Abstract

Acacia nilotica was assessed for active principles. The results showed that the stem bark extract of the plant possessed the active principles e.g. terpenoids, tannins, alkaloids, saponins and glycosides. The antimicrobial activity of the extracts was assayed against Streptococcus viridans,Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Shigella sonnei using the agar diffusion method. The plant extract exhibited antimicrobial activity against all the test microorganisms. B. subtilis was the most susceptible to the plant extract while Candida albicans was the most resistant. The minimum inhibitory concentration of the stem bark extract of the plant ranged between 35 and 50 mg/ml while the minimum bactericidal concentration ranged between 35 and 60 mg/ml. A. nilotica could be a potential source of antimicrobial agents.

Key words: Acaacia nilotica, active principles, microorganisms.