Marine algae, notably , are valuable sources of essential nutrients, including carbohydrates, vitamins, and minerals, as well as bioactive compounds, such as phenols and pigments. In this study, subcritical water extraction of , a brown seaweed, was conducted using a 10% (w/v) seaweed slurry at a temperature of 140°C for 10 min. The concentrations of mannitol, laminarin, and total phenolic content were determined to be 18.93 g/l, 10.79 g/l, and 1.94 mg GAE/g, respectively. The fermented using (SFL) resulted in a maximum biomass production of 4.43 g dcw/l and exhibited an inhibitory activity of 78.69% against pancreatic lipase. The fermented using (SFE) extracts exhibited α-glucosidase inhibitory and antioxidant activities of 59.23% and 65.60%-66.57%, respectively, at a concentration of 3.0 mg/ml. These results facilitate the development of functional seaweed food formulations derived from microbial fermentation.