Compositions comprising scleroglucan, articles containing scleroglucan, methods of making, and methods of use

Abstract

Compositions and articles comprising scleroglucan are described that are useful for culturing and counting microorganisms even after exposure to a sterilized dose of radiation. The composition also includes one or more water-swellable polymers, such as guar gum, locust bean gum or xanthan gum, in addition to scleroglucan. Methods of making and using the same are also described.

Description

[0001] CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 63 / 367,956, filed on July 8, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The field of the invention relates generally to polymer films and their preparation and use. Background Art

[0004] Thin film culture devices have become quite popular over the past few decades. Thin film culture devices generally include a film located on a substrate. The film includes or serves as a culture medium on which microorganisms can grow. These films have various uses, one of which is to assess the level of microbial contamination in a test sample.

[0005] US5869321 discloses a thin film culture plate having culture medium particles containing a mixture of nutrients and a gelling agent. The gelling agent is a material such as carbohydrates, proteins and minerals, in particular a mixture of xanthan gum, locust bean gum and guar gum.

[0006] US9988600 discloses a dry powder cell culture medium having polymer-embedded components.

[0007] US20200109431 discloses a device for distinguishing and counting coliform and Escherichia coli microbial colonies. The device comprises a first sheet and a second sheet, the first sheet having a first cold water-soluble gelling agent attached thereto, and the second sheet having a second cold water-soluble gelling agent attached thereto. As gelling agents, guar gum, polyacrylamide, locust bean gum and agar are mentioned, and guar gum and xanthan gum alone or in combination are preferred, and guar gum is exemplified.

[0008] US20150225691 teaches a method for preparing a flowable, agglomerated nutrient medium using a fluidized bed agglomeration chamber. A gelling agent may be included. A binder may optionally be included. Among the binders, PEG, polyvinyl pyrrolidone, polyvinyl alcohol, polysaccharides, dextran, dextrin, maltodextrin, microcrystalline cellulose, HPMC, methylcellulose, starch and sugar are mentioned.

[0009] US10995356 provides a culture device for counting microbial colonies. A cold water soluble gelling agent, a dry buffer system, a dry carbon dioxide generation system and a dry oxygen scavenger are configured in a growth compartment. The gelling agent mentioned includes algin, carboxymethyl cellulose, tara gum, hydroxyethyl cellulose, guar gum, locust bean gum, xanthan gum, polyacrylamide, polyurethane and polyethylene oxide. Guar gum, locust bean gum and xanthan gum are preferred, whether used alone or in combination.

[0010] Feng et al. published a study on “Determination of Petrifilm TM The article concluded that liquefied organisms can hydrolyze guar gum, which could have “two effects on the accuracy of [counts]: (i) liquefied areas may allow motile organisms to move and multiply…producing more than one colony from one cell, leading to an overestimation of the microbial load; and (ii) fuzzy areas obscure other colonies, leading to a potential underestimation.”

[0011] Scleroglucan is available from Cargill, Inc. (Minnetonka, MN USA) under the trade name ACTIGUM, which its manufacturer states provides stable viscosity over a pH range of 2.5-12 and temperatures between 10-120°C for use in construction, paints, home care, and cleaning agents for drilling, oil recovery, and asphalt emulsion applications. Summary of the invention

[0012] The present invention relates to compositions, articles, devices and methods involving films comprising scleroglucan and one or more water-swellable polymers.

[0013] In some embodiments, the present invention includes a composition comprising scleroglucan and one or more water-swellable polymers other than scleroglucan.

[0014] In some embodiments, the present invention includes a culture device comprising a base member, a cover sheet connected to the base member, a growth compartment disposed between the cover sheet and the base member, and a scleroglucan layer comprising scleroglucan. In some embodiments, the scleroglucan layer is located within or near the growth compartment. In some other embodiments, the scleroglucan layer further comprises one or more water-swellable polymers other than scleroglucan.

[0015] In some embodiments, the present invention includes a method of culturing a microorganism. The culturing method may include contacting the microorganism with a composition of the present invention described herein to form an inoculated composition, and allowing the microorganism to undergo at least one replication.

[0016] In some embodiments, the invention includes a method of culturing a microorganism, the method comprising contacting the microorganism with an article of the invention described herein (e.g., a culture device described herein) to form an inoculated article, and allowing the microorganism to undergo at least one replication.

[0017] In some embodiments, the present invention includes a method for sterilizing a culture device. The sterilization method may include providing an article of the present invention described herein (e.g., a culture device described herein), wherein the article comprises one of the compositions of the present invention described herein. The sterilization method may further include irradiating the article sufficiently to sterilize the culture device.

[0018] In some embodiments, the present invention includes a film comprising one of the inventive compositions described herein.

[0019] In some embodiments, the present invention includes an article comprising a substrate and an inventive film described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a series of photographic images of the thin film culture device CE-A (not exposed to radiation), the thin film culture device CE-A (exposed to 30 kGy of radiation) and the thin film culture devices AA, BB, CC and DD (exposed to 30 kGy of radiation) (Table 5) of Example 5 after inoculation with Escherichia coli (ATCC 25922) and incubation for 48 hours. For each type of thin film culture device, photos of three individual devices are presented.

[0021] Figure 2 It is a series of photographic images of the thin film culture device CE-A (not exposed to radiation), the thin film culture device CE-A (exposed to 30 kGy of radiation) and the thin film culture devices AA, BB, CC and DD (exposed to 30 kGy of radiation) (Table 5) of Example 5 after inoculation with Proteus mirabilis (ATCC 14153) and incubation for 48 hours. For each type of thin film culture device, photos of three individual devices are presented.

[0022] Figure 3It is a series of photographic images of the thin film culture device CE-A (not exposed to radiation), the thin film culture device CE-A (exposed to 30 kGy of radiation) and the thin film culture devices AA, BB, CC and DD (exposed to 30 kGy of radiation) (Table 5) of Example 5 after inoculation with Bacillus subtilis (ATCC 6633) and incubation for 48 hours. For each type of thin film culture device, photos of three individual devices are presented.

[0023] Figure 4 It is a series of photographic images of the thin film culture device CE-A (not exposed to radiation), the thin film culture device CE-A (exposed to 30 kGy of radiation) and the thin film culture devices EE, FF, GG and HH (exposed to 30 kGy of radiation) (Table 6) of Example 5 after inoculation with Escherichia coli (ATCC 25922) and incubation for 48 hours. For each type of thin film culture device, photos of three individual devices are presented.

