92 THE TYPES OF MILK BACTERIA. 



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are manufactured from milk by different processes. Those 

 which are best known are as follows : 



Kumiss. This is a material which has long been prepared 

 by the Arabs, and commonly made from mare's milk. The 

 milk of this animal will undergo an alcoholic fermentation 

 much more readily than the milk of the cow, and the material 

 that is formed is a favorite beverage. It is characterized by 

 the development of alcohol, but along .with alcohol a quantity 

 of lactic acid is produced and the beverage obtained is a drink 

 that is very much enjoyed by Arabs. This kumiss is pro- 

 duced by a combination of microorganisms acting together. 

 There is present a species of yeast, a common lactic organism, 

 thought to be the common Bact. lactis acidi, and in addition 

 a third bacillus which is known as the kumiss bacillus (97). 

 What the relation of the three organisms is in the production 

 of kumiss is not known, but it is doubtful whether the special 

 kumiss bacillus has anything to do with the process. 



Although kumiss was made originally from mares' milk, 

 a close imitation of the product is now frequently manu- 

 factured artificially from cow's milk. The method of manu- 

 facture is usually to add to the milk a certain quantity of 

 cane sugar and then to inoculate it with some common 

 species of yeast. The yeast begins quickly to produce an 

 alcoholic fermentation of the cane sugar, and the lactic bac- 

 teria present produce lactic acid from the milk sugar. The 

 total result is a combination of lactic and alcoholic fermenta- 

 tions and a product which closely resembles kumiss, and 

 which commonly goes by this name. 



Matzoon. This is a material somewhat resembling kumiss 

 and having its origin in Armenia. It is produced out of 

 ordinary cow's milk which is fermented by placing in it 

 small white, fatty, cheese-like grains which can be used over 

 and over and preserved a long time. These grains start up 

 a fermentation that is the result of the action of several 

 organisms. The bacterial study of the product shows the 



