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Factors affecting the rate of breakdown of bacterial protein in rumen fluid

Published online by Cambridge University Press:  09 March 2007

R. J. Wallace  and
Carol A. McPherson
R. J. Wallace
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
Carol A. McPherson
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
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Abstract

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1. The cellular proteins of Butyrivibrio jibrisolvens, Lactobacillus casei, Megasphaera elsdenii, Selenomonas ruminantium and Streptococcus bovis were labelled by growth in the presence of L-[14C]leucine, and the breakdown of labelled protein was measured in incubations of these bacteria with rumen fluid to which unlabelled 5 mM-L-leucine was added. The rate of protein breakdown was estimated from the rate of release of radioactivity into acid-soluble material.

2. Protein breakdown occurred at different rates in different species. The mean rates for B. fibrisolvens, L. casei, M. elsdenii, Sel. ruminantium and Str. bovis were 28.6, 18.1, 17.7, 10.5 and 5.3% /h respectively in samples of strained rumen fluid (SRF) with different protozoal populations. Rates of 3% /h or less were found in SRF from ciliate-free sheep or in faunated SRF from which protozoa had been removed by centrifugation. Further removal of mixed rumen bacteria had little effect. Suspensions of washed protozoa degraded bacterial protein at rates which were of the same order as those found in SRF.

3. The rate of breakdown of bacterial protein in different samples of SRF tended to increase as the numbers of small entodiniomorphid protozoa increased. The numbers of larger entodiniomorphs and holotrichs had no obvious influence on this rate.

4. Autoclaved and u.v.-treated bacteria were generally no different from live bacteria in their susceptibility to breakdown in SRF from faunated sheep, indicating that endogenous protein turnover was not a significant cause of bacterial protein catabolism.

5. The rate of bacterial protein breakdown was unrelated to the proteolytic activity of SRF.

6. It was concluded that predation by small protozoa is by far the most important cause of bacterial protein turnover in the rumen, with autolysis, other lytic factors and endogenous proteolysis being of minor importance.

Type
General Nutrition papers
Information
British Journal of Nutrition , Volume 58 , Issue 2 , September 1987 , pp. 313 - 323
Copyright
Copyright © The Nutrition Society 1987

References

REFERENCES

Cheng, K.-J. & Costerton, J. W. (1977). Journal of Bacteriology 129, 1506–1512.CrossRefGoogle Scholar
Coleman, G. S. (1979). Tropical Animal Production 4, 199–213.Google Scholar
Coleman, G. S. (1980). Advances in Parasitology 18, 121–173.CrossRefGoogle Scholar
Demeyer, D. (1981). Agriculture and Environment 6, 295–337.CrossRefGoogle Scholar
Demeyer, D. & Van Nevel, C. J. (1979). British Journal of Nutrition 42, 515–524.CrossRefGoogle Scholar
Eadie, J. M. & Gill, J. C. (1971). British Journal of Nutrition 26, 155–167.CrossRefGoogle Scholar
Hobson, P. N. (1969). Methods of Microbiology 3B, 133–149.CrossRefGoogle Scholar
Hobson, P. N. & Wallace, R. J. (1982). Critical Reviews in Microbiology 9, 253–320.CrossRefGoogle Scholar
Hoogenraad, N. J. & Hird, F. J. R. (1970). Journal of General Microbiology 62, 261–264.CrossRefGoogle Scholar
Hoogenraad, N. J., Hird, F. J. R., Holmes, I. & Millis, N. F. (1967). Journal of General Virology 1, 575–576.CrossRefGoogle Scholar
Hoogenraad, N. J., Hird, F. J. R., White, R. G. & Leng, R. A. (1970). British Journal of Nutrition 24, 129–144.CrossRefGoogle Scholar
Jarvis, B. D. W. (1968). Applied Microbiology 16, 714–723.CrossRefGoogle Scholar
Leng, R. A. & Nolan, J. V. (1984). Journal of Dairy Science 67, 1072–1089.CrossRefGoogle Scholar
Lindsay, J. R. & Hogan, J. P. (1972). Australian Journal of Agricultural Research 23, 321–330.CrossRefGoogle Scholar
Mandelstam, J. (1963). Annals of the New York Academy of Sciences 102, 621–636.CrossRefGoogle Scholar
Orpin, C. G. & Munn, E. A. (1974). Experientia 30, 1018–1020.CrossRefGoogle Scholar
Pine, M. J. (1972). Annual Review of Microbiology 26, 103–126.CrossRefGoogle Scholar
Robinson, J. P. & Hungate, R. E. (1973). International Journal of Systematic Bacteriology 23, 171–181.CrossRefGoogle Scholar
Rowe, J. B., Davies, A. & Broome, A. W. J. (1985). British Journal of Nutrition 54, 105–119.CrossRefGoogle Scholar
Scott, H. W. & Dehority, B. A. (1965). Journal of Bacteriology 89, 1169–1175.CrossRefGoogle Scholar
Ushida, K., Jouany, J. P. & Thivend, P. (1986). British Journal of Nutrition 56, 407–419.CrossRefGoogle Scholar
Wallace, R. J. (1983 a). British Journal of Nutrition 50, 345–355.CrossRefGoogle Scholar
Wallace, R. J. (1983 b). British Journal of Nutrition 49, 101–108.CrossRefGoogle Scholar
Wallace, R. J. (1986). Applied and Environmental Microbiology 51, 1141–1143.CrossRefGoogle Scholar
Wallace, R. J., Broderick, G. A. & Brammall, M. L. (1987). British Journal of Nutrition 58, 87–93.CrossRefGoogle Scholar
Whitelaw, F. G., Bruce, L. A., Eadie, J. M. & Shand, W. J. (1983). Applied and Environmental Microbiology 46, 951–953.CrossRefGoogle Scholar