ASYMMETRICA-LANATA 429 



remains white if the mold is P. caseicolum. At about the same time, the 

 curd in contact with the mycehum begins to soften to a smooth buttery- 

 texture which gradually extends from all sides toward the center of the 

 mass (fig. 111). The curd is at first markedlj' acid to litmus but becomes 

 alkaline to litmus as the softening progresses inward. In a period varying 

 with the water content of the mass, the temperature and the humidity, 

 (in commerce usually about four weeks), the entire mass is softened by 

 P. camemherti. In Dox's studies (1908, 1909, 1910a) the change was found 

 associated with the elaboration of a proteolj^tic enzyme similar to erepsin. 



Penicillium caseicolum Bainier produces the same type of cheese as P. 

 camemherti but of somewhat firmer texture and to most connoisseurs a less 

 attractive flavor. 



So long as the industry was restricted to the comparatively localized 

 region in Northern France where it developed, the problems of propagation 

 and control were not significant. Attempts to develop Camembert manu- 

 facture in other regions of France and in Germany, however, necessitated 

 investigations to overcome the handicaps of infection by other organisms 

 in factories subject to different climatic conditions. These difficulties 

 were even greater when the task of establishing an industry was attempted 

 in America (Thom 1909, 1945). Successful manufacture in this country 

 was accomplished only when environmental conditions similar to those 

 actually prevailing in northern France were artificially produced (Thom 

 and Fisk, 1918). 



Cheeses of the Camembert type have never gained wide popularity in 

 the United States, hence the amount of study devoted to these products 

 and to the molds used in their manufacture has been rather limited. Chief 

 biochemical interest in Penicillium. camemherti and P. caseicolum rests in 

 the enzymes that they produce. Dox (1908, 1903, 1910a) paid particular 

 attention to proteolytic enzjones and their relation to cheese ripening. 

 Ayres and Xiedercorn (1942) obtained a patent covering the commercial 

 production of proteolytic enzymes bj^ P. camemherti. Bobbins (1916) 

 reported on certain factors influencing diastase production in the same 

 species. Dox (1910b) investigated catalase production in numerous 

 species of Aspergillus and Penicillium, including P. camemherti. 



Sartory, Sartory and Meyer (1927) studying the optimum pH of differ- 

 ent molds reported Penicillium caseicolum to grow best at 6.5 to 7,0. 



Penicillium commune Series 



Outstanding Characters 



Colonies on Czapek's agar growing fairly rapidly, typically loose-textured, 

 floccose, comparatively deep, commonly up to 1 or 2 mm., usually 

 medium to heavy sporing with conidial areas in dull bluish green or 

 yellowish green shades, with vegetative hyphae and conidiophores 



