1923] 



KLOTZ — NITROGEN METABOLISM IN FUNGI 



331 



TABLE II 



EFFICIENCY OF AERATION METHOD FOR SEPARATION OF (NHi) AND (NH,)N 





Ml. 1055 N 

 HaSO* 



Mgm. N 



1. N from (NH«),SO« by Kjeldahlization 



9.10 

 9.15 

 9.15 



13.52 

 13.52 



2. N from alanine by Kjeldahlization 



9.10 

 9.10 



13 . 538 



3. N from (NH 4 )jS04 by aeration 



9.10 

 9.10 



13.45 



4. N from (NH^aSOi-alanine by aeration 



8.95 

 9.05 



13.376 



5. N from alanine by aeration 





— 





Ml. N, 



Mgm. NH* N 



6. Amino N from 0.05 N alanine, 2 ml. 

 Before aeration 24° C. — 766 mm. 



24° C— 766 mm. 

 22° C.— 766 mm. 



* 



2.33 

 2.35 

 2.35 



1.3106 

 1.3218 

 1 . 3348 



After aeration 22° C— 766 mm. 



2.35 

 2.34 



1 .3348 

 1.329 



7. Amino N from alanine (NH 4 ):S04 

 After aeration 21° C— 766 mm. 



21° C— 766 mm. 



2.338 

 2.355 



1.335 



1.3447 



These experiments show that aeration for 18 hours at the rate of 

 30-50 liters per hour is a satisfactory means of determining 

 NHj.N, and of separating NH, from amino N. Glucose and 

 other constituents of the media were not found to interfere with 

 the comnleteness of aeration. 



The van Slyk 



i i * 1) 



micro 



method ('11, '11a, '12, '13, '15), 

 rather than the "macro," was adopted because the apparatus 

 used in the former is much more stable, requires only a fifth of 

 the quantity of reagents, and the modification is as accurate as 



the 



' ' macro ' ' 



method. Special 



must be 



observed in this determination. A definite period of reaction 

 must be adopted and maintained throughout a given piece of 

 work to obtain comparable results, because the blanks with 

 water as well as the determinations on solutions containing 

 NH 2 .N vary with the time. In all the following work 5 minutes 



