Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Interactions among Ruminal Cellulolytic Bacteria in Cellobiose-Limited Chemostats

Authors
item Shi, Yan - UNIV OF WISCONSIN
item Weimer, Paul

Submitted to: Conference on Rumen Function
Publication Type: Abstract Only
Publication Acceptance Date: November 16, 1995
Publication Date: N/A

Technical Abstract: Interactions among Fibrobacter succinogenes S85, Ruminococcus flavefaciens FD-1 and R. albus 7 were examined in cellobiose-limited continuous cultures (pH 6.5-6.8) fed 1-4 g cellobiose/L. Populations were assessed via characteristic fermentation products and via signature membrane fatty acids (MFAs). When FD-1 was inoculated into a steady-state (D=0.17 h**-1) culture of S85, or when the chemostat was simultaneously inoculated with both strains, FD-1 quickly predominated, as indicated by acetate/succinate ratios similar to FD-1 monocultures, and MFAs characteristic of FD-1, but not S85. The predominance of FD-1 is consistent with the measured Monod growth parameters (KS and maximum growth rate) for these strains. Chemostats co-inoculated with 7 and either FD-1 (D=0.024 h**-1) or S85 (D=0.07 h**-1) produced abundant ethanol and acetate but no succinate, and contained MFAs characteristic of 7. Similar results were obtained when 7 was inoculated into steady-state cultures of FD-1 or S85 (D=0.07 h**-1). The predominance of 7 was not expected based on the measured Monod growth parameters for these strains. Supernatants of effluents collected from chemostats dominated by 7 did not contain factors that inhibited growth of FD-1 or S85 in batch culture.

Last Modified: 11/1/2014
Footer Content Back to Top of Page