Microbial responses to environmental arsenic
Microbial responses to environmental arsenic
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DOI：
10.1007/s10534-008-9195-y
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发表时间：
2009-02-01
期刊：
影响因子：
3.5
通讯作者：
Canovas, David
中科院分区：
文献类型：
--
作者：
Paez-Espino, David;Tamames, Javier;Canovas, David
微生物对环境中砷的毒性具有动态的反应机制。从这个意义上说，参与元素生物地球化学循环的微生物代谢也会影响砷的形态和迁移。ars操纵子构成了细菌中最普遍和最重要的砷耐受机制。这个系统介导亚砷酸盐从细胞中挤出。还有其他微生物活动改变砷的化学特性：一些菌株能够氧化亚砷酸盐或减少砷酸盐，这是它们呼吸过程的一部分。这些类型的微生物需要膜相关蛋白将电子从砷（分别为AoxAB和ArrAB）转移到砷（AoxAB和ArrAB）。其他酶转化，如甲基化-去甲基化反应，将无机砷交换成有机形式，有助于其复杂的环境周转。本文简要介绍了近年来在细菌中这些过程的生态学、生物化学和分子生物学方面的研究进展，并提供了一些基于植物螯合蛋白或金属硫蛋白样蛋白的基因工程增强砷积累的例子。
Microorganisms have evolved dynamic mechanisms for facing the toxicity of arsenic in the environment. In this sense, arsenic speciation and mobility is also affected by the microbial metabolism that participates in the biogeochemical cycle of the element. The ars operon constitutes the most ubiquitous and important scheme of arsenic tolerance in bacteria. This system mediates the extrusion of arsenite out of the cells. There are also other microbial activities that alter the chemical characteristics of arsenic: some strains are able to oxidize arsenite or reduce arsenate as part of their respiratory processes. These type of microorganisms require membrane associated proteins that transfer electrons from or to arsenic (AoxAB and ArrAB, respectively). Other enzymatic transformations, such as methylation-demethylation reactions, exchange inorganic arsenic into organic forms contributing to its complex environmental turnover. This short review highlights recent studies in ecology, biochemistry and molecular biology of these processes in bacteria, and also provides some examples of genetic engineering for enhanced arsenic accumulation based on phytochelatins or metallothionein-like proteins.