Abstract

Trapa natans L. fruit rind was extracted in different solvents with increasing polarity; 1,4-dioxan, chloroform, acetone, dimethylformamide, ethanol and water.  The extractive yield ranged from 0.62 – 12.62%. The antibacterial activity of all the extracts was determined by agar disc diffusion method.  Maximum antibacterial activity was observed against Gram negative bacteria. The resistant Gram negative strains were C. fruendii,E. aerogenes, E. coli, P. vulgaris, P. aeruginosa and S. typhimurium.  Amongst Gram positive bacteria, M. flavus was the most susceptible bacteria and B. subtilis was most resistant. The moulds showed better antifungal activity than yeast. A. niger was the most resistant fungal strain. The best antimicrobial activity was with 1,4-dioxan extract and the least activity was with petroleum ether extract. The inhibitory effects of the extracts were comparable with the standard antimicrobics used.  This work has highlighted the antimicrobial effects of fruit rind of Trapa natans L. on some of the medically important pathogens.

Key words: Trapa natans L, antimicrobial, pathogenic microorganisms, polar solvents, non-polar solvents.