The Influence of Certain Factors on the Methylene Blue Reduction Test for Determining the Number of Bacteria in Milk

Autor: Audrey Davenport, W.H. Wright, E.G. Hastings
Rok vydání: 1922
Předmět:
Popis: Summary The importance of the bacterial content of milk in determining its quality is discussed and the need of some simple and inexpensive method for the bacteriological analysis of milk is presented. The methylene blue reduction test seems to meet the need. The literature treating of the reduction test has been reviewed and a study has been made of a number of factors which influence the results obtained with the test. In the work herein reported attention has been directed to the influence of the concentration of the dye, to the age of the solution of the dye, and to the source or brand of the methylene blue. The influence of temperature on the reduction time has been investigated. The direct dependence of the test on the vital activities of the cells is shown by the effect of heating the milk to relatively low temperatures and by the effect of antiseptics. The relationships which may exist between different groups of bacteria are discussed and data are presented to illustrate the effect of these relationships in influencing the reduction time. The reducing action of different groups of milk bacteria has been studied as well as the relation of reduction time to keeping quality. Directions for making the test are given.
Databáze: OpenAIRE