EXPERIMENT STATION BULLETINS. 



467 



Starch agar was poured into sterile petri dishes and allowed to harden. 

 Aerobic streaks of each organism were made and incubated at 37°. The 

 solvent action of the organisms on starch was determined by the iodine 

 reaction and recorded after twenty-four hours growth. 



Cultures I B, VIII A, VII B and XI A produces a zone of starch digestion 

 from 2 to 8 mm. in width. These five cultures were all alkaline to C-R 

 (China-blue-rosolic acid) in the starch agar. 



Anaerobic starch digestion was determined by maldng plates as above, 

 then covering with melted agar and sterile paraffin. Starch digestion was 

 determined as above after four daj^s at 20°C. 



These same cultures grown under anaerobic conditions showed much wider 

 areas of starch digestion. VI A and VIII A reacted distinctly acid to C-R. 

 I A was pink to iodine showing the presence of erythrodextrin. VI B showed 

 only very shght starch digestion anaerobically. 



Cultures I A, I B, VI B and VII B organisms were sleeted from the seven 

 studied, for thermal death point determinations. The remaining three were 

 eliminated because the}' seemed to be identical with one of the four selected, 

 and also because lack of time prevented complete investigation. 



Twenty-one day broth cultures grown at 20° were used for thermal death 

 point determinations. Duplicate tests were made of each organism in ten 

 minute holding periods. 



Table III, — Thermal Death Point Determinations of Cultures Isolated 



Cultures I A and VII B seem to be quite resistant to heat, I B resists a 

 temperature of 90° for ten minutes, VI B is killed at a lower temperature of 

 80°. In general, the thermal death point seems to be above 80° and below 

 110°C, 



Sterile cans of string beans, lima beans, corn, peas, pumpkin, and tomatoes 

 were inoculated with each of the four organisms used above in triplicate. 

 One set was incubated at 20°, 37° and 55°C respectively, Uninoculated 

 opened and unopened controls also were placed at 20° and 37°. Only un- 

 opened controls were placed at 55°. 



The cans were inoculated during the latter part of March, 1920, and the 

 observations taken in November of the same year on the 20° cans seem to 

 indicate that the organism introduced into the can in quite a few cases could 



