IVAN C. HALL 205 



these have been more useful in the cultivation of micro-aerophilcs than of obligate 

 anaerobes. Yet the fact that obligate anaerobes can be cultivated on the surface of 

 solid media without actual contact of aerobes is a sufBcient rebuttal of Kedrowsky's 

 assumption of a vital ferment and convinces one of the accuracy of Pasteur's original 

 hypothesis of oxygen-tension reduction through bacterial respiration as at least one 

 of the important factors in aerobe-anaerobe symbiosis. 



Bienstock' later experimented with several anaerobes in symbiosis with a large 

 variety of aerobes. Heat-killed cultures of aerobes were also tried, but of these only 

 Bad. pyocyancnm in a fibrin medium would support the growth of anaerobes. Con- 

 trol cultures in similar media in which Bad. pyocyanemn had not been cultivated 

 failed. This exception was disturbing to Bienstock as an apparent confirmation of 

 Kedrowsky's view but may be interpreted in the light of present-day information as 

 providing a viscous deep medium sufficiently impervious to air for anaerobic growth. 

 Proca' has since cultivated B. tetani and B. botulimis in freshly sterilized liquid cul- 

 tures of Bad. coll, Bad. typ/iosnm, and Vibrio cholcrae. Solid media failed, however, 

 to yield surface colonies, and certain species of aerobes, Staphylococcus dorc and Bad. 

 pyocyaneum, seemed unsatisfactory. Such discrepancies are difficult to interpret; one 

 cannot help regarding the results as somewhat accidental. 



Many practical considerations in addition to those already mentioned grow out 

 of the phenomena of aerobe-anaerobe symbiosis, as, for example, the necessity of 

 autoclave sterilization of broth intended for the manufacture of diphtheria toxin,^ the 

 inhibition by certain aerobic bacteria of tetanus^ and botulism^ toxin formation, the 

 somewhat questionable use of inert aerobes in fermentation tests of anaerobes,^ and 

 the use of symbiotic cultures in the isolation of B, putrificus.'' At the present time 

 most of the technical applications of aerobic symbionts in the cultivation of 

 anaerobes have been supplanted by more precise methods; their significance is mainly 

 academic therefore, but important as confirming Pasteur's conception of the life of 

 anaerobic micro-organisms in nature. 



Use of animal and plant tissues in the so-called "aerobic culture" of obligate 

 anaerobes. — In 1877 Gunning,^ of the University of Amsterdam, studied the growth of 

 putrefactive anaerobes in media containing meat and coagulated egg, and Nencki^ 

 and his pupil Jeanneret were led into the same problem in studying the activity of 

 the pancreas and its ferments in the absence of air. Others, such as Gaffky and Hesse 

 (quoted by Novy),'° were interested in the isolation of organisms from infected tissues 

 and perhaps did not appreciate that the tissue exerted a favorable influence in an- 



' Bienstock: Ann. de Vlnst. Paslcur, 17, 850. 1903. 



^ Proca, G.: Coinpt. rend. Soc. de bioL, 63, 620. 1907. 



3 Smith, T.: J. Exper. Med., 3, 647. 1898. 



t Francis, E.: Hyg. Lab. Bull., No. 95. 1914. 



5 Hall, I. C, and Peterson, E. C: J. Bad., 8, 319. 1923. 



nVilson, W. J., and Steer, P.: Brit. M. /., 2, 568. 1918. 



'Sturges, W. S., and Rettger, L. F.: /. BacL, 4, 171. 1919. 



* Gunning, J. W.: J.f. prakt. Chemie, 16, 314. 1877; 17, 266. 1878; 20, 434. 1879. 



»Nencki, M.: ibid._ 19, 337. 1879. 



"Novy, F. G., Jr.: /. Infect. Dis., 36, 343. 1925. 



