( 795 ) 
Microbiology. — “Emulsion laevulan, the product of the action 
of viscosaccharase on cane sugar”. By Prof. M. W. Beijerinck. 
In the proceedings of the Academy of 9 February 1910 an enzyme 
was described which produces from cane sugar and raffinose a 
viscous matter incapable of diffusion. My further investigations, made 
conjointly with Mr. D. C. J. Minkman, proved that this substance is 
closely related to the laevulan of Lippmann *) but not identic with it. 
Our emulsion laevulan originates in watery nutrient solutions in 
quite the same way as in the agarplates, so that these solutions 
change into a milkwhite emulsion; the liquid between the suspending 
laevulan droplets opalises very strongly. In hot water the substance 
is fairly soluble and the specific rotation of the polarised light, which, 
on account of the opalisation can only approximately be determined, 
is about 
“*=- 80 ° 
whilst Lippmann gives for his laevulan 
0j> = -221‘. 
On account of this considerable difference in its rotating power, 
a new name, e.g. “sinistran”, might seem desirable. But the word 
laevulan having a collective meaning to which also the more and 
the less soluble forms of our substance may be brought, we shall 
here use the general denomination, the more so as it is sure that 
the laevulan of the literature, like ours, consists of the cell-wall 
substance of bacteria. 
Besides by Lippmann the formation of laevulan by bacteria has 
also been observed by Maassen 2 ), who does not, however, describe 
the appearance of the emulsion, so that in this case, too, a modifica¬ 
tion of our emulsion laevulan seems to be produced. The here 
concerned microbe is a sporulating fermentation organism, called by 
Maassen Semiclostridium commune , but not yet found by us. 
Preparation and propei'ties of emulsion laevulan. 
We were first of opinion that emulsion laevulan might be best 
prepared by using Bacillus emulsionis, for we had stated that this 
species does not decompose the once formed laevulan, whilst B. 
megatherium and B. mesmtericus, which likewise produce emulsion 
i) Gbemie der Zuckerarten 3 te Aufl. 1904. Pag. 906, 1312. 
8) 4 r beiten au§ deni Kaiserl. Gesundheitsamte. BioL Abt. Bd. 6, p. 2, 1905. 
