Isolation and structure elucidation of cell surface polysaccharides from Oenococcus oeni

Area of Science:

• Microbiology
• Food Science
• Biochemistry

Background:

• Oenococcus oeni is crucial for malolactic fermentation in wine.
• Bacteriophages infecting O. oeni can cause fermentation failures.
• Cell wall polysaccharides are suspected bacteriophage receptors.

Purpose of the Study:

• To develop an efficient protocol for extracting O. oeni cell wall polysaccharides.
• To elucidate the chemical structures of the major polysaccharides.
• To determine the surface exposure of these polysaccharides.

Main Methods:

• Stepwise extraction protocol.
• Methylation analysis.
• 1D and 2D-NMR spectroscopy.
• MALDI-QIT-TOF mass spectrometry.
• HR-MAS NMR analysis.

Main Results:

• Two major polysaccharides were successfully extracted and purified.
• The structure of a heteropolysaccharide with a branched hexasaccharide and glycerol residue was determined.
• A galactofuranan chain with specific linkages and substitutions was elucidated.
• Both polysaccharides were confirmed to be exposed on the O. oeni cell surface.

Conclusions:

• The study provides detailed structural information on O. oeni cell wall polysaccharides.
• These polysaccharides are potential receptors for bacteriophages.
• This knowledge can inform strategies to control bacteriophage infections and ensure wine quality.