Influence of dipeptidyl peptidase inhibitors on growth, peptidase activity, and ammonia production by ruminal microorganisms.
The aim was to investigate known and potential new inhibitiors of dipeptidyl peptidases (DPP) for their effects on ruminal microorganisms. Gly-Phe diazomethylketone (GPD), Ala-Ala chloromethylketone (AAC), benserazide (DL-serine 2-(2,3,4- trihydroxybenzyl) hydrazide), and diprotin A (Ile-Pro-Ile) inhibited DPP activities of Prevotella albensis, P. ruminicola, P. bryantii, P. brevis, and mixed ruminal microorganisms, though incompletely and, except for diprotin A, without absolute specificity for any of the peptidases. Leucine aminopeptidase activity of Streptococcus bovis was also inhibited by GPD and benserazide. The inhibitors had no effect on the growth of the bacteria, except for GPD, which inhibited growth of P. albensis when only peptides were available for growth. Benserazide had some inhibitory effects on the growth of Megasphaera elsdenii and Prevotella spp., even in the absence of peptides. The predatory activity of ciliate protozoa on bacteria was unaffected by DPP inhibitors. Ammonia production from casein by mixed ruminal microorganisms was inhibited significantly (P < 0.05) by AAC (29% inhibition) and benserazide (33%). It was concluded that DPP inhibitors can influence the rate of NH3 production in the rumen and may form the basis for developing protein-sparing feed additives for ruminants.
Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, United Kingdom.
Hongrong
H
Wang
Nest
N
McKain
Nicola D
ND
Walker
R John
RJ
Wallace
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000641:Ammonia / Q000032:analysis / Q000378:metabolism*; D000818:Animals; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D001545:Benserazide / Q000494:pharmacology; D002364:Caseins / Q000378:metabolism; D016798:Ciliophora / Q000378:metabolism; D003978:Diazomethane / Q000031:analogs & derivatives* / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000378:metabolism*; D007931:Leucyl Aminopeptidase / Q000187:drug effects / Q000378:metabolism; D045851:Megasphaera / Q000187:drug effects / Q000254:growth & development; D009842:Oligopeptides / Q000494:pharmacology; D018720:Prevotella / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology*; D012417:Rumen / Q000382:microbiology*; D016985:Streptococcus bovis / Q000187:drug effects / Q000378:metabolism
D000590:Amino Acid Chloromethyl Ketones; D002364:Caseins; D004151:Dipeptides; D009842:Oligopeptides; D011480:Protease Inhibitors; C089960:glycylphenylalanine diazomethyl ketone; D003978:Diazomethane; D001545:Benserazide; D000641:Ammonia; C041445:diprotin A; D007931:Leucyl Aminopeptidase; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases