Abstrict
A disposable fermenter that may be used in the place of a more
expensive jar fermenter giving the same performance in a temperature
controlled room in place of a sterilized room, with the advantage
of not being made of glass which breaks and which may be transported
as is, by just sealing the bag. A flat tube made of plastic film
is inserted into the bottom of the bag with the tube sealed to the
bag, leaving an opening through the tube so the opening may not
be closed. Once the addition of liquid, semi fluid or solid media
is made, the breather is set and the bag opening is sealed, the
bag is sterilized before or after the bag opening is sealed and
the aeration is done through the flat tube.
Claims
What is claimed is:
1. A disposable fermenter comprising a fermenting bag for containing
a medium, the fermenting bag having a flat tube affixed at a bottom
or lower portion of the bag and at least one means for breathing
inserted and fixed to the bag at a position where the means for
breathing is always above a maximum level of the medium contained
in the bag, the bag being made of a plastic film, the flat tube
being made of a plastic film and extending inwardly into the bag
and outwardly from the bag, the flat configuration and position
of the tube preventing the egress of the medium from the bag and
the ingress of contamination into the bag by pressure exerted on
the tube by the medium while permitting aeration.
2. A disposable fermenter according to claim 1 wherein an air permeable
filter is located inside the flat plastic tube.
3. A disposable fermenter according to claim 1, wherein the plastic
film of the bag withstands pressure sterilization at 125.degree.
C. for greater than thirty minutes.
4. A disposable fermenter according to claim 1, wherein the plastic
film of the bag and of the tube is a transparent plastic film selected
from the group consisting of polypropylene, high density polyethylene
and polyolefin.
5. A disposable fermenter according to claim 1, wherein a portion
of the tube extending inwardly into the bag has a plurality of holes.
6. A process for fermenting using the disposable fermenter of claim
1, comprising sealing the bag, sterilizing a medium contained in
the bag, inoculating the medium contained within the bag with microorganisms
and continuously supplying air through the flat plastic tube.
7. A disposable fermenter according to claim 1, wherein the bag
includes means for independently standing in an upright position.
8. A disposable fermenter according to claim 1, wherein the bag
has four side walls and a bottom.
9. A disposable fermenter comprising a fermenting bag for containing
a medium, the fermenting bag having a flat tube affixed at a bottom
or lower portion of the bag and a staggered seal to an upper portion
of the bag resulting in an opening which permits the egress of gas
and prevents the ingress of contamination, the bag being made of
a plastic film, the flat tube being made of plastic film and extending
inwardly into the bag and outwardly from the bag, the flat configuration
and position of the tube preventing the egress of the medium from
the bag and the ingress of contamination into the bag, by pressure
exerted on the tube by the medium, while permitting aeration.
10. A disposable fermenter according to claim 9, wherein the staggered
seal comprises two parallel sealed lines horizontally aligned with
the upper portion of the bag, the two sealed lines each having a
portion thereof which is unsealed, the unsealed portion of one sealed
line is not vertically aligned with the unsealed portion of the
other sealed line.
11. A disposable fermenter according to claim 9, wherein an air
permeable filter is located inside the flat plastic tube.
12. A process for fermenting using the disposable fermenter of
claim 9, comprising sealing the bag, sterilizing a medium contained
in the bag, inoculating the medium contained within the bag with
microorganisms and continuously supplying air through the flat plastic
tube.
13. A disposable fermenter according to claim 9, wherein the bag
includes means for independently standing in an upright position.
14. A disposable fermenter according to claim 9, wherein the bag
has four side walls and a bottom.
15. A disposable fermenter according to claim 9, wherein the plastic
film of the bag withstands pressure sterilization at 125.degree.
C. for greater than thirty minutes.
16. A disposable fermenter according to claim 9, wherein the plastic
film of the bag and of the tube is a transparent plastic film selected
from the group consisting of polypropylene, high density polyethylene
and polyolefin.
17. A disposable fermenter according to claim 9, wherein a portion
of the tube extending inwardly into the bag has a plurality of holes.
Description BACKGROUND OF THE INVENTION
In the past, glass and stainless steel have been used as the material
for fermenters and required at the minimum, aeration sparger and
air outlet as well as mixer and sampling port. These fermenters
are available in several sizes such as the mini jar fermenter with
volumes of 1 to 5 liters made of glass, the jar fermenters made
of stainless steel with volumes of 10 to 200 liters and finally
even larger fermenters.
The small scale fermenters have been used to generate laboratory
data and for fermentation tests and at times, 10 or more are run
simultaneously but in general, they are expensive so only a selected
number of researchers can use these fermenters.
Recently, more precise and easy control of the temperature in fermentation
rooms have become possible due to the efficiency and increased popularity
of air conditioners and the size of the fermentation rooms in general
have increased. More efficient use of the fermentation rooms by
placing numerous identical size fermenters to make more effective
use of the space, and simple fermenters with high fermentation efficiency,
transportation of the fermentation product, and finally efficient
waste disposal of the fermenter are now in demand.
