A Difference in Growth Requirements between Bacteria in the L-phase and Organisms of the Pleuropneumonia Group

Abstract

SUMMARY: Serum could be replaced in media for growing the L-phase of Proteus vulgaris by a phospholipid fraction from egg yolk and for growing the L-phase of Streptobacillus moniliformis by the addition of this fraction + bovine albumin. Organisms of the pleuropneumonia group grew in media in which serum was replaced by these materials; only with the further addition of cholesterol. The L-phase organisms thus differ in nutrient requirements from the pleuropneumonia group. They also differ in their requirements from the parent bacteria. Differences were noted in colonial appearances between the L-phase organisms studied and the organisms of the pleuropneumonia group.