ANTI-BACTERIAL ACTIVITY OF THREE SPECIES OF SEA URCHIN EXTRACTS FROM PULAU BIDONG, TERENGGANU

Abstract

Sea urchins have been known to be among the main threats to the sea-bed community, especially to the reefs. Sea urchins are important grazers in most marine benthic sublittoral communities, where the species composition and sea urchin population directly indicates the health status ofthe sea-bed community in terms ofpollution aspects. Sea urchin study has been conducted to ascertain the anti-bacterial compound in three respective sea urchin species such as Diadema setosum, D. savignyi and Echinomatrix calamaris collected from the sea-bed of Pulau Bidong, Terengganu. This study consisted of utilising three kinds of solvent for extraction method such as methanol, ethanol and phosphate buffer solution (PBS) for water-soluble substance extraction. Inner tissues and outer layers of each sea urchin species were subjected to be extracted. Negative results occurred for PBS extraction method in all extract samples. However, for inner-tissues extraction method, ethanol and methanol solvent exhibits positive results for inhibitory effects against several test strains of Gram-positive bacteria such as Staphylococcus aureus, Enterococcus faecalis and Gram-negative bacteria such as Salmonella typhimurium, Pseudomonas aeruginosa andEscherichia coli. Methanol solvent solely exhibits positive inhibitory effects against two Grampositive bacteria, Staphylococcus aureus and Bacillus cereus for outer-layer extraction method of three sea urchins species. Methanol and ethanol solvent-extraction methods for inner tissues oftwo sea urchin species, D. setosum and D. savignyi gave promising results against the test strains. These results revealed that the sea urchins' extracts of Pulau Bidong, Terengganu have great potential in developing anti-bacterial compounds.