Rapid Biotransformation of Arsenate into Oxo-Arsenosugars by a Freshwater Unicellular Green Alga, Chlamydomonas reinhardtii
Rapid Biotransformation of Arsenate into Oxo-Arsenosugars by a Freshwater Unicellular Green Alga, Chlamydomonas reinhardtii
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DOI：
10.1271/bbb.100751
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发表时间：
2011-03
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影响因子：
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通讯作者：
S. Miyashita;S. Fujiwara;M. Tsuzuki;T. Kaise
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作者：
S. Miyashita;S. Fujiwara;M. Tsuzuki;T. Kaise
研究了淡水单细胞绿藻莱茵衣藻（Chlamydomonas reinhardtii）野生型菌株CC-125 24小时内砷酸盐的短期代谢过程。采用高效液相色谱/电感耦合等离子体质谱法对水藻提取液中的砷进行鉴定。砷的形态分析表明，细胞内亚砷酸盐、砷酸盐和甲基胂酸的含量在30 min至1 h内迅速升高，二甲基胂酸和氧砷糖-甘油的含量在24 h内也有持续升高的趋势，而氧砷糖-磷酸的含量则很低，在整个实验过程中都有波动。这些结果表明，该藻类可以通过将合并的砷酸盐还原为亚砷酸盐，并通过甲基胂酸作为可能的中间体将亚砷酸盐和/或保留在细胞中的砷酸盐甲基化为二甲基胂酸，快速地将砷酸盐转化为氧砷糖-甘油，然后再将氧砷糖-磷酸转化为氧砷糖-磷酸，时间至少为10分钟。
We examined the short-term metabolic processes of arsenate for 24 h in a freshwater unicellular green alga, Chlamydomonas reinhardtii wild-type strain CC-125. The arsenic species in the algal extracts were identified by high-performance liquid chromatography/inductively coupled plasma mass spectrometry after water extraction using a sonicator. Speciation analyses of arsenic showed that the levels of arsenite, arsenate, and methylarsonic acid in the cells rapidly increased for 30 min to 1 h, and those of dimethylarsinic acid and oxo-arsenosugar-glycerol also tended to increase continuously for 24 h, while that of oxo-arsenosugar-phosphate was quite low and fluctuated throughout the experiment. These results indicate that this alga can rapidly biotransform arsenate into oxo-arsenosugar-glycerol for at least 10 min and then oxo-arsenosugar-phosphate through both reduction of incorporated arsenate to arsenite and methylation of arsenite and/or arsenate retained in the cells to dimethylarsinic acid via methylarsonic acid as an possible intermediate.