The Influence of Certain Factors on the Bacterial Counts and Proteolytic Activities of Several Psychrophilic Organisms

Abstract

A plate incubation for 3 days at 25[degree]C was recommended for enumeration of bacteria growing in refrigerated milk and related products. Most of the psychrophiles were able to grow over a wide range of temperatures (5-32[degree]C). With the exception of one, all organisms had a short lag phase even at lower holding temperatures. No relation was evident between level of population and proteolytic activity. There appeared to be some relationship between values for the production of soluble N and tyrosine and tryptophan.