UREOLYTIC RUMEN BACTERIA: I. CHARACTERISTICS OF THE MICROFLORA FROM A UREA-FED SHEEP

1964 ◽  
Vol 10 (3) ◽  
pp. 371-378 ◽  
Author(s):  
G. A. Jones ◽  
R. A. MacLeod ◽  
A. C. Blackwood
Keyword(s):  
Anaerobic Bacterium ◽  
Urease Activity ◽  
Rumen Fluid ◽  
Mixed Cultures ◽  
Rumen Bacteria ◽  
Differential Centrifugation ◽  
Serial Transfer ◽  
Facultatively Anaerobic ◽  
Viable Bacteria ◽  
Rumen Microflora

Measurement of the urease activity of fractions of strained rumen fluid from a urea-fed sheep showed that intracellular bacterial urease was responsible for ureolysis by rumen contents. Subjection of the rumen microflora to differential centrifugation showed that 65% of its total urease activity was associated with a group of larger organisms which sedimented at 1200 × g. An average of 35% of the total viable bacteria in rumen fluid was found by a dilution count technique to manifest urease activity. Mixed cultures of rumen bacteria, in which the urease activity per unit concentration of cells was enriched fourfold over that in rumen-fluid, were obtained by serial transfer in a medium containing 80% rumen supernatant liquor (clarified rumen fluid) supplemented with glucose, phytone, and urea. A facultatively anaerobic bacterium with a low urease activity was isolated from rumen fluid, but attempts to isolate obligately anaerobic urease-producing species from enrichment cultures of rumen bacteria were unsuccessful.

Biphasic breakdown of peptides by rumen bacteria

1996 ◽  
Vol 1996 ◽  
pp. 237-237
Author(s):  
R.J. Wallace
Keyword(s):  
Dry Matter ◽  
Rumen Fluid ◽  
Rumen Bacteria ◽  
Mixed Diet ◽  
Supernatant Fluid ◽  
Differential Centrifugation ◽  
Ammonia Production ◽  
Protein Breakdown ◽  
Adult Sheep ◽  
Mixed Bacteria

Excessive protein breakdown and ammonia production often lead to inefficient N utilisation in ruminants. Peptides are intermediates in the breakdown process. The aims of this study were to characterize peptidase activities of rumen bacteria and to determine which species of bacteria were responsible for the different steps of peptide breakdown in the rumen.Four rumen-fistulated adult sheep received a mixed diet (hay, barley, molasses, fishmeal and minerals and vitamins: 500, 99.5, 100, 91 and 9.5 g/kg dry matter respectively) fed in equal meals of 500 g at 0800 and 1600 h. Rumen fluid was removed 3 h after the morning feeding, strained, and mixed bacteria were prepared by differential centrifugation. Bacteria were sonicated and debris was removed by centrifugation. Peptidase activities were determined on the supernatant fluid.

Effects of heavy metals and other trace elements on the fermentative activity of the rumen microflora and growth of functionally important rumen bacteria

1978 ◽  
Vol 24 (3) ◽  
pp. 298-306 ◽  
Author(s):  
C. W. Forsberg
Keyword(s):  
Trace Elements ◽  
Rumen Fluid ◽  
Inhibitory Effect ◽  
Rumen Bacteria ◽  
Inhibitory Effects ◽  
Butyrivibrio Fibrisolvens ◽  
Fermentative Activity ◽  
Rumen Microflora ◽  
High Concentrations

The inhibitory effects of high concentrations of essential and non-essential trace elements were tested on the rumen microflora using the rate of fermentation in vitro as the assay. The elements (and the concentration causing 50% inhibition) in decreasing order of toxicity were Hg2+ (20 μg/ml), Cu2+ (21 μg/ml), Cr6+ (70 μg/ml), Se4+ (73 μg/ml), Ni2+ (160 μg/ml), Cd2+ (175 μg/ml), As3+ (304 μg/ml), and As5+ (1610 μg/ml). The elements tested that were either weak or non-inhibitory at concentrations greater than 400 μg/ml included Zn2+, Cr2+, Fe2+, Mn2+, Pb2+, and Co2+. Methylmercury was as inhibitory as mercuric chloride to the fermentation. When the inhibitory effect of Cd2+ was tested on separated bacterial and protozoal fractions, it was more inhibitory to the bacteria. The inhibitory effects of trace elements were also determined for a number of axenic cultures of rumen bacteria. The bacteria which most frequently exhibited the greatest sensitivity were Bacteroides succinogenes, Ruminococcus albus, Bacteroides amytophilus, and Eubacterium ruminantium. Those often exhibiting intermediate sensitivities included Butyrivibrio fibrisolvens, Selenomonas niminantium, and Megasphera elsdenii, while Streptococcus bovis was very refractory to all elements tested. Rumen fluid provided a modest protective effect for the bacteria.

