Fig. 4

Growth and riboflavin production in the WT and MT strains in the presence of Fe³⁺ and glycine. a Growth of WT and MT strains on the minimum medium plate containing Fe³⁺ and glycine. Fe³⁺ and glycine were supplemented at 27 mg/L and 1 mM, respectively. b Riboflavin production of MT strain n minimal medium supplemented with 27 mg/L Fe³⁺ and 1 mM glycine. The amount of riboflavin and dry cell was measured at 4 days. Metal ions except for Fe³⁺ were not supplemented in both cultivations