[0024] Figure 5 It is a series of photographic images of the thin film culture device CE-A (not exposed to radiation), the thin film culture device CE-A (exposed to 30 kGy of radiation) and the thin film culture devices EE, FF, GG and HH (exposed to 30 kGy of radiation) (Table 6) of Example 5 after inoculation with Proteus mirabilis (ATCC 14153) and incubation for 48 hours. For each type of thin film culture device, photos of three individual devices are presented.

[0025] Figure 6 It is a series of photographic images of the thin film culture device CE-A (not exposed to radiation), the thin film culture device CE-A (exposed to 30 kGy of radiation) and the thin film culture devices EE, FF, GG and HH (exposed to 30 kGy of radiation) (Table 6) of Example 5 after inoculation with Bacillus subtilis (ATCC 6633) and incubation for 48 hours. For each type of thin film culture device, photos of three individual devices are presented.

[0026] Figure 7 One embodiment of an article of manufacture of the invention is shown in the form of a culture device.

[0027] Figure 8 A flow chart illustrating an embodiment of a method of the present invention for making or preparing the compositions and articles described herein is shown.

[0028] Fig. 9 A flow chart is shown that illustrates an embodiment of the method of the present invention using the composition, layer, film, or article described herein. DETAILED DESCRIPTION

[0029] In this application, references without a specific number do not refer to only a single entity, but include a general category that can be illustrated using specific examples. References without a specific number can be used interchangeably with the phrases "at least one" and "one or more." The phrases "at least one of" and "including at least one of" followed by a list refer to any one of the items in the list and any combination of two or more items in the list.

[0030] Terms such as “common,” “usually,” “frequently,” and “commonly” are used to refer to features that are commonly employed in the invention, but unless otherwise stated, do not imply that such described features were known or common prior to this disclosure.

[0031] Unless stated otherwise, the use of "or" means "and / or".

[0032] The use of "comprising" and "including" is interchangeable and does not mean limitation. In addition, when the description of one or more embodiments uses the term "comprising", those skilled in the art will understand that in some specific cases, the embodiment may also be described using the language "consisting essentially of..." and / or "consisting of..."

[0033] The term "about" as used herein refers to a difference of ±10% from the nominal value. It should be understood that such variation is always included in any given value provided herein, whether or not specifically mentioned.

[0034] Any range given in absolute terms or approximate terms is intended to encompass both, and any definitions used herein are intended to clarify rather than limit. Although the numerical ranges and parameters setting forth the broad scope of the present invention are approximate, the numerical values ​​set forth in the specific examples are reported as accurately as possible. In addition, all ranges disclosed herein are understood to encompass any and all subranges (including all fractional and integer values) contained therein.

[0035] The word "sterile" is used herein only as an adjective, never as a verb. It can be used with or without reference to ISO 11137 or ISO 11137-2:2013. Whether used with or without reference to ISO 11137 or ISO 11137-2:2013, "sterile" means that the noun it describes, such as a composition, membrane, article, or culture device, has a "negative sterility test," as that term is defined in ISO 11137-2:2013. A negative sterility test may be determined under either Method 1 or Method 2 of ISO 11137-2:2013; thus, a product that has a negative sterility test when tested according to Method 1 of ISO 11137-2:2013 and no negative sterility test when tested according to Method 2 of ISO 11137-2:2013, or vice versa, or a negative sterility test when tested according to both Method 1 and Method 2 of ISO 11137-2:2013, is considered "sterile" (as that term is used herein).

[0036] The word "sterilize" is used herein only as a verb and never as an adjective. (i) sterilizing an article (e.g., a composition, a film, a product, or a culture device), (ii) sterilizing an article (e.g., a composition, a film, a product, or a culture device), (iii) the sterilized article (e.g., a composition, a film, a product, or a culture device), or (iv) the action of sterilizing an article (e.g., a composition, a film, a product, or a culture device) all have the same meaning, differing only in the grammatical requirements of the verb "sterilize" form. In each case, the verb ("sterilize") means to render its object sterile (as defined above for the term "sterile"). References to ISO 11137 or ISO 11137-2:2013 are references to the English version of ISO 111347-2:2013.

[0037] Thin film culture devices, such as those disclosed in US5869321, US9988600, and US202001943, comprise a substrate having a membrane that may be incorporated with a water-swellable polymer such as a gum (e.g., guar gum, xanthan gum, or locust bean gum). These water-swellable polymers can provide a matrix in which target microorganisms can replicate and form colonies.

[0038] Exemplary thin film culture devices are available from Neogen Corporation, Lansing, MI USA as PETRIFILM TM Brand name acquired. PETRIFILM TM The instructions for use ("IFU") for the brand's culture devices state that they are decontaminated but not sterilized.

[0039] The present disclosure recognizes that prior art culture media and culture devices, such as culture media and culture devices containing one or more water-swellable polymers (e.g., one or more of guar gum, xanthan gum, and locust bean gum), and in particular thin film culture devices containing such polymers, cannot be provided in a sterile state. The inventors attempted to expose such prior art culture devices to a radiation dose sufficient to sterilize the device, such as at least 25 kGy or at least about 30 kGy, or about 25 to about 30 kGy; however, when using prior art culture devices exposed to sterilizing doses of radiation, the inventors found that the cultured microorganisms could not be seen as distinct colonies, but formed plaques. Therefore, it is difficult or impossible to count the resulting colonies and accurately count the number of colony forming units ("cfu") on the culture device.

[0040] Although non-sterile culture devices that have been decontaminated to reduce bioburden (e.g., PETRIFILM TM Devices sold under the brand name TRANSPORT® can be used in many applications, but some applications, such as medical diagnostics, clean room monitoring, and biopharmaceutical purification, require the cultivation of microorganisms under sterile conditions.

[0041] Thus, one problem can be stated as how to form a water-swellable polymer composition that is suitable for use in culture media, for example as a component of a culture device, and that does not exhibit an undue increase in microbial mobility after sterilization, particularly after exposure to radiation of at least about 25 kGy, or at least about 30 kGy, or about 25 to about 30 kGy. Another problem can be stated as how to form a sterile composition of a water-swellable polymer composition that is suitable for use in a culture device and does not exhibit an undue increase in microbial mobility.

[0042] Another problem can be stated as how to prepare a sterile membrane for microbial cultivation, which membrane comprises a water-swellable polymer composition and does not exhibit an undue increase in microbial mobility after sterilization, particularly after exposure to radiation of at least about 25 kGy or at least about 30 kGy or about 25 to about 30 kGy.

