Abstract

Microbial polysaccharides can find distinct applications as stabilizer agents including synthesis of nanoparticles. In this study, a dextran-type exopolysaccharide (EPS) was used as the stabilizer agent for the green synthesis of silver nanoparticles (AgNPs-Dex) with antimicrobial characteristics. UV–vis spectroscopy analysis was used to test the formation of AgNPs-Dex. The uniform morphology at around 10 nm size was observed for AgNPs-Dex by TEM analysis and importantly EDX analysis demonstrated the embedment of Ag⁺ ions within dextran as the stabilizer agent. XRD analysis confirmed the crystalline nature of AgNPs-Dex and FTIR analysis demonstrated the interactions of dextran functional groups with silver. DSC and TGA analysis showed the alteration in the thermal stability of AgNPs-Dex compared to the stabilizer dextran. The antibacterial and antifungal activities of AgNPs-Dex were determined against food originated pathogenic bacteria and fungi and important inhibition levels were observed at 1 mg ml⁻¹ concentration of AgNPs-Dex and this activity was observed to be concentration dependent.

抽象的

微生物多糖可以作为稳定剂找到独特的应用，包括纳米颗粒的合成。在这项研究中，葡聚糖型外多糖（EPS）被用作绿色合成具有抗菌特性的银纳米颗粒（AgNPs-Dex）的稳定剂。紫外可见光谱分析用于测试AgNPs-Dex的形成。通过TEM分析观察到AgNPs-Dex在约10 nm尺寸处具有均匀的形态，重要的是EDX分析表明Ag ⁺的嵌入葡聚糖中的离子作为稳定剂。XRD分析证实了AgNPs-Dex的晶体性质，FTIR分析证实了葡聚糖官能团与银的相互作用。DSC和TGA分析表明，与稳定剂葡聚糖相比，AgNPs-Dex的热稳定性发生了变化。测定了AgNPs-Dex对食物来源的致病细菌和真菌的抗菌和抗真菌活性，并且在1mg ml ^-1的AgNPs-Dex浓度下观察到重要的抑制水平，并且该活性是浓度依赖性的。