Toxicity and bioaccumulation of iron in soil microalgae

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• 作者：Vidhyasri Subramaniyam ; Suresh Ramraj Subashchandrabose…
• 关键词：Chlorella sp. ; Chlamydomonas sp. ; Chlorococcum sp. ; Iron salts ; Toxicity ; Bioremoval
• 刊名：Journal of Applied Phycology
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：28
• 期：5
• 页码：2767-2776
• 全文大小：1,340 KB
• 刊物主题：Plant Sciences; Freshwater & Marine Ecology; Plant Physiology; Ecology;
• 出版者：Springer Netherlands
• ISSN：1573-5176
• 卷排序：28

文摘

Microalgae are extensively used in the remediation of heavy metals like iron. However, factors like toxicity, bioavailability and iron speciation play a major role in its removal by microalgae. Thus, in this study, toxicity of three different iron salts (FeSO₄, FeCl₃ and Fe(NO₃)₃) was evaluated towards three soil microalgal isolates, Chlorella sp. MM3, Chlamydomonas sp. MM7 and Chlorococcum sp. MM11. Interestingly, all the three iron salts gave different EC50 concentrations; however, ferric nitrate was found to be significantly more toxic followed by ferrous sulphate and ferric chloride. The EC₅₀ analysis revealed that Chlorella sp. was significantly resistant to iron compared to other microalgae. However, almost 900 μg g−1 iron was accumulated by Chlamydomonas sp. grown with 12 mg L−1 ferric nitrate as an iron source when compared to other algae and iron salts. The time-course bioaccumulation confirmed that all the three microalgae adsorb the ferric salts such as ferric nitrate and ferric chloride more rapidly than ferrous salt, whereas intracellular accumulation was found to be rapid for ferrous salts. However, the amount of iron accumulated or adsorbed by algae, irrespective of species, from ferrous sulphate medium is comparatively lower than ferric chloride and ferric nitrate medium. The Fourier transform infrared spectroscopy (FTIR) analysis shows that the oxygen atom and P = O group of polysaccharides present in the cell wall of algae played a major role in the bioaccumulation of iron ions by algae.