266 



GAS METABOLISM OF BACTERIA 



Some of the data presented by Anderson are given in Table IV. The general pro- 

 cedure was as follows: 300 cc. of medium were inoculated in each case; the culture 

 flasks were evacuated, sealed, and incubated. After seven days the resulting gases 

 were removed by evacuation, measured, and analyzed. No evidence of the presence 

 of NH3, N2O, CO, CH4, or other carbonaceous gas was found. The odorous gas 

 fraction was composed mostly of H2S. This substance may have been present in con- 

 centrations of 2-3 per cent, but the methods used for its determination were too un- 

 satisfactory to give precise data. 



When glucose was added to the peptone broth, B. botulinus, B. sporogenes, and 

 B. welchii utilized the carbohydrate with a marked increase in the total volumes of 



TABLE IV* 



CO2 



Showing Gas Production at 0° C, 760 Mm., and --- Ratios; Cultures Grown in 300 Cc. of 



Broth in vacuo, 7 Days; Medium: 2 Per Cent "Difco" Peptone and 2 Per Cent 

 "DiFCo" Peptone plus i Per Cent Glucose 



* Assembled from Anderson's Tables 2,A and sB. 



gas produced. B. histolyticus did not decompose glucose, hence its presence had no 

 effect on the quantity of gas produced. By providing only a very small amount of 

 protein material it was possible to force this organism to utilize glucose, but a poor 

 growth was obtained. 



The accurate detection and estimation of such gases as CH^, CO, etc., produced 

 by pure strains of organisms has not been reported. CH^ has been detected and esti- 

 mated in cultures of B. lactis aerogenes (Baginsky),' in the gaseous effluent from sewage 

 tanks, and in intestinal gases. 



The evolution of large quantities of gases other than CO2 and H, has been reported 

 when special media have been used for the growth of organisms. The addition of NO/ 

 and NO3' to the nutrient substance frequently results in a marked evolution of N,. 

 However, such reactions have not been thoroughly investigated. Such problems, and 

 the interesting question of gas production by so-called "bacterial synergism," offer 

 new and fascinating fields for investigations. 



' Baginsky, A.: Zlschr.f. phys. Chemic, 12, 434-62. 1888. 



