Gluconate Metabolism by a Thiamine-requiring Species of Corynebacterium

Part IV. Accumulation of D-Ribulose

Abstract

A thiamine-requiring strain of Corynebacterium was found to accumulate a ketopentose extracellularly from gluconate. The ketopentose was isolated from the culture medium and identified as Dribulose. The accumulation of D-ribulose was significantly influenced by the concentration of thiamine in the medium. The maximum yield of D-ribulose was obtained at a thiamine concentration of 10μg per liter, whereas good growth was favored at thiamine concentrations greater than 50μg per liter. The accumulation of Dribulose reached the concentration of 9.5mg per ml after cessation of cell growth in shake culture at 30°C in a medium containing 6% potassium gluconate as a carbon source.