State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China.
Department of Biochemistry and Molecular Biology, Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University , Nanjing 210029, Jiangsu, China.
ACS Appl Mater Interfaces. 2017 Jul 12;9(27):22808-22818. doi: 10.1021/acsami.7b02908. Epub 2017 Jun 26.
Continuing efforts have been made to explore novel exopolysaccharides (EPSs) for valuable applications. In this research, we report for the first time that a novel non-glucan EPS named EPS-605 can self-assemble to form spherical nanosize particles of ∼88 nm in diameter, expanding both the range of EPS type and structural type that EPSs self-assemble into. Characterization of EPS-605 shows that it is composed of mannose, glucose, and galactose with several modifications including acylation, phosphorylation, sulfation, and carboxylation, and a highly negative charge. EPS-605 showed a record biosorption capability for Pb, Cu, Cd, and methylene blue as compared to that of other reported EPSs, biosorbents, and nanosorbents. The adsorption ability of EPS-605 is affected by pH, temperature, the initial adsorbate concentration, the contact time, and the presence of background electrolytes. The mechanism of EPS-605 adsorbing heavy metals seems to be different to that for dyes. Moreover, EPS-605 can serve as the reductant in the synthesis of Au nanoparticles (AuNPs) and AgNPs enabling good monodispersity within the shortest time (of 30 min) compared to that from other EPSs and without any extra pretreatment. Our research advances the development of novel EPSs and provides a new, eco-friendly, and renewable platform for both the bioremediation and green synthesis of nanomaterials.
人们一直在努力探索新型胞外多糖 (EPSs)，以寻求其在有价值领域的应用。在这项研究中，我们首次报道了一种新型非葡聚糖 EPS，命名为 EPS-605，它可以自组装形成直径约 88nm 的球形纳米颗粒，扩大了 EPS 自组装成的 EPS 类型和结构类型的范围。对 EPS-605 的特性分析表明，它由甘露糖、葡萄糖和半乳糖组成，并经过几种修饰，包括酰化、磷酸化、硫酸化和羧基化，具有高度的负电荷。与其他报道的 EPS、生物吸附剂和纳米吸附剂相比，EPS-605 对 Pb、Cu、Cd 和亚甲基蓝具有创纪录的生物吸附能力。EPS-605 的吸附能力受 pH 值、温度、初始吸附质浓度、接触时间和背景电解质的存在的影响。EPS-605 吸附重金属的机制似乎与染料不同。此外，EPS-605 可用作金纳米颗粒 (AuNPs) 和银纳米颗粒 (AgNPs) 的还原剂，与其他 EPS 相比，在最短的时间（30 分钟）内实现良好的单分散性，而无需任何额外的预处理。我们的研究推进了新型 EPS 的发展，并为生物修复和绿色合成纳米材料提供了一个新的、环保和可再生的平台。
