Effcets Of Iron On Growth And Physiology Of Three Kinds Of Micro-Algae

The effects of iron on the growth and physiology of algal bloom of Oscillatoria planctonica , Microcystis aeruginosa and red tide algae of Alexandurium tamarense were studied systemically and comprehensively.As for the two kinds of algal bloom, the maximal cell concentration and the specific growth rate were all limited when iron concentration was below 10 nmol/L, at the same time the synthesis of chlorophyll and protein were restricted evidently too. But it was unlimited when the iron concentration was above 10000 nmol/L. By comparison with the results under Fe-stress and Fe3+-replete condition , the cell-specific light saturated net photosynthetic capacity (Pm ) , dark respiration rate (Rd ) and apparent photosynthetic efficiency ( a ) increase proportionately under the Fe3+-replete condition, whereas the cells light compensation point and light saturated irradiance were lower than it under Fe3+-stress.The different between the two kinds of micro-algea was that the media of Oscillatoria planctonica, needed to replenish iron after 10 days, while it was 20 days for Microcystis aeruginosa under Fe-stress condition. Compared with Microcystis aeruginosa, Oscillatoria planctonica, needed...