Some fundamental microbiology and biochemistry of peptide breakdown in the rumen is described. Peptides are extensively broken down in the rumen and only small quantities of peptide-N were found in rumen fluid from sheep 7 h after feeding. The main determinant affecting the rate of hydrolysis of different peptides added to rumen fluid in vitro was the structure of the N-terminus of the peptide chain. Neutral and basic peptides also tended to be hydrolysed more rapidly than acidic peptides. Peptide hydrolysis was carried out mainly by rumen bacteria, apparently by a dipeptidyl peptidase type I (DP-1) mechanism. Bacteroides ruminicola was the only rumen bacterial species found to possess significant DP-1 activity.
|Title of host publication||The Rumen Ecosystem|
|Subtitle of host publication||The Microbial Metabolism and its Regulation|
|Editors||S. Hoshino, R. Onodera, H. Minato, H. Itabashi|
|Place of Publication||Tokyo|
|Publisher||Japanese Scientific Societies Press-Springer Verlag|
|Number of pages||8|
|Publication status||Published - 1990|