[0043] Another problem that can be stated is how to prepare sterile culture devices, particularly thin film culture devices, which have been exposed to radiation of, for example, at least about 25 kGy or at least about 30 kGy or about 25 to about 30 kGy, and do not show an undue increase in microbial mobility.

[0044] In the context of these issues, when microorganisms form plaques or spots after incubation on a membrane or culture device, it may not be possible to identify CFUs or count the number of colonies with reasonable accuracy.

[0045] In short, one solution to one or more of the above problems, and possibly some other problems, involves the use of scleroglucan alone or with other water-swellable polymers in compositions, films or articles for cell culture.

[0046] Scleroglucan is a polysaccharide commercially available from Cargill, Inc. (Minnetonka, MN USA) under the trade name ACTIGUM. The chemical structure of scleroglucan is similar to that of polysaccharides such as guar gum, xanthan gum and locust bean gum. However, it has been surprisingly and unexpectedly found that scleroglucan can withstand irradiation without the above-mentioned problems, while polysaccharides generally cannot.

[0047] Composition

[0048] Compositions that can be used as culture media in culture devices such as thin film culture devices can use scleroglucan alone or a combination of scleroglucan and one or more other water-swelling polymers other than scleroglucan as its matrix. The one or more other water-swelling polymers may include at least partially water-soluble polymers. For example, water-soluble polymers that can be used in compositions disclosed herein include those polymers disclosed in US5869321, US9988600 or US20200109431 for water-swelling or water-gelling compositions. In some embodiments, when one or more other water-swelling polymers are used, they may include one or more of guar gum, xanthan gum or locust bean gum. In other embodiments, a combination of locust bean gum and xanthan gum may be used.

[0049] When one or more other water-swellable polymers are used, the weight ratio of the scleroglucan to the one or more other water-swellable polymers may vary with the requirements of the final product. In some embodiments, the total weight of the one or more water-swellable polymers to the weight of the scleroglucan may be about 1:99 to about 99:1, optionally about 1:10 to about 10:1, and further optionally about 3:1 to about 1:3. In other embodiments, the total weight of the one or more water-swellable polymers to the weight of the scleroglucan may be about 10:90 to about 90:10, about 20:80 to about 80:20, about 25:75 to about 75:25, about 30:70 to about 70:30, about 40:60 to about 60:40, or about 55:45 to about 45:55.

[0050] The amount of the one or more other water-swellable polymers can be characterized as a percentage of the total weight of the one or more other water-swellable polymers and the total weight of the scleroglucan. In some embodiments, the weight percentage of the one or more other water-swellable polymers can be about 1 or more, optionally about 5 or more, optionally about 10 or more, optionally about 20 or more, optionally about 25 or more, optionally about 30 or more, optionally about 33 or more, optionally about 40 or more, optionally about 50 or more, optionally about 60 or more, optionally about 67 or more, optionally about 70 or more, optionally about 75 or more, optionally about 80 or more, optionally about 90 or more, or optionally about 95 or more, or about 1 to about 95 wt%, or about 5 to about 75 wt%, or about 10 to about 50 wt%, or about 5 to about 30 wt%, based on the total weight of the other water-swellable polymers and the total weight of the scleroglucan.

[0051] The amount of scleroglucan can also be characterized as a percentage of the total weight of the one or more other water-swellable polymers and the total weight of scleroglucan. In some embodiments, the weight percentage of scleroglucan can be about 1 or more, optionally about 5 or more, optionally about 10 or more, optionally about 20 or more, optionally about 25 or more, optionally about 30 or more, optionally about 33 or more, optionally about 40 or more, optionally about 50 or more, optionally about 60 or more, optionally about 67 or more, optionally about 70 or more, optionally about 75 or more, optionally about 80 or more, optionally about 90 or more, or optionally about 95 or more, 100 wt%, or about 1 to 100 wt%, or about 25 to about 100 wt%, or about 10 to about 70 wt%, based on the total weight of the one or more other water-swellable polymers and the total weight of scleroglucan.

[0052] Other components can be used in the compositions disclosed herein. Examples of such other components include one or more nutrients that promote the growth of one or more microorganisms. In some embodiments, the nutrients include one or more sugars (e.g., one or more of glucose, lactose, fructose, maltose, and dextrose), soluble starch, tryptone, Peptone, soy peptone, yeast extract, casamino acids, casein, casein pancreatic digest, casein acid hydrolyzate, soybean papain digest, sodium pyruvate, sodium chloride, magnesium chloride, magnesium sulfate or dipotassium phosphate. In other embodiments, glucose can be used as an additional component.

[0053] Other components that may be used include selection agents (eg, antibiotics), detection agents (eg, dyes such as redox dyes), carbon dioxide generators, and oxygen reducing agents.

[0054] In some embodiments, the composition can be a sterile composition, such as an irradiated composition, such as a composition that has been exposed to about 25 kGy or more of radiation, or even about 30 kGy or more of radiation.

[0055] The composition may preferably meet the ISO 11737-1: 2013 standard. In some embodiments, the composition may be configured in a package, such as a sterile package, and while it may be in the package, it may meet this standard, but once removed from its package, it may not meet the standard because, for example, it may be contaminated shortly after being removed from its package.

[0056] Products

[0057] Another aspect of the present invention relates to an article comprising any composition discussed herein. It is also contemplated that a coated and / or dried layer, such as a film, comprising any composition discussed herein. The article may comprise a coated or dried layer, such as a film, which in turn may comprise any composition discussed herein. In some embodiments, the article may also comprise a substrate that may contact the layer or film. In other embodiments, the article may be sterile. The sterile article may be an irradiated article that has been exposed to 25 kGy or higher radiation, optionally 30 kGy or higher radiation.

[0058] The article may take the form of a culture device such as a culture plate. However, other forms are also possible; an example of another form may be a bag with the composition contained therein.

[0059] In some embodiments, when the article may be a culture device, particularly a culture plate, it may have a base member, a cover sheet (sometimes referred to as a "cover sheet") above the base member, and a growth compartment between the cover sheet and the base member. The growth compartment may comprise any composition described herein, such as a scleroglucan without another water-swellable polymer or a combination of scleroglucan and another one or more water-swellable polymers. Other components may also be included, such as those discussed above with reference to the composition. In some embodiments, the cover sheet is removable and optionally removable to expose the growth compartment and allow the growth compartment to be inoculated.

[0060] The composition comprising scleroglucan may be disposed on the substrate element, in which case the cover sheet may be configured to cover the composition. In an alternative configuration, the composition or film may be disposed on the cover sheet. In another alternative configuration, the composition or film may be disposed on both the substrate and the cover sheet.

