737ASSAY OF ANTIMICROBIAL ACTIVITY OF ROOT EXTRACTS OF OROXYLUM INDICUM (L.) VENT. AGAINST SEVEN PATHOGENIC BACTERIARoots of medicinally important and endangered tree Oroxylum indicum (L.) Vent is a source of various important flavonoids, has been a long standing history in many ayurvedic preparations & continues to provide remedies for many harmful diseases. To analyze the effect of different flavonoids present in the crude root extract, they have been separated by fractionization. Antimicrobial assay of different fractions (chloroform, ethyl acetate, n -butanol and aqueous) of crude methonolic extract of root of O. indicum was observed against seven pathogenic bacterial strains named Klebsiella pneumoniae, Staphylococcus epidermidis, Bacillus subtilis, Escheirchia coli, Listeria monocytogens, Pseudomonas aeruginosa and Staphylococcus aureus. Antibacterial action of all fractions is an indication of presence of antipathogenic potential possessing flavonoids in each fraction. Among the entire fractions n-butanol fraction was a strong growth inhibitor of Staphylococcus epidermidis, Listeria monocytogens and Pseudomonas aeruginosa. Staphylococcus epidermidis was highly susceptible for nbutanol, ethyl acetate and chloroform fractionsmamtashrirang@gmail.comResearch732016Medicinal plant,Oroxylum indicum (L.) Vent,root extract,antibacterial activity, pathogenic bacterial strains, a gar well diffusion assay,standard errorGokhale Mamta,Saini MonicaSt. Aloysius College, Assistant Professor, Department of Botany and Microbiology, Sadar Cantt., 4 82001, Jabalpur, Madhya Pradesh, India,St. Aloysius College, Assistant Professor, Department of Botany and Microbiology, Sadar Cantt., 4 82001, Jabalpur, Madhya Pradesh, India