Regional Center for Mycology and Biotechnology (RCMB), Al-Azhar University, Cairo, Egypt.
Desert Research Center (DRC), Cairo, Egypt.
Mater Sci Eng C Mater Biol Appl. 2020 Apr;109:110617. doi: 10.1016/j.msec.2019.110617. Epub 2019 Dec 31.
The present study was performed to synthesize, for the first time, the magnesium oxide nanoparticles (MgO NPs) using the cell filtrate of the endobacterium Burkholderia rinojensis. The MgO NPs were characterized by Ultraviolet-visible (UV-Vis), Fourier-transform infrared (FTIR), X-ray diffraction (XRD), Energy dispersive X-ray (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and zeta potential (ZP). The UV spectrum of the MgO NPs showed a sharp absorption peak at 330 nm. The FTIR results confirm that the bioactive compounds act as reducing and capping agents of synthesized MgO NPs. The XRD pattern showed three major peaks of the crystalline metallic MgO NPs. Presence of magnesium and oxygen were confirmed by EDX profile. Both SEM and TEM revealed the MgO NPs as roughly spherical granular structures, and the size was 26.70 nm. The zeta potential was -32.1 mV, which indicated the stability of the MgO NPs in suspension. The MgO NPs showed considerable antifungal and antibiofilm activities against Fusarium oxysporum f. sp. lycopersici. At the concentration of 15.36 μg/ml, the MgO NPs completely inhibited the mycelial growth of the fungus. The biofilm formation of the pathogen was completely suppressed by MgO NPs at 1.92 μg/ml. The MgO NPs caused severe morphological changes on the hyphal morphology and biofilm formation of the fungus with significant damage on the fungal membrane integrity.
本研究首次利用内生菌伯克霍尔德菌（Burkholderia rinojensis）的细胞滤液合成了氧化镁纳米粒子（MgO NPs）。通过紫外-可见（UV-Vis）、傅里叶变换红外（FTIR）、X 射线衍射（XRD）、能谱（EDX）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和 Zeta 电位（ZP）对 MgO NPs 进行了表征。MgO NPs 的紫外光谱在 330nm 处显示出一个尖锐的吸收峰。FTIR 结果证实，生物活性化合物是合成 MgO NPs 的还原剂和封端剂。XRD 图谱显示出结晶金属 MgO NPs 的三个主要峰。EDX 图谱证实了镁和氧的存在。SEM 和 TEM 均显示 MgO NPs 为大致球形的颗粒状结构，尺寸为 26.70nm。Zeta 电位为-32.1mV，表明 MgO NPs 在悬浮液中稳定。MgO NPs 对尖孢镰刀菌（Fusarium oxysporum f. sp. lycopersici）表现出相当强的抗真菌和抗生物膜活性。在 15.36μg/ml 的浓度下，MgO NPs 完全抑制了真菌的菌丝生长。在 1.92μg/ml 的浓度下，MgO NPs 完全抑制了病原体的生物膜形成。MgO NPs 导致真菌菌丝形态和生物膜形成的严重形态变化，对真菌膜完整性造成显著损伤。
