BIOCHEMICAL FEATURES 69 



in strains that had undergone changes in morphology and viru- 

 lence induced by longer or shorter cultivation on artificial media. 

 Berry drew attention to the lack of uniformity in the serum-water 

 medium and in commercial preparations of inulin. With a reliable 

 lot of inulin serum-water, however, some non-inulin-fermenting 

 strains acquired or regained this fermentative property after 

 animal passage. 



In a more recent paper, Berger and Silberstein 103 reported the 

 results of a study on strains of pneumococci, of the "B" modifica- 

 tion* of this species, and of green-producing and hemolytic strep- 

 tococci. The hemolytic streptococci; none of which affected inulin, 

 were the only group with constant behavior toward this carbo- 

 hydrate. Of the typical pneumococci, four strains showed redden- 

 ing without coagulation of the medium and two had no inulin-fer- 

 menting power. These two strains were found to be modification 

 "A"* when tested with optochin. Of nine strains of modification 

 "B" obtained from Pneumococcus, but behaving otherwise as green 

 streptococci, two retained the inulin-fermenting property. Of 

 thirty green streptococci, five gave marked inulin fermentation, 

 while four others showed slightly positive reactions. Other authors 

 to report strains incapable of fermenting inulin among the pneu- 

 mococci are Hiss ; Park and Williams ; Levy ; Avery ; and Burger 

 and Ryttenberger.f 



In addition to inulin, the polysaccharide, glycogen, is equally 

 susceptible to the saccharolytic action of Pneumococcus. First re- 

 ported by Hiss, 649 this reaction has been quantitatively studied by 

 Barnes and White, 85 who compared the fermentative reactions of 

 strains of Type I, II, III, and V pneumococci on glucose, inulin, 

 mammalian glycogen, and glycogen obtained from scallops. The 

 authors decided that, on the whole, the four type strains used fer- 

 mented glycogen to essentially the same degree as they did glucose 

 and inulin. 



Pneumococcus attacks still other carbohydrates, but no specific 



* To be described in Chapter V. f Quoted by Neufeld and Sehnitzer. 



