POLYSACCHARIDES OF MICRO -ORCIANISMS 365 



galactose and an al(l()1)i()nic acid composed of galactose 

 and glucuronic acid. The water vibrios produce a poly- 

 saccharide containing arabinose linked with the same 

 aldobionic acid. The Inaba variant of V. comma, Group 

 VI, gives a polysaccharide having [a]n-f58°, and con- 

 taining 2-6 per cent, of nitrogen, which yields 58 per cent, 

 of reducing sugar on hydrolysis. The sugar is glucose 

 only, no galactose or arabinose being present. The 

 polysaccharides present in rough strains, and which also 

 occur in the corresponding smooth strains, are stable to 

 alkali, whilst the polysaccharides peculiar to the smooth 

 variants are not stable to alkali. 



The gonococcus and meningococcus contain non- 

 antigenic and non-toxic polysaccharides which both react 

 with antisera to Type III pneumococcus. That from 

 the meningococcus is probably the sodium salt of an 

 acid polysaccharide. The gonococcus gives two poly- 

 saccharides corresponding to two serological types. 



Both capsulated and non-caps ulated forms of B. 

 anthracis yield a non-toxic, non-antigenic polysaccharide, 

 containing 0-8 per cent, of nitrogen, which gives 60 per 

 cent, of glucose on hydrolysis together with pentoses and 

 a uronic acid. Another polysaccharide from virulent and 

 avirulent B. anthracis has been described. It gives 

 equimolecular proportions of galactose and of acetylated 

 fZ-glucosamine on hydrolysis (corresponding to 68 per 

 cent, of the pure polysaccharide) but no pentose and no 

 uronic acid. This polysaccharide is antigenic. The 

 capsules, unlike those of the pneumococcus, are not 

 polysaccharide in nature but contain peptides (see p. 338). 



Proteus yields two polysaccharides, one of which, 

 stable to hot alkali, appears to be the common antigenic 

 factor between Proteus XI 9 and Rickettsia. 



Micrococcus lysodeikticus yields a polysaccharide of 

 high molecular weight which is the specific substrate of 

 the enzyme lysozyme, which splits it into an N-acetyl- 

 aminohexose and a ketohexose. The polysaccharide can 



