These observations confirmed that the lower ligand of the corrinoid in the sample extracts was DMBI as in cyanocobalamin, which is critical for the binding of the B12 vitamer to the intrinsic factor to make it bio- available for humans (Nielsen et al., 2012).
The UHPLC analysis of P. freudenreichii cells obtained from the fermented SWP accounted for a vitamin B12 production of 620 ng/mL. In a study by Hugenschmidt et al. (2010), 37 screened P. freudenreichii strains produced vitamin B12 of approximately 100–2500 ng/mL in SWP with added cobalt and DMBI, showing an inter-strain diversity of vitamin B12 synthesis. In our study, the medium was not supplemented with DMBI. Thus, DMBI had