Purification and structural data of a highly substituted exopolysaccharide from Pseudomonas stutzeri AS22

Carbohydr Polym. 2014 Nov 4:112:404-11. doi: 10.1016/j.carbpol.2014.06.003. Epub 2014 Jun 10.

Abstract

Pseudomonas stutzeri AS22, when grown on media containing starch and yeast extract and incubated at 30 °C and 200 rpm for 24h, was found to produce an acidic and high-molecular mass exopolysaccharide (EPS22). The EPS22 was purified and a yield of 1.3g/l was achieved. The average molecular mass of the EPS22 was determined by high-performance size-exclusion chromatography (HPSEC) and showed an average molecular mass of 9.9 × 10(5)Da and a polydispersity index Mw/Mn (Mw, weight-average and Mn, number-average) of 1.197 ± 0.015. Structural data of this EPS22 were determined using a combination approach including monosaccharide composition (HPAEC-PAD and GLC), methylation analysis (GC-MS) and NMR spectroscopy analysis. EPS22 was found to be a complex heteropolysaccharide with a repeating unit mainly composed of glucose, mannose and lactyl rhamnose in a molar ratio of 1:1.1:0.7. The acidic nature of the polysaccharide is due to the presence of three non-osidic substituents consisting of a lactyl, acetyl, and pyruvyl groups.

Keywords: Exopolysaccharide EPS22; High molecular mass; Pseudomonas stutzeri AS22; Purification; Structural data.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrate Conformation
  • Glucose / chemistry
  • Hydrolysis
  • Magnetic Resonance Spectroscopy
  • Molecular Weight
  • Polysaccharides, Bacterial / chemistry*
  • Polysaccharides, Bacterial / isolation & purification
  • Pseudomonas stutzeri / chemistry*
  • Rhamnose / analysis

Substances

  • Polysaccharides, Bacterial
  • Glucose
  • Rhamnose