School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, PR China.
Microbiology (Reading). 2020 Apr;166(4):359-366. doi: 10.1099/mic.0.000891. Epub 2020 Feb 5.
Iron (Fe), which is a necessary micronutrient for algal growth, plays an important role in the physiological metabolism and enzymatic reactions of algae. This study aimed to investigate the absorption process of four kinds of complexing iron absorbed by . Results showed that the absorptive capacity of to complex iron was inversely proportional to the stability of the complex bond of complex iron. Complex iron with weak binding ability can be quickly adsorbed by . The absorptive rate was as follows: ferric humate, ferric oxalate >ammonium ferric citrate >EDTA Fe. For EDTA-Fe with a strong binding ability, a moderate iron concentration (e.g. 0.6 mg l) is favourable for iron uptake by . Our experiments also revealed that the process of separating iron from complex iron before entering algal cells was probably as follows: iron complexed with organic ligands were firstly adsorbed on the surface of algae cells; afterwards, iron ions were captured by organic matter on the surface of algae cells, accompanied by the rupture of the bond between Fe and ligand; finally, the Fe entered into the cell of algae while the organic ligands returned to the medium.
铁（Fe）是藻类生长所必需的微量元素，在藻类的生理代谢和酶反应中起着重要作用。本研究旨在探讨四种络合铁被吸收的过程。结果表明，对络合铁的吸收能力与络合铁的键合稳定性成反比。结合能力弱的络合铁可以被迅速吸附。吸收率如下：腐植酸铁、草酸酸铁 >柠檬酸铁铵 >EDTA-Fe。对于结合能力强的 EDTA-Fe，适中的铁浓度（例如 0.6 mg/L）有利于通过藻类吸收铁。我们的实验还表明，进入藻类细胞之前从络合铁中分离铁的过程可能如下：与有机配体络合的铁首先被吸附在藻类细胞的表面；随后，铁离子被藻类细胞表面的有机物捕获，伴随着 Fe 和配体之间的键断裂；最后，Fe 进入藻类细胞，而有机配体返回介质。
