Universidade Federal de São Paulo. Instituto de Ciência e Tecnologia; Departamento de Ciência e Tecnologia, São José dos Campos, SP, Brazil.
Instituto de Aeronáutica e Espaço (IAE), Departamento de Ciência e Tecnologia Aeroespacial (DCTA), Zip-code 12228-904, São José dos Campos, SP, Brazil.
J Environ Manage. 2023 Jul 15;338:117804. doi: 10.1016/j.jenvman.2023.117804. Epub 2023 Mar 28.
The bacterial synthesis of copper nanoparticles emerges as an eco-friendly alternative to conventional techniques since it comprises a single-step and bottom-up approach, which leads to stable metal nanoparticles. In this paper, we studied the biosynthesis of Cu-based nanoparticles by Rhodococcus erythropolis ATCC4277 using a pre-processed mining tailing as a precursor. The influence of pulp density and stirring rate on particle size was evaluated using a factor-at-time experimental design. The experiments were carried out in a stirred tank bioreactor for 24 h at 25 °C, wherein 5% (v/v) of bacterial inoculum was employed. The O flow rate was maintained at 1.0 L min and the pH at 7.0. Copper nanoparticles (CuNPs), with an average hydrodynamic diameter of 21 ± 1 nm, were synthesized using 25 g.L of mining tailing and a stirring rate of 250 rpm. Aiming to visualize some possible biomedical applications of the as-synthesized CuNPs, their antibacterial activity was evaluated against Escherichia coli and their cytotoxicity was evaluated against Murine Embryonic Fibroblast (MEF) cells. The 7-day extract of CuNPs at 0.1 mg mL resulted in 75% of MEF cell viability. In the direct method, the suspension of CuNPs at 0.1 mg mL resulted in 70% of MEF cell viability. Moreover, the CuNPs at 0.1 mg mL inhibited 60% of E. coli growth. Furthermore, the NPs were evaluated regarding their photocatalytic activity by monitoring the oxidation of methylene blue (MB) dye. The CuNPs synthesized showed rapid oxidation of MB dye, with the degradation of approximately 65% of dye content in 4 h. These results show that the biosynthesis of CuNPs by R. erythropolis using pre-processed mine tailing can be a suitable method to obtain CuNPs from environmental and economical perspectives, resulting in NPs useful for biomedical and photocatalytic applications.
铜纳米粒子的细菌合成作为一种环保的替代方法出现,因为它包含一个单一的步骤和自下而上的方法,这导致了稳定的金属纳米粒子。在本文中,我们研究了使用预处理的矿山尾矿作为前体通过红球菌 ATCC4277 合成基于铜的纳米粒子。使用因子时间实验设计评估了纸浆密度和搅拌速度对粒径的影响。实验在 25°C 的搅拌罐生物反应器中进行了 24 小时,其中使用了 5%(v/v)的细菌接种物。O 流速保持在 1.0 L min,pH 值为 7.0。使用 25 g.L 的矿山尾矿和 250 rpm 的搅拌速度合成了平均水动力直径为 21±1nm 的铜纳米粒子(CuNPs)。为了可视化所合成的 CuNPs 可能的一些生物医学应用,评估了它们对大肠杆菌的抗菌活性及其对鼠胚胎成纤维细胞(MEF)的细胞毒性。在 0.1 mg mL 下,CuNPs 的 7 天提取物导致 MEF 细胞活力为 75%。在直接方法中,在 0.1 mg mL 下 CuNPs 的悬浮液导致 MEF 细胞活力为 70%。此外,CuNPs 在 0.1 mg mL 下抑制了 60%的大肠杆菌生长。此外,通过监测亚甲基蓝(MB)染料的氧化来评估 NPs 的光催化活性。所合成的 CuNPs 显示出 MB 染料的快速氧化,在 4 小时内染料含量约降解 65%。这些结果表明,从环境和经济角度来看,红球菌使用预处理的矿山尾矿合成 CuNPs 是一种获得 CuNPs 的合适方法,得到的 NPs 可用于生物医学和光催化应用。