The Uptake and Metabolism of Glucose, Maltose and Starch by the Rumen Ciliate Epidinium ecaudatum caudatum

Abstract

[14C]Glucose taken up by E. ecaudatum caudatum was found in the pool, in the protozoan polysaccharide and in the bacteria associated with the Protozoa. The amount incorporated into the polysaccharide depended on the square of the glucose concentration. Glucose was probably taken up initially into the pool unchanged, and then rapidly converted into G-6-P and maltose which were subsequently hydrolyzed to glucose. [14C]-Maltose was taken up at 20-30% of the rate of [14C]glucose, with 14C appearing initially in maltose and G-6-P 14C from 14C-labeled soluble starch appeared in the pool as maltose, G-6-P and glucose in that order, but incorporation into protozoan polysaccharide was poor. Hexokinase phosphoglucomutase, .alpha.-glucan and maltose phosphorylases, glucose-6-phosphatase and maltase activities were found in the Protozoa.