SUMMARY OF THE INVENTION
The present invention has been developed to solve the problem mentioned
above. The invention consists of permanently fixing to the bottom
of the bag fermenter, a flat plastic film tube which allows free
passage through the tube into the bag. The media placed into the
bag can be liquid, semi-liquid or solid media. The bag is sealed
leaving only the breather open and the media may be sterilized before
or after sealing the bag. The aeration is done through the flat
plastic tube at the bottom. These are the characteristics of this
invention.
The material used to make the fermentation bag should be strong
enough to support the weight of the contents of the bag once filled
and should be strong enough to withstand pressure sterilization
of 125.degree. C. for over 30 minutes. The material should be transparent
plastic film made from either polyproplyene, high density polyethylene
or polyolefin. The plastic flat tube should be made from the same
material as the bag fermenter.
The present invention does not limit the fermentation bag to any
particular shape and can be a gusset type bag where both sides of
the tube material are folded inward, vertically sealed cylinder
type, or a tube type film which has been folded and sealed along
the sides, or a cylinder shaped which has been sealed along the
sides, or a tube type film with one end sealed. The gusset bag is
particularly good because the bottom of the bag when full becomes
triangular and keeps the contents from spilling.
A flat plastic tube is inserted into the bottom of the bag prior
to sealing the bottom and both sides of the tube in contact with
the site to be sealed at the bottom will be sealed with the exception
of the inner portion of the tube allowing free passage through the
tube into the bag. The flat tube may already have been inserted
with a thin stick coated with a material that can be easily pealed
off such as fluorine resin or silicone resin. This flat tube may
be inserted near the bottom or at the bottom of the vertically sealed
bag and fixed. At the same time, the bag may be sealed at the bottom
or vertically sealed and then the thin stick may be removed constructing
an opening into the bag.
This invention deals with the insertion of a flat tube into the
bottom of the bag which acts as a port for passage of air. In general,
the flat tube is made of fine film sealed on both ends but also
the fine film may be folded with the free sides heat sealed with
the other side folded. Moreover, it may be a cylinder type without
any sealed portion and the folded side may be sealed at the same
time when the bottom of the bag is sealed. However, ideally the
flat tube should be sealed on both ends. The port for air passage
should be a minimum of 2 cm or ideally larger than 3 cm.
The air port rather than closed may be open but to obtain the most
efficient aeration, very small openings in the film may be made
near the end of the closed tube.
Since it is difficult to keep the opening of the air port located
on the outside of the bag open, it would be best not to seal the
tip of the flat plastic tube outside the bag. It may be helpful
to change the length of the front and back portions of the tube
or to cut the tip of the tube in a zig zag manner.
The breather may be inserted and fixed to the top of the bag in
the same way as the air port by using one or more flat plastic tubes.
The position of the breather should be such that it will always
be above the maximum level of media in the bag. This breather may
be used for sampling or may be used as the site for inoculation
of microorganisms.
The breather is not absolutely required. The bag opening may be
sealed in such a way that there are partial openings. The unsealed
portion of the closed opening may be such that it will not interfere
in air removal as well as will prevent the contamination from outside,
or an opening near the top of the bag which is then wrapped with
a special filter.
The air port or breather or both may be inserted with a continuous
porous plastic foamed material such as urethane foam or a textile
complex material. This material would act as filters and therefore
non-sterile air may be used in a non-sterile room without having
to worry about contamination. The filter should be made of a hydrophobic
material.
The media used in this invention should be composed of material
which will allow for uniform distribution of air from the bottom
of the bag. Liquid media, fluid or semifluid media may be used.
Solid state fermentation media may also be used, but the material
must be such that there is room for air to pass through the individual
granules.
To make a fermentation using the present invention, a predetermined
quantity of media is added to the bag. If the flat plastic tubes
are placed as the breathers at the top of the bag, then the opening
at the top of the bag may be sealed and a pipe may be inserted into
the flat plastic tube. This pipe will insure an opening and then
the whole bag may be heat sterilized. After cooling, the media may
be inoculated through the breather or the inoculation may take place
via a syringe. The sterilization may be accomplished while the top
of the bag is open and after inoculation, the top of the bag may
be sealed.
In the case where flat plastic tubes are not used as breathers
at the top of the bag, the top of the bag can be partially sealed
and the distance of this partial seal should be 2.5 cm from the
edge of the bag and ideally more than 3 cm. If there is not enough
bag film material before the partial opening this can lead to contamination.
The bag opening can be partially sealed two or more times with
the open portion staggered. If this is done, the distance between
the two should be at a minimum of 1.5 cm and ideally more than 2
cm. The bag opening may be folded twice and then partially sealed.
The bag may be sealed before or after sterilization but if the bag
is sealed before sterilization, then the inoculation should be done
with a syringe.
