Carbon Dioxide Production in Early Anaerobiosis

Abstract

1. Slices of swede tissue placed under nitrogen produce carbon dioxide and ethanol in equal amounts after an initial phase lasting about 1.5 hours. During this initial phase some 2 μM./g. fr. wt. of extra carbon dioxide is produced. The production of such extra carbon dioxide is not affected by iodoacetate, fluoride, or arsenite which inhibit glycolysis or by dinitrophenol which stimulates glycolysis. Slices incubated in air in the presence of cyanide also produce extra carbon dioxide. 2. A second extra burst of carbon dioxide can be induced after some hours of anaerobiosis by treating slices with methylene blue, DPN, or TPN, or as a result of a short air experience. 3. Experiments with labelled sugars support the view that the extra carbon dioxide originates ultimately from carbohydrate, being released, it is proposed, in the oxidative decarboxylation of either pyruvate or 6-phosphogluconate. Carbon dioxide production then continues so long as oxidants are available in the cell, finally coming to a standstill when cell components reach their reduced states.