|Jung, Hans Joachim|
|Engels, Ferdinand - WAGENINGEN UNIVERSITY|
Submitted to: Conference on Gastrointestinal Function
Publication Type: Abstract Only
Publication Acceptance Date: March 10, 2003
Publication Date: March 10, 2003
Citation: JUNG, H.G., WEIMER, P.J., ENGELS, F.M. DEGRADATION OF ALFALFA CELL WALL POLYSACCHARIDES BY PURE CULTURES OF FIVE RUMEN BACTERIAL SPECIES. CONFERENCE ON GASTROINTESTINAL FUNCTION. 2003. ABSTRACT P. 23. Technical Abstract: The rumen bacterial strains Fibrobacter succinogenes S85 (Fs), Ruminococcus albus 7 (Ra), R. flavefaciens FD-1 (Rf), Butyrivibrio fibrisolvens H17c (Bf), and Lachnospira multipara 40 (Lm) were compared for their ability to degrade alfalfa stem cell wall polysaccharides in pure culture, as a five-species mixture, and with rumen fluid. Two maturity stages of alfalfa (bud and full flower) were utilized as substrates and incubation periods of 16- and 96-h were employed. Substrates and fermentation residues were analyzed for cell wall concentration and composition by the Uppsala Dietary Fiber procedure. Cell wall glucose was considered to represent the cellulose fraction; the sum of xylose, mannose, and fucose residues composed the hemicellulose fraction; and pectin was the sum of uronic acids, galactose, arabinose, and rhamnose residues. Degradation of the immature alfalfa stems was significantly greater than for the mature stems for total cell wall polysaccharides and all polysaccharide fractions. The 96-h incubation period resulted in significantly more degradation of all cell wall polysaccharides than observed after 16-h. The Ra culture was able to degrade all cell wall polysaccharide fractions as well or better than any other culture, including rumen fluid. Co-culture of Ra with the other four rumen species did not improve degradation of any of the cell wall polysaccharides compared to Ra alone.