Antibacterial activity of the seaweed Gracilaria edulis associated epiphytic bacteria against human bacterial pathogens

摘要

Bacteria associated with marine sources are rich in bioactive metabolites. Epiphytic bacterial strains associated with the seaweed Gracilaria edulis (Rhodophyta, Gigartinales, Gralilariaceae) distributed along Tuticorin coast, were studied for antibacterial activity against 10 human pathogenic bacteria. The epiphytic strains which showed activity against nine pathogens were further cultured and extracted separately with solvents hexane, ethyl acetate, chloroform and butanol. Wide spectrum activity with an inhibition zone range of 2 to 4 mm was observed in ethyl acetate extract. The bioassay guided fractionation using Column chromatography indicated the non-polar nature of the active substance.