The Effects of Operational Parameters on the Iron(III) Uptake by Micro-Algae Dunaliella salina

The uptake of Fe(III) by living cells of unicellular green algae Dunaliella salina ions is investigated. The effects of operational conditions such as contact time, biomass concentration, initial pH, and initial Fe(III) concentration on iron uptake are studied. The time profile of the Fe(III) uptake by living cells of D. salina shows a time lag in the first 15 min, which is associated with the production of metal chelating agents. In addition, it is found that the optimum pH for maximal iron uptake is 8. At optimal conditions, the uptake is increasing gradually along with the increase of biomass concentration. Furthermore, the uptake increased with the rising of the initial metal ion concentration. Dry samples of iron free and iron containing biomass of D. salina are analyzed using Fourier-transform infrared (FTIR) spectroscopy. Comparison of the obtained FTIR spectra revealed the presence of amino, carboxylic, hydroxylic, phosphate and sulphonate groups of the lipids, proteins and polysaccharides localized at the cell surface, which are involved in the process of Fe(III) acquisition.