1058 
Microbiology. — “Metabolism of the fosfor in Aspergillus niger”. 
By Dr. H. J. WarerMaN. (Communicated by Prof. Dr. M. W. 
BEIJRRINCK). 
(Communicated in the meeting of December 28, 1912). 
In an earlier communication >) I have shown that the metabolism 
of the nitrogen in this organism is analogous to that of the carbon *). 
These two elements are accumulated in the organism and are 
later partly exereted, the carbon as carbonic acid, the nitrogen as 
ammonia. | 
We find besides that an excess of these elements retards the 
spore-formation. For the carbon compare tables Ha, Hé and Hl 
(p. 451, 452, and 464 Folia microbiologica); for the nitrogen see 
table VI (Preceding paper). 
I have further fonnd that the fosfor behaves in the same manner 
as the above elements. 
In the first place I ascertained that the rate of fosfor of an old 
mature culture of Aspergillus niger is constant, independent of the 
way in which it is obtained. 
The mould layer was before the analysis washed with distilled 
water and after drying destroyed by strongly concentrated nitric 
acid in a closed tube. In the thus obtained solution the fosfor was 
determined after FiInkENER") as ammonium fosfor molybdate (NH), 
PO, 12 MoO,. The results are found in Table TI. 
For shortness’ sake I shall as for the nitrogen make use of the 
word <“fosfornumber’, which means the fosfor fixed in the mould 
per 100 parts of assimilated carbon. As in the experiments of table 
I all the glukose (1000 mers.) had been assimilated and this quan- 
tity corresponds with 400 mgrs. of carbon; the number of mgrs. 
of fosfor must thus be divided by 4 to find the fosfornumber. 
As the table shows the fosfornumber is for an old mature mould- 
1) See the preceding paper. 
2) Wolin microbiologica (1912) Bd I. p 442. 
3) The liquid containing ammoniumnitrate and the nitric. acid is heated tll the 
first bubbles appear, then precipitated with ammoniummolybdate under continuous 
stirring. The precipitate is then washed out with a solution containing ammonium: 
nitrate and nitrie acid and dissolved in dilate ammonia. To the thus obtained clear 
solution is added an excess of ammoniumnitrate and a small quantity of ammo- 
niummolybdate, after which it is again heated until the first bubbles appear; 
finally hot nitric acid is added under continuous stirring. The precipitate is dried 
in an air current to constant weight at 160° C. in a Gooer s crucible. 
