Hetero-exopolysaccharide secreted by Bacillus tequilensis FR9 (BtqEPS), was produced and fractioned on DEAE-Sepharose and phenyl sepharose CL-6B column. HPLC analysis revealed the existence of five monosaccharides including glucose, galactose, mannose, arabinose and xylose. FT-IR spectroscopy confirmed the presence of carboxyl and hydroxyl groups. 1H NMR and 13C NMR spectra analysis showed the presence of α and β-d-(+)-glucose residues and glycosidic linkages. The fibrous, porous nature and elemental composition (C, O, N, Cl, Na, P, S) of BtqEPS was inferred from SEM and EDX analysis. AFM proved that the micro-structure of BtqEPS is compact and rough. XRD analysis confirmed the amorphous nature of BtqEPS with 15.6% crystallinity index. TGA curve indicated the degradation temperature (Td) of 239.72°C. Furthermore, BtqEPS exhibited antioxidant effects by scavenging reactive oxygen species (ROS) and demonstrated strong reducing power. All the above findings on BtqEPS paves way to find novel insights of its potential applications in industries.
Keywords: Antioxidant activity; Bacillus tequilensis; Exopolysaccharide.
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