Methods for Isolation and Enumeration of Lipolytic Organisms

Two double-layer techniques for detecting lipolytie organisms are described in which the organisms are grown on nutrient agar overlaid on either tributyrin agar or a thin layer of milk fat saturated with Victoria Blue. Advantages of these methods are that the colonies can be isolated after detection, lipolysis can be followed from beginning of incubation, and there is no toxic action by dyes or substrates. The tributyrin emulsion assay has the further advantages that its sensitivity can be altered by varying the concentration of substrate, the organisms can be grown if necessary on a carbohydrate mediun b and apparent inhibition of lipolysis as observed with Victoria Blue milk fat does not occur.