Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-19T04:40:49.626Z Has data issue: false hasContentIssue false

Studies on thiaminase I activity in ruminant faeces and rumen bacteria

Published online by Cambridge University Press:  27 March 2009

J. W. Boyd
Affiliation:
Virginia–Maryland Regional College of Veterinary Medicine, Division of Pathobiology and Public Practice, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, U.S.A.

Summary

Kinetic studies of thiaminase I in extracts of ruminant faeces showed that the affinity for one substrate varied with the concentration of the other substrate in the manner of a two-step transfer mechanism. When the alternate substrate concentration was optimal, the apparent Michaelis constant (Km) for thiamine was 176 μΜ and the apparent Km for aniline was 3·19 mΜ. It is recommended that in routine thiaminase assays, the thiamine and aniline concentrations should be at least 1·5 and 25 mΜ, respectively. When non-saturating concentrations of thiamine are used in thiaminase assays the results should be reported as unimolecular reaction constants since the enzyme activity can be calculated only if suitable Km data have been determined.

Improved radioactive and colorimetric thiaminase assays with saturating substrate concentrations gave similar results. The analytical variation of the colorimetric method was rather high but this method may be useful for laboratories which lack radioactive isotope facilities.

Thiaminase assays were performed on cultures of 14 species of rumen bacteria. Only Megasphaera elsdenii had thiaminase activity and its cosubstrate specificity was different from the rumen thiaminase associated with cerebrocortical necrosis in ruminants. It was concluded that the source of rumen thiaminase in that disease has yet to be identified.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1985

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Boyd, J. W. & Walton, J. R. (1977). Cerebrocortical necrosis in ruminants: an attempt to identify the source of thiaminase in affected animals. Journal of Comparative Pathology 87, 581589.CrossRefGoogle ScholarPubMed
Cushnie, G. H., Richardson, A. J., Lawson, W. J. & Sharman, G. A. M. (1979). Cerebrocortical necrosis in ruminants: effect of thiaminase type 1 – producing Clostridium sporogenes in lambs. Veterinary Record 105, 480482.CrossRefGoogle ScholarPubMed
Edwin, E. E. (1979). Determination of thiaminase activity using thiazole-labelled thiamine. Methods in Enzymology 62, 113117.CrossRefGoogle ScholarPubMed
Edwin, E. E. & Jackman, R. (1973). Ruminal thiaminase and tissue thiamine in cerebrocortical necrosis. Veterinary Record 92, 640641.CrossRefGoogle ScholarPubMed
Edwin, E. E. & Jackman, R. (1974). A rapid radioactive method for determination of thiaminase activity and its use in the diagnosis of cerebrocortical necrosis in sheep and cattle. Journal of the Science of Food and Agriculture 25, 357368.CrossRefGoogle ScholarPubMed
Edwin, E. E. & Jackman, R. (1982). Ruminant thiamine requirement in perspective. Veterinary Research Communications 5, 237250.CrossRefGoogle Scholar
Edwin, E. E., Jackman, R. & Jones, P. (1982). Some properties of thiaminase associated with cerebrocortical necrosis. Journal of Agricultural Science, Cambridge 99, 271275.CrossRefGoogle Scholar
Evans, E. T. R., Evans, E. C. & Roberts, H. E. (1951). Studies on bracken poisoning in the horse. British Veterinary Journal 107, 364371, 399–411.CrossRefGoogle Scholar
Evans, W. C., Evans, I. A., Thomas, A. J., Watkins, J. E. & Chamberlain, A. G. (1958). Studies on bracken poisoning in cattle. Part IV. British Veterinary Journal 114, 180198.CrossRefGoogle Scholar
Fujita, A. (1954). Thiaminase. Advances in Enzymology 15, 389421.Google ScholarPubMed
Leinhard, G. E. (1970). Kinetic evidence for a (4-amino-2-methyl-5-pyrimidinyl) methyl-enzyme intermediate in the thiaminase I reaction. Biochemistry 9, 30113020.CrossRefGoogle Scholar
Morgan, K. T. & Lawson, G. H. K. (1974). Thiaminase type 1 – producing bacilli and ovine polioencephalomalacia. Veterinary Record 95, 361362.CrossRefGoogle ScholarPubMed
Roberts, G. W. & Boyd, J. W. (1974). Cerebrocortical necrosis in ruminants. Occurrence of thiaminase in the gut of normal and affected animals and its effect on thiamine status. Journal of Comparative Pathology 84, 365374.CrossRefGoogle ScholarPubMed
Rowett Research Institute (1978). Annual Report, pp. 5152.Google Scholar
Sealock, R. R., Livermore, A. H. & Evans, C. A. (1943). Thiamine inactivation by the Fresh-fish or Chastek-paralysis factor. Journal of the American Chemical Society 65, 935940.CrossRefGoogle Scholar
Shreeve, J. E. & Edwin, E. E. (1974). Thiaminaseproducing strains of Cl. sporogenes associated with outbreaks of cerebrocortical necrosis. Veterinary Record 94, 330.CrossRefGoogle ScholarPubMed
Webb, E. C. (1961). The estimation of enzymes. Proceedings of the IVth International Congress on Clinical Chemistry, pp. 5562. Edinburgh: E. and S. Livingston.Google Scholar
Wittliff, J. L. & Airth, R. L. (1970). Thiaminase I (thiamine: base 2-methyl-4-aminopyrimidine-5-methenyl-tranaferase, EC 2.5.1.2). Methods in Enzymology, vol. 18 (ed. McCormick, D. B. and Wright, L. D.), pp. 229234.CrossRefGoogle Scholar