Hostname: page-component-848d4c4894-nmvwc Total loading time: 0 Render date: 2024-07-08T02:24:33.568Z Has data issue: false hasContentIssue false

480. The role of micro-organisms in dye-reduction and keeping-quality tests: II. The effect of micro-organisms when added to milk in pure and mixed culture

Published online by Cambridge University Press:  01 June 2009

Ellen I. Garvie
Affiliation:
National Institute for Research in Dairying, University of Reading
A. Rowlands
Affiliation:
National Institute for Research in Dairying, University of Reading

Extract

1. A study of the ability of pure cultures to reduce methylene blue and resazurin at 37·5° C., to reduce methylene blue at 22° C. and to cause milk spoilage as measured by precipitation with 68 % alcohol, and the clot-on-boiling test has revealed marked differences in behaviour between cultures.

2. At 37·5° C., with the exception of two cultures, there was good agreement between the time of reduction of methylene blue and resazurin. The two exceptions were a group B Streptococcus which reduced methylene blue but failed to reduce resazurin during the 9 hr. period of observation and an unclassified Streptococcus growing at 45° C. which reduced resazurin before methylene blue; the latter dye was found to retard the multiplication of the culture slightly.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1952

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)Wilson, G. S. (1935). Spec. Rep. Ser. Med. Res. Coun., Lond., no. 206.Google Scholar
(2)Jensen, H. O. (1937). Zbl. Bakt. (II. Abt.), 96, 110.Google Scholar
(3)Hobbs, B. C. (1939). J. Dairy Res. 10, 35.CrossRefGoogle Scholar
(4)Thomé, K. E. (1941). Medd. Mejerifürsük. no. 7.Google Scholar
(5)Egdell, J. W. & Bird, E. R. (1951). Dairy Industries. 16, 143.Google Scholar
(6)Anderson, E. B., Meanwell, L. J. & Wright, R. C. (1949). XII Int. Dairy Congr. 3, Sec. 3, 17.Google Scholar
(7)Frazier, W. C. & Whittier, E. O. (1931). J. Bact. 21, 239.CrossRefGoogle Scholar
(8)Iya, K. K. & Frazier, W. C. (1948). Bact. Proc. (Proc. Soc. Amer. Bact.). 1, 32.Google Scholar
(9) Ministry of Health (1937). Memo 139/Foods.Google Scholar
(10)Garvie, E. I. & Rowlands, A. (1952). J. Dairy Res. 19, 133.CrossRefGoogle Scholar
(11)Miles, A. A. & Misra, S. S. (1938). J. Hyg., Camb., 38, 732.Google Scholar
(12)Bartram, M. T. & Black, L. A. (1936). Food Res. 1, 551.CrossRefGoogle Scholar
(13)Jones, V. E. & Davis, J. G. (1944). Proc. Soc. appl. Bact. p. 36.Google Scholar
(14)Malcolm, J. F. (1939). J. Dairy Res. 10, 410.CrossRefGoogle Scholar