Antibiosis between Ruminal Bacteria and Ruminal Fungi

ABSTRACT Cellulose digestion, bacterial numbers, and fungal numbers were monitored over time in vitro by using a purified cellulose medium with and without antibiotics (penicillin and streptomycin). All fermentations were inoculated with a 1:10 dilution of whole rumen contents (WRC). Without antibiotics, cellulose digestion was higher (P < 0.01) at 24, 30, 48, and 72 h; fungi had almost disappeared by 24 h, while bacterial concentrations increased over 100-fold in 24 h and then decreased gradually up to 72 h. In those fermentations with added antibiotics, fungal concentrations increased 4-fold by 30 h and up to 42-fold at 72 h; bacterial concentrations were markedly reduced by 24 h and remained low through 72 h. Similar results were obtained with ground alfalfa as a substrate. In further studies, the in vitro fermentation of purified cellulose without antibiotics was stopped after 18 to 20 h, and the microbial population was killed by autoclaving. Antibiotics were added to half of the tubes, and all tubes were reinoculated with WRC. After 72 h, extensive cellulose digestion had occurred in those tubes without antibiotics, as compared to very low cellulose digestion with added antibiotics. The extent of this inhibition was found to increase in proportion to the length of the initial fermentation period, suggesting the production of a heat-stable inhibitory factor or factors. The inhibitory activity was present in rumen fluid, could be extracted from lyophilized rumen fluid (LRF) with water, and was stable in response to proteolytic enzymes. In addition, the water-extracted residue of LRF was found to contain growth factor activity for rumen fungi in vitro.

Download Full-text

Some effects of potassium chlorate administration onin vitroandin vivorumen fermentation

The Journal of Agricultural Science ◽

10.1017/s0021859600055453 ◽

1978 ◽

Vol 90 (2) ◽

pp. 345-353 ◽

Cited By ~ 3

Author(s):

T. N. Barry ◽

F. J. Harte ◽

B. N. Perry ◽

D. G. Armstrong

Keyword(s):

Continuous Culture ◽

Propionic Acid ◽

Microbial Population ◽

Rumen Fluid ◽

Rumen Fermentation ◽

Potassium Chlorate ◽

Temporary Reduction ◽

Cellulose Digestion

SummaryHay was fed to anin vitrocontinuous culture of the rumen microbial population and to sheep kept in metabolism cages, and the effects of potassium chlorate addition on the rumen fermentation were studied. The compound was given for 8 daysin vitroand for either 3 or 8 daysin vivo.Potassium chlorate additionin vitro(13·7 mg/g hay D.M.) depressed the production of CH4and acetate, had little effect on propionate production and caused a small increase in the production ofn-butyrate andn-valerate. The treatment also depressed cellulose digestion and the concentration of DNA in fermentor liquor, but increased the CO2:CH4ratio in fermentor gas.When givenin vivofor 8 days at 6·7 mg/g hay D.M., potassium chlorate progressively depressed total VFA concentration in rumen fluid, had no effect on VFA molar proportions but caused a small increase in the CO2:CH4ratio in rumen gas. When administeredin vivofor 3 days at 14·4–15·3 mg/g hay D.M. the treatment increased the molar proportions of propionate and depressed those of acetate in rumen fluid without affecting total VFA concentration. There were considerable differences between animals in propionate response, and the maximum responses were generally obtained 2–5 days after dosing had ceased. Potassium chlorate addition also caused a temporary reduction in appetite with some sheep.It was concluded that potassium chlorate was toxic to the rumen microbial population when given for 8 days, but that large doses given over 3 days could be used to increase the ratio of propionic acid relative to acetic and butyric acids produced from the rumen fermentation.

Download Full-text

Effect of monensin, fish oil or their combination on in vitro fermentation and conjugated linoleic acid (CLA) production by ruminal bacteria

Animal Feed Science and Technology ◽

10.1016/j.anifeedsci.2005.02.021 ◽

2005 ◽

Vol 120 (3-4) ◽

pp. 341-349 ◽

Cited By ~ 7

Author(s):

J.H. Wang ◽

B.W. Zhu ◽

M.K. Song ◽

Y.J. Choi

Keyword(s):

Linoleic Acid ◽

Fish Oil ◽

Conjugated Linoleic Acid ◽

Ruminal Bacteria ◽

In Vitro Fermentation

Download Full-text

Effects of Cellobiose and Monensin on In Vitro Fermentation of Organic Acids by Mixed Ruminal Bacteria

Journal of Dairy Science ◽

10.3168/jds.s0022-0302(97)76039-9 ◽

1997 ◽

Vol 80 (6) ◽

pp. 1126-1135 ◽

Cited By ~ 32

Author(s):

T.R. Callaway ◽

S.A. Martin

Keyword(s):

Organic Acids ◽

Ruminal Bacteria ◽

In Vitro Fermentation

Download Full-text

In vitro fermentation of key dietary compounds with rumen fluid: A genome-centric perspective

The Science of The Total Environment ◽

10.1016/j.scitotenv.2017.01.096 ◽

2017 ◽

Vol 584-585 ◽

pp. 683-691 ◽

Cited By ~ 9

Author(s):

Stefano Campanaro ◽

Laura Treu ◽

Mirko Cattani ◽

Panagiotis G Kougias ◽

Veronica Vendramin ◽

...

Keyword(s):

Rumen Fluid ◽

In Vitro Fermentation ◽

A Genome

Download Full-text

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

British Journal Of Nutrition ◽

10.1079/bjn19830102 ◽

1983 ◽

Vol 50 (2) ◽

pp. 345-355 ◽

Cited By ~ 43

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.

Download Full-text

Influence of ionophores on in vitro fermentation by rumen fluid from sheep receiving yeast culture (Yeasacc; YC)

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600020286 ◽

1991 ◽

Vol 1991 ◽

pp. 78-78

Author(s):

C.J. Newbold ◽

R.J. Wallace ◽

I.M. Nevison

Keyword(s):

Feed Efficiency ◽

Rumen Fluid ◽

Basal Diet ◽

Rumen Fermentation ◽

Animal Production ◽

Yeast Culture ◽

Microbial Protein ◽

In Vitro Fermentation ◽

Wide Range

A wide range of compounds has been described which have the potential to improve animal production by manipulating the rumen fermentation. Prominent among these rumen modifiers are the ionophores. Ionophores, such as monensin and tetronasin, improve feed efficiency, partly by increasing the flow of amino-N from the rumen and partly by stimulating the production of propionate in the rumen with an associated reduction in the production of methane (Russell and Strobel, 1988). Recently there has been increasing interest in the use of yeast culture (YC) and other fungal preparation to modify the rumen fermentation. These products have been shown to increase bacterial numbers within the rumen with an associated increase in the breakdown of fibre and supply of microbial protein (Williams and Newbold, 1990). YC has also been reported to increase the production of propionate in the rumen. Little appears to be known about the effect a combination YC and an ionophore would have on the rumen fermentation. This study describes the effects of the ionophores monensin and tetronasin on the fermentation of hay by rumen fluid from sheep fed a basal diet with or without YC.

Download Full-text