Isolation of Group Specific Products from Lactobacillus casei and L. casei var. rhamnosus

Abstract

An examination has been made of serologically reactive products obtained from four strains of Lactobacillus casei (serological groups B and C) and two strains of Lactobacillus casei var. rhamnosus (serological group C). Cell wall preparations were hydrolysed with a preparation of Streptomyces muralytic enzyme and the soluble in-diffusible products isolated. Rhamnose is the major component of both the cell wall and soluble extracts from group B organisms, whereas glucose is the major component of preparations from L. casei group C. Two products differing considerably in composition have been isolated from each strain of L. casei var. rhamnosus. The serological properties of the preparations have also been studied and the results confirm that strains of Lactobacillus casei can be divided into two serological groups. It is concluded that group B specificity is primarily dependent on rhamnose and group C specificity on glucose, which is probably joined by a 1-6 [beta] linkage to the adjacent sugar. The two fractions isolated from L. casei var. rhamnosus differ in their serological properties; antibodies formed on injection of this organism are predominantly directed against one component (in fraction I) whereas extracts react with sera against strains of L. casei group C because of the presence of a second component (in fraction II).