( 678 ) 
slime which has set off on the fat. This disturbs the movement of 
the substances and retards the rapidity of the process. 
A denitrification by B. Stutzeri was set up in a similar way with 
0.547 or. of fat; the evolved gases were collected above caustic alkali, 
the medium was not renewed. From 9 to 28 October 1909 102 ec. 
of nitrogen were caught; on the 28th of October the fermentation 
produced less than a half ce. of gas per 24 hours, hence the experi- 
ment was stopped although part of the fat was still present. 
In fig. 5 the rate of velocity of the gas evolution is represented 
in a way similar to that of the previous experiment. 
Denitrifications with fatty acids proceed correspondingly to those 
with fats; on the other hand, denitrification with glycerin by 2. 
Stutzert occurs rapidly and completely ; it is quite finished within- 
a few days. About */, of the carbon of the glycerin is then conyerted 
into carbonic acid and */, is assimilated for the building up of 
organic material. 
IV. FaAtT-SPLITTING BACTERIA IN MILK. 
Milk belongs to the most favourable culture media for fat-splitting 
microbes ; beside a finely divided and very easily saponifying fat, 
it contains excellent sources of nitrogen and carbon for these bacteria. 
The number of fat-splitting organisms varies exceedingly in spon- 
tancously infected milk, some hours after the milking we can already 
point out from 180—20000 per ee, among which may oeeur the 
species mentioned above. 
Two factors chiefly influence the growth of fat-splitting bacteria 
in milk, namely temperature and admission of oxygen. 
If we wish to accumulate fat-splitting microbes in milk the surest 
way is by aérobic culture at 10°—15°; at which grow chiefly 
Jluorescents, B. punctatum, micrococci and so-called aromatic bacteria *). 
Also at aërobie cultivation at 27°—30° a considerable growth of 
fat-splitting microbes may occur, but this depends on the primitive 
composition of the bacterial mixture. At anaérobic cultivation, however, 
the lactic acid ferments in a short time overgrow all other species. 
In connection with the lactic acid ferments we can admit as a 
general rule that the conditions of growth for fat-splitting organisms 
in milk are wholly opposed to those wanted for the thriving of 
lactic acid ferments. 
1) Berertnck. Fermentation lactique dans le lait. Archives Néerl. des Sciences 
exactes et naturelles Serie II, 1. XIII. 
Van DER Lex Aromabildende Bakt. in Milch. Centralbl. f. Bakt. B. 17. 
