GB2043420A - Containers for mushroom cultivation - Google Patents

Abstract

A mushroom cultivation vessel has a cover including an outer member 10 having at least one aperture, an inner member 20 correspondingly apertured and snap- fitting into a peripheral groove within the outer member, and a filter element 30 of plastics film material permeable to gas but impermeable to bacteria and microbes detrimental to mushroom cultivation, the element 30 being held across the aperture(s) by engagement of an edge portion thereof between cooperating ridge and groove arrangement 14, 23 on the cover members. <IMAGE>

Description

SPECIFICATION Vessel for mushroom cultivation This invention relates to a vessel which is suitable for use in the cultivation of mushrooms, e.g. by seed culture or bottle cultivation, and partiCularly relates to such a vessel provided with a securable cover which is permeable to gas but which is impermeable to bacteria and microbes.

Hitherto for cultivating mushrooms, socalled material wood cultivation has been used, employing material woods such as Quercus serrata and Quercus glandulifera. Recently however fungus bed cultivation has extensively been used which provides shorter cultivation times. Varieties of mushrooms including Collybia Velutipes, Pholiota Mutabilis, Pleurotus Ostreatus and Amanita Caesarea have been cultivated using a vessel e.g. a bottle, and a cover therefor.An example of such a vessel is illustrated in vertical section in Fig. 1 of the accompanying drawing, wherein a bottle of plastics material e.g. polypropylene, is provided with a cover 1 screwattachable thereto, said cover having an aperture 2 in the top part thereof and a cotton plug 3 is inserted in the aperture whereby invasion of bacteria or infectious microbes into the bottle is prevented and the necessary airpermeability for the growth of mushrooms is ensured.

A further example of a known combination of bottle and cover is illustrated in Fig. 2, wherein an air-permeable sheet composition 4 comprising an asphalt paper is secured over the neck of the bottle with a rubber band 5.

However such constructions have the following drawbacks: (1) A considerable amount of skill is required for applying a cotton plug properly, (2) Infectious organisms can in fact intrude through the cotton plug or asphalt paper, resulting in e.g. up to 20% of rejects, (3) It is becoming increasingly difficult to obtain the special kind of cotton used for the plug, and (4) The growth rate using asphalt paper covers is slow.

Our British Patent Application 7928342, corresponding to Japanese Patent specification 102460/1978, describes and claims a vessel for cultivating mushrooms comprising a container and a cover therefor provided with an aperture, and a separate element is also provided comprising a porous plastics film material which is permeable to gas but is impermeable to bacteria and microbes which are infectious to mushroom cultivation, and which is adapted to be disposed between the said cover and the said container when the vessel is in a closed condition. Thus the element may comprise the said porous film mounted between two packing materials, or stuck onto an annular support.

The invention is directed to an arrangement for providing a vessel for mushroom cultivation having a cover of plastics material associated with a porous plastics film material, which is cheap to manufacture and which is expeditious in use.

The invention provides a vessel for cultivating mushrooms comprising a container and a securable cover therefor containing one or more apertures for the passage of air therethrough, and an element comprising a porous plastics film material which is permeable to gas but which is impermeable to bacteria and microbes infectious to mushroom cultivation and which is adapted to be disposed between the said cover and the said container to extend over the said aperture(s) in the said cover whereby when the said vessel is in a closed position air can pass into the said vessel only through the said element of porous plastics material, characterized in that the said cover comprises a flat outer cover of plastics material containing one or more apertures centrally disposed therein and having a peripheral side portion adapted to be secured to the said container, the undersurface of the said flat outer cover having a recess or ridge thereon surrounding the said aperture(s); and a separate inner flat cover of plastics material adapted peripherally to snap-fit into a peripheral groove on the inner surface of the said side portion of the outer cover and containing one or more apertures substantially corresponding to the apertures in the said outer cover portion, and also having on a flat surface thereof a ridge or groove corresponding in configuration to the said recess or ridge respectively on the undersurface of the said flat outer cover and of dimensions to provide a clearance when fitted therein by snap-fitting the said inner cover within the said outer cover so as to secure a peripheral portion of the said porous plastics film between the said flat outer and inner covers.

