Use of a luminescent bacterial biosensor for biomonitoring and characterization of arsenic toxicity of chromated copper arsenate (CCA)
Use of a luminescent bacterial biosensor for biomonitoring and characterization of arsenic toxicity of chromated copper arsenate (CCA)
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DOI：
10.1023/a:1008281028594
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发表时间：
1997-01-01
期刊：
影响因子：
3.6
通讯作者：
DuBow, MS
中科院分区：
文献类型：
--
作者：
Cai, J;DuBow, MS
砷氧阴离子诱导的大肠杆菌染色体操纵子（arsRBC）先前已被发现。荧光素酶转录基因融合（arsB::luxAB）的构建表明，砷盐以浓度依赖的方式诱导ars操纵子的表达和伴随的细胞发光。本研究旨在评估arsB::luxAB转录基因融合作为生物传感器监测砷化合物毒性的潜力。将该基因融合菌株的培养物暴露于浓度不断增加的木材防腐剂铬化砷酸铜（CCA）及其成分砷酸钠和铬化铜溶液（CC）中。荧光素酶活性分析显示，arsB::luxAB基因融合在CCA和砷酸钠溶液中表达，而在CC溶液中不表达。砷的检测限为0.01 μ g As/ml（十亿分之十，10 ppb），因此完全在环境问题的范围内。当细胞的磷酸盐被限制时，观察到砷酸盐更大的发光诱导，因为磷酸盐可以作为砷酸盐离子的竞争性抑制剂。我们的研究结果表明，大肠杆菌arsB::luxAB融合菌株在使用cca处理过的木材的地点附近作为一种特异性和敏感的生物传感器监测砷的生物可利用水平和毒性具有广阔的前景。
An arsenic oxyanion-inducible Escherichia coli chromosomal operon (arsRBC) has been previously identified. Construction of a luciferase transcriptional gene fusion (arsB::luxAB) showed that ars operon expression, plus concomitant cell luminescence, was inducible in a concentration-dependent manner by arsenic salts. The present study was conducted to evaluate the potential of the arsB::luxAB transcriptional gene fusion for use as a biosensor in monitoring the toxicity of arsenic compounds. Cultures from this gene fusion strain were exposed to increasing concentrations of the wood preservative chromated copper arsenate (CCA), as well as its constituents, sodium arsenate and chromated copper solution (CC). Analysis of luciferase activity revealed that the arsB::luxAB gene fusion was expressed in response to CCA and sodium arsenate, but not to the CC solution. The detection limit of arsenic was found to be 0.01 mu g As/ml (10 parts per billion, 10 ppb) and therefore well within the range of environmental concerns. A greater induction of luminescence by arsenate was observed when cells were limited for phosphate, as phosphate can act as a competitive inhibitor of arsenate ions. Our results suggest that the E. coli arsB::luxAB fusion strain has a promising future as a specific and sensitive biosensor for monitoring bioavailable levels and toxicity of arsenic near sites where CCA-treated wood has been used.