COMPARATIVE STUDIES ON THE MECHANISM OF MICROBIAL GLUTAMATE FORMATION

I. PATHWAYS OF GLUTAMATE FORMATION FROM GLUCOSE IN BREVIBACTERIUM FLAVUM AND IN MICROCOCCUS GLUTAMICUS

Abstract

1. The pathways of glutamate formation from glucose and acetate
were compared in Brevibacterium flavum No. 2247 (ATCC No. 14067) and Micrococcus glutamicus No. 534 (ATCC No. 13032) using biotin-poor media.
2. B. flavum and M. glutamicus produced large amounts of glutamate from glucose in biotin-poor media, and resting cells of both strains produced α-ketoglutarate, or glutamate in the presence of ammonium salt, from glucose with a yield of 45-55%.
3. Oxidative metabolism of glucose in resting cells of both M. glutamicus
and B. flavum was inhibited by arsenite, and 1 mole of pyruvate
was formed from 1 mole of glucose, accompanied by 1 mole of O₂ uptake
and 1 mole of CO₂ evolution.
4. Labeled pyruvate was formed from glucose-1-, -6-, and -U-¹⁴C in the presence of arsenite by resting cells of M. glutamicus. From the 294 ÔTSUKA, MIYAJIMA and SHIIO Vol. 11 relative specific activity of pyruvate to substrate glucose and from distribution of ¹⁴C in pyruvate molecule, it was concluded that glucose was metabolized aerobically by both the EM and HMP pathways in the approximate ratio 85:15.
5. It was confirmed that glutamate was formed from acetate by resting cells of B. flavum, while acetate was completely oxidized to carbon dioxide by resting cells of M. glutamicus. Acetate oxidation of both strains was markedly inhibited by 5×10^-2M of monofluoroacetate.