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

Cengiz Atasoglu, Carmen Valdes, Nicola D. Walker, C. J. Newbold, R. John Wallace

Research output: Contribution to journalArticlepeer-review

56 Citations (SciVal)


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, Prevotella bryantii B 14, Selenomonas ruminantium HD4, and Streptococcus bovis ES1, was determined by growing these bacteria in media containing 15NH 4Cl and various additions of pancreatic hydrolysates of casein (peptides) or amino acids. The proportion of cell N and amino acids formed de novo decreased as the concentration of peptides increased. At high concentrations of peptides (10 and 30 g/liter), the incorporation of ammonia accounted for less than 0.16 of bacterial amino acid N and less than 0.30 of total N. At 1 g/liter, which is more similar to peptide concentrations found in the rumen, 0.68, 0.87, and 0.46 of bacterial amino acid N and 0.83, 0.89, and 0.64 of total N were derived from ammonia by P. bryantii, S. ruminantium, and S. bovis, respectively. Concentration-dependent responses were also obtained with amino acids. No individual amino acid was exhausted in any incubation medium. For cultures of P. bryantii, peptides were incorporated and stimulated growth more effectively than amino acids, while cultures of the other species showed no preference for peptides or amino acids. Apparent growth yields increased by between 8 and 57%, depending on the species, when 1 g of peptides or amino acids per liter was added to the medium. Proline synthesis was greatly decreased when peptides or amino acids were added to the medium, while glutamate and aspartate were enriched to a greater extent than other amino acids under all conditions. Thus, the proportion of bacterial protein formed de novo in noncellulolytic ruminal bacteria varies according to species and the form and identity of the amino acid and in a concentration-dependent manner.

Original languageEnglish
Pages (from-to)2836-2843
Number of pages8
JournalApplied and Environmental Microbiology
Issue number8
Publication statusPublished - Aug 1998


  • UREA
  • Rumen/microbiology
  • Streptococcus bovis/growth & development
  • Ammonia/metabolism
  • Prevotella/growth & development
  • Gram-Negative Anaerobic Bacteria/growth & development
  • Peptides/metabolism
  • Animals
  • Protein Hydrolysates/metabolism
  • Culture Media
  • Amino Acids/biosynthesis
  • Sheep
  • Nitrogen/metabolism
  • Caseins/metabolism


Dive into the research topics of 'De novo synthesis of amino acids by the ruminal bacteria Prevotella bryantii B(1)4, Selenomonas ruminantium HD4, and Streptococcus bovis ES1'. Together they form a unique fingerprint.

Cite this