Bioactive compounds, nutritive properties and adaptation of five seaweeds growing in Cox’s Bazar, Bangladesh

Abstract The study focused on evaluating the adaptation, nutrient properties, and bioactive compounds of five different seaweed species. Samples were collected in March 2023 from the Rezu Khal estuary, North Nuniachara and St. Martin’s Island on the western coast, Cox’s Bazar District, Bangladesh. The research found diverse nutrient properties, with varying concentrations of minerals like Na (42.08 to 245.43 mg/kg) and K (71.15 to 445.48 mg/kg) among the seaweeds. Hypnea musciformis and H. spinella have been found to accumulate more Na than K. Research showed fluctuating levels of heavy metals like Pb, Cr, Ni, and Cd, but they remained within tolerable limits, making these seaweeds non-toxic and suitable for consumption. The seaweed was found to be rich in bioactive compounds, including tannins, saponins, terpenoids, phenols, flavonoids, and steroids having industrial and medicinal applications. Enteromorpha intestinalis and Gracilaria tenuistipitata exhibited the highest chlorophyll and carotenoid content, respectively. Significant variations (P <0.05) in soluble protein, total phenolic, and flavonoid content were observed, with G. tenuistipitatafrom North Nuniachara standing out for elevated phenols, flavonoids, and protein. These findings highlighted the adaptability of seaweeds to changing marine environments, showcasing their resilience to stress, and microbial attacks, owing to their rich nutrient contents and diverse bioactive metabolites. However, in short, this study underscores the potential of seaweed as valuable natural resources with both nutritional and industrial significance.