Effects of quillaja and yucca saponins on communities and select populations of rumen bacteria and archaea, and fermentation in vitro
Article first published online: 13 SEP 2012
© 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 113, Issue 6, pages 1329–1340, December 2012
How to Cite
Patra, A.K., Stiverson, J. and Yu, Z. (2012), Effects of quillaja and yucca saponins on communities and select populations of rumen bacteria and archaea, and fermentation in vitro. Journal of Applied Microbiology, 113: 1329–1340. doi: 10.1111/j.1365-2672.2012.05440.x
- Issue published online: 16 NOV 2012
- Article first published online: 13 SEP 2012
- Accepted manuscript online: 28 AUG 2012 03:04AM EST
- Manuscript Accepted: 8 AUG 2012
- Manuscript Revised: 24 JUL 2012
- Manuscript Received: 23 APR 2012
- OARDC. Grant Number: 2010-007
- rumen fermentation;
The objective of this study was to comprehensively evaluate quillaja (QSP) and yucca saponin (YSP) products with respect to their effects on diversity of rumen bacteria and archaea, abundance of selected microbes, and feed degradability and fermentation.
Methods and Results
Both QSP and YSP at doses 0–0·6 g l−1 tended to increase degradability of feed substrate in in vitro rumen cultures, but to different extents. Neither one of the saponins affected the concentrations of ammonia, total volatile fatty acids, or molar proportion of acetate. However, QSP increased molar proportion of propionate and decreased that of butyrate, whereas YSP tended to decrease that of butyrate. As determined by qPCR, QSP and YSP did not affect the abundance of total bacteria or Ruminococcus albus. The QSP did not affect the abundances of Fibrobacter succinogenes or genus Prevotella, but tended to decrease that of Ruminococcus flavefaciens, whereas YSP significantly increased the abundance of R. flavefaciens and Prevotella, and numerically increased that of F. succinogenes. Both saponins increased archaeal abundance, although to small magnitudes (0·3–0·4 log). The protozoal populations were decreased significantly by QSP, but not by YSP. Based on DGGE and T-RFLP analysis, both saponins altered the bacterial community and species organization, but less so the archaeal community.
This study demonstrated that saponins, although not effective in mitigating methane emission, may improve feed utilization at low doses, and modulate ruminal microbial communities in a dose-dependent manner.
Significance and Impact of the Study
The results of this study suggest that saponins at low doses may directly stimulate the growth of some rumen bacteria including cellulolytic bacteria, thus improving digestibility of feeds, independent of their defaunation activity. In contrast, saponins at high doses modulate rumen fermentation characteristically similar to defaunation.