[Influence of thiamine on bacterial proteosynthesis in sheep].
To determine the effect of thiamin on the activity of rumen microorganisms we measured the extent of bacterial protein synthesis by in vitro incubations in the presence of filtered rumen juice and a protein-free purified diet with 4 p. 100 urea. This was verified by the amount of protein formed in the incubation medium. Comparing the process in the absence of thiamin, the incorporation of that vitamin at the rate of 4 mg/g resulted in a mean increase of 65 p. 100 of the bacterial proteins synthesized in vitro in 3 hrs. Parallel to this thiamin effect on protein synthesis, the fatty acid analysis showed a modification of the microbial aspect with increased formation of propionic acid (p. 100 of C3 for diet with thiamin vs p. 100 of C3 for the thiamin-free diet = 40.39 +/- 5.08 vs 25.12 +/- 2.99). This was an improvement of energetic yield following the stochiometric calculations. These observations might explain the effect of this additive nutrient on rumen bacterial proteosynthesis.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001419:Bacteria / Q000187:drug effects; D001426:Bacterial Proteins / Q000096:biosynthesis*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D007700:Kinetics; D012417:Rumen / Q000382:microbiology*; D012756:Sheep / Q000502:physiology*; D013831:Thiamine / Q000494:pharmacology*
D001426:Bacterial Proteins; D005232:Fatty Acids, Volatile; D000255:Adenosine Triphosphate; D013831:Thiamine
Influence de la thiamine sur la protéosynthèse bactérienne chez le mouton.