Potential extract of brown algae Sargassum sp. and Padina sp. as antibacterial Vibrio harveyi

Abstract

Vibrio sp. in shrimp farming ponds cause infection with Vibriosis which results in crop failure. Various efforts have been made, such as the administration of antibiotics derived from chemicals that can cause resistance to bacteria. One of the other efforts that can be done is to use marine organisms as natural antibacterial agents, such as brown algae of the genus Padina and Sargassum which have antibacterial activity. The purpose of this study was to determine the best concentration of Sargassum sp. and Padina sp. in inhibiting the growth of Vibrio harveyi bacteria and knowing which brown algae extract was more effective in inhibiting the growth of V. harveyi bacteria. The extraction process was carried out using the maseration method with methanol as a solvent. Testing of antibacterial activity using agar diffusion method. The results showed that the extract of brown algae that was more effective in inhibiting the growth of V. harveyi was Padina sp., because the six treatments and positive control at 3 times of observation showed a clear zone that was greater than that of Sargassum sp. The best concentration of Sargassum sp. and Padina sp. in inhibiting the growth of V. harveyi bacteria was at a concentration of 2000 ppm for Sargassum sp. with the resulting inhibition zone of 18.2 ± 1.15 and 2000 ppm and 3000 ppm for the extract of Padina sp. with the resulting inhibition zones of 19.2 ± 2.75 and 19.5 ± 2.35. The resulting inhibition zone falls into the category of strong inhibitory activity.