Physicochemical characterization and antioxidant activity of cell-bound exopolysaccharides from Lactobacillus fermentum S1 obtained by two extraction methods

Physicochemical Characteristics of Novel Cell-Bound Exopolysaccharide from Probiotic Limosilactobacillus fermentum (MTCC 5898) and Its Relation to Antioxidative Activity

“…As depicted in Figure 2D, the elution profile of EPS-b revealed it to be majorly comprising glucose and galactose residue, indicating EPS-b to be a heteropolysaccharide molecule, which was similar to the observation of Tallon et al 27 who reported EPS-b of L. plantarum EP56 to be composed of glucose and galactose units. Contrarily, EPS-b of L. fermentum S1 was found to be constituted of mannose, rhamnose, glucose, and galactose 28 and L. helveticus MB2−1 EPS-b with additional arabinose unit, 25 further indicating the strain-dependent difference in the physicochemical properties of EPS-b. Moreover, in the present observation, the presence of disaccharide unit, i.e., lactose and an unknown component, indicated that the incomplete hydrolysis of EPS-b, which was in agreement with the study conducted by Tukenmez et al 29 who showed the presence of disaccharide units as a result of partial hydrolysis.…”

“…27 Conversely, in a recent study, all three methods yielded an equivalent amount of EPS-b from L. fermentum S1, which indicated strain-dependent variation in the interaction of cell-bound exopolysaccharides. 3,28 Therefore, in the present investigation, the ultrasonication method was used for the extraction of EPS-b in subsequent experiments.…”

“…11 Similarly, the molecular weight of L. fermentum MTCC 5898 EPS-b was also found to be smaller than EPS-b of L. rhamnosus JAAS8 (550 kDa) and L. fermentum S1 (719 kDa). 26,28 The monosaccharide composition of EPS-b was also determined by HPLC using the chromatogram of standard monosaccharides and disaccharides as shown in Figure 2C. As depicted in Figure 2D, the elution profile of EPS-b revealed it to be majorly comprising glucose and galactose residue, indicating EPS-b to be a heteropolysaccharide molecule, which was similar to the observation of Tallon et al 27 who reported EPS-b of L. plantarum EP56 to be composed of glucose and galactose units.…”

“…Such the broad absorption peaks at 3273 cm −1 (peak 1) and 2929 cm −1 (peak 2) were similar to the peaks obtained for L. fermentum S1 EPS-b and corresponded to −OH and −CH 2 − vibrations. 28 However, peaks at 1053 cm −1 (peak 8) and 1640 cm −1 (peak 4) were assigned to C  O groups. 11,30 In the present study, a moderate peak at 1394 cm −1 (peak 6) depicted the presence of −CH 2 − and −C−OH groups, which was similar to the observation in the study conducted by Wang et al 11 Further, the bands at 1529 cm −1 (peak 5) were assigned to the presence of stretching vibrations of the secondary amine group, indicating the existence of the bounded protein.…”

Rheological and Thermal Properties of Levan from Bacillus mojavensis

“…The weak bands at 2950 and 2910 cm − 1 were due to the C-H stretching vibration [19]. The peak at 1654 cm − 1 is attributed to the bound water [43]. The peaks observed at 1129 cm − 1 and 1015 cm − 1 represent the pyranose form of sugars.…”