Hydrogenosomes in known species of rumen entodiniomorphid protozoa

Abstract

The distribution of hydrogenosomal enzymes in several species of rumen entodiniomorphid protozoa grown in vivo and in vitro was investigated. Eudiplodinium maggii and Epidinium ecaudatum caudatum were shown to possess pyruvate synthase and hydrogenase enzyme activities associated with a fraction sedimentable at 105/ g/min and enriched in granular microbody-like organelles about 0.3 μm in diameter; these organelles are therefore morphologically and enzymically similar to hydrogenosomes from the rumen holotrichs. However, hydrogenase and pyruvate synthase were undetectable in several of the entodiniomorph species investigated.