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The variability in gel-Producting properties of commercial agar and its influence on bacterial growth

Published online by Cambridge University Press:  15 May 2009

A. J. Fulthorpe
A. J. Fulthorpe
Affiliation:
The Army Vaccine Laboratory, Everleigh, nr Marlborough, Wiltshire
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1. The rigidity of agar gel in poured agar plates can be tested by a comparatively simple and easily repeatable method.

2. Commercial agar from different sources varies in the rigidity of gel it produces at a given concentration.

3. The rigidity of gel produced by any agar at a given concentration is affected by processing and by the mode of production of poured plates and to some extent by the diluent used.

4. The appearance of a spurious S-R change in colonies of Salmonella and Shigella on media with an increasing agar content is a measure of the rigidity of the agar gel used and not directly of the agar concentration of the medium.

5. The appearance of this spurious S-R change induced by rigid agar bears no relation to the agglutinability of the organism.

6. Both increased or decreased agglutinability of cultures of Salmonella and Shigella is associated with the appearance of colonies of an apparently rough morphology at a lower level of agar rigidity than that at which spurious S-R change develops in a normally agglutinable culture.

7. Without some standardization of the rigidity of the gel used in agar plates, erroneous conclusions may be drawn regarding the antigenic state of the organisms under test.

8. Samples of agar of differing gel rigidity can be blended to form a product producing a gel of a calculated 12 sec. value.

I am indebted to the Director-General, Army Medical Services, for permission to publish this article.

Type
Research Article
Information
Journal of Hygiene , Volume 49 , Issue 2-3 , June 1951 , pp. 127 - 139
Copyright
Copyright © Cambridge University Press 1951

References

REFERENCES

Arkwright, J. (1920). J. Path. Bact. 23, 358.Google Scholar
Arkwright, J. (1921). J. Path. Bact. 24, 36.CrossRefGoogle Scholar
Arkwright, J. (1924). Brit. J. exp. Path. 5, 23.Google Scholar
Campbell, L. E. (1938). J. Soc. chem. Ind., Lond. 57, 413–17.Google Scholar
Chakraborty, D. (1948). Quart. J. Pharm. 21, 159–61.Google Scholar
Felix, A. (1938). J. Hyg., Camb 38, 6.Google Scholar
Felix, A. (1944). Trans. R. Soc. trop. Med. Hyg. 37, 5.CrossRefGoogle Scholar
Kizevetter, I. V. (1937). Bull. Pacif. Sci. Inst. Fish. Oceanog. Vladivostock, 13, 1–33 (English summary).Google Scholar
Marshall, S. M., Newton, W. & Orr, A.P. (1949). A study of certain British sea weeds and their Utilization in the Preparation of Agar. London: H.M. Stationery Office.Google Scholar
Wilson, G. S. (1930 a). J. Hyg., Camb., 28, 295.CrossRefGoogle Scholar
Wilson, G. S. (1930 b). J. Hyg., Camb., 30, 40.CrossRefGoogle Scholar