This study delves into the nutraceutical potential of microalgae in brackishwater aquaculture, with a focus on a case study conducted in the Muttukadu estuary, Tamil Nadu, India. The research involved the collection, identification, culture standardization, nutrient profiling, antioxidant and antibacterial properties of seven microalgal species in the brackishwater ecosystem, including Thalassiosira weissflogii, Chaetoceros gracilis, Nannochloropsis oculata, Chlorella marina, Tetraselmis sp, Isochrysis galbana and Arthrospira maxima. The growth kinetics analysis highlighted N. oculata and C. marina with an extended log phase and significantly higher growth rates. Proximate analysis revealed the highest protein content (62.46 ± 3.45%) in A. maxima. I. galbana showed significantly higher lipid content (33.08 ± 2.18%), while T. weissflogii had 20.11 ± 1.02%. Fatty acid profiling identified the highest percentage of polyunsaturated fatty acids (69.51%) in A. maxima, followed by Tetraselmis sp (56.32%). Methanolic extracts from C. marina and T. weissflogii displayed notably higher total phenolic content. A. maxima exhibited the highest total antioxidant activity, and C-Phycocyanin (CPC) extracts showed the highest inhibition zones against pathogenic bacteria. This study underscored the diversity of commercially important microalgal species in the tropical estuarine brackishwater ecosystem. The nutrient composition analysis emphasized the abundance of essential macronutrients, micronutrients, vitamins, and bioactive compounds. These findings contribute to understanding microalgae's nutraceutical potential in brackishwater aquaculture, suggesting their suitability for large-scale cultivation and utilization in aquaculture and other food-producing industries. Moreover, the bioactive compounds present in these microalgae offer opportunities for developing novel nutraceutical formulations with potential health benefits.

本研究深入探讨了微藻在咸水水产养殖中的营养潜力，重点是在印度泰米尔纳德邦穆图卡杜河口进行的案例研究。该研究涉及咸水生态系统中七个微藻物种的收集、鉴定、培养标准化、营养成分分析、抗氧化和抗菌特性，包括Thalassiosira weissflogii、Chaetoceros gracilis、Nannothropsis oculata、Chlorella marina、Tetraselmis sp、Isochrysis galbana和Arthrospira maxima。生长动力学分析强调了N. oculata和C. marina具有延长的对数期和显着更高的生长速率。初步分析显示，大圆蛤的蛋白质含量最高（62.46 ± 3.45%）。I. galbana 的脂质含量显着较高 (33.08 ± 2.18%)，而T. weissflogii 的脂质含量为 20.11 ± 1.02%。脂肪酸分析发现，大圆弧菌中多不饱和脂肪酸的比例最高（69.51%），其次是Tetraselmis sp（56.32%）。C. marina和T. weissflogii的甲醇提取物显示出明显更高的总酚含量。A. maxima显示出最高的总抗氧化活性，C-藻蓝蛋白 (CPC) 提取物显示出对病原菌的最高抑制区。这项研究强调了热带河口微咸水生态系统中具有重要商业价值的微藻物种的多样性。营养成分分析强调必需大量营养素、微量营养素、维生素和生物活性化合物的丰富性。这些发现有助于了解微藻在咸水水产养殖中的营养潜力，表明它们适合在水产养殖和其他食品生产行业中大规模种植和利用。此外，这些微藻中存在的生物活性化合物为开发具有潜在健康益处的新型营养制剂提供了机会。