234 UTILIZATION OF CARBOHYDRATES 



tives of the a-glucose series have not thus far been obtained from the vegetable king- 

 dom. Also, the glucosides derived from sugars other than glucose, d- and /-arbinose, 

 /-xylose, galactose, mannose, and fructose do not seem to have been carefully investi- 

 gated. 



Glucoseamine, a cleavage product of chitin, as well as mucin from the submaxil- 

 lary gland, and from mucous membranes,' seems to have been isolated from the body 

 substance of certain bacteria.^ Meyer^ states that this substance may be fermented 

 by a considerable number of bacteria, i.e., it may be a source of energy for these 

 microbes. In the list is Bacillus proteiis. If indeed it be true that the proteus bacillus 

 will ferment glucoseamine, then some evidence will have been produced in favor of 

 the glucose rather than the mannose formula for this substance— a point of contention 

 at the present time, because Bacillus proteus does not ferment the mannose configura- 

 tion. ^ 



THE CARBOHYDRATE FRACTION OF PROTEINS 



Many proteins contain a carbohydrate nucleus in their molecule. Mathews' states 

 that egg white contains 0.5 per cent of glucose. Some evidence of the occurrence of 

 such a carbohydrate-like substance is afforded by a study of the nitrogenous me- 

 tabolism of active cultures of Staphylococcus aureus in suitable nitrogenous media. It 

 has been found that the deamination induced by this organism is comparatively 

 slight until the Molisch reaction' disappears. Also an acidity develops which increases 

 progressively with the persistence of the Molisch reaction. When the Molisch reaction 

 disappears, however, usually by the end of the fifth day of growth, deamination 

 proceeds rapidly, and concurrently the reaction becomes quite alkaline, due to the 

 accumulation of basic products of the nitrogen metabolism of the organism. It seems 

 very probable that both the initial acidity and low ammonia formation are associated 

 with the utilization of the carbohydrate nucleus of the protein molecule for energy. 

 Little nitrogenous change would be expected under these conditions. When the 

 carbohydrate is used up, the organism attacks the residual nitrogenous fraction for 

 its energy requirements, bringing about the typical evidences of deamination and 

 accumulation of basic substances. 



Not many bacteria thus far studied exhibit this phenomenon, however. It seems 

 not unreasonable to explain this difference on the basis of the nature of the peptid 

 linkages in the protein molecule, which are broken by the staphylococcus in such a 

 manner as to liberate the carbohydrate nucleus early in the digestive process, on the 

 one hand, and differently cleaved by most bacteria, on the other hand. 



BACTERIAL UTILIZATION OF CARBOHYDRATES 

 EFFECT OF CONFIGURATION OF THE CARBOHYDRATE MOLECULE 



Seventy years ago Pasteur^ noticed that the green mold, Pemcillium glaucum 

 attacked the d- and /-forms of tartaric acid at materially different rates, utilizing the 

 (/-tartaric acid quite rapidly, leaving the /-tartaric acid practically untouched. Not 



' Meyer and Jacobson: Lehrb. d. org. Chem. (II. Aufl., Vol. I, Part 2), 1913. 



' Viehover, A.: loc. cit. ^ Meyer, K : Biochem. Ztschr., 57, 297. 1913. 



^ Kendall, A. I., Cheetham, H. C, and Hamilton, C. S.: loc. cit. 



5 Mathews, A. P.: Physiol. Chem. (2d ed.), 151. 1916. 



* Kendall, A I., and Farmer, C. J.: /. Biol. Chem., 12, 215. 1912. 



7 Pasteur, L.: Compt. rend. Soc. de biol., 46, 615. 1858. 



