فهرست نشریات علمی دسترسی آزاد ایران

The increasing interest in Arthrospira (Spirulina) can be attributed to its high protein content, ease of digestion, and significant levels of vitamins, minerals, amino acids, and pigments. Nitrogen is known to exert a strong influence on the metabolism of lipids and proteins in various microalgae. In the present study, the production of Arthrospira platensis was optimized in terms of biomass and protein by utilizing different nitrogen sources: KNO3, NH4NO3, and urea. A. platensis was grown in Zarrouk’s medium within a 3000 ml Erlenmeyer flask, where KNO3, NH4NO3, and urea replaced NaNO3 at concentrations of 0.010 M, 0.025 M, and 0.050 M. The results clearly indicated that A. platensis can be successfully cultivated using different nitrogen regimes; although maximum biomass production occurred in medium containing NH4NO3, there were no significant differences between treatments (p> 0.05). The highest protein content was obtained from cultures containing NH4NO3 followed by KNO3; treatments had no significant differences (p> 0.05). Furthermore, for all A. platensis cultures examined, increases in nitrogen concentrations led to corresponding increases in both maximum biomass and protein content. Chlorophyll a content increased with rising nitrogen concentrations across all treatments; relatively high values (9.18 µg.ml-1) occurred when KNO3 was used as the nitrogen source on day fourteen of the culturing period. Overall, the results from this study suggest that using NH4NO3 can be considered as a promising nitrogen source for cultivating A. platensis aimed at achieving optimal biomass and protein production.