Genetic Aspects of Growth Responses in Fungi 



E. L. TATUM 



THE study of growth factors of fungi may be said to have been 

 initiated by the pioneering work of Wildiers with yeast in 1901 

 (89). Further investigations of the nutritional requirements of this 

 nonfilamentous fungus have contributed outstandingly to the fields of 

 nutrition of both microorganisms and higher organisms. These contribu- 

 tions began with the identification by Eastcott (19) of meso-inositol as 

 one of the bios constituents. The relationship of the nutrition of this 

 microorganism to that of higher organisms first became apparent with 

 the work of Williams (90), who showed that vitamin Bi was a required 

 growth factor. With this information as a starting point, further in- 

 vestigations with yeast to date have added two additional new vitamins 

 to the list of those important to both microorganisms and higher forms. 

 These are biotin (43) and pantothenic acid (91). Shortly after thiamin 

 had been demonstrated as a growth factor for yeast this vitamin was 

 reported by Schopfer as the first identified essential metabolite required 

 by a filamentous fungus, Phycotnyces blakesleeanus (70). Investigations 

 with other filamentous fungi initiated by Kogl and Fries (42) and ex- 

 tended since then to a great variety of other fungi (25,67) have fully 

 substantiated the concept that these organisms require essentially the 

 same metabolites as do other forms of life. Strains of fungi are now known 

 which as isolated from nature require the vitamins thiamin, biotin, 

 pyridoxine, inositol, and nicotinic acid. Although not yet identified as 

 a requirement of a filamentous fungus, /^-aminobenzoic acid is required 

 by certain yeasts. These include Rhodotorula aurantiaca (68) as well as 

 strains of Saccharomyces cerevisiae (63,64). The available information 

 thus amply supports the generalization that microorganisms, bacteria 

 as well as fungi, and higher organisms have similar requirements for 

 most of the vitamins of the B complex. 



