Zymomonas mobilis exopolysaccharide structure and role in high ethanol tolerance. (1st December 2018)

• Record Type: Journal Article
• Authors: Pallach, Mateusz; Marchetti, Roberta; Di Lorenzo, Flaviana; Fabozzi, Antonio; Giraud, Eric; Gully, Djamel; Paduano, Luigi; Molinaro, Antonio; D'Errico, Gerardino; Silipo, Alba
• Is Part Of: Carbohydrate polymers. Volume 201(2018)
• Page Start: 293
• Page End: 299
• Publication Date: 2018-12-01
• Subjects: D self-diffusion coefficient -- Rh hydrodynamic radius -- η solvent viscosity -- NMR nuclear magnetic resonance -- DOSY Diffusion Ordered Spectroscopy -- SLS Static Light Scattering -- DLS Dynamic Light Scattering -- EPS exopolysaccharide -- PFG Pulsed-Field Gradient -- TOCSY total correlated spectroscopy -- COSY correlation spectroscopy -- NOESY nuclear overhauser effect spectroscopy -- ROESY rotation frame nuclear overhauser effect spectroscopy -- HSQC heteronuclear single quantum coherence -- HMBC heteronuclear multiple bond correlation -- GC–MS gas chromatography mass spectrometry; Zymomonas mobilis -- Exopolysaccharide -- NMR spectroscopy -- DLS -- DOSY -- Ethanologenic bacteria; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2018.08.072
• Languages: English
• ISSNs: 0144-8617

Abstract

Graphical abstract: Highlights: Two EPSs from Zymomonas mobilis were extracted and purified. A mannose homopolymer and a galactose containing polysaccharide were characterized. DOSY NMR and DLS were used to assess their role in Z. mobilis high ethanol tolerance. Abstract: Bacterial cell surface exopolysaccharides (EPS) provide a protective barrier from the external milieu and participate in host-environment interactions. Zymomonas mobilis, an ethanologenic Gram negative bacterium, is used by the industry in bio-ethanol production process, due to its extraordinary resistance to a highly ethanolic environment. We found that Z. mobilis produces a mixture of two EPSs, an [α−(1→6)-D-Man p ] mannose homopolymer and a galactose containing polysaccharide: [→2)-β-D-Gal f -(1→3)-β-D-Gal p -(1→]n . A physico-chemical study, conducted with diffusion-ordered spectroscopy (DOSY) and Dynamic Light Scattering (DLS), allowed to demonstrate that, differently from the majority of polysaccharides, ethanol is a good solvent for the galactose containing EPS, revealing that its chemical structure is specifically connected with the Zymomonas mobilis high ethanol tolerance.