Earlier work on the growth of Lactobacillus bulgaricus at low temperatures (Voss and Frazier, 1945) had indicated that dissociation might have been affecting the results. Therefore a study was begun of the dissociation of some of the lactobacilli and its effect on their characteristics in the hope that the information obtained would prove helpful in the production and use of starter cultures for cheese. LITERATURE Most workers agree that dissociation is the change of colony form from smooth to rough or rough to smooth, with or without the appearance of intermediate types of colonies, and whether or not other characteristic reactions of the organism are altered. Dissociation does not necessarily imply a change in other than the type of colony, but various characteristics are frequently reported as being correlated with different phases or types (Hadley, 1937). Because of the usual association of virulence and nonvirulence with smooth and rough cultures most of the reports in the literature deal with dissociation in pathogenic bacteria. Although different types of colonies of lactobacilli had been observed and reported, it was not until 1930 that definite reference to dissociation, as such, was made. At that time Hadley, Bunting, and Delves (1930) reported rough, smooth, and intermediate types of colonies, and observed dissociation from

The Millipore Filter technique is a new method for the concentration, removal, and enumeration of bacteria in liquids and air. Its application to the evaluation of the sanitary condition of pipe lines cleaned in place is discussed, together with other possible applications to water, milk, and food bacteriology. This procedure will be a valuable tool in quality control and bacteriological research.

A study of coliform tests on fruit ice cream has shown that there are organisms other than coliforms present in the ice cream which give positive test results. Investigations on the source, types, and reactions of the bacteria involved indicate a need for confirmed coliform tests and caution in the interpretation of coliform test results on fruit ice cream.

No abstract

No abstract