This CbiA catalyzed amidations to a side chain of cobyrinic acid in the
biosynthesis of cobalamin (vitamin B12) from uroporphyrinogen III. The
lower ligand of cobamine is covalently linked to a phosphoribosyl
moiety through an alpha-glycosidic bond formed by the CobT enzyme.
Both enzymes are important for the synthesis of cobalamin. However,
CobT was reported that it is responsible for the production of analogs
(Crofts et al., 2014). In our work, it has shown (Fig. 1) that expression
of cbiA and cobT was significantly raised with an increase of glycerol
supplementation. It was figured out that glycerol induced cobT and
cbiA expression up to 202% and 188% in contrast to control, but the
high concentration of fructose supplementation had suppressed the
expression of cobT and cbiA. Regarding CbiA, the expression under
high concentrations of fructose was still higher than control. The higher