Faculty of Food Sciences and Biotechnology, University of Life Sciences in Lublin, St. Skromna 8, 20-704 Lublin, Poland.
Int J Mol Sci. 2022 Oct 5;23(19):11820. doi: 10.3390/ijms231911820.
Zinc oxide nanoparticles (ZnO NPs), due to their antibacterial effects, are commonly used in various branches of the economy and can affect rhizobacteria that promote plant growth. We describe the effect of ZnO NPs on two model bacteria strains, and , that play an important role in the environment. The MIC (minimum inhibitory concentration) value determined after 48 h of incubation with ZnO NPs was more than 1.6 mg/mL for both strains tested, while the MBC (minimum bactericidal concentration) was above 1.8 mg/mL. We tested the effect of ZnO NPs at concentrations below the MIC (0.8 mg/mL, 0.4 mg/mL and 0.2 mg/mL (equal to 50%, 25% and 12,5% MIC, respectively) in order to identify the mechanisms activated by species in the presence of these nanoparticles. ZnO NPs in sublethal concentrations inhibited planktonic cell growth, stimulated endospore formation and reduced decolorization of Evans blue. The addition of ZnO NPs caused oxidative stress, measured using nitroblue tetrazolium (NBT), and reduced the activity of catalase. It was confirmed that zinc oxide nanoparticles in sublethal concentrations change metabolic processes in bacteria that are important for their effects on the environment. after treatment with ZnO NPs decreased indole acetic acid (IAA) production and increased biofilm formation, whereas decreased IAA production but, inversely, increased biofilm formation. Comparison of different species in a single experiment made it possible to better understand the mechanisms of toxicity of zinc oxide nanoparticles and the individual reactions of closely related bacterial species.
氧化锌纳米粒子（ZnO NPs）由于其抗菌作用，常用于经济的各个领域，并可能影响促进植物生长的根际细菌。我们描述了 ZnO NPs 对两种模型细菌菌株 和 的影响，它们在环境中起着重要作用。在孵育 48 小时后，用 ZnO NPs 确定的 MIC（最小抑菌浓度）值对两种测试菌株均超过 1.6 mg/mL，而 MBC（最小杀菌浓度）则高于 1.8 mg/mL。我们测试了 ZnO NPs 在 MIC 以下浓度（0.8 mg/mL、0.4 mg/mL 和 0.2 mg/mL（分别相当于 MIC 的 50%、25%和 12.5%）的效果，以确定在这些纳米粒子存在下 种被激活的机制。亚致死浓度的 ZnO NPs 抑制浮游细胞生长，刺激内生孢子形成，并减少 Evans 蓝的脱色。添加 ZnO NPs 会导致氧化应激，用硝基四氮唑蓝（NBT）测量，并降低过氧化氢酶的活性。证实亚致死浓度的氧化锌纳米粒子改变了 细菌的代谢过程，这些过程对其环境影响很重要。经 ZnO NPs 处理后， 生产吲哚乙酸（IAA）的能力降低，生物膜形成增加，而 生产 IAA 的能力降低，但相反，生物膜形成增加。在单个实验中比较不同的 种，使我们能够更好地理解氧化锌纳米粒子的毒性机制以及密切相关的细菌种的个体反应。
