172 



PHYSIOLOGY OF THE FUNGI 



synthetic medium composed of pure chemicals (glucose, asparagine, salts, 

 and micro elements). Phycomyces hlakesleeaniis makes no growth on 

 this medium unless thiamine is added. We may conclude that A. niger 

 either does not need thiamine in its metabolism or is capable of synthesiz- 

 ing from the compounds of the medium all vitamins in sufficient quantities 

 to meet its needs. The growth of P. blakesleeanus on the culture filtrate 

 of A. niger is proof that thiamine is synthesized by the latter species. 

 Thus, A. niger may be called a self-sufficient fungus with respect to 

 vitamins. Schopfer (1943) has applied the term autotrophic with respect 

 to vitamins to this group of organisms. The detection of self-sufficient 

 fungi in the laboratory is dependent upon their ability to grow on vitamin- 

 free synthetic media containing suitable sources of carbon and nitrogen. 

 A discussion of the economic importance of certain vitamins as metabolic 

 products of fungi is given in Chap. 13. 



Some fungi which have been reported to be self-sufficient with respect 

 to vitamins are listed below: 



Aspergillus (most species tested) 

 Basisporium gallarum 

 Botrytis allii 

 Cercospora apii 

 C. beticola 



Chaetomium globosum 

 Cordyceps militaris 

 Daldinia concentrica 

 Fusarium (most species tested) 

 Glomerella cingulata 

 Helminthosporium gramineum 



H. victoriae 



Monascus purpurea 



Monilinia fructicola (some isolates) 



Neocosmopara vasinfecta 



Penicillium (most species tested) 



Phoma betae 



Rhizopus nigricans 



Sclerotinia sclerotiorum 



Septoria nodorum 



Sphaeropsis malorum 



Ustilago striiformis 



Growth curves of Chaetomium globosum are presented in Fig. 29, as an 

 example of a self-sufficient fungus. It is evident that good mycelial 

 growth was made in the vitamin-free medium and that the addition of 

 four vitamins caused no significant increase in the rate of growth at any 

 time. 



VITAMIN DEFICIENCIES IN FUNGI 



As pointed out above, some fungi do not grow on synthetic media 

 composed of pure chemicals, because they are unable to synthesize certain 

 vitamins. These fungi have been called variously vitamin-deficient, 

 vitaminless, or heterotrophic with respect to one or more specific vitamins. 

 We prefer to use the term vitamin-deficient, following Robbins and 

 Kavanagh (1942). Vitamin deficiencies among the fungi have been 

 detected only for certain members of the water-soluble B-complex group. 

 The most common vitamins involved are thiamine, biotin, inositol, 

 pyridoxine, nicotinic acid, and pantothenic acid. Vitamin deficiencies 

 can be detected accurately only on synthetic media which, other than 



