PRODUCTS OF THE LOWER FUNGI 



Ethyl Acetate. — P. digitatum, wliich causes the olive - 

 green rot of citnis fniits, produces ethyl acetate, which 

 appears to be characteristic of the species. 



Mannitol. — Mannitol is produced in yields as high as 

 50 per cent, of the sugar fermented by several species of 

 Aspergillus, notably A. nidulans, A. elegans and some 

 white species, and also by Byssochlamys fidva, Clastero- 

 sporum, H. geniculatum and P. chrysogemun, from all 

 sugars except fiiictose. On the other hand, when 

 mannitol is formed as a bacterial product it is derived 

 only from fructose and not from any other sugar. The 

 reaction is, apparently, a direct reduction : — 



CH2OH 



I 

 CO 



(CH0H)3 



CH2OH 



(fructose) 



I 



CHOH 



I 

 (CH0H)3 



CH2OH 



(mannitol) 



When mixtures of fructose and glucose are fermented by 

 bacteria the former disappears rapidly with formation 

 of mannitol and acetic acid, whilst the glucose is fermented 

 more slowly to lactic acid. 



In the case of the moulds it has been suggested that 

 two molecules of glucose, for instance, undergo a 

 Cannizzaro reaction with formation of gluconic acid and 

 mannitol : — 



CHO + H2O + CHO 



I 



HCOH 

 HOCH 

 HCOH 

 HCOH 

 CH2OH 



(glucose) 



HCOH 



HOCH 



I 

 HCOH 



I 

 HCOH 



CH2OH 



(glucose) 



CH2OH 



HOCH 

 HOCH 





COOH 



HCOH 



I 

 HOCH 



HCOH 



OH 



(mannitol) 



ul 



OH 



CH2OH 



(gluconic acid) 



