( 676 ) 
of such a culture to a fresh medium, arranged in the same way, 
yield again a good growth, whereby the described changes of fat 
and culture liquid return. 
The bacteria which cause the denitrification with fat may be 
studied better by sowing the culture on broth gelatine or tapwater 
gelatine with addition of 0,5 °/, tributyrine, 0,05°/, K,HPO,, and 
Ot, KNO; or NEL 
On the two plates the same species of bacteria develop, but they 
thrive better on broth gelatine than on the other medium. 
The most vigorous bacteria denitrifving with fat proved to be 
B. Stutzeri L and N, B. pyocyaneum, B. punctatum, and a bacterium 
producing lipase and diastase,-a representative of B. denttro fluorescens 
non-liquefaciens, deseribed by vaN [rERSON'). 
By cultivation at + 20° the denitrifying species are more obvious, 
whereas at + 34° the same flora appears as at 28°, but the growth 
is less vigorous; B. sphaerosporus and B. nitrovos deseribed by 
Brverinck *) denitrify neither with fat nor with glycerin or fatty acid. 
The varieties of B. Stutzeri and B. denitrojluor. non-lig. are 
characterised as well by the different structure of their colonies as 
by their different power of denitrification and fat-splitting. 
The above mentioned microbes denitrify with glucose, fatty acid, 
calcium lactate, humate of natron, asparagine and peptone. The various 
stocks of B. Stutzeri denitrify besides with maltose, glycerin, glycol 
and mannite, aethylacetate, maltose and butylaleohol; no acid is 
formed from saccharose, lactose and raffinose. 
B. denitro fluor. non-lig. produces a little acid from glucose, but 
none from any of the said compounds; nor does it denitrify with 
mannite, glycerin, maltose, or glycol. 
The fat-splitting of both bacteria under aërobie conditions was 
ascertained by cultivation in an ERLENMEIJER flask of 300 ce. with the 
culture liquid: 200 ce. tapwater, 1 gr. finely divided fat, 0.1 gr. 
ammonium chloratum, 0.1 gr. bikaliumphosphate and 0.5 gr. chalk. 
After inoculation with 5 ec. of a 48 hours old brothpeptone cul- 
ture of these bacteria, after 30 days at 28° C. 
B. Stutzeri. . . . . . had split 680 mG. and assimilated 65 mG. 
B. den. fluor. n. lig. had split 920 mG. and assimilated 80 mG, 
These experiments show that by B. Stutzert and B. denitrofluor. 
non lig. respectively 70°/, and 100°/, of the fat are split and 
1) Accumulation experiments with denitrifying bacteria. Royal Ac. 1902. 
2) Bildung und Verbrauch von Stickoxydul durch Bakterien. Centralbl. f. Bakt. 
Abt. 2, Bd. 25, S. 30. 
