Vitamin B12 production from crude glycerol by Propionibacterium freudenreichii ssp. shermanii: Optimization of medium composition through statistical experimental designs

Abstract A two-step statistical experimental design was employed to optimize the medium for vitamin B 12 production from crude glycerol by Propionibacterium freudenreichii ssp. shermanii . In the first step, using Plackett–Burman design, five of 13 tested medium components (calcium pantothenate, NaH 2 PO 4 ·2H 2 O, casein hydrolysate, glycerol and FeSO 4 ·7H 2 O) were identified as factors having significant influence on vitamin production. In the second step, a central composite design was used to optimize levels of medium components selected in the first step. Valid statistical models describing the influence of significant factors on vitamin B 12 production were established for each optimization phase. The optimized medium provided a 93% increase in final vitamin concentration compared to the original medium.