The constitutive nature of alkaline phosphatase in rumen bacteria

1980 ◽  
Vol 26 (2) ◽  
pp. 268-272 ◽  
Author(s):  
C. W. Forsberg ◽  
K.-J. Cheng
Keyword(s):  
Alkaline Phosphatase ◽  
Batch Culture ◽  
Culture Medium ◽  
Rumen Fluid ◽  
Inorganic Phosphorus ◽  
Phosphorus Concentration ◽  
Rumen Bacteria ◽  
Megasphaera Elsdenii ◽  
Rumen Microflora ◽  
Apase Activity

Alkaline phosphatase (APase) activity of Megasphaera elsdenii was enhanced by PO42− limitation in batch culture; however, six other species of rumen bacteria tested showed no increase in APase activity under these conditions. Alkaline phosphatase was produced by the mixed rumen microflora even though the inorganic phosphorus concentration was as high as 10 mM. The APase activity of the bacterial fraction from rumen fluid was not increased during incubation in a phosphorus-free culture medium. Since bacteria may account for greater than 80% of the APase activity in the rumen, this would suggest that the bulk of the APase activity in the rumen is synthesized constitutively. The bacterium responsible for most of the APase activity probably is Bacteroides ruminicola.

Biphasic breakdown of peptides by rumen bacteria

1996 ◽  
Vol 1996 ◽  
pp. 237-237
Author(s):  
R.J. Wallace
Keyword(s):  
Dry Matter ◽  
Rumen Fluid ◽  
Rumen Bacteria ◽  
Mixed Diet ◽  
Supernatant Fluid ◽  
Differential Centrifugation ◽  
Ammonia Production ◽  
Protein Breakdown ◽  
Adult Sheep ◽  
Mixed Bacteria

Excessive protein breakdown and ammonia production often lead to inefficient N utilisation in ruminants. Peptides are intermediates in the breakdown process. The aims of this study were to characterize peptidase activities of rumen bacteria and to determine which species of bacteria were responsible for the different steps of peptide breakdown in the rumen.Four rumen-fistulated adult sheep received a mixed diet (hay, barley, molasses, fishmeal and minerals and vitamins: 500, 99.5, 100, 91 and 9.5 g/kg dry matter respectively) fed in equal meals of 500 g at 0800 and 1600 h. Rumen fluid was removed 3 h after the morning feeding, strained, and mixed bacteria were prepared by differential centrifugation. Bacteria were sonicated and debris was removed by centrifugation. Peptidase activities were determined on the supernatant fluid.

Studies with the Cellulolytic Fraction of Rumen Bacteria Obtained by Differential Centrifugation

1960 ◽  
Vol 19 (4) ◽  
pp. 1098-1109 ◽  
Author(s):  
Burk A. Dehority ◽  
Khaled el-Shazly ◽  
Ronald R. Johnson
Keyword(s):  
Rumen Bacteria ◽  
Differential Centrifugation

PSIX-5 Diet is more powerful than age in shaping the rumen bacterial community and function of dairy cattle

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 444-444
Author(s):  
YangYi Hao ◽  
Shuai Huang ◽  
Shengli Li
Keyword(s):  
Bacterial Community ◽  
Dairy Cattle ◽  
Rumen Fluid ◽  
Rumen Bacteria ◽  
Great Ability ◽  
Linear Discriminant ◽  
High Fiber ◽  
Fiber Diet ◽  
High Fiber Diet ◽  
And Function

Abstract The objective was to understand the effects of diet and age on the rumen bacterial community and function, 48 dairy cattle were selected. Rumen fluid samples were collected from each animal at 1.5 (1.5M, milk and starter diet, n=8), 6 (6M, starter and oat grass, n=8), 9 (9M, high fiber diet, n=8), 18 (18M, high fiber diet, n=8), 23 (23M, high fiber diet, n=8) and 27 (27M, high grain diet, n=8) months old. The acetate/propionate ratio (A/P) at M9, M18, and M23 were significantly higher than M27 and M1.5 (P < 0.05), while the A/P at M6 was lower than others (P < 0.05). The total volatile fatty acid at M23 and M27 was higher than others (P < 0.05). The urease at M18 was significantly lower than M1.5, M6, and M9 (P < 0.05), and the xylanase at M18 was significantly higher than M1.5, M23, and M27 (P < 0.05). 16S rRNA sequencing data and the Linear discriminant analysis showed that thirty-three bacteria were identified as biomarkers among ages and diets. The age and diet contributed 7.98% and 32.49% to the rumen bacteria community using the variation partitioning approach analysis. The norank_f_p-251-o5 was significantly and positively correlated with age (r = 0.83, P < 0.01), while Eubacterium was significantly and negatively correlated with age (r = -0.84, P < 0.01). Dietary fiber showed a strong correlation (r > 0.80, P < 0.01) with Lachnospiraceae, NK4A214_group, Saccharofermentans, Clostridia, Pseudobutyrivibrio Bacteroidales_UCG-001. These genera also negatively correlated with dietary crude protein and starch (r < - 0.80, P < 0.01). All these bacteria were significantly correlated with A/P, acetate, and urease (r > 0.5, P < 0.05). These findings collectively indicated that diet drives the great ability to shape the rumen bacteria community and function than age.