[0061] In some embodiments, a spacer element may be disposed between the base element and the cover sheet. When present, the spacer element may provide space for the growth compartment, such as a scleroglucan-containing composition, which may also include one or more of the other components discussed herein.

[0062] In some embodiments, an adhesive can be used. Depending on the desired configuration of the device, the adhesive can be configured on the substrate, the cover sheet, or both. Suitable adhesives include adhesives known for thin film culture devices, such as acrylates (e.g., adhesives based on isooctyl acrylate) or a mixture of one or more acrylates and acrylamide.

[0063] Figure 7 One embodiment of an article of the invention is shown in the form of a culture device 700. The culture device 700 includes a base member 702 and a cover sheet 704. The cover sheet 704 covers one side of the base member 702. Figure 7 Two enlarged views of different portions of device 700 are shown. Enlarged view 706 shows a cross-sectional view of cover sheet 704, while enlarged view 708 shows a cross-sectional view of base member 702.

[0064] As shown in the enlarged view 706, the cover sheet 704 includes at least three different layers: a plastic film layer 710, an adhesive layer 712, and a composition layer 714 of the present invention. The plastic film layer 710 is above both the adhesive layer 712 and the composition layer 714 of the present invention. The plastic film layer 710 is impermeable and flexible, allowing the cover sheet 704 to be peeled off from the base member 702. The adhesive layer 712 is disposed below the plastic film layer 710 and above the composition layer 714 of the present invention, and provides improved adhesion between the layers 710 and 714. The composition layer 714 of the present invention is below both the layers 710 and 712, and comprises one of the scleroglucan-containing compositions of the present invention described herein.

[0065] As shown in the enlarged view 708, the substrate element 702 includes at least three different layers: a plastic-coated paper layer 720, an adhesive layer 718, and a composition layer 716 of the present invention. The plastic-coated paper layer 720 is below both the adhesive layer 718 and the composition layer 716 of the present invention. The plastic-coated paper layer 720 is impermeable to water and provides a relatively rigid substrate for the substrate element 702, from which the cover sheet 704 can be peeled off or pressed. The adhesive layer 718 is configured above the plastic-coated paper layer 720 and below the composition layer 716 of the present invention, and provides improved adhesion between layers 720 and 716. The composition layer 716 of the present invention is above both layers 718 and 720 and includes one of the compositions containing hard glucan of the present invention described herein. The plastic-coated paper layer 720 is printed with a grid, allowing the user to more easily count cfu during use of the device 700.

[0066] Device 700 includes spacing element 722, which is a plastic or plastic-coated paper layer disposed between the lower surface of cover sheet 704 and the upper surface of base member 702. Cover sheet 704 acts as a spacer between cover sheet 704 and base member 702 and defines a circular or oval space therebetween in the form of growth compartment 724. Growth compartment 724 is essentially a void defined above by the lower surface of layer 714 of the composition of the invention of cover sheet 704, below by the upper surface of layer 716 of the composition of the invention of base member 702, and laterally by spacing element 722. In some embodiments, one of the compositions of the invention described herein is disposed within the growth compartment of the culture device of the invention.

[0067] Preparation method

[0068] The compositions and articles described herein can be prepared by any suitable method. Figure 8 The illustrated flow chart illustrates one embodiment of a method of the present invention in the form of method 800 that can be used to make or prepare the compositions and articles of the present invention.

[0069] Step 802 of method 800 includes forming one of the compositions of the present invention described herein.

[0070] In some embodiments, the composition of the present invention is prepared by mixing its components. For example, when the composition comprises scleroglucan and one or more nutrients that promote the growth of one or more microorganisms, the components can be mixed as powders, or in some embodiments, mixed in the presence of a liquid to form a dispersion. Similarly, when the composition comprises scleroglucan and one or more other water-swellable polymers, the components can be mixed as powders, or mixed in combination with a liquid to form a dispersion.

[0071] In some embodiments, when a liquid is used, it can be water or a combination of water and an organic solvent. When an organic solvent is used, it can be preferably selected so that the mixture of water and the organic solvent can be a single phase. This can be achieved, for example, by selecting a solvent that is miscible with water, such as a short-chain alcohol (such as methanol, ethanol or propanol) or an ester (such as ethyl acetate) or some ethers (such as tetrahydrofuran); or by using a sufficiently low concentration of an organic solvent so that the mixture of water and the organic solvent can only form a single phase.

[0072] When the components are mixed as a liquid dispersion, the concentration of the components in the liquid will depend on the precise nature of the components being used and the type of article intended. When a film is to be formed from the liquid, the concentration of the scleroglucan and one or more other water-swellable polymers (if used) must be such that the viscosity of the dispersion is low enough that it can be manipulated and coated onto a substrate. If the concentration is too high, a gel will form, making it impossible to coat the solid components of the dispersion. However, if a film is not to be formed, but the solid components and liquid are to be used as a gel in an article, for example as a gel in a culture bag, then it may be acceptable to use a concentration that forms a gel.

[0073] Step 804 of method 800 comprises forming a film or layer from the composition of the present invention formed in step 802. When a film or layer can be formed, the liquid can be coated on the desired substrate in any suitable manner. Examples include knife coating, die coating, spray coating, spin coating, etc. After coating, the film can be partially or completely dried to remove all or part of the liquid. This can be achieved by any known method, heating, exposure to reduced pressure, or allowing the film or article to air dry under ambient conditions.

[0074] In some embodiments, when a spray can be formed, such as when the components are mixed as a powder and the powder is sprayed onto the base element, cover sheet, or both, any known powder spraying or powder coating device can be used. In other embodiments, an adhesive can be applied to the cover sheet, base layer, or both to adhere the powder composition to one or more appropriate components of the device.

[0075] Step 806 of method 800 is optional and includes packaging the composition, film or article of the invention. In some embodiments, the packaging includes a barrier layer that seals the contents (including the film, article or composition) from the external environment. Any packaging known for this purpose can be used, such as those known for medical devices or PETRIFILM TM Packaging of branded film culture plates.

[0076] Step 808 of method 800 includes sterilizing the composition, film or article of the present invention. When performing the optional packaging step, the sterilization step can be performed before, at the same time or after the optional packaging step. In other embodiments, the sterilization step can be performed at the same time as or after the optional packaging step, so that the composition, film or article can be protected by the packaging and remain sterile for a period of time, such as until the packaging is opened.

[0077] Sterilization steps can be used to make the composition, film or article sterile. This can be achieved by exposing the composition, film or article to ionizing radiation (e.g., actinic radiation). For this purpose, various radiation types can be used, such as gamma rays, electron beams (eBeams) and x-rays. In some embodiments, the composition, film or article can be irradiated with actinic radiation to make it sterile. Typically, at least 25kGy of radiation is used. In some cases, at least 30kGy of radiation is used.

