Intestine of Ascaris: oxygen consumption, fermentation acids, and anaerobic synthesis of protein.

The oxygen uptakes by pieces of gut from the porcine roundworm, Ascaris suum, under Po2 10 to 710 torr were from 0.6 to 3.0 mul/mg dry wt/hr (Qo2). Increasing concentrations of tissue, 30 to 90 mg (dry wt/3 ml) decreased Qo2 in air from 1.9 to 1.1 and only technical grade catalase was found to relieve this inhibition. Conversely aerobic fermentation, judged by acid production, was directly proportional to the amount of tissue present: the acids from this fermentation were 2-methyl-butyric (1% of the total), succinic (8%), propionic (40%), and acetic (51%). Glucose did not increase Qo2 but it doubled the incorporation of labeled carbon into protein from glycine-1-14C. Judged by this, protein synthesis proceeded at the same rate under low Po2 (0.01 torr) as under air.