title: Effect of ferrous ion on amino acid metabolism in mildiomycin production by Streptoverticillium rimofaciens
abstract: The physiological features of the mildiomycin production by Streptoverticillium rimofaciens were examined in iron-sufficient and -deficient media. Activities of NADP-linked glutamate dehydrogenase (GDH) and aspartate aminotransferase (AAT) were markedly enhanced by the addition of 10 micrograms/ml of ferrous ion into culture. Ammonium nitrogen assimilation increased with the increase in mildiomycin production. These indicate that ferrous ion contributes the supply of amino acids as a precursor of mildiomycin production. In the iron-sufficient medium, glutamate, aspartate, serine and arginine in cells were 2 to 10-fold to those in the iron-deficient medium. The major amino acid excreted from cells was arginine in the iron-sufficient culture, while in the iron-deficient culture, valine. Change in the amino acid profile by addition of ferrous ion was useful for mildiomycin biosynthesis, in which ferrous ion played a leading role in amino acid metabolism.
authors.affiliation: Technology Department, Hikari Branch Lab., Takeda Chemical Industries, Ltd., Japan.
authors.initials: K
authors.lastname: Kishimoto
authors.initials: YS
authors.lastname: Park
authors.initials: M
authors.lastname: Okabe
authors.initials: S
authors.lastname: Akiyama