608 SELMAN A. WAKSMAN 



Th. thioparus practically makes no growth on this medium, 

 due to its acid reaction. In the original Beijerinck medium, 

 however, containing dibasic phosphate and NaHCOs, Th. 

 thiooxidans makes no growth, while Th. thioparus grows in the 

 form of minute pinpoint colonies covered with sulfur, which is 

 separated from the thiosulfate by the action of the latter or- 

 ganism. The Th. thiooxidans separates no sulfur, oxidizing the 

 thiosulfate completely to sulfate; Th. thioparus oxidizes the 

 thiosulfate to sulfate, persulfates and elementary sulfur. 



REFERENCES 



Beijeeinck, M. W. 1904 Centralbl. f. Bakt., 2 Abt., U, 593. 



LiPMAN, J.G.,Waksman, S.A.,AND JoFFE, J.S. 1921 Soil Sci., 12, 475. 



Waksman, S.A. 1922 Soil Sci., 13, 329. 



Waksman, S. A., AND JoFFB, J. S. 1922 J. Bact., 7, 239. 



