ANTIBACTERIAL ACTIVITY OF Sargassum sp. IN INHIBITING Vibrio sp. ISOLATED FROM CANTANG GROUPER (Epinephelus fuscoguttatus x Epinephelus lanceolatus)

Abstract

Treatment of vibriosis using natural ingredients such as Sargassum sp. extract in cantang grouper cultivation activities needs to be studied. Testing the effectiveness of solvents in producing phytochemical compounds as antibacterials and modifying the extraction process to make it simpler aims to be replicated by farmers in the field. The tested bacterial isolates were isolated directly from cantang grouper fish showing symptoms of vibriosis from fish farmers in Senggarang Besar, Tanjungpinang City. Testing the antibacterial activity of Sargassum sp. extract in inhibiting the growth of Vibrio sp. was carried out through an inhibition zone test using the paper disc diffusion method (Kirby-Bauer method). The results showed that the use of 70% alcohol solvent in the extraction process resulted in a clearer and better inhibition zone diameter of 13 mm at the highest treatment concentration (10%) compared to the extract using 96% alcohol solvent at the same concentration of 11.67 mm. It should be noted that the inhibition zone formed is classified as partial because it is not clear or completely clear due to the presence of thin bacterial growth in the zone even though the circle shape of the inhibition zone is quite clear. The use of 70% alcohol solvent can be used for the extraction process of Sargassum sp. considering that it is cheaper and the results are better than 96% alcohol based on the results shown through this study.