POLYHYDRIC ALCOHOLS 



123 



mellea (24). Intact cells of Fusarium lini oxidize erythritol to erythru- 

 lose (86), and it is likely that similar reactions occur in those fungi 

 which themselves accumulate sugar alcohols. 



Glycerol. The formation of glycerol by fungi is mentioned in Chap- 

 ter 7 as an indication of the functioning of the Embden-Meyerhof 

 respiratory pathway. The available data (86, 187, 188) are consistent 

 with the metabolism of glycerol via this pathway, i.e.: 



Glycerol -» triose phosphate — » pyruvic acid (11) 



No enzymatic studies have, however, been made, and the role of 

 phosphorylated intermediates is only conjectural. 



Glycerol phosphates are hydrolyzed by phosphomonoesterases 

 (phosphatases), which also attack other organic phosphates (196). 

 Hydrolysis of organic phosphates at acid pH is brought about by 

 mycelial extracts of Actinomyces Israeli (104), and of fungi (5, 55, 58, 

 198, 199). In Trichophyton rubrum cytochemical tests suggest the 

 presence of another phosphomonoesterase active at alkaline pH values 

 (159), and enzymes of this type (alkaline phosphatases) have been 

 reported in other fungi (50, 236). These and other phosphatases are 

 considered elsewhere (Chapter 9). 



Baba (7, 8) isolated an unusual metabolite, monoallyl phosphoric 

 acid, CH 2 =CH — CH 2 — OPO s H 2 , from cultures of Aspergillus niger 

 metabolizing glycerol, and showed in addition the presence of an 

 enzyme, a phosphatase, able to dephosphorylate the compound. 



Glycols. Exogenously supplied glycols are oxidized by some fungi, 

 e.g., Fusarium lini converts ethylene glycol to glycolaldehyde (86), and 

 Aspergillus ??/ge?dehydrogenates 1,2-butanediol to hydroxymethylethyl- 

 ketone (246). The dehydrogenation of ethylene glycol may be effected 

 by alcohol dehydrogenase, known to catalyze this reaction in other 

 systems. 



Fusarium lini also oxidizes 2,3-butylene glycol to acetoin (CH 3 — 

 CO — CHOH — CH 3 ) (86). Acetoin occurs as a metabolite of sugar or 

 pyruvic acid in fungi and actinomycetes (109, 221, 225), but its im- 

 portance and the pathway of formation in the fungi are not known. 

 In yeast, but not in bacteria, it seems that ketols of this type are 

 formed with the participation of acetyl-coenzyme A and the free 

 aldehyde (215). 



