As a necessary micronutrient for algal growth, iron (Fe) has important effects on the physiological metabolism and enzymatic reactions of algae. In this study, a series of experiments were designed to compare the effects of different kinds of iron on the growth of Anabaena flos-aquae. Results showed that the promotion of iron species on algae growth was in order of ferric ammonium citrate > EDTA-Fe > iron ions > iron oxalate. When the concentration of iron is in the range of 0.1-0.8 mg/L, iron species have more significant influences on Anabaena bloom compared with iron concentration. Our experiments also revealed that A. flos-aquae has the strongest adsorption capacity for iron ion among the four iron sources and further induced. This leads to the toxicity of the iron ion group to algal cells at low concentration.
Keywords: Microalgae growth; freshwater; iron concentration; iron species.