• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.81-87
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• 2005

This study was performed to investigate the antimicrobial activities of the Plagiorhegama dubium extracts against food-borne pathogens. The methanol extract was partitioned into petroleum ether, chloroform, ethyl acetate, and methanol portions. The antimicrobial activity of the P. dubium extracts was determined using a paper disc method against food-borne pathogens and food spoilage bacteria. The methanol extracts of P. dubium showed the highest antimicrobial activity against Staphylococcus aureus and Escherichia coli. The synergistic effect has been found in combined extracts of P. dubium and Hedyotis diffsa as compared to each extracts alone. Finally, the growth inhibition curve was determined using methanol extracts of P. dubium against S. aureus and E. coli. The methanol extract of P. dubium showed strong antimicrobial activity against S. aureus at the concentration of 4,000 ppm. The 4,000 ppm of ethyl acetate portion from P. dubium retarded the growth of S. aureus more than 36 hours and E. coli up to 60 hours. The methanol extracts of P. dubium has been shown the antimicrobial activity against S. aureus and E. coli.