zi6 



THE QUARTERLY REVIEW OF BIOLOGY 



as such in the cultivation of Bact. abortus, 

 rather than the necessity of reduced 

 oxygen. 



ADAPTATION OF BACTERIA TO DIFFERENT 

 GASES 



Rockwell and McKann (192.1) investi- 

 gated the effects of various gaseous 

 environments on the growth of the 

 gonococcus. Their results showed that 

 this organism could be trained to tolerate 

 rather high concentrations of hydrogen, 

 carbon dioxide and oxygen, when mixed 

 with air or in combination with each 

 other. When a certain strain had become 

 adapted to grow under high concentration 

 of hydrogen, growth was inhibited by 

 the presence of much oxygen and carbon 

 dioxide. As high as 100 per cent of any 

 one of these gases could be used in growing 

 the organism. They concluded, therefore, 

 that the gonococcus can be made to grow 

 under various gaseous environments. It 

 is believed by them that such expressions 

 as aerobic, anaerobic or partial-tension 

 strains, are expressions of the previous 

 gaseous adaptations in nature. 



Rockwell (1911) studied the gaseous 

 requirements of the gonococcus, B. subtilis, 

 M. tuberculosis 801, 8oz, and 803, Bact. 

 coli, Staph, aureus, Prot. vulgaris, and 

 B. anthracis; CI. welch ii and CI. tetani 

 were the anaerobes used. Enclosing the 

 cultures either in hydrogen or nitrogen, or 

 under anaerobic conditions with pyro- 

 gallol, it was observed that the cultures 

 failed to grow. If, however, the respira- 

 tory C0 2 was not removed, or if C0 2 

 was supplied to cultures under nitrogen, 

 growth followed. The author concluded 

 that growth of the aerobic bacteria and 

 those of the facultative group is in some 

 way favored by C0 2 . 



Torrey and Buckell (19x1) refuted the 

 idea of a reduced oxygen requirement for 

 the gonococcus, and believed that success 



in obtaining growth in a closed system 

 is due entirely to the increased moisture 

 retained in the medium or in the air over 

 the medium. 



Corper, Gauss and Reusch (19Z1) 

 reported inhibition of M. tuberculosis 

 without carbon dioxide, and inhibition 

 of growth when the C0 2 approached 3 

 per cent; they considered iz per cent 

 C0 2 definitely tuberculocidal. In further 

 studies concerning the importance of the 

 growth of tubercle bacilli as determined by 

 gaseous tension Corper, Lurie and Uyei 

 (19x7) conclude that a slightly better 

 growth is observed in an atmosphere 

 enriched with carbon dioxide than with- 

 out the added C0 2 . 



COLON-TYPHOID BACTERIA IN CARBONATED 

 WATERS 



Koser and Skinner (19Z2.) investigated 

 the viability of the colon-typhoid group 

 of organisms in carbonated waters and 

 carbonated beverages. In their experi- 

 ments the waters and beverages under 

 observation were prepared under experi- 

 mental conditions simulating those of 

 the factory as far as possible. The 

 authors came to the conclusion that the 

 chief bactericidal influence of C0 2 was 

 due to the increased hydrogen ion concen- 

 tration in the solution. Bact. coli showed 

 considerable resistance to carbon dioxide 

 and could be recovered from various non- 

 acid beverages after 7 days under z8 lbs. 

 pressure at Z4°C. In acid beverages the 

 longevity of Bact. coli was reduced. The 

 plates were sterile in 3 days, but not in 

 Z4 hours. When kept at i°C, viable 

 organisms were not recovered in 10 cc. 

 amounts of the liquids after one month. 

 Bact. typhosum was less resistant. It 

 was evidently destroyed in Z4 hours at 

 Z5 pounds pressure, at room temperature. 

 At i°C, this organism persisted for 4 days. 

 Paratyphosum B. was positive in 10 cc. 



