A COMPARATIVE STUDY OF BIOPOTENTIAL OF CRUDE AND FRACTIONATED EXTRACTS OF SOME SEA WEEDS FROM TUTICORIN COAST

ABSTRACT

Marine algae are known as a potential source of bioactive substances. In the present work, we used four seaweeds Ulva lactuca, Padina tetrastromatica, Caulerpa scalpelliformis, Stoechospermum marginatum which were collected from Hare Island in the Gulf of Mannar of Tuticorin coast. Ethanol was taken as the solvent for extraction. The crude extract was purified using column chromatography. Antibacterial activity of crude and column purified fractions were tested against Klebsiella, Aeromonas, Staphylococcus, Escherichia and Pseudomonas using well diffusion method. Maximum zone of inhibition (8mm) was exhibited by Padina tetrastomatica against Klebsiella. Minimum zone of inhibition (1mm) was exhibited by Ulva fasciata. Highest antibacterial activity was obtained in brown seaweed, whereas, green seaweed showed less antibacterial activity. From this study, we can conclude that column purified fraction showed higher antibacterial activity than crude extracts.  The extracts were also analyzed for the secondary metabolites. When the zone of inhibitions was statistically tested (ANOVA) there was a significant difference among the different pathogens only for the fraction of Padina tetrastomatica.

Key words: Marine algae, Seaweeds, Antibacterial activity, Secondary metabolites.