Studies on a Neutral Exopolysaccharide of Lactobacillus fermentum TDS030603

Abstract

A neutral exopolysaccharide produced in large amounts by Lactobacillus fermentum TDS030603 was purified from culture supernatants and its structure determined by monosaccharide analysis, methylation analysis and 1 H-NMR spectroscopy. Optimum conditions for the production of this exopolysaccharide by the above bacterial strain, when cultured using cheese whey medium or MRS broth, were also investigated. The exopolysaccharide was found to be composed of D-galactose and D-glucose in the molar ratio of 1:2.5 and to consist of one major as well as one minor saccharide, both of which contained a tetrasaccharide repeating unit consisting of two α and two β anomers. The major saccharide contained non-reducing glucopyranose, O-3 substituted glucopyranose, O-6 substituted galactopyranose and O-2,3 disubstituted glucopyranose. The minor saccharide consisted of non-reducing galactopyranose, O-3 substituted glucopyranose, O-6 substituted galactopyranose and O-2,3 disubstituted glucopyranose. The results suggest that these exopolysaccharides are novel saccharides that differ from previously reported products of Lactobacillus fermentum strains. Their presence may contribute to the ropy properties of the medium.

Effects of carbohydrate source on physicochemical properties of the exopolysaccharide produced by Lactobacillus fermentum TDS030603 in a chemically defined medium

“…As the result, the molar ratio of glucose to galactose ranged from 2.6 to 2.8 (Table 2). This result was similar to the value of 2.5 which had been previously determined for the EPS produced by L. fermentum TDS030603 in MRS (Leo et al, 2007). The 1 H NMR spectra of the EPSs released in MRS and CDMs were very similar (Fig.…”

“…Generally, the viscosity of EPS is affected by (i) electrostatic interactions between charged residues, (ii) entanglement of long sugar chains, and (iii) the effect of branching. The electrostatic interaction is not the case for L. fermentum TDS030603 producing EPS, since it was revealed to be a neutral polysaccharide (Leo et al, 2007). 1 H NMR and monosaccharide composition analysis demonstrated that the chemical structures of the EPSs were very similar (Figs.…”

“…Lactobacillus fermentum TDS030603 was obtained from the bacterial collection of our own laboratory (Leo et al, 2007). MRS was from Oxoid (Cambridge, UK).…”

Exopolysaccharides of Lactic Acid Bacteria for Food and Colon Health Applications

“…Heterofermentative in addition to homofermentative LAB can produce EPS. Lactobacillus fermentum is an EPSproducing heterofermentative LAB for which the EPS structure has been determined [50]. Figueroa et al reported that Lactobacillus brevis and Lactobacillus buchneri showed ropiness on glucose-or sucrose-containing media, although they did not investigate whether such ropiness derived from hetero-EPS or from other slimy substances [51].…”

Optimization of production of Microbial Exopolysaccharides (EPS) with essential oils from two medicinal plants

“…Leo et al, 2007 indicated that Lactobacillus fermentum TDS030603 is able to produce more EPS at 37 than at 40°C. On the other hand, the growth and exopolysaccharide (EPS) production by Lactobacillus fermentum F6 increased to a maximum value of 44.49 mg/l of EPS at 37°C (Zhang et al, 2011).…”