Hostname: page-component-84b7d79bbc-g5fl4 Total loading time: 0 Render date: 2024-08-01T10:28:51.970Z Has data issue: false hasContentIssue false
  • English
  • Français

249. Studies on the methylene-blue reduction test II. Comparison between the old and the modified methods

Published online by Cambridge University Press:  01 June 2009

T. Matuszewski  and
J. Supińska
T. Matuszewski
Affiliation:
Institute of Fermentative Industry and AgriculturalBacteriology, Warsaw, Ploand
J. Supińska
Affiliation:
Institute of Fermentative Industry and AgriculturalBacteriology, Warsaw, Ploand
Get access Rights & Permissions [Opens in a new window]

Extract

In order to compare the old and the modified methods of the methyleneblue reduction test, 185 samples of raw milk were examined. We followed Wilson's method absolutely, but included two tubes in each test, one of which was inverted and the other not.

The results obtained and their interpretation agreed with the theoretical expectations given in our previous paper, and briefly outlined at the beginning of the present paper.

It is found that the deviations in the reduction time, corresponding to a given initial number of cells, are smaller by the modified than by the old method, and that the average time of reduction is shorter.

The smaller variation in the reduction time corresponding to a given number of cells at the beginning of the test is due probably to a more uniform distribution of the bacteria in the milk following the inversion of the tube. Wilson's suggestion that the shortening of the reduction time in the modified method is due to the stimulation of bacterial growth proves to be entirely correct. We obtained the average coefficients of multiplication in the old method of 0·660, and in the modified of 0·885.

Our results confirm on the whole the positive value of the modification of the methylene-blue reduction test as suggested and worked out by Wilson.

Type
Original Articles
Information
Journal of Dairy Research , Volume 11 , Issue 1 , January 1940 , pp. 43 - 50
Copyright
Copyright © Proprietors of Journal of Dairy Research 1940

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

REFERENCES

(1) Johns, C. K. (1938). J. Dairy Sci. 21, 227.CrossRefGoogle Scholar
(2) Matuszewski, T. & Supińska, J. (1939). Zbl. Bakt. ii, 100 (in the Press).Google Scholar
(3) Rahn, O. (1930). J. Bact. 19, 383.CrossRefGoogle Scholar
(4) Supińska, J. & Matuszewski, T. (1936). Zbl. Bakt. ii, 94, 499.Google Scholar
(5) Thornton, H. R. (1937). Amer. J. publ. Hlth, 27, 791.CrossRefGoogle Scholar
(6) Wilson, G. S. (1935). Spec. Rep. Ser. med. Res. Coun., Lond., no. 206. London: H.M.S.O.Google Scholar