434 



STATE BOARD OF AGRICULTURE. 



TABLE XVI. 

 LaHone + 1 cc FiUrate of Yeast LZ. 



•These counts were most probably influenced by the presence of mold in the check. 



The above experiment was duplicated using Stock lactic in place of 

 Lactone. A 4 day milk culture of Stock lactic (not cuided) was us('<l in 

 the following experiment: 



TABLE XVII. 

 Stock Lactic + 1 cc. FUtrate of Yeast LZ. 



From Tables XVI and XVII it is evident that the filtrate possesses 

 some stimulating influence u])on the lactic organisms, causing both an 

 increase in virility and in acid production and a consequent decrease in 

 numbers. 



Expt. II. 



Determination of the Nature of the Extracellular Substances present 



in the Filtrate of Yeast LZ. 



To ascertain whether this stimulating influence is due to an enzyme 

 or to peptone formed by the yeast (see Tables XV, XVI, and XVII in 

 Tech. Bui. No. 10) one lot of filtrate was heated for 5 minutes in flow- 

 ing steam to destroy any enzyme i)resent and the unheated filtrate was 

 kept as control. Lactone was used in this ex])erimcnt. One cc. of a 

 20 day culture of Lactone (not curded) was added to each of 3 flasks, to 

 one of these was added 1 cc. of heated filtrate, to the second, 1 cc. of un- 

 heated filtrate, leaving the ^rd flask for control. 



