Action of Microorganisms from Soil on Type-Specific and Nontype-Specific Pneumococcus Type-I Carbohydrates

Abstract

The report of Avery and Dubos 1 that the specific carbohydrate of pneumococcus type III was split by an enzyme from a soil microorganism appeared to offer a new approach to the study of relationships and differences between chemically and immunologically different preparations of the specific carbohydrates.

Organisms which decompose the specific carbohydrates of pneumococcus types II and III were described in a previous report. 2 We now have in pure culture a microorganism which utilizes to some extent the specific carbohydrate of pneumococcus type I. As in the study of the bacteria that decomposed the carbohydrates of pneumococcus types II and III, the precipitation test with antipneumococcus serum was used as an indication of the presence or absence of the carbohydrate, but, unlike the results obtained with these microorganisms, the precipitation reaction never entirely disappeared. It has not yet been ascertained whether this residual reaction is due to an unused portion of the original carbohydrate or to products of decomposition, which might either be present in the original sample or be formed as a result of the action of the microorganism from the soil.

In mixed culture, as it was first obtained from soil, this microorganism could not be cultivated on the purified specific carbohydrate, and, until it was isolated in pure culture, it had to be maintained on a mineral medium to which specific carbohydrate only partly purified had been added. In pure culture, the microorganism utilized the soluble specific substance obtained from broth culture and the specific carbohydrate isolated from pneumococcus type-I cells as well.