Self-Assembled Exopolysaccharide Nanoparticles for Bioremediation and Green Synthesis of Noble Metal Nanoparticles

Abstract

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.

Development of Functional Bionanocomposites Using Cyanobacterial Polysaccharides

“…In addition, other kinds of micro‐organismal EPS such as EPS‐605 and MSI021 showed metal adsorption properties. EPS‐605 was harvested from Lactobacillus plantarum‐605 . The structure comprised of mannose, glucose, and galactose with several modifications including acylation, phosphorylation, sulfation, and carboxylation.…”

Microbial Nanotechnology: Challenges and Prospects for Green Biocatalytic Synthesis of Nanoscale Materials for Sensoristic and Biomedical Applications

“…Results have showed its reducing actions for rapid (30 min.) biosynthesis of good monodispersed gold and silver nanoparticles without any pretreatment or modification [38]. Bacterial nanowires are conductive proteinaceous pilus-like nanostructures involved in extracellular electron transport processes of anaerobic dissimilatory metal-reducing bacteria like Geobacter and Shewanella genera [39], aerobic bacteria like Pseudomonas aeruginosa [40] and aerobic photosynthetic cyanobacteria like Microcystis and Synechocystis genera [41].…”

SERS imaging elucidates the folate receptor-mediated photothermal/photodynamic synergistic anticancer nanodrugs-induced cell apoptosis

“…Along with rapid development of nanotechnology, phototherapy, owning obvious advantages in tissue selectivity, process controlling, low toxicity and reproducible treatment, has become very promising, especially for the photothermal therapy (PTT) and the photodynamic therapy (PDT) [9,10]. In PTT, by using special materials with high photothermal conversion under the excitation of near infrared light (NIR), the local temperature of cell or tissue can rapidly increase and ablate targeting tumours [11][12][13].…”