Abstract

MENDEZ-DIAZ, Diana Patricia et al. Structural and functional characterization of ZnO-EPS nanoparticles synthesized from exopolysac-charides produced by Lactiplantibacillus fabifermentans BAL-27-ITTG. Biotecnia [online]. 2023, vol.25, n.3, pp.55-64.  Epub May 27, 2024. ISSN 1665-1456.  https://doi.org/10.18633/biotecnia.v25i3.1950.

Exopolysaccharides (EPS) can be used as reducing agents and stabilizers, improving the physical and chemical properties of metallic nanoparticles. This study aimed to synthesize and evaluate the physicochemical, structural, and functional characteristics of ZnO particles obtained from EPS produced by Lactiplantibacillus fabifermentans BAL-27-ITTG. The structural characterization of the EPS exhibited a high molecular weight structure composed mainly of mannose and glucose, possibly linked by α-1-4, α-1-3, α-1-6 according to the RMN spectrum. The increase in EPS concentration during the synthesis leads to an increase of particle size at micrometric scale, decreasing the polydispersity index. The synthesis was confirmed with a UV-vis spectral scan, while the FT-IR spectrum showed absorption peaks at 600 cm-1 associated with the Zn-O bond. SSynthetized nano (NP) and microparticles (MP) showed improved functional characteristics comparing to free EPS. The highest values of antioxidant activity (80.25 %), water holding capacity (3.06 g H2O/g sample), emulsifying activity (69.85 %), and flocculant activity (69.07 %) were obtained from MpZnO-EPS synthetized with a concentration of 6 mg/mL of the reducing agent. Bacteriostatic activity was observed against S. aureus and L. fabifermentans. The absence of hemolysis confirms the biocompatibility of the particles.

Keywords : Particles; zinc oxide; exopolysaccharides; Lactiplantibacillus.