Antibacterial activity of gracilaria verrucosa seaweed methanol extract, greville, 1830 (Florideophyceae: Gracilariaceae) at the brackish aquaculture fisheries center jepara

Abstract

Pathogenic bacterial infection become a world health problem. Antibiotics for prevention of infection make bacteria resistant due to the incorrect dosage. One of these problems can be overcome by finding a new source of antibiotics including seaweed. This study aims to determine the antibacterial activity of methanol extract of G. verrucosa against Escherichia coli, Bacillus cereus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Vibrio anguillarum, and Vibrio alginolyticus. Laboratory experimental method was used in this study. Seaweed samples from the cultivation at Brackish Water Aquaculture Center (BBPBAP) Jepara were dried and then macerated with methanol for 2x24 hours. The antibacterial activity of the extract was tested at concentration of 100 µg / disk, 50 µg / disk, 25 µg / disk, and 10 µg / disk then phytochemical tests were carried out. The results of antibacterial activity test showed that G. verrucosa methanol extract did not have antibacterial activity. The phytochemical test showed that seaweed extract contained flavonoids, saponins, steroids, and triterpenoids.