[0078] Gamma irradiation can be produced using commercially available sources, such as those available from Atomic Energy of Canada, Inc. Some such sources may use a cobalt-60 high energy source. Electron beam irradiation sources are also commercially available, such as an electron beam system available from ESICB-300. X-ray machines are also well known and available to skilled artisans.

[0079] How to use

[0080] The present invention also includes methods of culturing one or more microorganisms using the compositions, layers, films, or articles disclosed herein. Fig. 9 The illustrated flow chart illustrates one embodiment of a method of using a composition, layer, film, or article disclosed herein in the form of method 900 .

[0081] In step 902 of method 900, a sample (eg, an aqueous sample) containing one or more microorganisms can be contacted with the composition, layer, film, or article to form an inoculated composition, layer, film, or article.

[0082] In step 904 of method 900, the composition, layer, film or article of the inoculation can then be allowed to incubate enough time at high temperature to allow at least one replication of the one or more microorganisms. Exemplary high temperature includes about 30 ℃ to about 80 ℃, such as about 30 ℃, about 32 ℃, about 37 ℃, about 40 ℃, about 42 ℃, about 45 ℃, about 50 ℃, about 60 ℃ or about 70 ℃ etc. Depending on the precise content of the composition, film or article, the nature of the cultivated microorganism and other factors known to those skilled in the relevant art, other temperatures can be used. The required time can be about 30 minutes to about 72 hours, about 1 hour to about 60 hours, about 2 hours to about 50 hours, about 5 hours to about 40 hours, about 6 hours to about 30 hours, about 7 hours to about 25 hours or about 8 to 24 hours. The desired time can be from about 8 hours to about 10 hours, from about 10 hours to 12 hours, from about 12 hours to 14 hours, from about 14 hours to 16 hours, from about 16 hours to about 18 hours, from about 18 hours to about 20 hours, from about 20 hours to about 22 hours, or from about 22 hours to about 24 hours.

[0083] In optional step 906 of method 900, the composition, film or article may optionally be counted to determine the number of CFUs of one or more microorganisms that may have been formed. This may be done manually by human observation or using commercially available instruments such as the PETRIFILM designed for this purpose. TM The analysis was performed using an Advanced Plate Reader (3M Company, St Paul, MN, USA).

[0084] Example

[0085] Material

[0086] BACTO Tryptic Soy Broth (TSB) powder was obtained from Becton, Dickinson and Company, Franklin Lakes, NJ. The manufacturer reports the composition of the TSB powder as: tryptone (57 wt %), soy peptone (10 wt %), dextrose (8 wt %), sodium chloride (17 wt %), dipotassium phosphate (8 wt %).

[0087] R2A bouillon powder was obtained from HIMEDIA Laboratories (Mumbai, India). The manufacturer reports the composition of the R2A bouillon powder as: casein acid hydrolysate (16 wt%), yeast extract (16 wt%), Peptone (16 wt%), dextrose (16 wt%), soluble starch (16 wt%), dipotassium phosphate (9.6 wt%), magnesium sulfate (0.8 wt%), sodium pyruvate (9.6 wt%).

[0088] Scleroglucan was obtained from Cargill, Incorporated under the trade name ACTIGUM CS-6 Scleroglucan.

[0089] 2,3,5-Triphenyltetrazolium chloride (TTC) and sodium pyruvate were obtained from MilliporeSigma Company, St. Louis, MO.

[0090] 3M PETRIFILM Aerobic Count Plates were obtained from 3M Company, Maplewood, MN, and were designated Comparative Example A (CE-A).

[0091] Butterfield buffer was obtained from 3M Company.

[0092] Xanthan gum and locust bean gum were obtained from CP Kelco Company, Atlanta, GA.

[0093] Guar gum (Meyprogat 150) was obtained from Danisco, Copenhagen, Denmark.

[0094] Bacterial strains Escherichia coli (ATCC 25922), Bacillus subtilis (ATCC 6633) were obtained from Microbiologics, St. Cloud, MN.

[0095] The Proteus mirabilis strain (ATCC 14153) was obtained from ATCC (American Type Culture Collection), Manassas, Va.

[0096] Unless otherwise stated, water was obtained from a MILLI-Q water purification system (EMD Millipore, Billerica, MA).

[0097] preparation Example 1 .Inoculum preparation

[0098] Sterile TSB liquid medium (30 g TSB powder per liter of purified water, pH 7.3 ± 0.2) was prepared according to the manufacturer's instructions and sterilized using an autoclave. Cultures of each bacterial strain were prepared separately in sterile test tubes containing 9 mL of sterile TSB and incubated overnight at 30°C in an orbital shaking incubator at 225 rpm (revolutions per minute). Each inoculum was prepared by serial dilution of a single culture sample with Butterfield buffer. Escherichia coli (ATCC 25922) and Proteus mirabilis (ATCC 14153) inocula were serially diluted (10-fold dilutions) to a final 10 -8 Dilution samples. Bacillus subtilis (ATCC 6633) inoculum was serially diluted to a final concentration of 10 -7 Dilution Samples. Bacillus subtilis (ATCC 6633) inoculum samples were supplemented with sodium pyruvate (2 g / L) when used to inoculate thin film culture device AA-DD.

[0099] Example 1 .Preparation of cover sheets for thin film devices

[0100] Powder compositions AD were prepared from scleroglucan powder, xanthan gum powder and locust bean gum powder. Powder composition A contained only scleroglucan powder. Powder compositions BD were powder mixtures containing different weight percent (wt.%) concentrations of scleroglucan powder, xanthan gum powder and locust bean gum powder. For each powder mixture, the components were combined and mixed by shaking in a plastic bag for 30 seconds to form a uniform mixture. The proportions of the powder components in the compositions are summarized in Table 1.

[0101] The cover sheet component of each film unit started with a biaxially oriented polypropylene (BOPP) film (1.6 mil thick) with a pressure sensitive adhesive (96:4 weight ratio of isooctyl acrylate:acrylamide) at 1.3 mg / cm 2 The adhesive contained 0.1 wt % TTC based on the dry weight of the adhesive. The adhesive-coated surface of the film was powder coated with a single uniform powder mixture selected from powder compositions AD. Each powder composition was applied uniformly to the adhesive surface and excess powder was removed from the adhesive layer by hand shaking the film. The resulting powder-coated film was cut into 76 mm wide and 100 mm long sections to form thin film device cover sheets.

