BACTERIAL CARBOHYDRATES Ai\D LII'IXS 105 



The slimy material produced in cultures by some varieties of bac- 

 teria is, at least for certain forms, a body closely related to or identi- 

 cal with true mucin, ^^ but in certain cases {B. radicicola) it is a gum 

 related to the dextrans and free from nitrogen (Buchanan). ^^ Tu- 

 bercle bacilli grown for many years on artificial media may produce 

 a true mucin (Weleminsky).-^ Heim" considers that anthrax bacilli 

 also produce mucin. Some nonpathogenic bacteria contain granules 

 of sulfur in their protoplasm, and others have noteworthy quantities 

 of iron in the sheath. 



Bacterial Carbohydrates. — -The earlier descriptions of cellulose or 

 hemicellulose in the cell membrane of bacteria have been contested. ^^ 

 Numerous investigators have reported that the insoluble bacterial cell 

 wall consists chiefly of chitin, which on being split with acids yields 

 80 to 90 per cent, of the nitrogenous carbohydrate, glucosamin.^'^ The 

 distinction is a verj^ important one, since cellulose is a typically vege- 

 table product, while chitin is equally typically animal in origin, being 

 found chiefly in the shells of lobsters and crabs, the wings and cover- 

 ings of flies, beetles, etc. Chitin seems to be a polymeric form of 

 glucose-amine,^" an amino-carbohydrate, just as cellulose is a polymer 

 of a simpler carbohydrate. Other carbohydrates seem to be scanty in 

 the bacterial cell, but Tamura^^ does not accept the chitinous nature 

 of bacterial carbohydrate, finding in tubercle and diphtheria bacilli a 

 hemicellulose, apparently a pentosan yielding 1-arabinose on hydro- 

 lysis. Wester^^ found no chitin in several varieties of bacteria, and 

 cellulose only in B. xylinum; he therefore considers it probable that 

 bacterial cell walls do not alw^ays consist of the same substance. Cra- 

 mer could find no glucose in any variety, although there are some bac- 

 teria that contain material reacting like starch with iodin. Levene,^^ 

 however, found in B. tuberculosis a substance with some of the 

 properties of gl3^cogen. 



Bacterial Fats. — By staining methods, fats have been recognized in 

 many species, and by extraction with fat solvents lecithin, cholesterol, 

 simple fats, and specific bacterial fats have been isolated; this is par- 

 ticulary true of B. tuberculosis.^^ Numerous studies of these fats of 



-* Rettger, Jour. Med. Research, 1903 (10), 101. 



" Cent. f. Bakt., II Abt., 1909 (22), 371. 



-^ Berl. klin. Woch., 1912 (49), 1320. 



" Miinch. med. Woch., 1904 (51), 426. 



28 However, Dreyer (Zeit. ges. Brauw., 1913 (36), 201) states that the cell 

 wall of yeasts contains a hemicellulose and a manno-dextran. See also Kozniewski, 

 Zeit. physiol. Chem., 1914 (90), 208. 



=9 See Viehofer. Ber. Deut. Chem. Ges., 1912 (30), 443. 



'" Morgulis states that chitin consists of two parts, one containing'all the 

 glucose and amino groups, the other being a stable nitrogenous compound yielding 

 no glucose. (Science, 1916 (44), S66.) 



" Zeit. phvsiol. Chem., 1914 (89), 304. 



22 Pharm. Weekblad, 1916 (53), 1183. 



"Jour. Med. Research, 1901 (6), 135. 



^* See Camus and Pagniez, Compt. Rend. Soc. Biol., 1905 (59), 701. 



