SELECTIVITY OF CARBOHYDRATE ASSIMILATION BY THE ANAEROBIC RUMEN CILIATE DASYTRICHA-RUMINANTIUM

The extent of selectivity in the uptake and metabolism of soluble carbohydrates by the rumen ciliate Dasytricha ruminantium has been examined. The protozoon was not selective in the uptake of available carbohydrates and did not appear to regulate sugar entry by preferential or sequential utilization so that there was a concomitant assimilation of all utilizable soluble‐sugars regardless of molecular size or metabolic effects. The presence of readily fermentable substrates did not preclude the uptake and subsequent effects of the toxic monomers mannose and glucosamine hydrochloride. The characteristics of galactose co‐utilization differed from those of other monosaccharides examined. Although non‐metabolizable substrates did not impede the uptake or metabolism of effective substrates, maximum metabolite production rates were not maintained in the presence of slowly utilized substrates. Copyright © 1979, Wiley Blackwell. All rights reserved