4 
(515) 
the study of the conditions of nutriment of ureum-bacteria. It 
taught us that carbo-hydrates, salts of fatty acids and of organic 
multibasic acids can be assimilated. 
The so highly interesting studies of BeiserINcK about the decomposition 
of ureum by microbes principally treat of the ureum-decomposing 
organisms which in cultures, on application of his accumulation-method 
in bouillon 10 °/, ureum make themselves conspicuous. In the course of 
the investigation some experiments have been made with culture- 
liquids, composed of water, 5 °/, ureum, 0.025 K,HPO, and 1 °/, 
ammoniumoxalate, natriumacetate, seignette-salt, ammoniumcitrate and 
ammoniummalate. In these culture-media a strong decomposition of 
ureum takes place after infection with mould. 
The 5 °/, ureum added, however, are not entirely decomposed. The 
easily assimilable compounds, such as ammoniummalate and citrate, 
give rise to a greater ureum-decomposition, respect. 4°/, and 3°/,, than 
those which are not so easily assimilated, such as ammoniumoxalate 
and natriumacetate, in whose presence only 2 °/, ureum is decomposed. 
The study of the microbes which are found in these cultures, 
was not continued at that time. 
The purpose of this investigation is therefore principally to prove 
that the life of numbers of ureumbacteria is by no means dependent on 
the presence of albumen, but that for these ferments the large quantities 
of carbo-hydrates and salts of organic acids, which for microbial 
life are available in mould are extremely fit as a source of carbon, 
whilst at the same time the ureum can serve as a source of 
energy as well as as a source of nitrogen. 
Some preliminary experiments led to the conviction that the most 
different sources of carbon, in culture-liquids containing these com- 
pounds and ureum, dissolved in water, 0,05 °/, K,HPO, are excellently 
fit for the growth of weak as well as for very strong ureum- 
splitting microbes. 
Cultivated in a thin layer of liquid in Erlenmeyer-recipients at + 33°, 
being the optimumtemperature of the growth, strong species, especially 
those producing spores appear; at a low temperature, 15°—23°, less 
strong splitting ferments, especially micrococci are produced. 
The exclusion of other groups and the privilege of the ureum- 
bacteria in these culture-media is so complete, that the latter mixed 
with raw materials, such as mould, sewer or ditchmud, after some 
days contain only ureumsplitting organism. 
If one of these cultures, infected with raw material, is put into 
sterilised liquids of the same composition, the ureum-fermentation also 
progresses very well there. 
35* 
