Current Microbiology

, Volume 19, Issue 4, pp 231–235

The influence of peptides on the uptake of amino acids inFusobacterium; predicted interactions withPorphyromonas gingivalis

  • S. E. Gharbia
  • H. N. Shah
  • S. G. Welch
Article

Abstract

A study of the uptake of amino acids and its influence by a peptide source was carried out withFusobacterium varium as a convenient representative of the genus. Reference strains and a clinical isolate had similar amino acid uptake profiles, but most amino acids were incorporated at lower concentrations by the latter. In general, high levels of serine, asparagine, glutamate, cysteine, and arginine were incorporated by all species. Histidine, lysine, threonine, and aspartate were taken up at lower levels, whereas the nonpolar neutral amino acids such as alanine, valine, leucine, isoleucine, glycine, proline, phenylalanine, and methionine were poorly metabolized. Yeast extract, as a source of peptides, stimulated the uptake of several amino acids such as histidine and glutamate, whereas others such as methionine, threonine, and asparagine were repressed. The incorporation of some amino acids such as aspartate, ornithine, lysine, and arginine was unaffected by the presence of peptides. Equimolar nitrogen concentrations of amino acids or ammonia could not replace the peptide requirement, emphasizing the importance of peptides as an energy source. The limited capacity ofFusobacterium spp. to hydrolyze proteins increased approximately 30% in the presence of the proteolytic species,Porphyromonas gingivalis, and may represent one bacterial interaction in which peptides may become available toFusobacterium species in vivo.

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Copyright information

© Springer-Verlag New York Inc. 1989

Authors and Affiliations

  • S. E. Gharbia
    • 1
  • H. N. Shah
    • 1
  • S. G. Welch
    • 2
  1. 1.Department of Oral MicrobiologyThe London Hospital Medical CollegeLondonUK
  2. 2.Department of BiochemistryThe London Hospital Medical CollegeLondonUK

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