title: [The effect of different centrifugation conditions in the isolation of mixed rumen bacteria on their content of nitrogen and diaminopimelic acid: use of duodenal content as raw material].
abstract: The objective of the present study was, to investigate the effect of varying conditions of differential centrifugation of duodenal content on the isolation of bacteria (B-fraction) and feed particles + protozoa (FP-fraction). The treatments at low-speed centrifugation were as follows: 100 x g/5 min, 400 x g/10 min, 1000 x g/10 min and 2000 x g/10 min, high speed conditions were 30,000 x g/30 min/4 degrees C. The results of three experiments are given. Analytical examination gave similar results for N-contents for all treatments, the mean values being 7.90 +/- 0.27% (n = 12) for B-fractions and 6.53 +/- 0.73% (n = 12) for FP-fractions. Increasing the low-speed from 100 x g to 2000 x g lead to increasing DAP-contents and decreasing N:DAP-ratios of the bacterial isolates, the values being 2.43, 3.02, 3.22 and 3.39 mg DAP/g DM and 32.0, 27.4, 25.0 and 23.0 N:DAP-ratio. Decreased isolation of bacterial material in the B-fraction in conjunction with increased incorporation in the FP-fraction resulted in rising the speed of the low speed centrifugation. The rates of loss of DAP, measured by comparison with the total amount were 10, 32, 48 and 70% respectively. It was concluded to prefer the isolation of bacteria from rumen fluid.
authors.affiliation: Akademie der Landwirtschaftswissenschaften der DDR, Forschungszentrum für Tierproduktion Dummerstorf-Rostock.
authors.forename: R
authors.initials: R
authors.lastname: Krawielitzki
authors.forename: J
authors.initials: J
authors.lastname: Voigt
authors.forename: B
authors.initials: B
authors.lastname: Piatkowski
mesh_terms: D000599:Amino Acids, Diamino / Q000032:analysis*; D000818:Animals; D001419:Bacteria / Q000032:analysis / Q000302:isolation & purification*; D002417:Cattle; D002498:Centrifugation; D003960:Diaminopimelic Acid / Q000032:analysis*; D004386:Duodenum / Q000382:microbiology*; D005260:Female; D009584:Nitrogen / Q000032:analysis*; D012417:Rumen / Q000382:microbiology*
chemical_list: D000599:Amino Acids, Diamino; D003960:Diaminopimelic Acid; D009584:Nitrogen
vernacular_title: Der Einfluss unterschiedlicher Zentrifugationsbedingungen bei der Isolierung gemischter Pansenbakterien auf deren Gehalt an Stickstoff und Diaminopimelinsäure: Verwendung von Duodenalchymus als Ausgangsmaterial.