| Abstrakt: |
It has previously been found that trypanosomes can live either aerobically or anaerobically. The oxygen consumption has been measured and in some instances also compared with the glucose utilization.1,2,3,4In the present paper a report is given of measurements of the glucose and oxygen consumed and the products formed aerobically and anaerobically.The first set of experiments in which the oxygen consumed was compared with the total acid produced was carried out using the Barcroft-Warburg apparatus. The medium consisted as a rule of glucose dissolved either in Ringer solutions equilibrated with CO2or in isotonic phosphate buffer solutions, pH 7.4. It was found in experiments with phosphate buffer that the CO2produced is comparatively small. Hence, the CO2found liberated from bicarbonate solutions was chiefly due to the production of a non-volatile acid. The ratio of the mols acid produced to the oxygen consumed was fairly constant in all experiments and averaged 1.74 ± 0.07.In another set of experiments the fixed acid produced was determined by titration with NaOH and compared with the glucose utilized, as determined by the Hagedorn-Jensen method.5The ratio of the mols of acid produced to the mols of glucose consumed was again near to 2, viz., 1.80 ± 0.22 in aerobic experiments and near to 1, viz., 0.87 ± 0.11, in the anaerobic experiments.Lactic acid determinations by the Friedemann, Cotonio and Shaffer method6showed that only a negligible fraction of the non-volatile acid is lactic acid.∗The fact that in aerobic experiments the ratio of mols acid produced to mols glucose consumed was near to 2 and that nearly 2 equivalents of acid were produced per mol oxygen consumed, suggested that 2 molecules of pyruvic acid or an isomer thereof, were produced by oxidation of one molecule of glucose. Indeed, the presence of pyruvic acid in the solutions was shown by the isolation of its phenylhydrazone. In more quantitative experiments 53–75% of the titratable acid was isolated and identified by mixed melting point as the phenylhydrazone of pyruvic acid. |
