INFLUENCE OF VACUUM UPON GROWTH OF SOME 

 AEROBIC SPORE-BEARING BACTERIA' 



L. D. BUSHNELL 

 Kansas Agricultural Experiment Station 



Received for publication September 11, 1921 



In the course of a study of the bacteria present in canned foods, 

 we found that certain aerobic spore-bearing bacteria were pres- 

 ent in jars which showed no evidence of spoilage, if they were 

 properly sealed. These results were reported from this laboratory 

 in 1918 (Bushnell 1918), but no attempt was made to determine 

 the types present. 



Vaillard, in 1900 and 1902 examined bacteriologically, many 

 cans of meat, and found living organisms in seventy or eighty 

 percent of them. He believed that the bacteria survived in a 

 dormant state in the cans from five to seven years. Among the 

 spore-bearing types he isolated B. subtilis and B. mesentericus, 

 (three varieties, vulgatus, niber, and fuscus). 



Deichsetter, in 1901, reported on the examination of preserved 

 food provided for the Bavarian Army during a period of five 

 years and failed to find microorganisms in canned foods, save in 

 cans in which the food was sent in under suspicion. He con- 

 sidered that Vaillard's findings were probably due to faulty 

 technic. 



Pfuhl, in 1904, examined canned meats from five firms and 

 found bacteria in 29 out of 106 cans. He considered that the 

 findings of both Vaillard and Deichsetter were correct and that 

 the difference in results was due to a difference in the care with 

 which the foodvS were steriUzed. 



Very little work had been reported upon this point until 1919 

 when Weinzirl pubUshed the results of his findings on commercial 



* Gontribution Number 37 from the Bacteriological Laboratory of the Kansa.s 

 Agricultural Experiment Station. 



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