Living cells of Propionibacterium freudenreichii ssp. shermanii 1 and 4 were immobilized in 20 g/L, 30 g/L and 40 g/L alginate gels. Ammonia consumption, glucose utilization, biosynthesis of vitamin B12, productions of propionic and acetic acids were examined. A significant increase of propionic acid production and a decrease of vitamin B12 biosynthesis were observed. The best results were obtained in the fermentation with the strains immobilized in 40 g/L alginate gel being applied for the third time.