426 Bacteria in Relation to Country Life 



bert Penicillium and Oidium lactis to the production of 

 Camembert cheese is, therefore, well established." 



The ripening of Camembert cheese is, therefore, due 

 to lactic-acid bacteria and molds, the former bringing 

 about the initial changes, the latter modifying the 

 reaction, digesting the curd and developing the flavors. 

 Lactic-acid bacteria, with Penicillium camemberti alone, 

 were sufficient for the ripening and the proper texture 

 but were not adequate for the production of the typical 

 flavor. The latter appeared only when Oidium lactis 

 was also present. As to actual conditions in the manu- 

 facture of Camembert cheese, it still remains to be de- 

 termined whether the miscellaneous bacteria that 

 appear in large numbers in the later stages of ripening are 

 of decided significance. Similarly, in the case of other 

 soft cheeses, molds are almost invariably present. 



In Roquefort cheese, made out of goat's or sheep's 

 milk, lactic-acid bacteria and a characteristic Penicillium, 

 different from Penicillium camemberti, seem to be the 

 principal organisms concerned. In Stilton and Gorgon- 

 zola, made out of cow's milk, a green Penicillium re- 

 sembling that of Roquefort is prominent; and the same 

 may be said of Hungarian Brinse, prepared from sheep's 

 milk. The differences in flavor which these cheeses 

 exhibit must be sought, therefore, in differences of qual- 

 ity and treatment of the materials employed, as well as 

 in the varying predominance of the several groups of 

 microorganisms more or less common to them all. 

 It may be added that the American Brie and Isigny 

 cheeses examined by Thorn, contained no trace of Peni- 

 cillium camemberti, but always bore a growth of Oidium 



