Bioaccumulation of Fe^sup +2^ and its effects on growth and pigment content of spirulina (Arthrospira platensis)

A laboratory experiment was conducted to assess the bioaccumulation of Fe 2+ and its effects on growth and pigment contents of spirulina (Arthrospira platensis). The specimens were cultured in Zarrouk medium. The mentioned metal concentration enhanced separately to 10 and 20 fold of the Zarrouk (control) content. Although the values of dry weight in iron treatment were higher than values in control treatment however, the results indicated no significant differences in the dry weights for the different mediums. A gradual increase in the optical density (OD) was seen at all concentration of treatments but with different rates of increase however, there were no significant difference in values of OD for the different mediums. The maximum bioaccumulation value was observed 4465±39.68 mg kg-1 in Fe - 10 fold concentration and the extent of iron accumulation and enrichment factor (EF) of spirulina was significantly increased when applying sample with 10 fold fortified iron concentration. Also, the results indicated no significant differences in the Chl-a content after 14 day of inoculation. The maximum production of Chl-a occurred in 7th days of incubation at all concentration of treatments. The maximum Chl-a values being 1.34±0.784 mgL-1 in experiment with 20 fold iron fortified concentration, after 14 day of inoculation. Also, the results indicated no significant differences in the carotenoid contents after 14 day of inoculation. It was observed that an increase of Fe concentration caused reduction of phycobiliproteins of A. platensis. Consequently, it can be suggested for involvement in further functional food developments.