Extraction of Sulfated Polysaccharides from Ulva sp. Using Acid and Toxicity Testing with the Brine Shrimp Lethality Test (BSLT)

This study investigates the extraction of sulfated polysaccharides from Ulva sp. at pH 3 and evaluates their toxicity using the Brine Shrimp Lethality Test (BSLT) with Artemia salina. Artemia salina is utilized for its rapid life cycle and sensitivity to various chemical compounds, making it an effective bioassay organism for assessing the toxicity of natural extracts. The extraction process was conducted at both hot (80°C) and cold (room temperature) conditions, with the hot extraction yielding higher amounts of polysaccharides. The results indicated a wet extraction yield of 890 mL at 80°C and 800 mL at room temperature, while the highest dry weight yield was achieved at 80°C (0.57 g). The toxicity assessment revealed an LC50 value of 15,815.85 ppm, classifying the sulfated polysaccharides as non-toxic to Artemia salina. Maintaining optimal water quality parameters, including temperature, salinity, pH, and dissolved oxygen levels, is essential for the successful cultivation of Artemia salina. Furthermore, the acidic extraction pH significantly influences the structure and chemical properties of the resulting polysaccharides, emphasizing the importance of this parameter in future applications. These findings support the potential use of sulfated polysaccharides from Ulva sp. as a safe and effective feed ingredient in aquaculture.