CHAPTER IV 



CHEMICAL STUDIES OF BACTERIAL CELLULAR 

 SUBSTANCE 



Proteins. Xencki and Schaffer 1 obtained the cellular 

 substance from a mixed culture of putrefying bacteria, 

 dried it to a constant weight, first on the water-bath and 

 then at 110, pulverized, and extracted with alcohol and 

 ether. The residue thus obtained was extracted on the 

 water-bath with 0.5 per cent, potassium hydroxide. From 

 the alkaline extract a protein, designated as mykroprotein, 

 was precipitated by neutralization and saturation with 

 sodium chloride. Mykroprotein when freshly precipitated 

 was found to consist of amorphous flakes soluble in water, 

 but losing in solubility when dried at 110. It contains 

 52.32 per cent, of C, 7.55 per cent, of H, 14.75 per cent, 

 of N, and neither sulphur nor phosphorus. In aqueous 

 solution it gives an acid reaction, and is not precipitated 

 by alcohol, but is precipitated by picric acid and other 

 alkaloidal reagents. It gives the biuret and Millon reac- 

 tions, but not the xanthoproteic. On being fused with 

 potash it furnishes ammonia, amylamin, phenol, valerianic 

 acid, leucin, and traces of indol and skatol. 2 Later, Xencki 3 

 attempted to prepare mykroprotein from anthrax. He 

 obtained from anthrax spores a substance which he desig- 

 nated as anthrax protein, closely related to plant casein 

 and animal mucin, soluble in alkalies, but insoluble in 

 water, acetic, and dilute mineral acids. Like mykroprotein, 

 it contains no sulphur. Dyrmont 4 made an analysis of 



1 Jour. f. prakt, Chem., 1879, xx, 443. 



2 Ibid., 1881, xxiii, 302. 3 Berichte, 1884, xxvii, 2605. 

 4 Arch. f. exper. Path. u. Pharm., 1886, xxi, 309. 



