Biologia ( IF 1.4 ) Pub Date : 2021-06-28 , DOI: 10.1007/s11756-021-00814-w Ahmed H Sadek 1, 2 , Mohsen S Asker 3 , Sayeda A Abdelhamid 3
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Nanoscale zero-valent iron particles were investigated as an antibacterial agent against two Gram-positive bacteria; Staphylococcus aureus NRRL B-313 (S. aureus), Bacillus subtilus NRC (B. subtilus), and two Gram-negative bacteria; Escherichia coli NRC B-3703 (E. coli), Pseudomonas aeruginosa NRC B-32 (Ps. aeruginosa). The characterization of synthesized nZVI particles was obtained by XRD, SEM, EDX, and TG analyses. The results demonstrated that the nZVI particles have a spherical shape, mean crystalline size of 44.43 nm, and exhibited a good chemical and thermal stability performance under different physical conditions. The bacterial suspensions were subjected to the treatment using nZVI particle suspensions with a concentration of 10 mg/mL. The minimum inhibitory concentration of nZVI particles was determined using the well diffusion assay method and found to be 15, 10, 10, and 5 mg for the following four strains; S. aureus, B. subtilus, E. coli, and Ps. aeruginosa, respectively. The biological treatment results of municipal wastewater using nZVI particles revealed that the counts of total bacteria, total coliform, fecal coliform, S. aureus, fecal Streptococcus, and E. coli were decreased to 44.29%, 51.76%, 90.95%, 46.67%, 33.33%, and 93.89%, respectively, while the Ps. aeruginosa not detected in the wastewater sample. The enhanced inactivation performance of nZVI nanoparticles was mainly attributed to the reactive oxygen species (ROS) production, releasing of iron corrosion products like Fe2+/Fe3+ ions, and direct friction of nZVI particles with bacterial cells membranes. In addition, the nZVI particles presented a striking disinfection behavior in comparison with other widespread disinfection technologies such as chlorination. Accordingly, the obtained results introduce the nZVI particles as a promising disinfection technology.
Graphical abstract
中文翻译：
纳米零价铁对城市污水中病原菌的抑菌作用
研究了纳米级零价铁颗粒作为抗两种革兰氏阳性菌的抗菌剂；金黄色葡萄球菌NRRL B-313 ( S. aureus )、枯草芽孢杆菌NRC ( B. subtilus ) 和两种革兰氏阴性菌；Escherichia coli NRC B-3703 ( E.coli )、Pseudomonas aeruginosa NRC B-32 ( Ps. aeruginosa）。通过 XRD、SEM、EDX 和 TG 分析获得合成的 nZVI 颗粒的表征。结果表明，nZVI颗粒呈球形，平均晶体尺寸为44.43 nm，在不同物理条件下均表现出良好的化学和热稳定性能。使用浓度为 10 mg/mL 的 nZVI 颗粒悬浮液对细菌悬浮液进行处理。采用孔扩散测定法测定 nZVI 颗粒的最低抑菌浓度，发现以下四种菌株分别为 15、10、10 和 5 mg；金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌和Ps。绿脓杆菌， 分别。使用nZVI颗粒对城市污水进行生物处理的结果表明，总细菌、总大肠菌群、粪大肠菌群、金黄色葡萄球菌、粪链球菌和大肠杆菌的数量下降到44.29%、51.76%、90.95%、46.67%，分别为 33.33% 和 93.89%，而Ps。废水样品中未检测到铜绿假单胞菌。nZVI纳米粒子增强的失活性能主要归因于活性氧（ROS）的产生，释放铁腐蚀产物如Fe 2+ /Fe 3+离子，以及 nZVI 颗粒与细菌细胞膜的直接摩擦。此外，与其他广泛使用的消毒技术（如氯化法）相比，nZVI 颗粒表现出惊人的消毒行为。因此，所获得的结果将 nZVI 颗粒作为一种有前途的消毒技术。
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