On Carbohydrate-Like Specific Substance in the Colon Aerogenes Group.

Abstract

Specifically reacting polysaccharides have been isolated by various authors from pneumococci, pneumobacilli, tubercle bacilli and yeasts. Preliminary unpublished experiments convinced us that substances with varying chemical composition and carbohydrate content could be obtained easily and in large quantities from different encapsulated bacilli (B. coli, B. anthracis and encapsulated soil bacteria). B. lactis aerogenes was chosen in the present study, since in the early literature Emmerling 1 and Schardinger 2 succeeded in isolating a nitrogen free polysaccharide from the filtrated cultures of these organisms.

The strain chiefly used for the preparation of the polysaccharide was isolated from human feces. Its behavior in sugar media was typical, acid was produced on citrate agar, the indol reaction was negative and the Voges-Proskauer test positive. Capsule formation was distinct though not marked.

Following the method of Emmerling and Schardinger an attempt was made to isolate a carbohydrate from the filtrate of a synthetic fluid medium culture. The yield of specific substance was small and failed to cause precipitation in dilutions higher than 1:10,000 when layered over homologous immune serum. It was found, that even after 30 days incubation the bulk of the specific substance was associated with the bacterial bodies which still showed a small, but distinct capsule.

The method finally adopted was essentially the same as that described scribed by Toeniessen. 3 At first the bacilli were cultivated on a synthetic medium solidified with agar containing ammonium phosphate as a source of nitrogen, and sodium citrate as the carbon source. Among many substances tried, the addition of small amounts of prophyl-red more than doubled the growth. In later work meat infusion agar was used with equally satisfactory results. The two days old growth from 108 Kolle flasks, suspended in distilled water and precipitated with alcohol, yielded 11 gm. of dried bacteria.