Research Article: Optimizing a seawater-based medium for large-scale cultivation of Arthrospira platensis: Impact on biomass, biochemical composition, and growth performance

This study aimed to optimise the growth conditions of Arthrospira platensis by modifying the ionic composition of the standard Zarrouk medium using a seawater-based medium (MK۱B). The optimisation process involved three stages: adjusting the ionic composition, optimizing iron concentration, and comparing different iron sources. The final mass concentrations for the control, G۱, and G۲ were ۱.۲۵, ۱.۱, and ۱.۱۵ g. L-۱, respectively, with no significant differences (p>۰.۰۵). The specific growth rate of the control group was significantly higher than G۲ and G۱. Carbohydrate content was higher in G۱ and G۲ compared to the control, while the protein content was lower in G۱ and G۲ compared to the control. In the semi-industrial phase, A. platensis cultivated in MK۱B medium showed a productivity of ۲۷.۰۶۶ mg. L-۱ per day and a total biomass of ۰.۸۶۲ g. L-۱ after ۳۰ days. The average chlorophyll content was ۷.۸۲ mg. g-۱, beta-carotene ۱.۹ mg. g-۱, protein ۵۷.۹۶%, lipid ۹.۳۵%, and carbohydrate ۲۶.۵۲%. The microbial load of A. platensis in MK۱B medium met USP۴۳ and ISIRI۱۱۱۶۶ safety standards, confirming its suitability for food and pigment applications. Finally, using seawater for the sustainable production of Spirulina microalgae, with potential applications in food supplements and natural pigment resources is feasible.

کلیدواژه ها:

Arthrospira platensis ، Spirulina ، Seawater Medium ، Ionic Composition ، Pigment Enhancement ، Biochemical Analysis