Abstract
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.