174: Dairy Bacteriology. 



This organism, called by him Bacillus nolilis, the Edelpilz 

 of Emmenthaler cheese, has been subjected to comparative 

 experiments, and in the cheese made with pure cultures of 

 this germ better results are claimed to have been secured. 

 Sufficient experiments have not as yet been reported by 

 other investigators to warrant the acceptance of the claims 

 made relative to the effect of this organism. 



Lactic-acid bacterial theory. It has already been shown 

 that the lactic-acid bacteria seems to find in the green 

 cheese the optimum conditions of development; that they 

 increase enormously in numbers for a short period, and 

 then finally decline. This marked development, coincident 

 with the breaking down of the casein, has led to the view 

 which has been so ably expounded by Freudenreich ' that 

 this type of bacterial action is concerned in the ripening of 

 cheese. This group of bacteria is, under ordinary condi- 

 tions, unable to liquefy gelatin, or digest milk, or, in fact, 

 to exert, under ordinary conditions, any proteolytic or pep- 

 tonizing properties. This has been the stumbling-block to 

 the acceptance of this hypothesis, as an explanation of 

 the breaking down of the casein. Freudenreich has re- 

 cently carried on experiments which he believes solve the 

 problem. By growing cultures of these organisms in milk, 

 to which sterile, freshly precipitated chalk had been added, 

 he was able to prolong the development of bacteria for a 

 considerable period of time, and as a result finds that an 

 appreciable part of the casein is digested; but this action is 

 so slow compared with what normally occurs in a cheese, 

 that exception may well be taken to this type of experi- 

 ment alone. Weigmann 2 inclines to the view that the 



1 Freudenreich, Landw. Jahr. d. Schweiz, 1897, p. 85. 



* Weigmann, Cent. f. Bakt., II Abt., 1898, 4:593; also 1899, 5:630. 