This present invention deals with the use of a light plastic bag
which is the fermenter having a nozzle made of the same material
for aeration which is a flat tube. Placing this bag in a temperature
controlled room will give the same performance as a jar fermenter
as well as being simple and easy to transport. The flat tube will
not open by outside forces and will close from the pressure of the
inside media, so none of the contents will spill outside. During
the fermentation, proper aeration can be maintained through the
pipe inserted in the flat tube.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents the two dimensional view of the bottom of the
bag. FIG. 2 represents the cross-section 21 view of the method of
fixing the flat tube to the bag fermenter. FIG. 3 represents another
variation of the invention (shashizu). FIG. 4 represents the bag
under fermentation conditions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 fermenter bag, 1 has a sealed portion 2 on
the bottom and a folded portion 3 of the gusset. To the sealed site
of the bottom of the bag 2, the flat tube 4 is inserted and fixed.
Two pieces of film 5 are sealed at both lengths with the opening
in the middle 6. The open end of the tube 7 outside the bag is not
sealed.
In FIG. 2, the sealed portion 8 of the flat tube 4 and the film
of the bag is illustrated. When the flat tube 4 is inserted and
the bottom of the bag is sealed, four pieces of film will be sealed
together. To make certain the opening 6 is created, a TEFLON sheet
is inserted prior to the sealing process and removed after the sealing
process. In FIG. 2, the inner opening is closed, but with internal
pressure the opening will open easily.
In FIG. 3, the flat tube 4 placed at the bottom of the bag 1 is
sealed on only one side 5 and the end 9 of the flat tube inside
the bag is sealed. Near the end 9 of the flat tube 4 super fine
holes 10 are made. From the flat tube 4, air can pass into the bag
and the air will enter the bag as small bubbles.
The breather 11 is made of the same material as the flat tube shown
in FIG. 1 and is sealed near the top of the vertical sealed side
12. With this bag, fermentation is started by first introducing
the media, then the top is sealed, sterilized, and inoculation is
made through the breather 11. The air is introduced into the bag
through the flat tube 4 and the air is released through the breather
11. Moreover, after fermentation the bag may easily be transported
without concern of spillage. For added protection, the outer portion
of the flat tube may be sealed after fermentation.
FIG. 4 is a three dimensional illustration of a bag almost identical
to FIG. 3 without the breather 11. There needs to be an opening
to release the air coming from the flat tube 4 and to release the
steam generated after the bag is filled with media and sterilized.
This opening (breather) is constructed by partial sealing of the
top of the bag as shown in FIG. 4.
In FIG. 4, the two sealed lines 13, 14 which are about 2 cm apart
have the partial openings staggered. The distance from the top of
the bag to the sealed line 14 is 5 cm. The air within the bag will
first pass through the opening 15, through the space between the
two sealed lines 17 and finally to the outside through opening 16.
If the pressure inside the bag drops, the two sides of the film
opening close and stop the escape of air the outside as well as
prevent the outside air to from entering the bag and contaminating
it.
EXAMPLE 1
The media composition shown below was placed into a 60 micron thick
polyproplyene bag as shown in FIG. 3.
______________________________________ Potato treated by mixer
400 g Glucose 60 g Yeast extract 6 g Malt extract 6 g Distilled
water 1,000 ml pH 5.5 ______________________________________
The bag was then sealed at the top, glass wool was inserted into
the breather 11 and sterilized for 20 minutes at 120.degree. C.
The steam generated during the sterilization did not rupture the
bag but easily passed through the breather 11. After cooling, 20
g of maitake inoculum prepared beforehand was inoculated through
the breather 11. The bag was set in a 24.degree. C. room and sterilized
air was supplied through the flat tube 4 at a speed of 2,000 ml/minute.
After 7 to 10 days, uniform mycelia development of the maitake
was observed and this was determined to be appropriate for use as
the inoculum for inoculating the sawdust. Furthermore, this inoculum
may be transported or distributed in the bag and provides the ability
to offer liquid inoculum to the mushroom cultivators.
The above media was placed into the FIG. 4 bag and the top was
sealed as shown in the figure. The bag was sterilized for 60 minutes
at 120.degree. C., cooled, and 10 g of maitake inoculum was inoculated.
The bag was set in a 24.degree. C. room with sterilized air supplied
at a rate of 50 ml/minute. After 20 days, the media will be covered
with mycelium. The bag is transferred to an 18.degree. C. room and
after 30-35 days 400 g-500 g of maitake can be harvested. This production
cycle is less than the 45-75 days required by conventional cultivation
methods.
The present invention involves the use of an easy to use disposable
bag to be incubated in a temperature controlled room without the
need for a clean room, giving performance comparable to an expensive
jar fermenter. Moreover, the bag may not be easily ruptured and
may be transported as is after sealing. Once the bag is finished,
it may easily be discarded and will be of benefit in a distribution
system.
This invention allows for the fermentation of fungi and bacteria
requiring aeration with results comparable to the jar fermenter
and it is lightweight, simple, easy to transport, and easy to use
disposable fermenter. |