[0102] Table 1.

[0103]

[0104] Example 2 Preparation of the base element assembly of the thin film culture device containing TSB powder as nutrients

[0105] The base element assembly of each film device was prepared starting from a transparent polyethylene coated paper sheet (1 cm x 1 cm in size, 0.15 mm thick, coated on both sides). The paper sheet assembly was white with yellow grid lines (1 cm x 1 cm). One side of the polyethylene coated paper sheet was glued with a pressure sensitive adhesive (weight ratio of isooctyl acrylate: acrylic acid of 98:2) at 1.3 mg / cm 2 The adhesive coated surface was then powder coated with a single powder mixture selected from powder compositions EH (Table 2). For each powder mixture, the components were combined and mixed by shaking in a plastic bag to form a uniform mixture. Each powder composition was evenly applied to the adhesive surface and excess powder was removed from the adhesive layer by hand shaking the film. The resulting powder coated film was cut into 76 mm wide, 100 mm long sections to form a thin film device substrate element assembly.

[0106] Table 2.

[0107]

[0108] Example 3 Preparation of the base element assembly of the thin film culture device containing R2A broth powder as nutrients

[0109] The base member assembly was prepared separately from powder composition IL (Table 3) using the same procedure as described in Example 2, except that R2A broth powder was substituted for TSB powder in the mixture used.

[0110] Table 3.

[0111]

[0112] Example 4 .Preparation of thin film devices

[0113] The thin film culture devices were assembled by attaching a cover sheet selected from Example 1 to a base member assembly selected from Examples 2 and 3. Each cover sheet was attached to the base member (in a hinge-like manner) along one edge (76 mm edge) using a double-sided adhesive tape (approximately 9.5 mm wide). For each device, the cover sheet and base member were oriented so that the edges were aligned and the powder-coated surface of the cover sheet faced the powder-coated surface of the base member. The construction of thin film culture devices AA-HH is summarized in Table 4.

[0114] Table 4.

[0115]

[0116] Example 5 .Inoculation, incubation and colony observation of thin film devices

[0117] The film culture device AA-HH is exposed to 30kGy of gamma radiation. The film culture device AA-HH of irradiated embodiment 4 is inoculated with a single inoculum of Escherichia coli (ATCC 25922), Bacillus subtilis (ATCC 6633) or Proteus mirabilis (ATCC 14153). The device is placed on a flat horizontal surface. The cover sheet of each device is lifted, and 1mL of a single inoculum (i.e., the final dilution described in Preparation Example 1) is carefully added to the compact area of ​​the center of the coated substrate element once with a pipette. The cover sheet is gently returned to its original position. 3MPETRIFILM yeast and mold spreader (obtained from 3M Company) is applied to the outer surface of the cover sheet by hand pressure to spread the inoculum so that it forms a circular area of ​​about 2 3 / 8 inches (6.03cm) in diameter. The spreader is then removed and the plate is kept undisturbed for 1-5 minutes to allow gel formation. The inoculated devices were prepared in triplicate (n=3 for each device AA-HH). Each device was then incubated at 32°C for 48 hours. The same inoculation and incubation procedures were also performed using 3M PETRIFILM aerobic counting plates (CE-A) that had been exposed to a 30 kGy dose of gamma radiation and non-irradiated 3M PETRIFILM aerobic counting plates (CE-A).

[0118] The image of the device was taken using a 3M PETRIFILM advanced plate reader (obtained from 3M Company and operated in accordance with the manufacturer's instructions) and exported as a JPEG image file. The area of ​​the red colonies present in the device was measured using ImageJ software (National Institutes of Health, Bethesda, MD). After opening the image file, the scale of the image was set using the internal 10mm standard, and the "global" setting was selected. For each image, the image scale was set using the distance between the yellow grid lines in the substrate element. Next, the "Image Adjustment Color Balance" setting was selected, and the "Yellow" setting was selected from the drop-down menu. The minimum and maximum sliders were used to increase the contrast of the colony edges. The image was then converted to 8 bits, and a threshold was set to select only pixels representing colonies. In the "Analyze Particles" menu (in the "Analyze" menu of the software), the smallest bacterial colony in the image was visually identified and the area of ​​the colony was set to the minimum size for the software to identify the colony, and small non-colony particles were eliminated from the analysis. Select the "OK" button, and the area (mm) of the colony was measured by the software program. 2 ). The results are reported in Tables 5 and 6. For Escherichia coli (ATCC 25922) and Proteus mirabilis (ATCC 14153) samples, the average colony size was determined based on the analysis of 25-100 colony forming units (cfu) per device. For Bacillus subtilis (ATCC 6633) samples, the average colony size was determined based on the analysis of 5-10 colony forming units (cfu) per device.

[0119] The notation "ND" in Tables 5 and 6 indicates that the boundaries of multiple colonies merged together, resulting in large, diffuse and / or irregularly shaped patches that could not be counted for colony counting purposes.

[0120] Table 5.

[0121]

[0122] Table 6.

[0123]

[0124] List of implementation methods

[0125] The following is a non-limiting list of implementations:

[0126] 1. A composition comprising:

[0127] a. one or more water-swellable polymers other than scleroglucan, the one or more water-swellable polymers optionally comprising one or more of guar gum, locust bean gum or xanthan gum, and

[0128] b. scleroglucan (which may be present at about 1 or greater, optionally about 5 or greater, optionally about 10 or greater, optionally about 20 or greater, optionally about 25 or greater, optionally about 30 or greater, optionally about 33 or greater, optionally about 40 or greater, optionally about 50 or greater, optionally about 60 or greater, optionally about 67 or greater, optionally about 70 or greater, optionally about 75 or greater, optionally about 80 or greater, optionally about 90 or greater, or optionally about 95 or greater weight percent, 100 wt%, or about 1 to 100 wt%, or about 25 to about 100 wt%, or about 10 to about 70 wt%, based on the total weight of the one or more water-swellable polymers other than scleroglucan and the total weight of scleroglucan).

[0129] 2. A device comprising:

[0130] a. Base element;

[0131] b. a cover sheet connected to said base member; and

[0132] c. A growth chamber disposed between the cover sheet and the base member;

[0133] d. wherein the cover sheet can be moved to expose the growth chamber; and

[0134] e. Further, wherein the growth compartment comprises the composition of embodiment 1.

[0135] 3. The composition or device of any of the preceding embodiments, further comprising one or more nutrients that promote the growth of one or more microorganisms.

