Optimization of Cyanocobalamin Production by Propionibacterium Freudenreichii in Different Concentrations of Folic Acid and Methionine

Introduction: Vitamin B12 is a key factor in many growthrelated processes in the human body and its largescale industrial production is carried out using microorganisms, especially Propionibacterium freudenreichii. The aim of this study was to evaluate the effect of folic acid, methionine, and oxygen on the optimal production of vitamin B12 and Dry Cell Weight (DCW) of this bacterium. Materials and methods: Bacteria were maintained in four different conditions including anaerobic conditions and different concentrations of folic acid, aerobic conditions and different concentrations of folic acid, anaerobic conditions and different concentrations of folic acid and methionine 0.05% (w/v), aerobic conditions and different concentrations of folic acid and methionine 0.05% (w/v). Results: The maximum production of vitamin B12 and DCW was obtained in 750 mg / L of folic acid in the presence of methionine and aerobic conditions. By increasing the concentration of folic acid up to 1000 mg / L, the amount of vitamin B12 production and dry weight of the bacterium decreased. Discussion and conclusion: Due to the effect of folic acid on the fermentative processes of Propionibacterium freudenreichii, the present study could be an effective optimization to increase the final production of vitamin B12. Based on the above findings, aerobic conditions along with the presence of methionine can be effective in improving vitamin B12 production and this optimization may help as an effective strategy to improve vitamin B12 production at the industrial level.