DIGESTION AND FERMENTATION OF THE MICROCRYSTALLINE CELLULOSE BY THE RUMEN CILIATE PROTOZOAN EUDIPLODINIUM-MAGGII

The rumen ciliate protozoon Eudiplodinium maggii was grown in vitro in a medium containing microcrystalline cellulose. A positive correlatio n was found between the number of protozoa and the cellulose content o f the culture medium (r = 0.998; P < 0.01). The ciliates readily engul fed and digested cellulose particles intracellularly, while the supern atant fraction of broken protozoa hydrolyzed microcrystalline cellulos e to reducing sugars. Polyacrylamide gel electrophoresis (PAGE) combin ed with CMC-ase zymogram revealed beta-endoglucanase activity in proto zoal proteins precipitated from the supernatant fraction of bacteria-f ree broken protozoa. Eudiplodinium maggii, free of external bacteria, incubated with microcrystalline cellulose produced volatile fatty acid s in the presence of chloramphenicol. The production rate was 19.1 and 6.3 pM VFA/protozoon/h for ciliates incubated with and without cellul ose respectively. Acetate followed by butyrate were the main acids pro duced by Eudiplodinium maggii from microcrystalline cellulose.