Methylotrophic Bacteria with Cobalamin-dependent Mutases in Primary Metabolism As Potential Strains for Vitamin B Production

Several bacterial species are known for their ability to synthesize vitamin B but biotechnological vitamin B production today is restricted to Pseudomonas denitrificans and Propionibacterium freudenreichii. Nevertheless, the rising popularity of veganism leads to a growing demand for vitamin B and thereby interest in alternative strains which can be used as efficient vitamin B sources. In this work, we demonstrate that methylotrophic microorganisms which utilize the ethylmalonyl-CoA pathway containing B-dependent enzymes are capable of active vitamin B production. Several bacteria with an essential function of the pathway were tested for vitamin B synthesis. Among the identified strains, Hyphomicrobium sp. DSM3646 demonstrated the highest vitamin B levels reaching up to 17.9 ± 5.05 µg per g dry cell weight. These relatively high vitamin B concentrations achieved in simple cultivation experiments were performed in a mineral methanol medium, which makes Hyphomicrobium sp. DSM3646 a new promising cobalamin-producing strain.