POLYSACCHARIDE-SPLITTING ENZYMES 319 



C Fraction) from an attenuated strain of Type I Pneumococcus. 

 One organism was the aerobic, spore-forming bacillus that had 

 been found to utilize the soluble specific substance of Type III 

 Pneumococcus and agar; the other was a Gram-negative aerobic, 

 non-motile, non-sporulating bacillus which, so far as tested, di- 

 gested only this non-type-specific saccharide. From both of the 

 strains a soluble enzyme was obtained capable, like the living cells, 

 of splitting the non-type-specific carbohydrate and, in doing so, of 

 abolishing its power to produce purpura. 



Sickles and Shaw 1282 then undertook a systematic study of the 

 morphological, cultural, and biochemical characters of these vari- 

 ous polysaccharide-decomposing bacteria. The cultures had origi- 

 nated in the muck of swamps and in uncultivated soils of different 

 localities, while one strain came from manure. The organisms were 

 grown on the mineral medium of Dubos and Avery and a "Medium 

 S" of their own concoction. To these mineral media were added the 

 specific pneumococcal carbohydrates in concentrations varying 

 from 0.002 to 0.01 per cent as a source of carbon. 



Sickles and Shaw then subjected the strains to all the proce- 

 dures required for identification, and in their communication gave 

 a detailed account of the different biological characters of the or- 

 ganisms. To relate them would not be germane to the main subject 

 but, because of the importance of this class of bacteria, a con- 

 densed description of the main characters should be recorded here. 

 The cultures were of four distinct types: 



1. Large spore-bearing rods that decompose the specific carbohydrate 

 of Type III Pneumococcus, similar to the SIII bacillus of Dubos and 

 Avery, and, in addition, a strain that utilizes agar. For the strains 

 that digest only the Type III polysaccharide the authors suggested 

 the name Bacillus palustris, with the sub-designation, gelacticus, for 

 the variety also attacking agar. 



2. Very small non-sporulating rods that attack the non-type-specific 

 carbohydrate obtained from a degraded Type I Pneumococcus and the 

 C Fraction from typical strains. This organism the authors called, 

 Flavo-bacterium ferruginum. 



