  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 harzianum 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. harzianum
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 40
microgram/ ml, followed by S. aureus and K. pneumonia at the same
concentration. The lowest antimicrobial activity was against by S. aureus at
concentration of 60 microgram/ ml. The current study is confirmed that the
antimicrobial activity is due to bioactive compounds founded in endophytic
fungi.
