School of Environment and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, 150022, China.
College of Life Science, Northeast Forestry University, Harbin, 150040, China.
Environ Microbiol Rep. 2019 Apr;11(2):140-146. doi: 10.1111/1758-2229.12733. Epub 2019 Jan 21.
Biogenic magnetic nanoparticles (BMNPs) can be formed by numerous microorganisms. However, the significance of their formation and their possible functions have not been explored in detail. To explore a possible function of Fe O NPs in Burkholderia sp. strain YN01, we investigated their catalytic abilities in the elimination of intracellular reactive oxygen species (ROS). Changes in ROS content under different conditions were assessed and showed that low oxygen and high iron concentrations in the growth medium promoted ROS production. However, the levels of ROS gradually decreased with BMNP formation, suggesting that these particles possess intrinsic superoxide dismutase (SOD)-like activity and catalase (CAT)-like activity, as proven in this study. To ensure that the observed ROS decrease was not due to antioxidase overexpression caused by the oxidative stress response, SOD and CAT were inhibited in vivo to analyse the ROS variation and BMNP yield under microoxic and high-iron conditions respectively. The results demonstrated that the formation of these intracellular iron nanoparticles was required for the efficient scavenging of excess ROS, which was dependent on their antioxidase-like properties. This result reveals a novel physiological function of biogenic intracellular Fe O nanoparticles.
生物成因磁性纳米颗粒（BMNPs）可由多种微生物形成。然而，其形成的意义及其可能的功能尚未得到详细探讨。为了探究 Burkholderia sp. strain YN01 中 FeO NPs 的可能功能，我们研究了它们在消除细胞内活性氧（ROS）方面的催化能力。在不同条件下评估 ROS 含量的变化，结果表明，生长培养基中的低氧和高铁浓度促进了 ROS 的产生。然而，随着 BMNP 的形成，ROS 的水平逐渐降低，这表明这些颗粒具有内在的超氧化物歧化酶（SOD）样活性和过氧化氢酶（CAT）样活性，正如本研究证明的那样。为了确保观察到的 ROS 减少不是由于氧化应激反应引起的抗氧化酶过表达所致，我们在体内抑制 SOD 和 CAT，以分别分析微氧和高铁条件下 ROS 的变化和 BMNP 的产量。结果表明，这些细胞内铁纳米颗粒的形成对于有效清除过量的 ROS 是必需的，这依赖于它们的抗氧化酶样特性。这一结果揭示了生物成因的细胞内 FeO 纳米颗粒的一种新的生理功能。
