306 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 10 



having one less C atom than the corresponding amino acids. 

 Filamentous fungi, on the other hand, decomposed the amino 

 acid to the corresponding hydroxy acid. Yeasts, especially 

 Willia anomala and wild yeasts, were employed, as was Oidium 

 lactis, Rhizopus nigricans, Aspergillus, and other fungi. Tyrosine, 

 for example, was found to be hydrolytically decomposed by 

 yeasts and fungi respectively, according to the following equa- 

 tions : 



HC HC 



HC/\CCH,CHNH,COOH Hc/\cCH,CH,OH + CO, + NH, 



+ EuO 



HOCx ;CH ► HOCl ^CH Tyrosol 



CH 



HC 



HC 



HC 



HC/ \CCH 2 CHNH,COOH +Hj0 HC/ ^CCH.CHOHCOOH + NH, 



->■ 



HOC v /CH HOCv /CH p-hydroxy phenyl lactic acid 



CH 



CH 



The technique by which the alcohol and hydroxy acid were 

 isolated, identified, and quantitatively determined were given. 

 The yield in some cases was almost quantitatively equivalent to 

 the amount of amino acid consumed; that is, the N of the fungous 

 mat determined by Kjeldahlization plus the non-nitrogenous 

 complex, tyrosol, corresponded reasonably to the added amino 

 acid, tyrosine. The ammonia formed is used up by the organism 

 in its building of protoplasm and is not detectable in the culture 

 fluid. The tyrosol produced in the presence of other carbon 

 sources is not further used, but is really a by-product which dif- 

 fuses out through the plasma membranes of the yeast cells. 



Other amino acids were tried with similar results: for exanmle. 



from tryptophane (/3 indolalanine) was obtained tryptophol 

 (/3 indolethyl alcohol), a new compound whose properties were 

 described in detail (Ehrlich, '12). Likewise from leucine and 

 isoleucine yeasts formed amylalcohol and active amyl alcohol 

 respectively. That the amino acids probably served solely as 

 a source of N to the organism was indicated by the fact that 

 upon the addition of ammonium salts to the medium the amino 

 acids were not utilized. Boas and Leberle ('17), in this con- 



