| abstract |
A lactic acid bacterium having a 16S ribosomal RNA characteristic of the genus Streptococcus, cocci morphology, a growth optimum in the range of about 28° C. to about 45° C., having the ability to ferment D-galactose, D-glucose, D-fructose, D-mannose, and N-acetyl (D)-glucosamine, salicin, cellobiose, maltose, lactose, sucrose and raffinose, and imparting a viscosity of greater than 100 mPa.s at a shear rate of about 293 s −1 . The strain often produces an exopolysaccharide comprising a chain of glucose, galactose and N-acetylglucosamine in a proportion of 3:2:1 respectively. The new strain is identified as Streptococcus macedonicus . Other characteristics include a total protein profile obtained after culture in an MRS medium for 24 h at 28° C., extraction of the total proteins and migration of the proteins on an SDS-PAGE electrophoresis gel, exhibits a degree of Pearson correlation of at least 78 with respect to bacterium CNCM I-1920 or I-1926. The strain and its secreted polysaccharides can be used in preparing dietary compositions. The present invention further relates to a new exopolysaccharide synthesis operon and the genes thereof isolated from the new species and to transformed cells having inserted nucleotides that encode proteins of the EPS operon or at least one gene thereof. |