Biomethylation and Volatilization of Arsenic by Model Protozoan Tetrahymena pyriformis under Different Phosphate Regimes.
Biomethylation and Volatilization of Arsenic by Model Protozoan Tetrahymena pyriformis under Different Phosphate Regimes.
复制标题
模型原生动物梨形四膜虫在不同磷酸盐状态下砷的生物甲基化和挥发。
DOI：
10.3390/ijerph14020188
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发表时间：
2017-02-14
影响因子：
--
通讯作者：
Sun GX
中科院分区：
文献类型：
--
作者：
Yin X;Wang L;Zhang Z;Fan G;Liu J;Sun K;Sun GX
Tetrahymena pyriformis, a freshwater protozoan, is common in aquatic systems. Arsenic detoxification through biotransformation by T. pyriformis is important but poorly understood. Arsenic metabolic pathways (including cellular accumulation, effluxion, biomethylation, and volatilization) of T. pyriformis were investigated at various phosphate concentrations. The total intracellular As concentration increased markedly as the external phosphate concentration decreased. The highest concentration was 168.8 mg·kg−1 dry weight, after exposure to As(V) for 20 h. Inorganic As was dominant at low phosphate concentrations (3, 6, and 15 mg·L−1), but the concentration was much lower at 30 mg·L−1 phosphate, and As(V) contributed only ~7% of total cellular As. Methylated As contributed 84% of total As at 30 mg·L−1 phosphate, and dimethylarsenate (DMAs(V)) was dominant, contributing up to 48% of total As. Cellular As effluxion was detected, including inorganic As(III), methylarsenate (MAs(V)) and DMAs(V). Volatile As was determined at various phosphate concentrations in the medium. All methylated As concentrations (intracellular, extracellular, and volatilized) had significant linear positive relationships with the initial phosphate concentration. To the best of our knowledge, this is the first study of As biotransformation by protozoa at different phosphate concentrations.
