Maintenance of the Rumen Microbial Population in Continuous Culture

Rufener, W. H.; Nelson, W. O.; Wolin, M. J.

doi:10.1128/aem.11.3.196-201.1963

Cited by 45 publications

(20 citation statements)

References 4 publications

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“…In our experiments the dilution rate was 1.32 volumes/day, on the average, and the protozoa numbers at a steady-state were 2.5 x lOVml. Usually in the continuous culture systems based on a simple overflow (Rufner et al 1963, Slyter et al 1964, or also in the dual flow systems, when the dilution rate is too high (Hannah et al 1986) the protozoa survive only for short periods. The protozoa numbers in our system are at the same level as in dual flow systems (Hoover et al 1976).…”

Section: Discussionmentioning

confidence: 99%

Design and development of a continuous culture system for studying rumen fermentation

Miettinen

Setälä

1989

AFSci

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The present report describes an in vitro continuous culture system to simulate rumen fermentation. The complete assembly consists of six culture vessels (liquid volume 700 ml) fed twice daily with finely ground feed. The artificial saliva enters the vessel continuously, and the effluent leaves it continuously through the overflow port. The intermittent stirring of the fermentor content and the pH regulation are automatically controlled by a desktop computer. Two replicate experiments with ten fermentors given a diet of silage (50 %) and barley (50 %) were made in order to evaluate the system. The results indicate that the system reaches steady-state conditions within three to five days, ammonia concentration being an exeption. It takes for the ammonia concentration approximately 11—14 days to stabilize. The plateau values for the total volatile fatty acid (VFA) concentrations, the molar proportions of individual VFAs, and the ammonia concentrations were found to be within the accepted range in the rumen of animals given similar diets or in other artificial rumen systems. There was a tenfold decrease in the numbers of protozoa in the fermentors during the first four days of incubation. However, the average plateau value for the protozoa numbers (2.5 x 104/ml) is in the same range as in the dual flow continuous culture systems. The efficiency of the microbial N production was higher than that usually observed in vivo or in vitro (45 vs. 30 g/kg organic matter digested). The results indicate that this continuous culture system provides a reasonable estimate of rumen fermentation.

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Section: Discussionmentioning

confidence: 99%

Design and development of a continuous culture system for studying rumen fermentation

Miettinen

Setälä

1989

AFSci

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“…Each fermentor contained approximately 500 ml of culture fluid. The artificial saliva-water solution was identical to that described by Rufener et al (1963). The feeding, gassing with helium to remove air, and collection of effluent were as described by Slyter et al (1964).…”

Section: Methodsmentioning

confidence: 99%

“…The samples for plate counts were removed through a sampling tube. The level of the ration used to maintain the microbial population was calculated to be 50% of the calculated total digestible nutrient requirement of an equivalent ruminant (Rufener et al, 1963). Each fermentor was fed twice daily with 7.3 g of hay and 2.3 g of concentrate per feeding.…”

Section: Methodsmentioning

confidence: 99%

“…The experiments described in this report were designed to test various possible mechanisms for control of the E. coli population in the rumen. In some experiments, advantage was taken of a method developed for the maintenance of the rumen ecosystem in continuous culture in vitro (Rufener, Nelson, and Wolin, 1963;Slyter, Nelson, and Wolin, 1964). The continuous culture permitted studies of the fate of E. coli in the simulated rumen environment under carefully controlled conditions.…”

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Basis for the Exclusion of Escherichia coli from the Rumen Ecosystem

Hollowell¹,

Wolin²

1965

Applied Microbiology

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HOLLOWELL, C. A. (University of Illinois, Urbana), AND M. J. WOLIN. Basis for the exclusion of Escherichia coli from the rumen ecosystem. Appl. Microbiol. 13:918-924. 1965.-The possible causes for the exclusion of Escherichia coli from the rumen ecosystem were investigated. Evidence presented indicates that oxidation-reduction potential, temperature, pH, C02, volatile fatty acids, traces of heavy metals, and bacteriophage are not environmental factors which select against E. coli in the rumen ecosystem. The feeding of nutrients utilizable by E. coli to an artificially inoculated continuous-culture rumen ecosystem did not prevent the washout of the E. coli from the continuous cultures. The presence of an inhibitor of E. coli growth was demonstrated. High concentrations of rumen fluid (50 to 100%) were necessary to inhibit growth in Antibiotic Medium 3. The inhibitor may operate to control the growth of E. coli in the rumen ecosystem. Because of the presence of an inhibitor, the possibility that rumen fluid is deficient in nutrients to support the growth of E. coli cannot be eliminated.

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“…The chemical composition of the substrates is shown in Table 1. Mineral buffer solution according to Rufener et al [13] was used as a fermentation medium. If cellulose was used as a predominant fermenter feed, the fermentation medium was supplemented with 28 mmol-1-1 NH4C1 (loading rate of 13 g cellulose-1-1.d -1) or NH4HCO 3 (loading rates of 15 or 20 g. 1-1-d -1) and trace elements (0.2 ml.…”

Section: Fermenter Design and Operationmentioning

confidence: 99%

Contribution of rumen protozoa to fibre degradation and cellulase activity in vitro

Gijzen

Lubberding

Gerhardus

et al. 1988

FEMS Microbiology Letters

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The contribution of ciliates to rumen fermentation was estimated by determination of overall fibre degradation and cellulase activities (determined as carboxymethylcellulase activity) in faunated and defaunated ‘artificial rumen’ cultures. Experiments performed at loading rates of 22.5 and 35 g per liter per day of a grass‐grain substrate revealed that fibre degradation was significantly lower in the absence of ciliates only at the high loading rate. This effect of defaunation was smaller at dilution rates below 1.7 fermenter volume turnovers per day. Bacterial numbers were higher in all experiments after removal of ciliates. Fractionation studies demonstrated that ciliates accounted for 19–28% of the total cellulase activity in faunated cultures fed on filter paper cellulose.

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Maintenance of the Rumen Microbial Population in Continuous Culture

Cited by 45 publications

References 4 publications

Design and development of a continuous culture system for studying rumen fermentation

Design and development of a continuous culture system for studying rumen fermentation

Basis for the Exclusion of Escherichia coli from the Rumen Ecosystem

Contribution of rumen protozoa to fibre degradation and cellulase activity in vitro

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