Microalgal assimilation of vitamin B12 toward the production of a superfood

Abstract

A network of components from different metabolic pathways is the building scaffold of an indispensable compound in the human organism-vitamin B-12. The biosynthesis of this compound is restricted to a limited number of representatives of bacteria and archaea, while vitamin B-12-dependent enzymes are spread through several domains of life. Different attempts have been performed to increase vitamin B-12 levels in dietary products, particularly in vegetarian and vegan dietary regimes. The integration of vitamin B-12 in microalgae through symbiosis with microorganisms generally recognized as safe, for example the probiotic Lactobacillus reuteri, can even increase the nutritional value of the microalgal biomass. This study reviews the microbial production of vitamin B(12 )based on genetic analyses and chemical studies. Recent genetic approaches are focused, particularly potential metabolic engineering targets to increase vitamin B-12 production. The bioincorporation of vitamin B-12 in microalgae as an attempt to provide a superfood is also reviewed. Practical applications Novel food habits (i.e., vegan lifestyle) may lack relevant nutrients, including vitamin B-12. Therefore, there is an increased demand for dietary products rich in vitamin B-12. Of potential interest is the provision of microbial-based superfood rich in numerous nutrients, including this vitamin. This manuscript provides an in-depth and timely overview on vitamin B-12 biosynthesis and the major advances on metabolic engineering for improved vitamin B-12 production by probiotic bacteria and other microorganisms generally recognized as safe. A relevant advance would result from the bioincorporation of vitamin B-12 in alternative microorganisms (non-vitamin B-12 producers) increasingly recognized as superfood, that is microalgae.