Arsenic biotransformation in earthworms from contaminated soils
Arsenic biotransformation in earthworms from contaminated soils
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DOI：
10.1039/b904104d
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发表时间：
2009-01-01
影响因子：
--
通讯作者：
Watts, Michael J.
中科院分区：
文献类型：
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作者：
Button, Mark;Jenkin, Gawen R. T.;Watts, Michael J.
从英国德文郡某砷矿的23个地点采集了两种抗砷(As)蚯蚓，它们的寄主土壤和土壤排泄物。用电感耦合等离子体质谱(ICP-MS)测得的土壤总砷浓度为255至13,080毫克公斤(-1)，蚯蚓为11至877毫克公斤(-1)，蚯蚓粪为284至4221毫克公斤(-1)。此外，还利用高效液相色谱-电感耦合等离子体质谱对样品中砷的形态进行了测定，以探讨其作为生物转化途径的可能性。无机砷酸盐(As-V)和亚砷酸盐(As-III)是土壤中唯一检测到的物种。在蚯蚓和铸模材料中也发现了As-V和As-III，以及较少比例的有机物种甲基砷酸盐(MA(V))、二甲基砷酸盐(DMA(V))、砷甜菜碱(AB)和三种砷糖。蚯蚓体内的无机As含量随着体重的增加而增加，而有机物种的浓度保持相对恒定。这些结果表明，无机砷向有机物种的生物转化并不有助于样本蚯蚓种群对砷的抗性。土壤、蚯蚓和铸造物中As形态的定量研究为更全面地阐明蚯蚓中AB的形成提供了一条更全面的途径。
Two species of arsenic (As) resistant earthworm, Lumbricus rubellus and Dendrodrillus rubidus, their host soils and soil excretions (casts) were collected from 23 locations at a former As mine in Devon, UK. Total As concentrations, measured by ICP-MS, ranged from 255 to 13,080 mg kg(-1) in soils, 11 to 877 mg kg(-1) in earthworms and 284 to 4221 mg kg(-1) in earthworm casts from a sub-sample of 10 of the 23 investigated sites. The samples were also measured for As speciation using HPLC-ICP-MS to investigate potential As biotransformation pathways. Inorganic arsenate (As-V) and arsenite (As-III) were the only species detected in the soil. As-V and As-III were also the dominant species found in the earthworms and cast material together with lower proportions of the organic species methylarsonate (MA(V)), dimethylarsinate (DMA(V)), arsenobetaine (AB) and three arsenosugars. Whilst the inorganic As content of the earthworms increased with increasing As body burden, the concentration of organic species remained relatively constant. These results suggest that the biotransformation of inorganic arsenic to organic species does not contribute to As resistance in the sampled earthworm populations. Quantification of As speciation in the soil, earthworms and cast material allows a more comprehensive pathway for the formation of AB in earthworms to be elucidated.