In the vessel of the invention sealability is secured by the presence of the fitting parts on the peripheral margin of the inner cover and the outer cover, the porous film therebetween being gripped between the co-operating ridge and groove portions present on the outer and inner covers whereby leakage of infectious bacteria between said covers is prevented.

However it is preferable to provide a suitable clearance between the groove and the said ridge so that the film is not broken when the covers are fitted together or when expansion of the fitted parts takes place during steam sterilization treatment.

The said outer cover of the vessel according to the invention may be adapted to screw onto the container, i.e. the said peripheral portion of the outer cover may be adapted to screw onto a threaded portion of the con tainer. Preferably however the said outer cover is adapted to snap fit onto the container either by a lip portion on the peripheral side portion engaging a corresponding peripheral groove on a surface of the container, or by a groove engaging a corresponding peripheral lip on the container.

The porous film employed in the present invention can be prepared according to various known methods, for example as follows: (a) A substance which is soluble in a solvent is admixed with plastics material to form a thin film, and thereafter said substance is dissolved out of said film by a solvent therefor to form micropores therein; (b) A liquid functioning as a non-solvent to the polymer used as the film is employed as a coagulating agent; (c) A synthetic resin solution comprising a synthetic resin, a solvent and a non-solvent is freed of said solvent and thereafter freed of said non-solvent to form a film containing micropores; (d) A substance initially containing micropores is admixed with a polymer to form a microporous film product; (e) Polymer particles are sintered to form voids as micropores within a film of polymer particles;; (f) A film is irradiated by radiation to degrade portions of the film, which degraded portions are then dissolved to form micropores; (g) A swellable substance in a swollen state is mixed into a polymer and a film of the resulting mixture is dried to form voids as micropores through volume shrinkage; (h) A film of crystalline polymer is stretched under conditions to develop a lamella structure and thereafter thermal setting is effected after a suitable elongation deformation has been imparted to the film thereby to generate microvoids; (i) A film prepared from a polymer having a filler e.g. a fine powder of an inorganic substance added thereto is stretched to form micropores; (j) Thin fibres of several microns are meltblown to form a sheet having micropores.

Plastics material used to form the porous film employed in the present invention include for example polyolefins e.g. polyethylene and polypropylene, polycarbonates, polyamides, vinyl polymers, cellulosic polymers and fluorine-containing polymers. In general the pore size of pores in the plastics film is such as to prevent permeation therethrough of bacteria or infectious microbes which would cause contamination during the growing of mushrooms. Thus a pore diameter of 0.01 to ly may be used, a pore diameter of 0.01 to 0.4,u being preferred. In some circumstances, e.g.

when the pores meander through the film, a diameter of 10fez may be suitable for obtaining the object of the invention.

A commercially available microporous polypropylene film suitable for use in the present invention is obtainable under the Trade Mark DURAGARD, marketed by Polyplastics Co.

and which has elongate micropores of 0.4y maximum major diameter.

One embodiment of the invention is hereinafter described and illustrated in Figs. 3 and 4 of the accompanying drawings, of which Fig. 3 is a partial cross-section of the top portion of a vessel according to the invention, and Fig. 4 is a plan view of the inner cover thereof with associated porous film.

In Fig. 3 the peripheral wall 1 2 of a plastics outer cover 10 having a flat top portion 11 is fitted onto the opening 41 of the body 40 of a plastics bottle. In the embodiment illustrated, the outer cover is fitted onto the opening of the bottle by way of a snap fit, but a screw fit may be used if desired. The flat top portion 11 of the outer cover 10 has an aperture 1 3 at the centre thereof. If desired a plurality of apertures may be present. Surrounding this opening a circular recess 14 is provided on the underside of the flat top portion 11 of the outer cover 1 0. Further on the inner surface of the peripheral wall 1 2 of the outer cover 10 a circumferential groove 1 5 is provided adjacent to said flat top portion 10.An inner cover 20 (shown in plan view in Fig. 4) consists of a plastics disc whose periphery 21 has such a size that it exactly fits the groove 1 5 of the said outer cover with a snap fit, and has at the centre thereof an aperture 22 corresponding to the aperture 1 3 of the said outer cover, and also has a circular ridge 23 surrounding the opening 22 corresponding to the said groove 14 of the outer cover 10 when the bottle is assembled. The clearance between the groove 14 and the ridge 23 is such size that it corresponds to the thickness of a porous film 30 to be placed therebetween and the film 30 is not broken when the film is bent during assembly. As hereinbefore described, the embodiment illustrated may be modified so that the circular groove 14 is contained in the inner cover 20 and the corresponding ridge is on the outer cover 10.