Isolation and identification of rumen bacteria capable of anaerobic rutin degradation

1969 ◽  
Vol 15 (12) ◽  
pp. 1365-1371 ◽  
Author(s):  
K. -J. Cheng ◽  
G. A. Jones ◽  
F. J. Simpson ◽  
M. P. Bryant
Keyword(s):  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Anaerobic Bacteria ◽  
Heterocyclic Ring ◽  
Ring Structure ◽  
Water Soluble ◽  
Rumen Bacteria ◽  
Isolation And Identification ◽  
Pure Cultures ◽  
Rutin Degradation

Fifteen strains of bacteria capable of degrading rutin anaerobically were isolated from bovine rumen contents and identified by morphological and biochemical evidence as strains of Butyrivibrio sp. Three cultures from a laboratory collection of 53 strains of rumen bacteria also used rutin anaerobically. Two, Butyrivibrio fibrisolvens D1 and Selenomonas ruminantium GA192, cleaved the glycosidic bond of rutin and fermented the sugar but did not degrade the insoluble aglycone produced; the third strain, Peptostreptococcus sp. B178, degraded the substrate to soluble products. Butyrivibrio sp. C3 degraded rutin, quercitrin, and naringin to water-soluble products, showing that the organism cleaved the heterocyclic ring of these compounds. Butyrivibrio sp. C3 fermented the sugar moiety of hesperidin but did not cleave the heterocyclic ring. It did not attack quercetin, taxifolin, protocatechuic acid, or phloroglucinol. In a medium containing rumen fluid, Butyrivibrio sp. C3 degraded rutin more than twice as fast as it did in a medium containing enzymatic casein hydrolyzate, volatile fatty acids, yeast extract, and hemin in place of rumen fluid.The observations reported in this paper are believed to represent the first recorded demonstration of degradation of the heterocyclic ring structure of rutin and other bioflavonoids in pure cultures of anaerobic bacteria.

scholarly journals Hydrolysis of14C-labelled proteins by rumen micro-organisms and by proteolytic enzymes prepared from rumen bacteria

1983 ◽  
Vol 50 (2) ◽  
pp. 345-355 ◽  
Author(s):  
R. J. Wallace
Keyword(s):  
Proteolytic Enzymes ◽  
Rumen Fluid ◽  
Performic Acid ◽  
Cross Linking ◽  
Acid Oxidation ◽  
Rumen Bacteria ◽  
Rate Of Hydrolysis ◽  
Micro Organisms ◽  
Hydrolysis Of

1. Proteins were labelled with14C in a limited reductive methylation using [14C]formaldehyde and sodium borohydride.2. The rate of hydrolysis of purified proteins was little (< 10%) affected by methylation and the14C-labelled digestion products were not incorporated into microbial protein during a 5 h incubation with rumen fluid in vitro. It was therefore concluded that proteins labelled with14C in this way are valid substrates for study with rumen micro-organisms.3. The patterns of digestion of14C-labelled fish meal, linseed meal and groundnut-protein meal by rumen micro-organisms in vitro were similar to those found in vivo.4. The rates of hydrolysis of a number of14C-labelled proteins, including glycoprotein II and lectin from kidney beans (Phaseolus vulgaris), were determined with mixed rumen micro-organisms and with proteases extracted from rumen bacteria. Different soluble proteins were digested at quite different rates, with casein being most readily hydrolysed.5. Proteins modified by performic acid oxidation, by cross-linking using 1,6-di-iso-cyanatohexane or by diazotization were labelled with14C. Performic acid treatment generally increased the susceptibility of proteins to digestion, so that the rates of hydrolysis of performic acid-treated proteins were more comparable than those of the unmodified proteins. Cross-linking resulted in a decreased rate of hydrolysis except with the insoluble proteins, hide powder azure and elastin congo red. Diazotization had little effect on the rate of hydrolysis of lactoglobulin and albumin, but inhibited casein hydrolysis and stimulated the breakdown of γ-globulin.

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