Effects of Sainfoin ( <i>Onobrychis viciifolia</i> Scop.) Condensed Tannins on Growth and Proteolysis by Four Strains of Ruminal Bacteria

Abstract

Sainfoin leaf condensed tannins inhibited growth and protease activity in Butyrivibrio fibrisolvens A38 and Streptococcus bovis 45S1 but had little effect on Prevotella ruminicola B(1)4 or Ruminobacter amylophilus WP225. Tannins bound to cell coat polymers in all strains. Morphological changes in B. fibrisolvens and S. bovis implicated the cell wall as a target of tannin toxicity.