Che Feifei, Du Miaomiao, Yan Changzhou
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
J Environ Sci (China). 2018 Apr;66:41-49. doi: 10.1016/j.jes.2017.05.041. Epub 2017 Jun 7.
The arsenate (As(V)) biotransformation by Microcystis aeruginosa in a medium with different concentrations of nitrogen (N) and phosphorus (P) has been studied under laboratory conditions. When 15μg/L As(V) was added, N and P in the medium showed effective regulation on arsenic (As) metabolism in M. aeruginosa, resulting in significant differences in the algal growth among different N and P treatments. Under 0.2mg/L P treatment, increases in N concentration (4-20mg/L) significantly stimulated the cell growth and therefore indirectly enhanced the production of dimethylarsinic acid (DMA), the main As metabolite, accounting for 71%-79% of the total As in the medium. Meanwhile, 10-20mg/L N treatments accelerated the ability of As metabolization by M. aeruginosa, leading to higher contents of DMA per cell. However, As(V) uptake by M. aeruginosa was significantly impeded by 0.5-1.0mg/L P treatment, resulting in smaller rates of As transformation in M. aeruginosa as well as lower contents of As metabolites in the medium. Our data demonstrated that As(V) transformation by M. aeruginosa was significantly accelerated by increasing N levels, while it was inhibited by increasing P levels. Overall, both P and N play key roles in As(V) biotransformation processes.
在实验室条件下，研究了不同氮（N）、磷（P）浓度培养基中铜绿微囊藻对砷酸盐（As(V)）的生物转化。添加15μg/L As(V)时，培养基中的N和P对铜绿微囊藻的砷（As）代谢具有有效的调节作用，导致不同N、P处理下藻类生长存在显著差异。在0.2mg/L P处理下，N浓度升高（4 - 20mg/L）显著刺激细胞生长，从而间接提高了主要As代谢产物二甲基砷酸（DMA）的产量，DMA占培养基中总As的71% - 79%。同时，10 - 20mg/L N处理提高了铜绿微囊藻的As代谢能力，导致每个细胞中DMA含量更高。然而，0.5 - 1.0mg/L P处理显著阻碍了铜绿微囊藻对As(V)的吸收，导致铜绿微囊藻中As转化速率降低以及培养基中As代谢产物含量降低。我们的数据表明，增加N水平显著加速了铜绿微囊藻对As(V)的转化，而增加P水平则对其有抑制作用。总体而言，P和N在As(V)生物转化过程中都起着关键作用。