[0136] 4. The composition or device of any of the preceding embodiments, wherein the ratio of the weight of (i) the one or more water-swellable polymers to the weight of (ii) the scleroglucan is 1:99 to 99:1, optionally 1:10 to 10:1, further optionally 3:1 to 1:3.

[0137] 5. The composition or device of any of the preceding embodiments, wherein the weight percent of the water-swellable polymer, based on the total weight of the water-swellable polymer and the total weight of the scleroglucan, is 1 or greater, optionally 5 or greater, optionally 10 or greater, optionally 20 or greater, optionally 25 or greater, optionally 30 or greater, optionally 33 or greater, optionally 40 or greater, optionally 50 or greater, optionally 60 or greater, optionally 67 or greater, optionally 70 or greater, optionally 75 or greater, optionally 80 or greater, optionally 90 or greater, or optionally 95 or greater.

[0138] 6. The composition or device of any of the preceding embodiments, wherein the weight percentage of scleroglucan, based on the sum of the total weight of the water-swellable polymer and the total weight of scleroglucan, is 95 or less, optionally 90 or less, optionally 80 or less, optionally 75 or less, optionally 70 or less, optionally 67 or less, optionally 60 or less, optionally 50 or less, optionally 40 or less, optionally 33 or less, optionally 30 or less, optionally 25 or less, optionally 20 or less, optionally 10 or less, optionally 5 or less, or optionally 1 or less.

[0139] 7. The composition or device of any of the preceding embodiments, comprising scleroglucan and one or more nutrients that promote the growth of one or more microorganisms.

[0140] 8. The composition or device of any of the preceding embodiments, wherein the one or more nutrients comprise one or more of a sugar (wherein the sugar optionally comprises at least one of glucose, lactose, fructose, maltose, or sucrose), a soluble starch, tryptone, soy peptone, yeast extract, casamino acids, sodium pyruvate, sodium chloride, magnesium chloride, magnesium sulfate, or dipotassium phosphate.

[0141] 9. The composition or device of any of the preceding embodiments, wherein the one or more nutrients include glucose.

[0142] 10. The composition or device of any of the preceding embodiments, wherein the composition or device is an irradiated composition or device that has been exposed to 25 kGy or more radiation, optionally 30 kGy or more radiation.

[0143] 11. The composition or device of any one of the preceding embodiments, which is sterile.

[0144] 12. The composition or device of any of the preceding embodiments, disposed inside a package, optionally wherein the package provides a sterile barrier between the interior of the package and an external environment.

[0145] 13. An article comprising the composition or device of any one of the preceding embodiments, optionally wherein the article is a culture device, optionally a thin film culture device.

[0146] 14. The article of embodiment 13, wherein the article is an irradiated article that has been exposed to 25 kGy or more radiation, optionally 30 kGy or more radiation, or about 25 to about 35 kGy.

[0147] 15. The article of manufacture of any one of embodiments 13-14, which is sterile.

[0148] 16. The article of any one of embodiments 13-15, disposed inside a package, optionally wherein the package provides a sterile barrier between the interior of the package and an external environment.

[0149] 17. A film comprising the composition of any one of embodiments 1-12.

[0150] 18. An article comprising a substrate and the film of embodiment 17.

[0151] 19. A culture device comprising the membrane of any one of embodiments 17-18, wherein the culture device comprises a growth chamber defined by a backing and a covering element covering the growth chamber, and wherein the membrane is disposed on the backing, the covering element, or both.

[0152] 20. The composition of any one of embodiments 1-13, which is used for culturing one or more microorganisms.

[0153] 21. The membrane of embodiment 17, used for culturing one or more microorganisms.

[0154] 22. The article of any one of embodiments 14-16 or 18-20, which is used for culturing one or more microorganisms.

[0155] 23. A method for culturing a microorganism, the method comprising:

[0156] a. contacting a microorganism with a composition according to any one of embodiments 1-13 to form an inoculated composition, and

[0157] b. allowing the microorganism to undergo at least one replication.

[0158] 24. A method for culturing a microorganism, the method comprising:

[0159] a. contacting a microorganism with a device according to any one of embodiments 2-12 or a product according to any one of embodiments 13-15 to form an inoculated product, and

[0160] b. allowing the microorganism to undergo at least one replication.

[0161] 25. A method for culturing a microorganism, the method comprising:

[0162] a. contacting a microorganism with the film of embodiment 17 or the product of any one of embodiments 18-22 to form an inoculated product, and

[0163] b. allowing the microorganism to undergo at least one replication,

[0164] c. wherein the microorganism is optionally a microorganism of the genus Bacillus, and further optionally a species of the genus Bacillus.

[0165] 26. The method of any one of embodiments 24-25, further comprising incubating the inoculated composition or preparation, optionally at a temperature of 25°C to 80°C for 30 minutes to 72 hours.

[0166] 27. The method of any one of embodiments 24-26, further comprising the step of allowing the microorganism to form one or more microbial colonies and counting the number of microbial colonies.

[0167] 28. A method for preparing the composition of embodiment 7, the method comprising

[0168] The scleroglucan is mixed with one or more nutrients that promote the growth of one or more microorganisms and optionally a water-swellable polymer other than scleroglucan.

[0169] 29. A method of sterilizing the composition or device of any one of embodiments 1-14, the method comprising exposing the composition or device to sufficient radiation to render the composition sterile.

[0170] 30. The method of embodiment 28, further comprising exposing the composition to sufficient radiation to render the composition sterile.

[0171] 31. The method of any one of embodiments 28-30, further comprising exposing the composition to at least 25 kGy of irradiation, optionally at least 30 kGy of irradiation.

[0172] 32. The method of any one of embodiments 28-31, wherein the water-swellable polymer other than scleroglucan comprises one or more of guar gum, locust bean gum, and xanthan gum, and optionally comprises locust bean gum, xanthan gum, or a mixture of locust bean gum and xanthan gum.

[0173] 33. The method of any one of embodiments 28-31, wherein the ratio of the weight of (i) the water-swellable polymer to the weight of (ii) the scleroglucan is 1:99 to 99:1, optionally 1:10 to 10:1, further optionally 3:1 to 1:3.

[0174] 34. The method of any one of embodiments 28-32, wherein the weight percentage of the water-swellable polymer, based on the total weight of the water-swellable polymer and the total weight of the scleroglucan, is 1 or greater, optionally 5 or greater, optionally 10 or greater, optionally 20 or greater, optionally 25 or greater, optionally 30 or greater, optionally 33 or greater, optionally 40 or greater, optionally 50 or greater, optionally 60 or greater, optionally 67 or greater, optionally 70 or greater, optionally 75 or greater, optionally 80 or greater, optionally 90 or greater, or optionally 95 or greater.

