Nutrient Content, Active Compound and Antibacterial Activity of Padina australis against Aeromonas hydropilla

Background: Padina australis is one of the brown macroalgae that possess several compounds that can be used for various medicinal properties. Objective: This study aims to analyze the nutrient content, active compounds, and antibacterial activity of Padina australis against Aeromonas hydropilla. Methods: The nutrient content and phytochemical composition of P. australis were examined in this study. The antibacterial effect was evaluated using the disc method against A. hydropilla. Results: The nutrient content of P. australis include 38.5% carbohydrate, 2.07% fat, 13.89% protein, 16.12% water, 33.34% ash, 8.54% total amino acid, and minerals (11.36% calcium, 0.22% iron, and 1.81% potassium). Phytochemical analysis showed that P. australis contained phenols, tannin, flavonoid, and steroid. These compound may be responsible for inhibiting A. hydropilla, with an inhibition zone of 10.5 mm for water extract of P. australis and 10 mm for methanol extract P. australis. Conclusion: This study revealed that P. australis produced antibacterial effect against A. hydropilla which could be potential for further antimicrobial agent development.