Rumen ciliate protozoa intensively engulf bacteria. However, their ability to utilize murein which is the main polysaccharide of bacterial cell wall has hardly been recognized. The present study concerns the ability of the rumen protozoa Diploplastron affine to digest and ferment murein. The ciliates were isolated from the rumen fluid and grown in vitro or inoculated into the rumen of defaunated sheep. The results of long-term cultivation of protozoa showed a positive correlation between their number and murein content in the culture medium. It was also found that bacteria-free D. affine ciliates incubated with or without murein produced volatile fatty acids at the rate of 12.3 and 8.7 pmol/h per protozoan, respectively, acetic, butyric and propionic acids being the three main acids released to the medium. Enzyme studies performed with the use of protozoan cell extract prepared from bacteria-free ciliates degraded murein at a rate of 25 U/mg protein per h; two mureinolytic enzymes were identified by zymographic technique in the examined preparation.

The Kielanowski Institute of Animal Physiology and Nutrition Polish Academy of Sciences 05 110 Jabłonna Poland

See more in PubMed

Folia Microbiol (Praha). 2008;53(3):201-3 PubMed

Curr Microbiol. 1996 Mar;32(3):115-8 PubMed

J Gen Microbiol. 1972 Dec;73(3):509-21 PubMed

Br J Nutr. 1987 Sep;58(2):313-23 PubMed

J Chromatogr. 1973 Jun;80(2):250-4 PubMed

J Biol Chem. 1963 Aug;238:2691-7 PubMed

J Bacteriol. 1995 Sep;177(17):4947-62 PubMed

The ability of rumen ciliates, Eudiplodinium maggii, Diploplastron affine, and Entodinium caudatum, to use the murein saccharides

Ability of rumen protozoa Diploplastron affine to utilize β-glucans