Abu-Hussien Samah H, Khan Muhammad A, Al-Farga Ammar, Soliman Ahmed G, El-Sayed Salwa M, Adly Eslam
Department of Agriculture Microbiology, Faculty of Agriculture, Ain Shams University, Cairo, 11241, Egypt.
Department of Biological Sciences, Faculty of Sciences, International Islamic University (IIU), Islamabad, Pakistan.
BMC Biotechnol. 2025 Jul 21;25(1):75. doi: 10.1186/s12896-025-01011-2.
This study presents an eco-friendly approach for synthesizing silver nanoparticles (AgNPs) using olive cake hydrolysate (OCH), produced through microbial fermentation of olive cake waste by Pseudomonas fluorescens. The OCH was analyzed by gas chromatography-mass spectrometry (GC-MS), revealing the biotransformation of olive cake components into bioactive compounds, including 24-norursa-3,12-diene, methyl esters of 9,12-octadecadienoic acid and 9-octadecenoic acid, and α-sitosterol. The biosynthesized olive cake hydrolysate-silver nanoparticles (OCH-AgNPs) were characterized using ultraviolet-visible (UV-Vis) spectroscopy to confirm surface plasmon resonance at 420 nm; Fourier-transform infrared (FTIR) spectroscopy to identify the involvement of hydroxyl and carbonyl functional groups; X-ray diffraction (XRD) analysis to verify the crystalline structure, revealing prominent (111) lattice planes of face-centered cubic (fcc) silver; transmission electron microscopy (TEM) to assess morphology and particle size, showing spherical nanoparticles with an average diameter of 19.6 ± 6.1 nm; dynamic light scattering (DLS) to measure hydrodynamic diameter, yielding a size of 109.8 nm; and zeta potential analysis to determine surface charge, which indicated high colloidal stability with a zeta potential of - 47.0 mV. OCH-AgNPs exhibited superior antimicrobial activity compared to OCH alone, with low MIC values against P. aeruginosa, Candida albicans, Aspergillus brasiliensis, and Staphylococcus aureus MRSA. Larvicidal activity, optimized via Box-Behnken design, showed 98.86% mortality of Culex pipiens at 1.0 µg/mL (LC₅₀ = 0.40 µg/mL), significantly outperforming OCH (LC₅₀ = 57.22 µg/mL). Histopathological and biochemical analyses of treated larvae revealed structural damage, decreased protein and carbohydrate content, and inhibition of acetylcholinesterase. Cytotoxicity assays on human skin fibroblasts confirmed low toxicity (IC₅₀ >200 µg/mL). Molecular docking identified α-sitosterol as a key bioactive component. These findings underscore the potential of OCH-AgNPs as a sustainable and multifunctional biocontrol agent for microbial and vector management.
本研究提出了一种利用橄榄饼水解物（OCH）合成银纳米颗粒（AgNPs）的环保方法，该橄榄饼水解物是通过荧光假单胞菌对橄榄饼废料进行微生物发酵产生的。通过气相色谱 - 质谱联用（GC - MS）对OCH进行分析，揭示了橄榄饼成分向生物活性化合物的生物转化，包括24 - 去甲熊果 - 3,12 - 二烯、9,12 - 十八碳二烯酸甲酯、9 - 十八碳烯酸甲酯和α - 谷甾醇。使用紫外 - 可见（UV - Vis）光谱对生物合成的橄榄饼水解物 - 银纳米颗粒（OCH - AgNPs）进行表征，以确认在420 nm处的表面等离子体共振；使用傅里叶变换红外（FTIR）光谱确定羟基和羰基官能团的参与情况；通过X射线衍射（XRD）分析验证晶体结构，揭示面心立方（fcc）银的突出（111）晶格平面；使用透射电子显微镜（TEM）评估形态和粒径，显示平均直径为19.6 ± 6.1 nm的球形纳米颗粒；使用动态光散射（DLS）测量流体动力学直径，得出尺寸为109.8 nm；通过zeta电位分析确定表面电荷，表明具有 - 47.0 mV的zeta电位，具有高胶体稳定性。与单独的OCH相比，OCH - AgNPs表现出优异的抗菌活性，对铜绿假单胞菌、白色念珠菌、巴西曲霉和耐甲氧西林金黄色葡萄球菌（MRSA）的最低抑菌浓度（MIC）值较低。通过Box - Behnken设计优化的杀幼虫活性表明，在1.0 μg/mL时致倦库蚊的死亡率为98.86%（LC₅₀ = 0.40 μg/mL），明显优于OCH（LC₅₀ = 57.22 μg/mL）。对处理后的幼虫进行的组织病理学和生化分析显示结构损伤、蛋白质和碳水化合物含量降低以及乙酰胆碱酯酶受到抑制。对人皮肤成纤维细胞的细胞毒性试验证实毒性较低（IC₅₀ >200 μg/mL）。分子对接确定α - 谷甾醇为关键生物活性成分。这些发现强调了OCH - AgNPs作为用于微生物和病媒管理的可持续和多功能生物防治剂的潜力。
