POLYSACCHARIDE-SPLITTING ENZYMES 317 



colonies about two millimeters in diameter, which were yellowish 

 white, smooth, and round with entire edges. On blood agar, two of 

 the strains produced two types of colonies, one whitish and opaque 

 and the other grayish and semi-translucent. One of the strains iso- 

 lated from material from a decayed hickory stump covered with 

 sphagnum moss appeared to utilize agar as well as the Type III 

 polysaccharide. The cultures fermented dextrose, lactose, saccha- 

 rose, maltose, dextrin, mannitol, xylose, galactose, inulin, and sali- 

 cin as well as decomposing the specific polysaccharide of Type III 

 Pneumococcus. 



Sickles and Shaw made their enzyme preparations in a mineral 

 substrate, using the yeast extract medium of Dubos only for the 

 seed culture. The cultures were usually incubated for three days at 

 36°, filtered through a Berkefeld candle, and then concentrated by 

 ultrafiltration through a 7.5 per cent pyroxyline membrane, the 

 enzyme remaining on the membrane. In this manner a preparation 

 was obtained with an enzymatic activity of approximately twenty 

 units per cubic centimeter. The enzyme in a dose of 0.5 cubic centi- 

 meters, when given eighteen hours after inoculation, protected mice 

 against infection with ten minimal fatal doses of Type III Pneu- 

 mococcus and, when given seven hours after inoculatidn, the ex- 

 tract protected the animals against 1,000 fatal doses. 



The organism isolated by Sickles and Shaw from soil, possessing 

 the power to decompose Type II soluble specific substance, dif- 

 fered markedly from the bacillus attacking Type III SSS. It, too, 

 was an obligate aerobe, but oval in form, resembling a yeast. It 

 could be maintained by daily transfer on the mineral medium con- 

 taining 0.01 per cent Type II soluble specific substance, but no 

 growth could be induced in the mineral medium alone or on any of 

 the usual nutrient solid media. No growth could be seen in meat- 

 extract broth but microscopic examination indicated that slight 

 multiplication had taken place. The organism grew slowly in meat- 

 extract broth containing a fermentable carbohydrate, but did not 

 grow in meat-infusion broth, litmus milk, or peptone water, on po- 



