Improvements in Propagating Apparatus for Developing Pure Culture of Yeast and Bacteria.
Year: 1897

page_text: Date of Application, 9th June, 1897-Accepted, 17th July, 1897
COMPLETE SPECIFICATION.
Improvements in Propagating Apparatus for Developing Pure
Culture of Yeast and Bacteria.
I, NIELS BENDIXEN, of 4 Bakkegaards Alle Copenhagen, in the Kingdom of
Denmark, Superintendent of a laboratory, do hereby declare the nature of this in-
vention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
The present invention relates to an apparatus for the development of pure
culture of yeast and bacteria and which, owing to its simple and consequently
cheap construction, will remedy a much felt loss in the smaller yeast industries.
The smaller fermenting establishments, as for instance, small breweries and
dairies, have hitherto been placed at a disadvantage if they wished to follow the
example of the larger establishments and work with pure culture of yeast and
bacteria. They have either been forced to buy the pure culture from the bacteri-
clogical laboratories, and the cost has been so considerable that it is only very
seldom they have been able to do so and consequently have not been able to secure
a thoroughly rational and reliable manner of working; or they have been com-
pelled to spend a proportionately large amount in procuring the propagating
apparatus hitherto used and made for the larger establishments only.
The present apparatus meets this want of the smaller fermenting establishments,
inasmuch as it, compared with all previously known propagating apparatus, owing
to its very simple construction can be manufactured at a reasonable price.
In the hitherto known propagating apparatus, when they consist of two cylinders
as in the present apparatus, it has been the custom to use compressed air to force
the culture forward and backward between the cylinders and these consequently
must be constructed of specially strong material, but in the present apparatus the
culture is brought from cylinder to cylinder by the pressure of the fluid itself by
reason of a suitable difference of level between the surfaces of the fluid brought
about by raising or lowering one of the cylinders. By this arrangement air-pump
and air-chamber may be dispensed with and lighter material may be used in
construction.
The airing before and during the fermentation which is favourable for the
development af some microorganisms, is effected by means of an aspirator which
sucks the air into the fermenting cylinder through a cotton filter which retains
the germs of the air.
Referring to the accompanying drawing
The apparatus consist of three cylinders: a reserve cylinder A, a fermenting
cylinder B and an aspirator C.
The reserve cylinder A and the fermenting cylinder B are in the well-known
manner supplied with filters, water-gauge and draw cocks. A has also an infec-
tion tube and B a stirring apparatus b, and a spiral tube hereinafter referred to.
The connection between the two cylinders is effected by means of an india-
rubber tube or other movable connecting tube a.
A connecting tube 63 provided with cocks leads from the cylinder B to the
aspirator C.
When the apparatus is to be used it is sterilized by forcing steam through it
as is the case with all propagating apparatus.

page_text: The chyle is now brought into the cylinder B and the connecting tube to A
closed and while the tube to C is kept open, the chyle is sterilized by leading steam
through the spiral tube b¹ or by directly heating the cylinder from below.
When the chyle has become sterilized the connection to C is closed and the fluid
cooled down by running cold water through the spiral tube.
After the cooling has taken place the connection to the cylinder A is opened
and this cylinder is lowered below the level of the fluid in B whereupon some of the
fluid in B will run over into A. Through the infection tube of this cylinder A its
fluid is infected by the pure culture and when this is developing the connection to
B is opened, A is raised and the culture run over into the fermenting cylinder.
When the development in B has taken place, the culture is stirred, the con-
nection to the reserve cylinder A opened and by lowering the said cylinder some
of the culture from B is brought over into A.
The culture is now drawn off from B, fresh chyle is brought in, sterilized and
after being cooled off is infected with culture from the reserve cylinder A.
The working is continued in the manner above described.
During the development in B air is sucked into the cylinder through the filter
by the cock in the bottom of the water-filled and otherwise air-tight aspirator C
being opened so that the water can run out.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
Propagating apparatus for the development of pure cultures of yeast and
bacteria consisting of a fermenting cylinder B and a reserve cylinder A being
tually connected by a rubber tube or other movable means of connection so
that fluid may run from the reserve cylinder to the fermenting cylinder or vice
versa owing to the different levels of the fluid by the raising or lowering of the
reserve cylinder.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.