POLYSACCHARIDES OF MICRO-ORGANISMS 



359 



human tubercle bacillus and of 31. jjhlei contains fatty 

 acids linked to the non-reducing disaccharide, trehalose, 



CH- 



-CH- 



HCOH I 

 HOCH O 



HCOH 



I 

 HC 



HCOH 



I 

 HOCH 



I 

 HCOH 



CH2OH 



(glucose) 



(glucose) 



instead of to glycerol as in ordinary fats. The leprosy 

 bacillus also contains trehalose together with a dextro- 

 rotatory polysaccharide yielding pentoses on hydrolysis. 

 Heidelberger and Menzel have separated the polysac- 

 charide from the human tubercle bacillus into three 

 fractions having the properties outlined in Table 21 : — 



Table 21 



The polysaccharide C is common to avian, bovine and 

 human tubercle bacilli, whilst B, if present at all, occurs 

 in only very small amount in the avian and bovine types. 

 The removal of the magnesium palmitate from polysac- 

 charide C does not affect its serological behaviour (com- 

 pare the polysaccharide from Salmonella typhimurimn, 

 p. 361). An acetyl containing polysaccharide has been 



