De novo synthesis of amino acids by the ruminal bacteria Prevotella bryantii B(sub 1)4, Selenomonas ruminantium HD4, and Streptococcus bovis ES1

Research was conducted to examine the influence of peptides and amino acids on ammonia assimilation and de novo synthesis of amino acids by three predominant noncellulolytic species of ruminal bacteria, namely, Prevotella bryantii, Streptococcus bovis ES1 and Selenomonas ruminantium HD4. The bacteria were grown in media with 15 NH4Cl and additional pancreatic hydrolysates of casein or amino acids. Results suggest a wide variation in de novo synthesis between individual amino acids and individual species.