102 



THE FUNGI IMPERFECT! AND THE ASCOMYCETES 



group, tolerate higher temperatures, many of them growing readily 

 in the 37° C. incubator, a temperature too high for most molds. 



Among the important species, many of which will be discussed in 

 later chapters, are A. jumigatus and A. nidulans, pathogenic to man 

 and other animals but also occurring widely distributed as sapro- 



«8 



^» , 



Fig. 50. Aspergilltts Oryzae (XSOO): conidial head. 



Kenneth R. Raper. 



Photograph by Dr. 



phytes; A. Oryzae which, owing to the abundance of various enzymes, 

 has so many industrial applications; A. niger, and related species, 

 used in citric and gluconic acid production and in assaying available 

 phosphorus and potassium in soil; A. clavatus and other species from 

 which antibiotics may be prepared; A. terreus which produces itaconic 

 acid from sugar; and A. niveus which produces citrinin. 



Penicillium. The genus Penicillium is characterized by the produc- 

 tion of conidia from sterigmata much like those of Aspergillus, which 

 are produced in clusters or whorls, known as verticils, from short 



