Evaluation of the Efficiency of Ethanol Precipitation and Ultrafiltration on the Purification and Characteristics of Exopolysaccharides Produced by Three Lactic Acid Bacteria

Abstract

Exopolysaccharides (EPS) produced by three Lactic Acid Bacteria strains, Lactococcus lactis SLT10, Lactobacillus plantarum C7, and Leuconostoc mesenteroides B3, were isolated using two methods: ethanol precipitation (EPS-ETOH) and ultrafiltration (EPS-UF) through a 10 KDa cut-off membrane. EPS recovery by ultrafiltration was higher than ethanol precipitation for Lactococcus lactis SLT10 and Lactobacillus plantarum C7. However, it was similar with both methods for Leuconostoc mesenteroides B3. The monomer composition of the EPS fractions revealed differences in structures and molar ratios between the two studied methods. EPS isolated from Lactococcus lactis SLT10 are composed of glucose and mannose for EPS-ETOH against glucose, mannose, and rhamnose for EPS-UF. EPS extracted from Lactobacillus plantarum C7 and Leuconostoc mesenteroides B3 showed similar composition (glucose and mannose) but different molar ratios. The molecular weights of the different EPS fractions ranged from 11.6±1.83 to 62.4±2.94 kDa. Molecular weights of EPS-ETOH fractions were higher than those of EPS-UF fractions. Fourier transform infrared (FTIR) analysis revealed a similarity in the distribution of the functional groups (O-H, C-H, C=O, -COO, and C-O-C) between the EPS isolated from the three strains.

Lactic acid bacterial exopolysaccharides strongly bind histamine and can potentially be used to remove histamine contamination in food

“…For example, the EPS of Lact. plantarum WLPL04 is comprised of xylose, glucose and galactose [29], whereas the EPS of Lactococcus lactis SLT10 is comprised of glucose, mannose and rhamnose [30]. The EPS of Lactobacillus sakei L3 has a dextran containing d -glucose residues with α−1, 6 glycosidic linkage, which has high viscosity at high concentration, low temperature and acidic pH [31].…”

Selection of cereal-sourced lactic acid bacteria as candidate starters for the baking industry

“…To date, very few studies have described the ability of Leuconostocs to produce HePS. According to Ziadi et al [ 85 ], members of the genus Leuconostoc produce HePS that are mainly composed of glucose and mannose and, to a lower extent, of rhamnose and arabinose. This was not expected since Leuconostocs are acknowledged as primary producers of dextran as well as other HoPS, such as alternan and levan [ 85 , 86 ].…”

Extraction Improvement of the Bioactive Blue-Green Pigment “Marennine” from Diatom Haslea ostrearia’s Blue Water: A Solid-Phase Method Based on Graphitic Matrices

“…Still, those two bands were also found in a commercial fucoidan extract from Ascophyllum nodosum (Ascophyscient ® ), as well as in a further purified version following precipitation of polyuronic acids residues (i.e., ascophyllan) with calcium acetate [ 14 ]. To our knowledge, assignment of the 2359 cm band could not be found in the literature for fucoidans, but was assigned to O–H vibration of carbohydrates in bacterial extracellular polymeric substance [ 15 ].…”