Anaerobic biotransformation of organoarsenical pesticides monomethylarsonic acid and dimethylarsinic acid
Anaerobic biotransformation of organoarsenical pesticides monomethylarsonic acid and dimethylarsinic acid
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DOI：
10.1021/jf053223n
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发表时间：
2006-05-31
影响因子：
6.1
通讯作者：
Garbarino, John R.
中科院分区：
文献类型：
--
作者：
Sierra-Alvarez, Reyes;Yenal, Umur;Garbarino, John R.
单甲基砷酸(MMAV)和二甲基砷酸(DMAV)被广泛用作农药，向环境中引入大量的砷。这些有机砷一旦释放到环境中，就会发生微生物反应。对MMAV和DMAV的好氧生物降解性进行了评价，但对它们在厌氧环境中的去向知之甚少。本研究的目的是评价MMAV和DMAV在厌氧污泥中的生物转化。生物介导的转化发生在产甲烷或硫酸盐还原的条件下，而不是在硝酸盐存在的情况下。MMAIII一直被认为是MMAV降解的重要代谢物，其摩尔回收率在5%~47%之间。从DMAV代谢中鉴定出的主要生物转化产物是MMAV，其摩尔产率在8%到65%之间。代谢产物表明，还原和脱甲基化分别是MMAV和DMAV厌氧生物转化的重要步骤。
Monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) are extensively utilized as pesticides, introducing large quantities of arsenic into the environment. Once released into the environment, these organoarsenicals are subject to microbial reactions. Aerobic biodegradation of MMAV and DMAV has been evaluated, but little is known about their fate in anaerobic environments. The objective of this study was to evaluate the biotransformation of MMAV and DMAV in anaerobic sludge. Biologically mediated conversion occurred under methanogenic or sulfate-reducing conditions but not in the presence of nitrate. Monomethylarsonous acid (MMAIII) was consistently observed as an important metabolite of MMAV degradation, and it was recovered in molar yields ranging from 5 to 47%. The main biotransformation product identified from DMAV metabolism was MMAV, which was recovered in molar yields ranging from 8 to 65%. The metabolites indicate that reduction and demethylation are important steps in the anaerobic bioconversion of MMAV and DMAV, respectively.