Production and characterization of the polysaccharide from Propionibacterium acidi‐propionici on whey‐based media

M. RACINE, J. DUMONT, C.P. CHAMPAGNE AND A. MORIN. 1991. The effects of lactose, ammonium and phosphate on the production of extracellular polysaccharide from Propionibacterium acidi‐propionici VM‐25 were studied in whey‐based media. The polysaccharide was composed of a water‐soluble fraction (15% w/w), a water‐insoluble fraction (27% w/w) and ca 65% (w/w) of ash. Up to 15 g/l of polysaccharide was produced during growth on partially deproteinated whey, supplemented with lactose, NH 4 Cl and KH 2 PO 4 , after incubation at pH 7.0 and 25.C for 90 h. The final viscosity of the medium remained under 20 centipoises at the end of the fermentation (100–140 h). The fermentation of whey enabled a reduction of the lactose content up to 50%. The polysaccharide‐containing fractions were composed of glucose, galactose, mannose, rhamnose and fucose and had M, < 5800. The polysaccharide may have applications as a low viscosity stabilizing agent.