CHEMICAL STUDIES OF THE CONTENT OF MICROBIAL CELLS IQI 



Cellulose, so bound up with plant life and at one time so 

 much used to differentiate plant and animal life, has not been 

 positively demonstrated in any microorganism, even in molds and 

 yeasts. Substances, giving suggestive reactions, have been studied 

 and, at times, have been called cellulose, or some modified form of 

 cellulpse, yet recent analysts seem to think there is really no substantial 

 ground for this assumption. Vaughan* in his extensive analyses of 

 bacterial cells has never been able to identify cellulose. On the other 

 hand Vaughan calls attention to two carbohydrate bodies, one of which 

 furnishes a reducing sugar when boiled with dilute mineral acid and 

 the other does not. 



From time to time there have been detected suggestive traces of 

 various carbohydrate substances to which special names have been 

 attached but they seem to lack definiteness and individuality in their 

 chemical features. Chitin,t a substance quite generally found in 

 microbial cell- walls, consists apparently of a carbohydrate- amine or 

 glucosamine polymerized. Much emphasis is now placed upon this 

 substance as representing the most important constituent not only of 

 microbial cell-walls but of wings and coverings of insects and of many 

 lower animal forms. 



Fats. Many analyses indicate variable amounts of fat in all classes 

 of microorganisms. Whether this fat is the result of degradation proc- 

 esses at times, whether it may be ready for assimilation, whether it 

 exists as a reserve product, or whether it is the yield of direct absorption 

 cannot be asserted off-hand. Probably there are times when it may 

 answer to each of these explanations and times when indications are 

 such as to furnish a positive understanding. 



Fat globules may be readily revealed by the use of certain stains 

 as osmic acid and Sudan III when present in comparatively large 

 microbial cells, but in the case of bacterial cells this procedure is un- 

 availing, making it necessary to employ recognized chemical methods. 



In the analysis of molds, MarschallJ has obtained the following 



Aspergilhis Penicillium Mucor 



Ether extract 4.7 4.1 4.0 



Alcoholic extract 18.5 1 1 . 8 1 1 . 8 



*Vaughan, V. C. and his associates, loc. cit. 



tChitin when hydrolyzed yields glucosamine and acetic acid. The equation CigHsoX^Ois + 

 zO = 2CH 2 OH.CHOH.CHOH.CHOH.CHNH 2 .CHO + sCHsCOOH, has been suggested. 

 JMarschall, Arch. f. Hyg., 28, 19, 1897. 



