30 



LABORATORY MANUAL OF MICROBIOLOGY 



Sterilize in small flasks or tubes. After inoculation incubate 

 under an atmosphere of hydrogen sulphide as shown below. ^ To 

 obtain a solid medium, the amount of CaCOs in the above solu- 

 tion is increased to 50 gm. per liter and 0.5 per cent agar is added. 



JS^ 



Fig. 1. — Apparatus for the cultivation of pure cultures of sulfur bacteria using 

 H2S as a source of energy. A, apparatus for generation of H2S; B, hydrogen 

 tank; C, wash flask; D, gasometer; E, culture jar; F, manometer. {Bavendamm.) 



1 Bavendamm, W., Die farblosen und roten Schwefelbakterien des 

 Siiss- und Salzwassers. G. Fischer. Jena, 1924. 



MEDIA FOR HYDROGEN AND METHANE BACTERIA 



Medium 71 



Potassium Nitrate Solution for Hydrogen Bacteria^ 



Potassium nitrate (KNO3) 2.0 gm. 



Mono-sodium phosphate (NaH2P04) 0.5 gm. 



Magnesium sulphate (MgS04-7H20) 0.2 gm. 



Ferric chloride (FeClg-eHzO) trace 



Tap water 1,000.0 cc. 



^Lebedeff, A. E., (Russian). Odessa, 1910. 



Cultures grown in an atmosphere of hydrogen containing 5 to 

 15 per cent carbon dioxide. 



