Structure of the extracelluar polysaccharide produced by Lactobacillus delbrueckii subsp. bulgaricus 291

摘要

The lactic acid bacterium Lactobacillus delbrueckii subsp. bulgaricus 291,when grown in skimmed milk,produced 80 mg/L exopolysaccharide with an average molecular mass of 1.4×10~3 kDa. Monosaccharide analysis, methylation analysis, MS, nad 1D/2D NMR (~1H and ~(13)C) studies performed on the native polysaccharide, and on oligosaccharides obtained from a mild acid hydrolysate of the native polysaccharide, showed the polysaccharide to consist of branched pentasaccharide repeating units with the following structure.