抄録
1. Investigations were carried out on the formation of γ-pyrone derivatives, i.e. comenic acid, rubiginic acid and rubiginol from thirty kinds of carbohydrates, and fifteen kinds of organic acid. Gluconoacetobacter liq. was formed only from glucose, gluconate and 2-keto-gluconate.
2. Intact cells oxidized glucose, gluconate and 2-ketogluconate with carbon dioxide evolution, but in the presence of DNP (2×10-3M) evolution of carbon dioxide was not observed, and 1.5, 1.0 and 0.5 moles of oxygen were consumed per mole of glucose, gluconate and 2-ketogluconate, respectively. Dried cells and cell-free extracts also showed the same oxidative pattern as intact cells in the presence of DNP.
3. Oxidation of glucose, gluconate and 2-ketogluconate by dried cells proceeded in phthalate buffer and was not affected by phosphate. Sodium fluoride (5×10-2M) did not inhibit the oxidation of glucose.
4. Intact cells oxidized glucose, gluconate and 2-ketogluconate and formed the same oxidative products, i.e. the three γ-pyrone derivatives, and glycolic and tartronic acid.
5. As the oxidative product of Ca-2-keto-gluconate by dried cells, Ca-2, 5-diketo-gluconate was isolated and identified. Glu-conoacetobacter liq., formed the same oxidative products as described above from Ca-2, 5-diketogluconate.
6. The chemical pathway of glucose degradation by Gluconoacetobacter liq. was discussed and the most presumable pathway involving the formation of γ-pyrone deriva-tives was given.
