Characterization of high molecular weight dextran produced by Weissella cibaria CMGDEX3

Exopolysaccharide (EPS) producing Weissella cibaria CMGDEX3 was isolated from cabbage on sucrose containing De Man, Rogosa and Sharpe (MRS) agar. Dextransucrase activity and dextran yield was found to be 7.1 DSU ml(-1) and 2.4 g dl(-1), respectively. The structural characterization of purified EPS determined by FTIR, (1)H and (13)C NMR spectroscopy demonstrated that W. cibaria CMGDEX3 synthesized a linear dextran that predominately had α (1→6) glycosidic linkages with only a few (3.4%) α (1→3) linked branches. Molecular mass determination showed that it was a high molecular weight dextran of an average >2,000,000 Da. According to our knowledge this is the first report on isolation of dextran synthesizing Weissella genus from Pakistan.