APPENDIX 353 



Albuminoid-free culture solutions for studying urea 

 decomposition : 



I. Soil extract 100 c.c. 



K 2 HP0 4 O.OSgm. 



Urea 5 . 00 gms. 



II. Sohngen's solution. 



Tap water 100.00 c.c. 



Urea 5 . 00 gms. 



K 2 HPO 4 . 0.05gm. 



Ammonium or calcium malate, 



or, calcium citrate or tartrate. 0. 50 to 1.00 gm. 



B. pasteurii will not grow in these solutions as it requires 

 the presence of albuminoids in the medium. 



Solutions for cultivating nitrifying bacteria: 



I. Distilled water 1000.0 c.c. 



(NH 4 ) 2 SO 4 1.0 gm. 



K 2 HP0 4 1.0 gm. 



MgS0 4 .... 0.5gm. 



NaCl 2.0 gms. 



FeS0 4 0.4gm. 



Add basic MgCO 3 after sterilizing. 

 This solution is adapted for relatively increasing the 

 nitrite bacteria. 



H. Distilled water 1000.0 c.c. 



NaN0 2 1.0 gm. 



K 2 HPO 4 0.5gm. 



MgSO 4 0.3gm. 



NaCl 0.5gm. 



Na 2 CO 3 0.3gm. 



This solution causes a greater relative increase in the 

 nitrate producers. 



