Bactericidal Activity of Bulk Nanobubbles through Active Oxygen Species Generation
Bactericidal Activity of Bulk Nanobubbles through Active Oxygen Species Generation
复制标题
DOI：
10.1021/acs.langmuir.1c01578
复制
发表时间：
2021-08-02
期刊：
影响因子：
3.9
通讯作者：
Niwano, Michio
中科院分区：
文献类型：
--
作者：
Yamaguchi, Masato;Ma, Teng;Niwano, Michio
我们使用E.大肠杆菌，一种模式细菌。通过迫使气体通过具有与水接触的纳米级直孔的有序排列的多孔氧化铝膜来产生块状NB。产生具有不同气体含量（包括CO2、O-2和N-2）的NB，并评估其杀菌效果。E.大肠杆菌在含CO_2的NB（CO_2-NB水）悬浮液中显著降低。N2-NB水表现出少量的杀菌行为，但其影响不如CO2-NB水那么明显。当E.大肠杆菌在O-2-NB水中的存活率比在纯水（PW）中的存活率高。我们通过电子自旋共振谱研究了NB悬浮液中活性氧（ROS）的产生。NB水中产生的活性氧主要是羟基自由基和OH. CO2-NB水中活性氧的产生最强，这与杀菌效果测量结果一致。我们假设由ROS介导的NB会表现出杀菌行为，并提出了一个动力学模型来解释存活率的保留时间变化。基于该模型的计算结果与实验结果吻合较好。
We investigated the bactericidal activity of bulk nanobubbles (NBs) using E. coli, a model bacterium. Bulk NBs were produced by forcing gas through a porous alumina membrane with an ordered arrangement of nanoscale straight holes in contact with water. NBs with different gas contents, including CO2, O-2, and N-2, were generated and evaluated for their bactericidal effects. The survival rate of E. coli was significantly reduced in a suspension of CO2-containing NB (CO2-NB water). The N-2-NB water demonstrated a small amount of bactericidal behavior, but its impact was not as significant as that of CO2-NB water. When E. coli was retained in O-2-NB water, the survival rate was even higher than that in pure water (PW). We investigated the generation of reactive oxygen species (ROS) in NB suspensions by electron spin resonance spectroscopy. The main ROS generated in the NB water were hydroxyl radicals and OH., and the production of ROS was the strongest in CO2-NB water, which was consistent with the results of the bactericidal effect measurements. We assumed that NB mediated by ROS would exhibit bactericidal behavior and proposed a kinetic model to explain the retention time variation of the survival rate. The results calculated based on the proposed model matched closely with the experimental results.