Fermentation and the properties of some enzymes of carbohydrate metabolism in the trematode Calicophoron ijimai.

Glycogen content, glucose consumption and the production of metabolic end products by Calicophoron ijimai were determined under aerobic and anaerobic conditions. The major end products of fermentation were identified as lactic, acetic, propionic, isobutyric and alpha-methylbutyric acids, propionic acid predominating. The activities and properties of some of the enzymes of carbohydrate metabolism were determined. The worms showed high phosphoenolpyruvate carboxykinase, malate dehydrogenase and malate dehydrogenase (decarboxylating) but relatively low pyruvate kinase and very low lactate dehydrogenase activities. The pH optima, coenzyme, cofactor and ionic requirements of the enzymes were similar to those of other helminths. Malate dehydrogenase had an 8-fold greater affinity for oxaloacetate than malate, and was about 14 times more active for oxaloacetate reduction than malate oxidation. Phosphoenolpyruvate carboxykinase was 2.4 times more active and had a 2-fold greater affinity for phosphoenolpyruvate and dinucleotide than pyruvate kinase. The low activities of lactate dehydrogenase and pyruvate kinase but high activities of malate dehydrogenase and phosphoenolpyruvate carboxykinase suggest that anaerobic carbohydrate catabolism follows the fumarate reductase pathway.

Preliminary studies of lipids of the trematodes Eurytrema pancreaticum, Calicophoron erschowi and the turbellarian Penecurva sibirica.

The amount of total lipids, phospholipids, neutral lipids and fatty acids was determined in cattle parasites, namely the trematodes Eurytrema pancreaticum, Calicophoron erschowi, and in the free-living turbellarian Penecurva sibirica. Neutral lipids of these flatworms contained sterols, sterol esters, triacylglycerols and free fatty acids. P. sibirica also contained diacylglycerols. Parasitic and free-living flatworms differed in phospholipid composition: the turbellarian did not contain phosphatidylserine, and the trematodes had practically no sphingomyelin or lysophosphatidyl choline. E. pancreaticum, C. erschowi and P. sibirica contained high levels of phosphatidylcholine and phosphatidylethanolamine as well as lysophosphatidylethanolamine and cardiolipin. The fatty acid composition of total lipid extracts of flatworms and of the pancreas and rumen of the host animals were determined. The fatty acid composition of the flatworm lipids reflected the fatty acid composition of the host tissue but was not identical to it.