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Ethel M. Doidge 42.") 



The amount of ammonia and peDtone increases gradually; the 

 amino-acid, as in the case of the milk flasks, increases and then decreases, 

 the decrease being correlated with an increase in the ammonia content. 

 The large percentage of albumen reduced shows that the organism is 

 a fairly active proteolytic agent. 



A fair amount of ammonia is also produced in media containing 

 peptone, e.g. ordinary nutrient bouillon. 



Broth cultures after sterilisation cause no peptonisation of milk. 

 If a culture is killed by exposing it to a temperature of about 55° C. 

 for half-an-hour, and then 3-5 c.c. of the culture run into each of a 

 number of tubes of litmus milk, there is no change in the milk during 

 ten days. Bacterium nectarophilum gave positive results with this test, 

 the milk being slowly cleared in the same way as when the organism was 

 growing in the medium. 



Amylolytic action. The starch of steamed potato cylinders is not 

 destroyed at all rapidly; cylinders on which the organisms had been 

 growing for three weeks still gave a strong blue black reaction with 

 iodine. 



Tubes containing 10 c.c. nutrient bouillon and -01 gm. soluble starch 

 were planted with a vigorous culture and incubated at 30° C. It was 

 only after 14 days that the starch entirely disappeared. When a similar 

 set of tubes was planted with Bacterium citri the starch had entirely 

 disappeared at the end of 48 hours ; the amylolytic action of the tomato 

 organism is therefore comparatively feeble. 



Cultures in nutrient broth which had been incubated for five days 

 at 30° C. were tested for the presence of diastase. A mixture was made 

 of equal quantities of the cultivation and a thin starch paste containing 

 2 per cent, thymol ; this was placed in the incubator at 37° C. for six 

 hours and then tested with Fehling's solution, with negative results. 

 Control cultures of Bacillus subtilis tested in the same way gave a good 

 reaction for reducing sugars. 



Production of invertase. Nutrient bouillon in which the organism had 

 been growing for five days was tested for the presence of invertase. 

 A mixture was prepared containing equal quantities of the cultivation 

 and a 2 per cent, solution of cane sugar to which 2 per cent, of carbolic 

 acid had been added. After several hours the mixture was tested for 

 reducing sugars with negative results. 



When the organism is grown in nutrient broth containing cane sugar, 

 however, a certain amount of reducing sugar is produced. In flasks 

 containing 500 c.c. of nutrient broth with 2 per cent, saccharose, the 

 Ann. Biol, vn 28 



