228 HAROLD C. ROBINSON AND LEO F. RETTGER 



quite abundant. Two strains of B. tetani grew well in 2 per cent 

 opsine when in association with Staphylococcus aureus. Spore 

 production was quite apparent. 



For comparison, plain standard bouillon and 2 per cent opsine 

 having the same reaction were inoculated with the same organ- 

 isms and incubated side by side for five days at 37 °C. The 

 results are indicated in the following table. 



Growths in opsine and in bouillon; five days' incubation at 37 °C. 



B. edematis (maligni) 



B. anthracis-symptomatici (B. chauvei). 



B botulinus 



B. putrifictis (A) + Staphylococcus 



OPSINE 

 2 PER CENT 



+ + 

 + + . 

 + + + 

 + + 



BOUIIXON 



+ + + 



+ + + 

 + + 

 + + 



It was noticed that spore formation was always more advanced 

 in the opsine cultures than in the bouillon. B. putrificus (A) 

 was also grown with Staphylococcus aureus aerobically in these 

 two media for the same length of time (five days) . On the whole, 

 when in symbiosis with Staphylococcus aureus it grew as well in 

 free contact with the atmosphere as in Buchner tubes, and the 

 morphology was about the same in both cases. 



All of these anaerobes, except B. botulinus, were also tried in 

 1 per cent opsine + 1 per cent glucose, being grown in Buchner 

 tubes for five days. All grew well. B. edematis and B. anthracis- 

 sympto7natici formed no spores, but quite typical and generally 

 well-stained rods were numerous. 



B. bulgaricus and B. acidophilus produced a good growth with- 

 in twenty-four hours in 1 per cent opsine + 1 per cent glucose. 

 No loss of viability was apparent after six transplantations in this 

 medium. 



SUMMARY 



The protein-free enzyme-digestion product opsine serves as an 

 excellent culture medium for both pathogenic and non-patho- 

 genic bacteria. Practically all of the many organisms employed 



