428 



A MANUAL OF THE PENICILLIA 



longing to this series. Furthermore, the physiological adaptation of these 

 two species to the production of cheese is so close that they are thus far 

 unknown outside the dairy manufacturing industry. In the cheese fac- 

 tory, they dominate, overgrow, and suppress competing forms if the cheese 

 contains a favorable water content, if the humidity is maintained around 

 88 percent, and if the temperature is maintained at a proper level. Any 

 wide departure from either condition is commonly followed by the de. 



FiG. 111. C'aiueinbert cheese. Note the semi-iluid consistency of the cheese which 

 is characteristic of a well ripened and high quality product. (After Thorn, in Jour. 

 N. Y. Bot. Garden 1944.) 



i 



velopment of other microorganisms, particularly Scopulariopsis hrevi- 

 caulis (Sacc.) Bainier, to the detriment of the resulting cheese. 



In the manufactiu'e of these cheeses, the freshly made curd is fashioned 

 or molded into thin cakes, salted upon the surface, and inoculated with the 

 mold, or placed in a room in which the spores of the mold reach the sur- 

 face from their abundance in the atmosphere. The cheese contains 55 to 

 60 percent moisture at the outset and is exposed upon mats or boards in a 

 humid ripening room at temperatures preferably from 50° to 60°F. (op- 

 timum at 13° to 14°C.). The entire surface becomes covered in about a 

 week with a floccose white covering of mold, perhaps 1 or 2 mm. deep. 

 In about ten days the mold shows a characteristic bluish or greenish gray 

 cast from the developing conidia, if Penidllium camemberti is used, or 



