Effects of microelements (Fe, Cu, Zn) on growth and pigment contents of Arthrospira (Spirulina) platensis

Abstract

A laboratory experiment was conducted to assess the bioaccumulation of microelements Fe ²⁺, Cu ²⁺, Zn ²⁺ and their effects on the growth and pigment contents of <em>Spirulina</em> <em>platensis</em> in Zarrouk's media. The mentioned metals concentrations enhanced separately to tenfold of the Zarrouk's content. The results indicated no differences in the dry weights for the different medias (<em>p</em>>0.05). A rapid increase in optical density values has been observed in tenfold of Cu⁺² concentration giving the maximum optical density values (0.498± 0.234 mg L^-1). In contrast, a gradual increase rate in the optical density has been observed at all concentration of treatments. Enrichment factor (EF) improved with increasing the metal concentration of treatments. The maximum EF value has been observed at 13.54 in Zn⁺² concentrations. At all concentrations, the maximum production of chlorophyll A (1.213±0.514 mg L^-1) occurred in 7^th day of incubation. The highest total carotenoid concentration was recorded in <em>S</em>. <em>platensis</em> treated with Cu⁺² (0.0042± 0.0004 mg L^-1) after 14 days. The phycobiliproteins decreased in all of the treatments. Results suggested that <em>S.</em> <em>platensis</em> would be important part of in functional food developments.