[0175] 35. The method of any one of embodiments 28-31, wherein the weight percentage of the water-swellable polymer to the scleroglucan is 95 or less, optionally 90 or less, optionally 80 or less, optionally 75 or less, optionally 70 or less, optionally 67 or less, optionally 60 or less, optionally 50 or less, optionally 40 or less, optionally 33 or less, optionally 30 or less, optionally 25 or less, optionally 20 or less, optionally 10 or less, optionally 5 or less, or optionally 1 or less, based on the total weight of the water-swellable polymer and the total weight of the scleroglucan.

[0176] 36. A method for preparing a sterile culture device, the method comprising:

[0177] a. fixing the composition of any one of embodiments 1-13 to a substrate to form a culture device; and

[0178] b. exposing the culture device to sufficient radiation to render the composition sterile.

[0179] 37. The method of embodiment 36, comprising exposing the composition to at least 25 kGy of irradiation, optionally at least 30 kGy of irradiation, or about 25 to about 35 kGy.

[0180] 38. The method of any one of embodiments 36-37, further comprising placing the culture device in a package.

[0181] 39. The method of embodiment 38, wherein the step of exposing the culture device to radiation is performed while the culture device is configured in the package.

[0182] 40. The method of any one of embodiments 38-39, wherein the step of exposing the culture device to radiation is performed while the culture device is sealed in the package.

[0183] 41. The composition or device of any of the preceding embodiments, wherein the scleroglucan is present as a weight percentage of the scleroglucan of about 1 or greater, optionally about 5 or greater, optionally about 10 or greater, optionally about 20 or greater, optionally about 25 or greater, optionally about 30 or greater, optionally about 33 or greater, optionally about 40 or greater, optionally about 50 or greater, optionally about 60 or greater, optionally about 67 or greater, optionally about 70 or greater, optionally about 75 or greater, optionally about 80 or greater, optionally about 90 or greater, or optionally about 95 or greater, 100 wt%, or about 1 to 100 wt%, or about 25 to about 100 wt%, or about 10 to about 70 wt%, based on the total weight of the one or more other water-swellable polymers and the total weight of the scleroglucan.

[0184] References

[0185] A number of patents and publications are cited above in order to more fully describe and disclose the present invention and the prior art in the field to which the present invention belongs. Full citations for these references are provided below. Each of these references is incorporated by reference into the present disclosure in its entirety to the same extent as if each individual reference was specifically and individually indicated to be incorporated by reference.

[0186] All publications mentioned herein are incorporated by reference to the extent possible in support of the present invention.

Claims

1. A composition comprising: (i) one or more water-swellable polymers other than scleroglucan, and (ii) Scleroglucan.

2. The composition of claim 1, wherein the one or more water-swellable polymers comprise one or more of guar gum, locust bean gum, or xanthan gum.

3. The composition according to claim 1 or 2, wherein the weight ratio of the one or more water-swellable polymers to scleroglucan is from 1:99 to 99:

1.

4. The composition according to any one of claims 1 to 3, wherein the weight percentage of the one or more water-swellable polymers is 1 or greater, based on the sum of the total weight of the one or more water-swellable polymers and the total weight of the scleroglucan.

5. The composition according to any one of claims 1 to 4, wherein the weight percentage of the scleroglucan is 95 or less based on the sum of the total weight of the water-swellable polymer and the total weight of the scleroglucan.

6. The composition of any one of claims 1-5, further comprising one or more nutrients that promote the growth of one or more microorganisms.

7. The composition of claim 6, wherein the one or more nutrients include sugar, soluble starch, tryptone, soy peptone, yeast extract, casamino acids, sodium pyruvate, sodium chloride, magnesium chloride, magnesium sulfate, or dipotassium phosphate.

8. The composition of claim 7, wherein the one or more nutrients include glucose.

9. The composition of any one of claims 1-8, wherein the composition is an irradiated composition that has been exposed to 25 kGy or more of radiation.

10. The composition according to any one of claims 1-9, wherein the composition is sterile.

11. A culture device comprising: Base element; a cover sheet connected to the base member; a growth compartment disposed between the cover sheet and the base member; and A scleroglucan layer comprising scleroglucan is located within or adjacent to the growth compartment. 12 . The culture device according to claim 11 , wherein the scleroglucan layer further comprises one or more water-swellable polymers other than scleroglucan.

13. The culture device of claim 11, wherein the one or more water-swellable polymers comprise one or more of guar gum, locust bean gum, or xanthan gum. 14 . The culture device according to claim 12 , wherein in the scleroglucan layer, the weight ratio of the one or more water-swellable polymers to scleroglucan is 1:99 to 99:

1.

15. The culture device according to any one of claims 12 to 15, wherein the weight percentage of the one or more water-swellable polymers is 1 or greater based on the sum of the total weight of the one or more water-swellable polymers and the total weight of the scleroglucan. 16 . The culture device according to claim 12 , wherein the weight percentage of the scleroglucan based on the sum of the total weight of the water-swellable polymer and the total weight of the scleroglucan is 95 or less.

17. The culture device of any one of claims 11-17, wherein the scleroglucan layer further comprises one or more nutrients that promote the growth of one or more microorganisms.

18. The culture device of claim 18, wherein the one or more nutrients comprise sugar, soluble starch, tryptone, soy peptone, yeast extract, casamino acids, sodium pyruvate, sodium chloride, magnesium chloride, magnesium sulfate, or dipotassium phosphate.

19. The culture device of claim 19, wherein the one or more nutrients include glucose.

20. The culture device of any one of claims 11-20, wherein the culture device has been sterilized by exposure to 25 kGy or more of radiation.

21. The culture device of any one of claims 11-21, further comprising a package, wherein the culture device is disposed inside the package, and wherein the package provides a sterile barrier between the culture device and an external environment.

22. A method for culturing a microorganism, the method comprising: contacting a microorganism with a composition according to any one of claims 1 to 10 to form an inoculated composition; and The microorganism is allowed to undergo at least one replication.

23. A method for culturing a microorganism, the method comprising: contacting a microorganism with a culture device according to any one of claims 11 to 22 to form an inoculated culture device; and The microorganism is allowed to undergo at least one replication.

24. A method for sterilizing a culture device, the method comprising: Providing a culture device, the culture device comprising the composition according to any one of claims 1-10; and The culture device is exposed to sufficient radiation to sterilize the culture device.

25. A film comprising the composition of any one of claims 1-10.

26. An article comprising a substrate and the film of claim 23.

Images