Department of Natural Sciences, School of Health and Social Sciences, Middlesex University, The Burroughs, London, UK.
Int J Phytoremediation. 2011 Sep;13(8):834-44. doi: 10.1080/15226514.2010.525560.
The effect of arsenate (As5+) on growth and chlorophyll a production in Chlorella vulgaris, its removal by C. vulgaris and the role of glutathione (GSH) and phytochelatins (PCs) were investigated. C. vulgaris was tolerant to As5+ at up to 200 mg/L and was capable of consistently removing around 70% of the As5+ present in growth media over a wide range of exposure concentrations. Spectral analysis revealed that PCs and their arsenic-combined complexes were absent, indicating that the high bioaccumulation and tolerance to arsenic observed was not due to intracellular chelation. In contrast, GSH was found in all samples ranging from 0.8 mg/L in the control to 6.5 mg/L in media containing 200 mg/L As5+ suggesting that GSH plays a more prominent role in the detoxification of As5+ in C. vulgaris than PC. At concentrations below 100 mg/L cell surface binding and other mechanisms may play the primary role in As5+ detoxification, whereas above this concentration As5+ begins to accumulate inside the algal cells and activates a number of intracellular cell defense mechanisms, such as increased production of GSH. The overall findings complement field studies which suggest C. vulgaris as an increasingly promising low cost As phytoremediation method for developing countries.
砷酸盐 (As5+) 对普通小球藻生长和叶绿素 a 生成的影响、普通小球藻对其的去除作用，以及谷胱甘肽 (GSH) 和植物螯合肽 (PCs) 的作用进行了研究。普通小球藻能耐受高达 200mg/L 的 As5+，并能在广泛的暴露浓度范围内持续去除生长介质中约 70%的 As5+。光谱分析表明，PC 及其与砷结合的复合物不存在，这表明观察到的高生物累积和耐砷性不是由于细胞内螯合作用。相比之下，所有样品中都发现了 GSH，从对照中的 0.8mg/L 到含 200mg/L As5+的介质中的 6.5mg/L，这表明 GSH 在普通小球藻中对 As5+解毒的作用比 PC 更为突出。在低于 100mg/L 的浓度下，细胞表面结合和其他机制可能在 As5+解毒中发挥主要作用，而在这个浓度以上，As5+开始在藻类细胞内积累，并激活许多细胞内的防御机制，如增加 GSH 的产生。这些总体发现补充了田间研究，表明普通小球藻作为一种越来越有前途的低成本砷植物修复方法，适用于发展中国家。
