ASYMMETRICA-VELUTINA 403 



Real advances toward controlled production and an understanding of 

 critical microbiological processes were made when Thom and co-workers 

 successfully introduced the manufacture of Roquefort-type cheeses in this 

 country. Thom isolated a particular kind of mold regularly from the 

 better imported cheeses, and in 1906 described the form as Penicillium 

 roqueforti. Subsequent studies by Thom and Currie (1913) revealed sound 

 physiological bases for the dominance of this mold, and to a large degree 

 elucidated its role in cheese production. The mold was found to tolerate 

 high salt concentration in an acid environment, to grow in an atmosphere 

 containing as little as 5 per cent oxygen, and to produce abundant lipolytic 

 and proteolytic enzymes. Currie (1914) concluded that the presence of 

 caproic, caprylic, and capric acids, resulting from fat hydrolysis by water- 

 soluble lipase produced by the mold, were largely responsible for the char- 

 acteristic flavor of Roquefort cheese. Additional studies in the U. S. De- 

 partment of Agriculture were made by Matheson and others after Thom 

 and Currie turned to other fields. 



A marked revival of interest in Roquefort-type cheeses has occurred in 

 the United States during recent years, and .successful research programs 

 have been conducted in several laboratories. Those at the University of 

 Minnesota and at Iowa State College have been among the most active and 

 productive, and have contributed substantially to the establishment of a 

 limited but successful industry in that area. No attempt will be made to 

 present a complete bibliography, or to review the numerous significant 

 contributions that have been issued by these and other laboratories. How- 

 ever, a considerable list of titles is included in the Topical Bibliography 

 (see p. 723), and from these the interested reader can obtain a reasonably 

 comprehensive knowledge of the subject. As a partial guide to this litera- 

 ture, the following facts may be noted: Golding, in a series of papers from 

 1926 to 1945, investigated particularly the nutritional requirements and 

 gas relationships of Penicillium roqueforti. Gottlieb (1946) studied the 

 utilization of amino acids as a source of carbon by P. roqueforti. Hammer, 

 Lane, Bryant, Jensen, and others at Iowa State College have investigated 

 various factors affecting cheese manufacture, particularly flavor develop- 

 ment. Macy, Thibodeau, Coulter, Combs, George, and others at Minne- 

 sota have likewise studied factors influencing production, with special em- 

 phasis on enzymatic changes and the influence of acidity. Tomasi (1928), 

 Bryant and Hammer (1940), Funder (1946), and others have analyzed the 

 microflora of Roquefort-type cheeses as this relates to production, quality, 

 and storage. 



Ayres and Niedercorn received a patent (U. S. 2,278,236, March 31, 

 1942) covering the production of proteolytic enzymes by cultivating Peni- 



