ANTIBACTERIAL ACTIVITY AND TOTAL PHENOL CONTENTS OF Sargassum polycystum EXTRACT AGAINST Escherichia coli AND Staphylococcus aureus

Aim and Background: Brown algae contains various chemical constituent (carotenoids, laminarin, alginate, fucoidan, mannitol and phlorotannin) which function as anti-cancer agents, antioxidants and chemo-preventive agents for various degenerative diseases. Sargassum polycystum is one of the algae species belonging to the class Phaeophyceae or brown algae. The phenol content in S. polycystum can act as pathogenic anti-bacterial, especially E. coli and S. aureus bacteria. Because of this, the aim of this study was to determine the total phenol from semi-polar to polar extract and its antibacterial activity.

Materials and Methods: The extraction method used maceration with ethanol 96%, acetone and ethyl acetate as the solvent. Determination of total phenol content was carried out using folin ciocalteau reagent with a UV VIS spectrophotometer using gallic acid standard. While the antibacterial activity of the extract was carried out using the disc diffusion zone method with gram-negative E. coli and gram-positive S. aureus bacteria.

Results and Discussion: The results showed that the S. polycystum extract contained phenol with the total phenol content of ethanol 96% 3.75 mg EGA/g, ethyl acetate 5.78 mg EGA/g, and acetone 4.04 mg EGA/g. The antibacterial activity of ethanol 96%, ethyl acetate and acetone extracts was categorized as strong with inhibition zone diameter range from 10-13 mm. Ethyl acetate extract had the highest total phenol content and antibacterial activity.

Conclusion: The conclusion of this research is that the most effective solvent to attract phenol is ethyl acetate with the highest total phenol content of 5.78 mg EGA/g. This is positive correlation with the results of the antibacterial activity of ethyl acetate extract which has a higher inhibition zone activity compared to other extracts against both E. coli and S. aureus bacteria.