Molecular Characterization and Biocompatibility of Exopolysaccharide Produced by Moderately Halophilic Bacterium Virgibacillus dokdonensis from the Saltern of Kumta Coast

Abstract

The use of natural polysaccharides as biomaterials is gaining importance in tissue engineering due to their inherent biocompatibility. In this direction, the present study aims to explore the structure and biocompatibility of the EPS produced by Virgibacillus dokdonensis VITP14. This marine bacterium produces 17.3 g/L of EPS at 96 h of fermentation. The EPS was purified using ion exchange and gel permeation chromatographic methods. The porous web-like structure and elemental composition (C, O, Na, Mg, P, S) of the EPS were inferred from SEM and EDX analysis. AFM analysis revealed spike-like lumps with a surface roughness of 84.85 nm. The zeta potential value of −10 mV indicates the anionic nature of the EPS. Initial molecular characterization showed that the EPS is a heteropolysaccharide composed of glucose (25.8%), ribose (18.6%), fructose (31.5%), and xylose (24%), which are the monosaccharide units in the HPLC analysis. The FTIR spectrum indicates the presence of functional groups/bonds typical of EPSs (O-H, C-H, C-O-H, C-O, S=O, and P=O). The polymer has an average molecular weight of 555 kDa. Further, NMR analysis revealed the monomer composition, the existence of two α- and six β-glycosidic linkages, and the branched repeating unit as → 1)[α-D-Xylp-(1 → 2)-α-D-Glcp-(1 → 6)-β-D-Glcp-(1 → 5)]-β-D-Frup-(2 → 2)[β-D-Xylp-(1 → 4)]-β-D-Xylp-(1 → 6)-β-D-Fruf-(2 → 4)-β-D-Ribp-(1 →. The EPS is thermally stable till 251.4 °C. X-ray diffraction analysis confirmed the semicrystalline (54.2%) nature of the EPS. Further, the EPS exhibits significant water solubility (76.5%), water-holding capacity (266.8%), emulsifying index (66.8%), hemocompatibility (erythrocyte protection > 87%), and cytocompatibility (cell viability > 80% on RAW264.7 and keratinocyte HaCaT cells) at higher concentrations and prolongs coagulation time in APTT and PT tests. Our research unveils the significant biocompatibility of VITP14 EPS for synthesizing a variety of biomaterials.

Effect of the incorporation of polysaccharides from green alga Bryopsis plumosa on beef sausages quality

“…For emulsifying properties, PS exhibited a high emulsifying activity with corn oil ( 87.71 % at 1% of concentration), and this activity was maintained at 48h. In view of this, it could be an acceptable emulsifier because it has the capacity to maintain 50% of the original volume of the emulsion after 24h (39). Overall, the results suggest that PS has the required properties to be used as a surfaceactive compound, which are suitable for food processing (37).…”

Biological Activity of Lactic Acid Bacteria Exopolysaccharides and Their Applications in the Food and Pharmaceutical Industries

“…Therefore, EPS has broad application prospects in the field of drug carriers. EPS serves as an ideal carrier for drugs, primarily due to the following reasons: Firstly, EPS exhibits excellent biocompatibility and safety, which means it can minimize stimulation and immune response to human tissues, ensuring the safety and reliability of the drug delivery process [ 124 ]. Secondly, the structural characteristics of EPS endow it with abundant functional groups and modifiable side chains, which provide the possibility for chemical or biological modifications.…”

Exploring Extremophiles from Bulgaria: Biodiversity, Biopolymer Synthesis, Functional Properties, Applications

“…Another study focuses on the exploration of Virgibacillus dokdonensis VITP14’s EPS, with a substantial production of 17.3 g/L after 96 h of fermentation. The EPS, characterized by a porous web-like structure through elemental composition analysis and an identified monosaccharide composition (glucose, ribose, fructose, xylose), displays excellent water solubility, water-holding capacity, emulsifying properties, hemocompatibility, and cytocompatibility, making it a promising biomaterial for various applications in tissue engineering and beyond [ 98 ].…”