Abstract
1. Enzymatic studies were made on the oxidative decarboxylation of 6-phosphogluconate in typical heterolactic acid bacteria, and it was concluded that mechanism of the oxidative decarboxylation of 6-phosphogluconate in these bacteria can be classified into three types as follows:
(1)6-phosphogluconate+NAD→ribulose 5-phosphate+CO2+NADH2
(2) 6-phosphogluconate+NAD→2-keto-6-phosphogluconate+NADH2 2-keto-6-phosphogluconate→ribulose 5-phosphate+CO2
(3) mixed reactions of (1) and (2).
2. It was found that 6-phosphogluconate dehydrogenase (decarboxylating) [EC 1.1.1.44] obtained from Lactobacillus brevis ATCC 8281 consists of 6-phosphogluconate dehydrogenase (not decarboxylating) [EC 1.1.1.43] and 2-keto-6-phosphogluconate decarboxylase.
