi and screened for antimicrobial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) bacteria. Genomic DNA from active fungal strain of Trichoderma harzia was isolated, and the internal transcribed spacer (ITS) region was amplified using ITS4 and ITS5 primers and sequenced for genetic inference in fungus. The crude extract of T. harzia isolate with Ethyl acetate was showed significant antimicrobial activity against P. aeruginosa, S. aureus, K. pneumonia, B. subtilis and E. coli. The antimicrobial activity was highest against P. aeruginosa at concentration of 40µg/ml, followed by S. aureus and K. pneumonia at the same concentration. The lowest antimicrobial activity was against by S. aureus at concentration of 60µg/ml. The current study is confirmed that the antimicrobial activity is due to bioactive compounds founded in endophytic fungi.