Role of amino acids, betaine and choline in vitamin B 12 biosynthesis by strains of Propionibacterium

Abstract

This paper reports the role of amino acids, betaine and choline on vitamin B 12 biosynthesis in Propionibacterium shermanii 566, P. shermanii and Propionibacterium arl AKU 1251. l-Glutamic acid supplemented at the 0.05% (w/v) level in whey permeate stimulated vitamin B 12 production in the three organisms, whereas the influence of other amino acids differed in the three strains. A uniform increase in product formation in Propionibacterium cultures with increasing doses of betaine and choline was recorded, but with variable relative effectiveness. However, no significant difference at the 0.50 and 0.75% (w/v) levels of these two compounds was observed. The addition of betaine at 0.5% (w/v) concentration was considered optimal for maximum fermentation efficiency in the cultures. An increase of 2.8–25.7% and 5.1–40.8% in vitamin B 12 yield as compared to the control was observed by supplementing whey permeate medium with l-glutamic acid and betaine, respectively, at their optimum values in the organisms studied .