Abstract:
Significant postharvest losses and food safety issues persist in many developing nations, primarily due to fungal activities, including mycotoxin production. In this study, green synthesised zinc oxide nanoparticles (ZnO-NPs) were prepared from leaf extracts of Syzygium cordatum (ZnO 1), Lippia javanica (ZnO 2), Bidens pilosa (ZnO 3), and Ximenia caffra (ZnO 4). Physicochemical characteristics of the ZnO-NPs were determined using X-ray diffraction (XRD), Fourier transmission Infrared spectroscopy and ultraviolet-visible (UV-vis) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD analysis confirmed the presence of a wurtzite crystal structure in the hexagonal shape of the ZnO nanoparticles (NPs), with an average size ranging between 25 and 43 nm. The microscopic examination of the morphology revealed the presence of spherical particles with sizes ranging from 37 to 47 nm in diameter. The antifungal efficacy of the ZnO-NPs was assessed against pathogenic plant fungi, including Botrytis sp. (STEU 7866), Penicillium sp. (STEU 7865), and Pilidiella granati (STEU 7864), using the poisoned food technique. Further antifungal evaluation of the ZnOPs was performed using the broth microdilution assay. A significant interaction between the type of ZnO-NPs and fungal species was observed, with the highest susceptibility in Mucor sp. to ZnO 2, achieving over 50% inhibition. Penicillium sp. also showed high susceptibility to all ZnO-NPs. Molecular docking results confirmed the strong H-bonding interactions of ZnO-NPs with fungal receptors in Mucor sp. and Penicillium sp., Botrytis sp. and P. granati exhibited the least susceptibility. Further tests revealed that ZnO 2 exhibited the highest inhibitory effect on Botrytis sp., with a low minimum inhibitory concentration (MIC) of 25 µg/mL, attributed to its larger positive zeta potential. This study indicates that ZnO NPs, particularly those mediated using Lippia javanica (ZnO 2), have promising potential as effective antifungal agents, which could play a significant role in reducing postharvest decay and losses.
摘要:
许多发展中国家仍然存在重大的采后损失和食品安全问题,主要是由于真菌活动,包括霉菌毒素的生产。在这项研究中,绿色合成氧化锌纳米颗粒(ZnO-NPs)是由紫胶叶提取物(ZnO1),Lippiajavanica(ZnO2),Bidenspilosa(ZnO3),和Ximeniacaffra(ZnO4)。使用X射线衍射(XRD)测定ZnO-NP的物理化学特性,傅里叶透射红外光谱和紫外-可见(UV-vis)光谱,扫描电子显微镜(SEM),和透射电子显微镜(TEM)。XRD分析证实了在ZnO纳米颗粒(NPs)的六边形形状中存在纤锌矿晶体结构,平均尺寸在25到43nm之间。形态的显微镜检查显示存在直径为37至47nm的球形颗粒。评估了ZnO-NP对病原植物真菌的抗真菌功效,包括Botrytissp.(STEU7866),青霉。(STEU7865),andPiliellagranati(STEU7864),使用有毒食物技术。使用肉汤微量稀释测定对ZnOP进行进一步的抗真菌评估。观察到ZnO-NP的类型和真菌物种之间的显着相互作用,在Mucorsp中具有最高的敏感性。对ZnO2,达到50%以上的抑制作用。青霉。还显示出对所有ZnO-NP的高敏感性。分子对接结果证实了ZnO-NP与Mucorsp中真菌受体的强H键相互作用。和青霉菌sp.,Botrytissp.和P.granati表现出最小的易感性。进一步的试验表明,ZnO2对葡萄孢菌具有最高的抑制作用。,具有25µg/mL的最低抑制浓度(MIC),归因于其更大的正zeta电位。这项研究表明,ZnONPs,特别是那些使用Lippiajavanica(ZnO2)介导的具有作为有效抗真菌药物的潜力,这可以在减少采后腐烂和损失方面发挥重要作用。