The ability of alga Dunaliella salina strain UTEX-200 in bioremediation of aluminum from the environment

The effect of concentrations 0 (control)، 250، 500، 1000، 2000 and 4000 µM of aluminum on the growth rate and content total chlorophyll of Dunaliella salina strain UTEX-200 has been studied for duration of 27 days. The results indicated that an increase in aluminum concentration resulted in a decrease in the growth rate and chlorophyll content. It seems that these effects are probably due to destruction of cell membrane and suppression of essential elements uptake، such of Ca2+ and Mg2+، respectively. The treatment of algal suspension by different concentrations 0 (control)، 500، 1000، 2000، 3000 and 4000 µM of aluminum resulted in algal cells-Al3+ ions binding، cell agglutination and sedimentation، reduction of the algal cell number in supernatant of cell suspension and consequently removal of aluminum. The results of adding EDTA to algal suspension for binding of aluminum and preventing of cell sedimentation confirmed algal cells-Al3+ ions binding. Also، this study indicated that not only each cell of algal suspension has defined capacity for sedimentation of aluminum، but just intact cells can bind to Al3+ ions and aluminum bioremediation. In adding، the results of this study indicates that strong binding of algal cells-Al3+ ions resulted in reduction of growth rate and cell division، cell agglutination and sedimentation and aluminum bioremediation.