When the porous film 30 is placed between the outer cover 10 and the inner cover 20, and the inner cover is snap fitted into the peripheral groove 15, the assembled cover is then fitted onto the opening of the bottle 40, and the assembled container may then be used for mushroom cultivation.

Thus the containers of the present invention may be assembled by a simple operation, and as the inner cover is merely fitted, they are prepared at a cheap cost and economically.

Further the porous film may be used several times and then replaced. Furthermore the film is not subject to much deformation, and there is little likelihood of damage or breakage.

The following Example of the container is provided.

Example 500 g of a culture obtained by mixing sawdust of a broad leaved tree with rice bran in a ratio by volume of 4:1 and adding water to provide a water content of about 60%, were introduced into each of 100 polypropylene cultivation bottles of 1 ,000 c.c. capacity having a configuration and a polypropylene cover as shown in Fig. 3 and including a porous film of DURAGARD 4510. The bottles were then sterilized at 120"C. for one hour.

After the temperature of the bottles had cooled to 30"C. or lower, a seed fungus of Collybia Velutipes was introduced into the culture within the Bottles. Cultivation was then continued at 18 to 20"C. for 22 days.

Thereafter by steps of scratch of fungus, inhibition growth and paper-wrapping in a conventional manner, the resulting mushrooms cropped after 50 days. The same procedure was carried out with a conventional cultivation bottle employing a porous asphalt paper cover. With the bottles according to the invention no contamination by infectious microbes was observed, whereas using the cultivation bottle employing an asphalt paper cover, it was observed that 11 bottles of the 100 were contaminated. Furthermore the use of cultivation containers according to the invention enables the time for cropping to be reduced by 5 days on average, compared with the bottles using asphalt paper covers.

Claims (7)

1. A vessel for cultivating mushrooms comprising a container and a securable cover therefor containing one or more apertures for the passage of air therethrough, and an element comprising a porous plastics film material which is permeable to gas but which is impermeable to bacteria and microbes infectious to mushroom cultivation and which is adapted to be disposed between the said cover and the said container to extend over the said aperture(s) in the said cover whereby when the said vessel is in a closed position air can pass into the said vessel only through the said element of porous plastics material, characterized in that the said cover comprises a flat outer cover of plastics material containing one or more apertures centrally disposed therein and having a peripheral side portion adapted to be secured to the said container, the undersurface of the said flat outer cover having a recess or ridge thereon surrounding the said aperture(s); and a separate inner flat cover of plastics material adapted peripherally to snap-fit into a peripheral groove on the inner surface of-the said side portion of the outer cover and containing one or more apertures substantially corresponding to the apertures in the said outer cover portion, and also having on a flat surface thereof a ridge or groove corresponding in configuration to the said recess or ridge respectively on the undersurface of the said flat outer cover and of dimensions to provide a clearance when fitted therein by snap-fitting the said inner cover within the said outer cover so as to secure a peripheral portion of the said porous plastics film between the said flat outer and inner covers.

2. A vessel according to Claim 1, wherein the said peripheral side portion of the outer cover has a lip portion adapted to snap fit into a corresponding peripheral groove on a surface of the said container.

3. A vessel according to Claim 1, wherein the said peripheral side portion of the outer cover has a groove portion adapted to snap fit into a corresponding peripheral lip portion on the external surface of the said container.

4. A vessel according to Claim 1, wherein the said peripheral side portion of the outer cover is adapted to screw fit onto a threaded portion of the said container so as to be secured thereto.

5. A vessel according to any of Claims 1 to 4, wherein the said container is a bottle.

6. A vessel according to Claim 1, substantially as hereinbefore described and illustrated in Figs. 3 and 4 of the accompanying drawings.

7. The use in the cultivation of mushrooms of a vessel according to any of Claims 1 to 6.