Tsilo Phakamani H, Basson Albertus K, Ntombela Zuzingcebo G, Dlamini Nkosinathi G, Pullabhotla Rajasekhar V S R
Department of Biochemistry and Microbiology, Faculty of Science, Agriculture and Engineering, University of Zululand, P/Bag X1001, KwaDlangezwa, 3886, South Africa.
Writing Centre: Teaching and Learning Centre, University of Zululand, P/Bag X1001, KwaDlangezwa, 3886, South Africa.
Biotechnol Notes. 2025 Feb 21;6:106-116. doi: 10.1016/j.biotno.2025.02.003. eCollection 2025.
Studying the utilization of natural products in the biosynthesis of silver nanoparticles (AgNPs) recently appears to be a fascinating area of research within nanotechnology. These nanoparticles exhibit biocompatibility and inherent stability, making them highly suitable for various industrial applications. The utilization of bioflocculant-synthesized Ag nanoparticles was investigated in this study for the purpose of eliminating diverse pollutants and dyes from wastewater and solutions. In this study, Ag nanoparticles were successfully synthesized through a green method utilizing a bioflocculant derived from isolated from Kombucha tea SCOBY as a stabilizing agent. The resulting nanoparticles were then evaluated for their flocculation and antimicrobial properties. Different characterization techniques including SEM, EDX, FT-IR, TGA, and TEM were investigated from the synthesized nanoparticles. Furthermore, the cytotoxicity of the Ag nanoparticles was assessed on human embryonic kidney (HEK 293) cells. The EDX analysis showed elemental Ag constituted 61.93 wt% of the prepared AgNPs. SEM revealed particles with average size of 15.8 nm and were spherical in shape. Thermo-gravimetric analysis (TGA) demonstrated that AgNPs exhibited enhanced thermal stability, retaining over 85 % of their mass at elevated temperatures. In a concentration-dependent manner, the spherical biosynthesized nanoparticles exhibited notable cytotoxic effects on HEK 293 cell lines with over 68 % cell viability at 25 mg/mL concentration. The biosynthesized Ag nanoparticles displayed robust antimicrobial efficacy against both Gram-positive and Gram-negative pathogenic bacteria, though Gram-negative were more susceptible with MIC of 3.125 mg/mL concentration. The nanoparticles showcased a dye removal efficiency exceeding 78 % for all the tested dyes with highest removal efficiency of 96 % for methylene blue at a dosage concentration of 0.2 mg/mL of AgNPs. The Ag nanoparticles exhibited exceptional efficiencies in removing a wide range of pollutants present in wastewater. Compared to traditional flocculants, the biosynthesized Ag nanoparticles demonstrated significant potential in effectively removing both biological oxygen demand (BOD) (92 % removal efficiency) and chemical oxygen demand (COD) (86 % removal efficiency). Thus, the biosynthesized Ag nanoparticles show great potential as a substitute for chemical flocculants in the treatment of industrial wastewater, offering im-proved purification capabilities.
近年来，研究天然产物在银纳米颗粒（AgNPs）生物合成中的应用似乎已成为纳米技术领域一个引人入胜的研究方向。这些纳米颗粒具有生物相容性和内在稳定性，使其非常适合各种工业应用。本研究对生物絮凝剂合成的银纳米颗粒用于去除废水和溶液中的各种污染物及染料进行了调查。在本研究中，通过一种绿色方法成功合成了Ag纳米颗粒，该方法利用从红茶菌共生体中分离得到的生物絮凝剂作为稳定剂。然后对所得纳米颗粒的絮凝和抗菌性能进行了评估。对合成的纳米颗粒采用了包括扫描电子显微镜（SEM）、能谱分析（EDX）、傅里叶变换红外光谱（FT-IR）、热重分析（TGA）和透射电子显微镜（TEM）在内的不同表征技术。此外，还评估了Ag纳米颗粒对人胚肾（HEK 293）细胞的细胞毒性。能谱分析表明，元素银占制备的AgNPs的61.93重量%。扫描电子显微镜显示颗粒平均尺寸为15.8纳米，呈球形。热重分析（TGA）表明，AgNPs表现出增强的热稳定性，在高温下质量保留率超过85%。球形的生物合成纳米颗粒对HEK 293细胞系表现出显著的细胞毒性作用，在25毫克/毫升浓度下细胞活力超过68%。生物合成的Ag纳米颗粒对革兰氏阳性和革兰氏阴性病原菌均显示出强大的抗菌效果，不过革兰氏阴性菌更敏感，最低抑菌浓度为3.125毫克/毫升。纳米颗粒对所有测试染料的脱色效率均超过78%，在AgNPs剂量浓度为0.2毫克/毫升时，亚甲基蓝的脱色效率最高，为96%。Ag纳米颗粒在去除废水中存在的多种污染物方面表现出卓越的效率。与传统絮凝剂相比，生物合成的Ag纳米颗粒在有效去除生物需氧量（BOD）（去除效率92%）和化学需氧量（COD）（去除效率86%）方面显示出巨大潜力。因此，生物合成的Ag纳米颗粒在工业废水处理中作为化学絮凝剂的替代品具有巨大潜力，具有更好的净化能力。
