%A Kulwinder Singh Sran
%A Shiva S Sundharam
%A S Krishnamurthi
%A Anirban Roy Choudhury
%O Copyright of this article belongs to Elsevier Science.
%J International journal of biological macromolecules
%T Production, characterization and bio-emulsifying activity of a novel thermostable exopolysaccharide produced by a marine strain of Rhodobacter johrii CDR-SL 7Cii.
%X An exopolysaccharide (EPS) producing bacterial strain was isolated from the surface of marine macroalgae (Padina sp.). Based on polyphasic taxonomy, the strain CDR-SL 7Cii was assigned to the genus Rhodobacter and found to be the closest relative of the species Rhodobacter johrii. The strain was able to produce 6.2?g/l of EPS upon fermentation using R2A medium enriched with 2.5% glucose. FT-IR analysis revealed the presence of hydroxyl, carboxyl and diacyl-ester functional groups in the purified EPS. Further Chromatographic study revealed that R. johrii synthesized a high molecular weight anionic exopolysaccharide composed of glucose, glucuronic acid, rhamnose and galactose in a molar ratio of 3:1.5:0.25:0.25. The 1D and 2D NMR spectroscopy (COSY/HSQC) analysis revealed the presence of 1,6 linked-?-d-Glcp, 1,4 linked-?-d-Glcp, 1,3 linked-?-d-GlcA, 1,3 linked-?-d-Galp, 1,6 linked-?-d-Galf and 3-?-l-Rhmp residues. Moreover, the purified EPS has shown stability towards elevated temperature and also acted as a bio-emulsifier to create a high pH and temperature stable emulsion of hydrocarbon/water indicating its industrial potential. This is the first report of EPS production by a strain of Rhodobacter johrii.
%K Bio-emulsifier; Exopolysaccharide; Rhodobacter johrii; Structural characterization
%P 240-249
%V 127
%D 2019
%I Elsevier Science
%L open2178