SULFUR 



305 



(89), Aspergillus nidulans (83, 188), Penicillium chrysogenum (82), 

 Ophiostoma multiannulatum (64, 65), and Ustilago zeae (180). 



Some nutritional studies on sulfur are summarized in Table 2, from 

 which it appears that most or all fungi utilize sulfide, thiosulfate, and 



Table 2. The Sulfur Nutrition of Some Fungi* 



the more oxidized forms of inorganic sulfur (except dithionate). How- 

 ever, the data on some of these compounds must be questioned in 

 view of their known instability; thus, Steinberg (234) found that 

 Aspergillus niger grows much better on old than on fresh samples of 

 sodium sulfide and disulfide. 



It should be noted that the difference between Brevilegnia gracilis 

 and Saprolegnia delica in their sulfur nutrition parallels that seen 

 elsewhere (Chapter 3) in their carbon nutrition — the soil-inhabiting 

 B. gracilis is more omnivorous than its aquatic relative. 



The details of sulfate reduction are not fully known. The available 

 data suggest the following pathway (44): 



Sulfate (S0 4 --)-» sulfite (SO s — )-> sulfide (S — ) or thio- 

 sulfate (S 2 3 — ) — » cysteine — > methionine (1) 



The obviously necessary intermediates are not known, nor is it possible 

 to say at what point in Equation 1 the sulfur becomes attached to an 



