Twelve isolates of endophytic bacteria from Rosmarinus officinalis (Rosemary) have been screened for their
potential in preventing growth of pathogens (Bacillus subtilis, Staphylococcus epidermidis, Serratia marcescens, Proteus
vulgaris, Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, Fusarium oxysporum,
Acremonium solani, Aspergillus flavus and Penicillium griseofulvum) in addition to non-pathogenic Aspergillus columnaris
and Aspergillus ochraceus. Endophytic bacterial isolates displayed considerable antimicrobial activity. The mean zones of
inhibition produced by the different bacterial endophytes fluctuated between one and 49 mm. The most active endophyte
inhibited growth of Staphylococcus epidermidis (28.67mm), Serratia marcescens (48.67mm) and Bacillus cereus (10mm).
16S rRNA sequence has been deposited in the NCBI GenBank database under accession number: MH093646 (Bacillus
subtilis). Metabolic profiling analysis by GC-MS revealed that five compounds were major constituents of the crude
extract obtained from endophytic Bacillus subtilis MH093646; (Cyclo-hexanone / 2-butoxy-Ethanol / Acetic acid, butyl
ester / Propanoic acid, ethyl ester and 2-Butoxyethyl acetate). Twelve chemical constituents were identified from the crude
extract of Rosmarinus officinalis. Alpha-Pinene / Camphene / 3-Carene / p-Cymene / D-Limonene / Bornyl acetate and
Caryophyllene compounds had antimicrobial properties. Data indicated that antimicrobial activity of Rosmarinus
officinalis is not related to the activity of the endophytic bacteria.