DISTRIBUTION OF CELLULOSE-BINDING PROTEINS AMONG THE REPRESENTATIVE STRAINS OF RUMEN BACTERIA

The presence or absence of cellulose-binding proteins (CBPs) in the ce ll lysate of 31 strains representing 17 species of rumen bacteria was examined. Both carboxymethylcellulose (CMC) and sodium dodecyl sulfate (SDS) were used to elute CBPs of these bacteria from cellulose. For 1 6 strains classified into 4 species of Fibrobacter succinogenes, Fibro bacter intestinalis, Ruminococcus flavefaciens and Eubacterium cellulo solvens, the SDS-polyacrylamide gel electrophoresis (SDS-PAGE) pattern s of the CMC-eluted CBPs were identical with those of the SDS-eluted C BPs. For 4 strains representing 4 species of VEillonella parvula, Mega sphaera elsdenii, Prevotella ruminicola subsp. ruminicola and Eubacter ium ruminantium, the SDS-PAGE patterns of both the CMC-eluted CBPs and the SDS-eluted CBPs were different. In the case of 3 strains represen ting Ruminococcus bromii, Butyrivibrio fibrisolvens and Ruminobacter a mylophilus, CBPs were eluted only with SDS from cellulose, but not wit h CMC. On the other hand, none of the other strains tested contained a detectable amount of CBPs. Western immunoblot analysis indicated that CBP (120 kDa) of both the 10 strains of F. succinogenes and 1 strain of F. intestinalis was antigenically identical with CBP1 of F. succino genes S85, and CBPs of other bacteria did not cross-react with rabbit antiserum to CBP1.