Extracellular polymeric substances from two biofilm forming Vibrio species: Characterization and applications

The early biofilm colonizing Vibrio campbellii and Vibrio fortis produced 400 and 134 mg L−1 extracellular polymeric substances (EPS), respectively of distinct composition in planktonic cultures. The EPS of V. campbellii consisted of five monosaccharides: arabinose, galactose, glucose, mannose and rhamnose, however, that of V. fortis has only three monosaccharides: arabinose, galactose and mannose. The AFM topography analysis showed different morphology and physical characteristics of EPSs. FTIR and NMR spectral analyses revealed characteristic functional groups of the polysaccharides. EPSs were amorphous in nature and contained characteristic diffraction peaks. EPSs showed high emulsifying activity and pseudoplastic rheology. This is the first report of detailed characterization of EPS produced by V. campbellii and V. fortis, so far. Detailed analytical (FT-IR, 1H NMR, PXRD, etc.) and bio-physicochemical characteristics (thermostability, emulsifying and rheological properties) of EPSs showed potential for industrial applications.