Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.
Environ Pollut. 2012 Oct;169:81-9. doi: 10.1016/j.envpol.2012.05.009. Epub 2012 Jun 12.
The sub-toxic effects of CuO nanoparticles (nano-CuO) were evaluated using three recombinant luminescent Escherichia coli bacteria responding specifically to (i) reactive oxygen species (ROS), (ii) single-stranded DNA breaks and (iii) bioavailable Cu ions. Using these sensors we showed that nano-CuO induces the formation of superoxide anions, hydrogen peroxide and single-stranded DNA already at very low sub-toxic levels (0.1 mg Cu/L). The maximal sub-toxic response of all biosensors to nominal concentrations of nano-CuO, micro-CuO (size control) and CuSO(4) (solubility control) occurred at ~6, ~600 and ~0.6 mg Cu/L, respectively. According to the chemical analysis all the latter concentrations yielded ~0.6 mg of soluble Cu/L, indicating that dissolution of CuO particles was the key factor triggering the ROS and DNA damage responses in bacteria. Cu-ions chelation studies also showed that CuO particles were not involved in these stress responses. The solubilization results were confirmed by Pseudomonas fluorescens Cu-ion sensor.
采用 3 种专门针对（i）活性氧（ROS）、（ii）单链 DNA 断裂和（iii）生物可利用 Cu 离子的重组发光大肠杆菌细菌来评估 CuO 纳米粒子（nano-CuO）的亚毒性效应。利用这些传感器，我们表明 nano-CuO 在非常低的亚毒性水平（0.1 mg Cu/L）下就会诱导超氧阴离子、过氧化氢和单链 DNA 的形成。所有生物传感器对 nominal 浓度的 nano-CuO、micro-CuO（尺寸对照）和 CuSO4（溶解度对照）的最大亚毒性反应分别发生在约 6、约 600 和约 0.6 mg Cu/L。根据化学分析，所有这些较高浓度都产生了约 0.6 mg/L 的可溶性 Cu，表明 CuO 颗粒的溶解是触发细菌中 ROS 和 DNA 损伤反应的关键因素。Cu 离子螯合研究也表明，CuO 颗粒并未参与这些应激反应。荧光假单胞菌 Cu 离子传感器的溶出结果也得到了证实。
