478 



STATE BOARD OP AGRICULTURE. 



TABLE XXII. — Old Broth Culture after Addition of Lactose: Strain IV. 



Age of broth culture 



Time after 

 adding Bacteria per cc. 

 lactose. 



Acidity. 



Fermenting 

 capacity. 



2 days . 



4 days . 



hours. 

 16 hours. 

 24 hours. 



/ 10,200,000 

 I 13,500,000 



/ 591,000,000 

 1594.000,000 



/ 530,000,000 

 1540,000,000 



22 .5" I 

 22.5°; 



47.0° I 



47.5°/ 



53.5° 1 

 53.5°/ 



13.2x10" 



1.3x10 



hours. 

 10 hours. 

 24 hours. 



/ 21,000,000 

 I 22,800,000 



/4a5,000,000 

 1455,000,000 



/ 009,000,000 

 1083,000,000 



22.5° \ 

 22.5°/ 



30.0° 1 



30.5°/ 



49 .5° I 

 50.0°/ 



7. 9.x 10 



0.8x10' 



21 days . 



hours. 



10 hours. 



24 hours. 

 48 hours. 



300.000 



00,000,000 



415,000,000 



/ 22.5° 1 



I 22.5°/ 



/ 22 .5°! 



I 22.5°/ 



f 38 .5° \ 



'l 39.0°/ 



55.5° 



13.9x10 

 1.0x10 



VII. THF] INFLUENCE OF TEMPERATURE. 



The formation of acid by lactic bacteria is known to be caused by an 

 enzyme, lactacidase. This enzyme remains witliin the cell, but it acts 

 largely independent of the cell that produced it, and may continue its 

 activity even after the death of the cell. Enzymes have their maxi- 

 mum, oxjtimum, and minimum temperatures. Whether or not the opti- 

 mum temperature of the enzyme and the optimum temperature of growth 

 coincide, has never been determined. It is possible, but not necessary. 

 The determination would be very difficult unless the computation method 

 is used. Even then, the experiments would require much time. A series 

 of incubators for parallel experiments would be indispensable. 



The only data on the influence of higher temperatures upon the de- 

 velopment of the lactic bacteria are the following two experiments car- 

 ried on in the dairy laboratory of the University of Gottingen, six years 

 ago, with the assistance of Professor R. Iwazumi, now in Morioka, 

 .Japan.* Table XXIII gives the data obtained with a very slow grow- 

 ing bacterium in lacto.se broth at 35°C. 



*A few other experiments by Professor Twszumi are not published here except in the 

 averages of all strains in Table VI. 



