Extraction and characterization of dextran from Leuconostoc pseudomesenteroides YB-2 isolated from mango juice

Carbohydr Polym. 2019 Mar 1:207:218-223. doi: 10.1016/j.carbpol.2018.11.092. Epub 2018 Nov 29.

Abstract

An exopolysaccharide (EPS)-producing strain of YB-2 isolated from mango juice was identified as Leuconostoc pseudomesenteroides. The molecular weight (Mw) of this EPS was 7.67×105 Da. Gas chromatography (GC) analysis confirmed the presence of only glucose monomers. Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectra displayed the glucan nature of the EPS with 96.8% α-(1→6) and 3.2% branching α-(1→3) linkages. Scanning electron microscopy (SEM) showed smooth surfaces and compact structure. The water solubility index (WSI) and water-holding capacity (WHC) of dextran were 97.48±2.46% and 287.51±7.93%, respectively. The rheological analysis of dextran elucidated a non-Newtonian pseudoplastic behavior. The dextran revealed an inhibitory activity against Escherichia coli and Staphylococcus aureus with minimal inhibitory concentrations (MIC) of 2.0 mg/mL and 3.0 mg/mL, respectively.

Keywords: Antibacterial activity; Characterization; Dextran; Leuconostoc pseudomesenteroides; Structure.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / isolation & purification
  • Anti-Bacterial Agents / pharmacology
  • Dextrans / chemistry*
  • Dextrans / isolation & purification
  • Dextrans / pharmacology
  • Escherichia coli / drug effects
  • Fruit and Vegetable Juices / microbiology
  • Leuconostoc / chemistry*
  • Mangifera / microbiology
  • Molecular Weight
  • Polysaccharides, Bacterial / chemistry*
  • Polysaccharides, Bacterial / isolation & purification
  • Polysaccharides, Bacterial / pharmacology
  • Solubility
  • Staphylococcus aureus / drug effects
  • Viscosity

Substances

  • Anti-Bacterial Agents
  • Dextrans
  • Polysaccharides, Bacterial