Characterization of Exopolysaccharide Produced byStreptococcus thermophilusCC30

Abstract

An exopolysaccharide (EPS) producing strain CC30 was isolated from raw milk and identified as Streptococcus thermophilus with morphological and 16S sequencing analysis. The strain was shown to produce 1.95 g/L of EPS when grown in skim milk lactose medium at 30°C by increasing the viscosity of the medium. The EPS was isolated and purified, and it was shown to consist of glucose and galactose in 1 : 1 ratio, with molecular weights ranging from 58 to 180 kDa. FTIR spectroscopy indicated the EPS to have amide, hydroxyl, and carboxyl groups. Under Atomic Force Microscopy, EPS showed spike-like lumps of EPS. Scanning Electron Microscopy (SEM) studies showed that it had irregular lumps with a coarse surface. The EPS displayed pseudoplastic nature. Thermogravimetric analysis (TGA) reported a degradation temperature of 110.84°C. The purified EPS exhibited reducing activity, hydrogen peroxide radical scavenging activity, and emulsification activity. The results of the present study indicated that EPS producing Streptococcus thermophilus could serve as a promising candidate for further exploitation in food industry.

Characterization, antioxidant and immunomodulatory potential on exopolysaccharide produced by wild type and mutant Weissella confusa strains

“…Total antioxidant activity of EPS was determined using method of Mitsuda et al [ 41 ] as reported by Kanamarlapuda and Muddada [ 42 ]. Mixture of 1.235 g of ammonium molybtate (4 mM), 0.6 M Sulfuric acid (45 mL), 0.9942 g of Sodium sulphate (28 mM) and 250 mL with distilled water was used as total antioxidant capacity.…”

Characterization of lactic acid bacteria derived exopolysaccharides for use as a defined neuroprotective agent against amyloid beta1–42-induced apoptosis in SH-SY5Y cells

“…In the establishment of Aβ 1-42 group, cells were induced by 10 μM of Aβ 1-42 for 24 h. In protective experiments of l-EPSs, cells were pretreated with various concentrations (100, 250, 500, 1000, and 1250 μg/mL) of l-EPSs dissolved in serum-free media for 24 h respectively, and then exposed to 10 μM (final concentration) of Aβ 1-42 in the presence of l-EPSs for another 24 h. The control cells were added with the same medium without Aβ 1-42 . All experiments were repeated three times for each treatment condition 19,20 .…”

“…The freestanding Au and Ag films were put on a glass surface. The Si probes coated with Au had the sizes below: chip size, 3.6 * 1.6 * 0.4 mm, the radius of curvature, 10 nm; tip height 10-15 m. The Nova software was used to analyze the images 19,20 .…”

Probiotic properties of a phytase producing Pediococcus acidilactici strain SMVDUDB2 isolated from traditional fermented cheese product, Kalarei

“…Absence of peak around 1529.8 cm -1 which corresponds to an amino group was absent in our case. A peak at 1214 cm −1 corresponded to the presence of C-O stretching in ether or alcohol groups 24 . The peak around 1025 cm −1 recommended the presence of C-O-H link bond position 22 .…”