Methylotrophic bacteria with cobalamin-dependent mutases in primary metabolism as potential strains for vitamin B(12) production

Several bacterial species are known for their ability to synthesize vitamin B(12) but biotechnological vitamin B(12) production today is restricted to Pseudomonas denitrificans and Propionibacterium freudenreichii. Nevertheless, the rising popularity of veganism leads to a growing demand for vitamin B(12) and thereby interest in alternative strains which can be used as efficient vitamin B(12) sources. In this work, we demonstrate that methylotrophic microorganisms which utilize the ethylmalonyl-CoA pathway containing B(12)-dependent enzymes are capable of active vitamin B(12) production. Several bacteria with an essential function of the pathway were tested for vitamin B(12) synthesis. Among the identified strains, Hyphomicrobium sp. DSM3646 demonstrated the highest vitamin B(12) levels reaching up to 17.9 ± 5.05 µg per g dry cell weight. These relatively high vitamin B(12) concentrations achieved in simple cultivation experiments were performed in a mineral methanol medium, which makes Hyphomicrobium sp. DSM3646 a new promising cobalamin-producing strain. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10482-022-01795-9.