Parada Javiera, Díaz Marcela, Hermosilla Edward, Vera Joelis, Tortella Gonzalo, Seabra Amedea B, Quiroz Andrés, Hormazábal Emilio, Rubilar Olga
Chemical Engineering Department, Universidad de La Frontera, Temuco P.O. Box 54-D, Chile.
Biotechnological Research Center Applied to the Environment (CIBAMA-BIOREN), Universidad de La Frontera, Temuco P.O. Box 54-D, Chile.
Nanomaterials (Basel). 2022 Jun 22;12(13):2137. doi: 10.3390/nano12132137.
The antimicrobial activity of metal nanoparticles obtained by biogenic routes has been extensively reported. However, their combined use with other antimicrobial formulations, such as essential oils, remains scarcely explored. In this work, a manganese-ferrite/silver nanocomposite (MnFeO/Ag-NC) was synthesized in a two-step procedure: first, MnFeO nanoparticles were produced by a coprecipitation method, followed by biogenic reduction of silver ions using . MnFeO/Ag-NC was characterized using transmission electron microscopy (TEM), scanning electron microscopy equipped with an energy dispersive X-ray analyzer (SEM-EDX), and a vibrating sample magnetometer (VSM-SQUID). The antibacterial activity if MnFeO/Ag-NC was evaluated against by determining its minimum inhibitory concentration (MIC) in the presence of two essential oils: eucalyptus oil (EO) and garlic oil (GO). The fractional inhibitory concentration (FIC) was also calculated to determine the interaction between MnFeO/Ag-NC and each oil. The MIC of MnFeO/Ag-NC was eightfold reduced with the two essential oils (from 20 to 2.5 µg mL). However, the interaction with EO was synergistic (FIC: 0.5), whereas the interaction with GO was additive (FIC: 0.75). Additionally, a time-kill curve analysis was performed, wherein the MIC of the combination of MnFeO/Ag-NC and EO provoked a rapid bactericidal effect, corroborating a strong synergism. These findings suggest that by combining MnFeO/Ag-NC with essential oils, the necessary ratio of the nanocomposite to control phytopathogens can be reduced, thus minimizing the environmental release of silver.
通过生物途径获得的金属纳米颗粒的抗菌活性已被广泛报道。然而，它们与其他抗菌制剂（如精油）的联合使用仍鲜有研究。在本研究中，采用两步法合成了锰铁氧体/银纳米复合材料（MnFeO/Ag-NC）：首先，通过共沉淀法制备MnFeO纳米颗粒，然后使用[具体物质]对银离子进行生物还原。使用透射电子显微镜（TEM）、配备能量色散X射线分析仪的扫描电子显微镜（SEM-EDX）和振动样品磁强计（VSM-SQUID）对MnFeO/Ag-NC进行表征。通过在两种精油（桉叶油（EO）和大蒜油（GO））存在的情况下测定其最低抑菌浓度（MIC），评估了MnFeO/Ag-NC对[具体细菌]的抗菌活性。还计算了分数抑菌浓度（FIC）以确定MnFeO/Ag-NC与每种油之间的相互作用。两种精油使MnFeO/Ag-NC的MIC降低了八倍（从20降至2.5 µg/mL）。然而，与EO的相互作用是协同的（FIC：0.5），而与GO的相互作用是相加的（FIC：0.75）。此外，进行了时间-杀菌曲线分析，其中MnFeO/Ag-NC与EO组合的MIC产生了快速杀菌效果，证实了强烈的协同作用。这些发现表明，通过将MnFeO/Ag-NC与精油结合，可以降低控制植物病原体所需的纳米复合材料比例，从而最大限度地减少银在环境中的释放。
