In experiments on six sheep fed on a low protein diet (6.2 g N/day), it was found that the urease activity of the rumen fluid did not change significantly in the first 6 hours after feeding and that it ranged from 45 to 75 nkat.ml-1. The major portion was bound to the bacterial fraction and formed about 70% of total rumen fluid activity. Urease activity determined in food particles with adherent bacteria removed from the rumen before and 3 and 6 hours after feeding ranged from 20 to 26 nkat.g-1 food (wet weight), and on rumen wall samples with adherent bacteria from 30 to 800 nkat per 2.5 cm2 tissue. Again, no significant changes correlated to the time after feeding were found. The results show that urease activity in the sheep rumen is localized on food particles and on rumen wall epithelium with adherent bacteria, as well as in the rumen fluid.

• MeSH
• amoniak metabolismus   MeSH
• bachor enzymologie   mikrobiologie   MeSH
• Bacteria enzymologie   MeSH
• časové faktory MeSH
• ovce MeSH
• ureasa metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amoniak MeSH
• ureasa MeSH

In experiments on six sheep fed on a low nitrogen diet (3.7 g N/day), urease (EC 3.5.1.5) activity (nkat X mg-1 bacterial dry weight) 3 h after feeding was found to be highest in the bacteria adhering to the rumen wall (13.25 +/- 2.10), lower in the rumen fluid bacteria (8.96 +/- 1.35) and lowest in the bacteria adhering to feed particles in the rumen (5.69 +/- 2.13). The urease activity of bacteria adhering to the rumen wall and of the rumen fluid bacteria of six sheep fed on a high nitrogen diet (21 g N/day) was significantly lower than in sheep with a low N intake and in both cases was roughly the same (3.81 +/- 1.37 and 3.76 +/- 1.02 respectively); it was lowest in bacteria adhering to feed particles in the rumen (1.92 +/- 0.90). It is concluded from the results that the urease activity of rumen fluid bacteria and of bacteria adhering to the rumen wall and to feed particles in the rumen is different and that it falls significantly in the presence of a high nitrogen intake. From the relatively high ureolytic activity of bacteria adhering to the rumen wall in the presence of a low nitrogen intake it is assumed that this is one of the partial mechanisms of the hydrolysis of blood urea entering the rumen across the rumen wall and of its reutilization in the rumen-liver nitrogen cycle in ruminants.

• MeSH
• bachor enzymologie   MeSH
• Bacteria enzymologie   MeSH
• bakteriální adheze * MeSH
• dietní proteiny farmakologie   MeSH
• dusík farmakologie   MeSH
• krmivo pro zvířata MeSH
• ovce MeSH
• tělesné tekutiny enzymologie   MeSH
• ureasa metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dietní proteiny MeSH
• dusík MeSH
• ureasa MeSH

Six defined strains of adherent, coagulase-negative and catalase-positive staphylococci were isolated from the rumen wall of lambs. All the strains fermented maltose and had positive acetoin production. The strains were classified as follows on the basis of diagnostic tests, according to an identification key: three strains belonged to the species Staphylococcus warneri (SW34, SW64, SW6), two to the species S. epidermidis (SE30, SE49) and one to the species S. cohnii subsp. urealyticum (SCU32)--Tab. I. The adherence index of the different isolates ranged from 1.9 +/- 0.02 to 14.9 +/- 2.12 of bacteria adhering to one epithelial cell of the rumen wall. There were large differences in urease production (2.3 +/- 0.15 to 29.3 +/- 1.16 nkat/ml). But in general the isolated staphylococci can be taken as strains with low, medium or high adherence, and/or urease activity (Tab. II). In the group of facultative anaerobic bacteria the staphylococci are the first, lactic acid producing bacteria and the attained production (0.164 to 0.687 mol/l) is adequate to their portion in the rumen (Tab. II). The isolated strains produced bacteriocin-like substances which inhibited the growth of maximally four out of the six used indicator bacteria of the same species, and also of a related species (Tab. III) while they showed small but clear zones of inhibition of the size 2 to 5 mm. In general, the mentioned staphylococci can be considered as little active producers of bacteriocin-like substances. All the tested strains were resistant to the observed heavy metals.

• MeSH
• bachor mikrobiologie   MeSH
• bakteriální adheze * MeSH
• ovce mikrobiologie   MeSH
• Staphylococcus izolace a purifikace   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH