Xylanases and carboxymethylcellulases of the rumen protozoa Polyplastron multivesiculatum, Eudiplodinium maggii and Entodinium sp.

Endoglucanase and xylanase activities of three rumen protozoa, Polyplastron multivesiculatum, Eudiplodinium maggii, and Entodinium sp. were compared qualitatively by zymograms and quantitatively by measuring specific activities against different polysaccharides. A set of carboxymethylcellulases and xylanases was produced by the large ciliates whereas no band of activity was observed for Entodinium sp. in zymograms. Specific activity of endoglucanases from P. multivesiculatum (1.3 mumol mg prot (-1) min(-1)) was twice that of E. maggii, whereas xylanase specific activity (4.5 mumol mg prot(-1) min(-1)) was only half. Very weak activities were observed for Entodinium sp. A new xylanase gene, xynIID, from P. multivesiculatum was reported and its gene product compared to 33 other family I I xylanases. Phylogenetic analysis showed that xylanase sequences from rumen protozoa are closely related to those of bacteria. (C) 2005 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.