Previous Article | Next Article ![]()
Appl. Environ. Microbiol., 09 1995, 3288-3292, Vol 61, No. 9
RG Gardner, JE Wells, JB Russell and DB Wilson
Prevotella ruminicola B(1)4, TC1-1, TF1-3, and TS1-5 all produced
immunologically cross-reacting 88- and 82-kDa carboxymethyl cellulases
(CMCases). P. ruminicola 23, 118B, 20-63, and 20-78 had much lower CMCase
activities, and Western blots (immunoblots) showed no cross- reaction with
the B(1)4 CMCase antiserum. Fibrobacter succinogenes S85 and Selenomonas
ruminantium HD4 and D produced CMCase, but these enzymes were smaller and
did not cross-react with the B(1)4 CMCase antiserum. The B(1)4 CMCase
antiserum inhibited the B(1)4, TC1-1, TF1- 3, and TS1-5 CMCase activities
and agglutinated these cells, but it had no effect on the other strains or
species. On the basis of these results, the B(1)4 CMCase is a
strain-specific enzyme that is located on the outside surface of the cells.
P. ruminicola B(1)4 cultures, grown on sucrose, did not have significant
CMCase activity, but these cells could bind purified 88- and 82-kDa CMCase
but not 40.5-kDa CMCase. Because the 40.5-kDa CMCase is a fully active,
truncated form of the CMCase, it appears that the N-terminal domain of the
88-kDa B(1)4 CMCase anchors the CMCase to the cells. Cells grown on
cellobiose produced at least 10-fold more CMCase than the sucrose-grown
cells, and the cellobiose-grown cells could only bind 15% as much CMCase as
sucrose-grown cells. Virtually all of the CMCase activity of exponentially
growing cultures was cell associated, but CMCase activity was eventually
detected in the culture supernatant. On the basis of the observation that
the 88-kDa CMCase was gradually converted to the 82- kDa CMCase when
cultures reached the stationary phase without a change in specific
activity, it appears that the 82-kDa protein is probably a proteolytic
degradation product of the 88-kDa CMCase.
Copyright © 1995, American Society for Microbiology
The cellular location of Prevotella ruminicola beta-1,4-D-endoglucanase and its occurrence in other strains of ruminal bacteria
Section of Biochemistry, Molecular and Cellular Biology, Cornell University, Ithaca, New York 14853, USA.
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|