Mycelium leather and preparation method thereof

Abstract

The invention discloses mycelium leather and a preparation method thereof, and relates to the technical field of leather manufacturing. According to the mycelium leather preparation method, the mycelium leather is prepared through the liquid culture medium, and the problems that in the prior art, the growth cycle of solid-state cultured mycelium is long, the thickness of the mycelium is not uniform, part of the mycelium is dried and inactivated, and solid-state impurities of the mycelium are complex to clean can be effectively solved; and a new method is provided for more efficient and high-quality preparation of mycelium leather.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of leather manufacturing, in particular to a mycelium leather and a preparation method thereof. BACKGROUND

[0002] With the increasing demand for sustainable materials and environmentally friendly alternatives worldwide, large fungal mycelium (also known as mycelium leather) has attracted widespread attention as an innovative bio-based material. This material utilizes the network structure formed by edible mushroom mycelium under specific conditions, and after processing, it can simulate the performance and texture of traditional animal leather. Mycelium leather has significant advantages such as being green, biodegradable, and low carbon emissions during production.

[0003] In view of this, the present application is proposed. SUMMARY

[0004] Based on this, the purpose of the present application is to provide a mycelium leather and a preparation method thereof. The preparation method provided by the present application can effectively solve the problems of long growth cycle, uneven thickness of mycelium, partial mycelium drying and inactivation, and complex cleaning of solid-state impurities in the solid-state cultivation of mycelium in the prior art. The obtained mycelium leather has high breaking resistance. A new method for more efficient and high-quality preparation of mycelium leather is provided.

[0005] The present application is implemented as follows: On the one hand, the present application provides a preparation method of mycelium leather, which comprises the following steps: A strain activation step: inoculating the strain into an activation medium for cultivation; wherein the activation medium is a potato plate medium; and the strain is Ganoderma lucidum; An expansion culture step: inoculating the strain after activation culture into an expansion medium for cultivation; wherein the expansion medium comprises, by weight: 18-22 parts of glucose, 1-3 parts of wheat bran powder, 1-3 parts of yeast powder, 1-3 parts of peptone, 1-2 parts of potassium dihydrogen phosphate, 1-2 parts of magnesium sulfate, and 1000 parts of water; A fermentation culture step: inoculating the strain liquid after expansion culture for fermentation culture to obtain a mycelium skin.

[0006] Traditional mycelium leather preparation uses solid-state cultivation of mycelium, but has some drawbacks, such as but not limited to: 1. Solid-state cultivation of mycelium has a long growth cycle and is prone to uneven thickness of mycelium; 2. Partial mycelium will also dry out during long-term growth, affecting the quality of the whole mycelium leather; 3. The solid-state impurities contained in the solid-state cultivation of mycelium are complex to clean, and higher requirements are put forward for subsequent processing. A new method for more efficient and high-quality preparation of mycelium leather is provided.

[0007] The application provides a preparation method, and adopts liquid fermentation culture to prepare mycelium skin, so that the problems of long growth period of solid culture mycelium, uneven mycelium thickness, partial mycelium dryness and inactivation and complex solid impurity cleaning of the mycelium can be solved, and the mycelium leather obtained by the method has high breaking resistance.

[0008] Optionally, in some embodiments of the application, the potato plate culture medium is prepared by the following method: peeling 200g of potatoes (cut into blocks, boiling in water for 20min, and filtering with gauze to obtain a filtrate), adding 20-22g of glucose, 18-20g of agar powder and 5-8g of mulberry branch powder, and adding distilled water to 1L, and naturally adjusting pH, and sterilizing at 121℃ for 20-25min.

[0009] Optionally, in some embodiments of the application, the culture conditions of the activation culture step are as follows: culturing at 24-27℃ and 65-70% relative humidity for 9-15d.

[0010] Optionally, in some embodiments of the application, the culture conditions of the expansion culture step are as follows: culturing at 25℃ in a shaker with a rotation speed of 150rpm for 7d.

[0011] Optionally, in some embodiments of the application, the culture conditions of the fermentation culture step are as follows: culturing at 25-26℃ and 65-70% relative humidity for 22-26d.

[0012] Optionally, in some embodiments of the application, the preparation method further comprises a mycelium skin pretreatment step. The mycelium skin pretreatment step comprises placing the mycelium skin obtained from the fermentation culture step in a sodium carbonate solution for degreasing treatment. Through the degreasing treatment, hydrophobic proteins can be removed.

[0013] Optionally, in some embodiments of the application, the concentration of the sodium carbonate solution is 2-4%, the degreasing treatment temperature is 48-52℃, and the time is 2-4h.

[0014] Optionally, in some embodiments of the application, the preparation method further comprises a preliminary tanning step. The preliminary tanning step comprises placing the mycelium skin treated in the pretreatment step in a tannin acid solution for preliminary tanning treatment.

[0015] Optionally, in some embodiments of the application, the concentration of the tannin acid solution is 6-8%, and the preliminary tanning treatment is carried out under the conditions of keeping pH at 3-4, constant temperature oscillation at 38-42℃ for 22-26h. Through the rubbing treatment, the cross-linking can be increased, and the cross-linking density can be improved.

[0016] Optionally, in some embodiments of the present application, the preparation method further comprises a re-tanning step. The re-tanning step comprises replacing fresh tannin solution and performing re-tanning treatment; the re-tanning treatment is performed under the condition of pH 3-4, constant temperature oscillation at 38-42℃ for 22-26h.

[0017] Optionally, in some embodiments of the present application, the preparation method further comprises a post-treatment step. The post-treatment step comprises: The re-tanning step comprises replacing fresh tannin solution and performing re-tanning treatment; the re-tanning treatment is performed under the condition of pH 3-4, constant temperature oscillation at 38-42℃ for 22-26h.

[0018] Optionally, in some embodiments of the present application, the plasticizing treatment is performed under the condition of 48-52℃ for 5-7h.

[0019] Optionally, in some embodiments of the present application, the preparation method further comprises a post-finishing step. The post-finishing step comprises pressing the mycelium skin treated by the post-treatment step to obtain the finished mycelium leather; the pressing condition is hot pressing at 78-82℃, 9-11Mpa for 5-10min.

[0020] Optionally, in some embodiments of the present application, the Ganoderma lucidum strain can be selected from the common edible fungus strains such as Guoling 1, Hunan 1, rubber, or HZ.

[0021] Optionally, in some embodiments of the present application, the post-finishing step further comprises spraying anti-fouling agent and / or antibacterial treatment to the mycelium leather after pressing, for example, spraying polyurethane / beeswax emulsion; which can achieve the effect of water and dirt resistance.

[0022] Optionally, in some embodiments of the present application, the antibacterial treatment comprises 0.1% nanometer silver dispersion liquid soaking for 1h.

[0023] In another aspect, the present application provides a mycelium leather prepared by the preparation method as described in any one of the above. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0025] Figure 1 Photos of the activation culture results of each Ganoderma sp. in potato plate medium in Example 1.

[0026] Figure 2 Photos of the expansion culture results of each Ganoderma sp. in liquid medium in Example 1.

[0027] Figure 3 Photos of the fermentation culture results of each Ganoderma sp. in fermentation medium in Example 1.

[0028] Figure 4 Photos of the leather appearance made of the mycelium obtained by culturing each Ganoderma sp. in Example 1. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. If specific conditions are not indicated in the embodiments, the conditions are implemented according to conventional conditions or the conditions suggested by the manufacturers. If the reagents or instruments used are not indicated by the manufacturers, they are all conventional products that can be purchased in the market.

[0030] The features and performances of the present application are further described in detail below in combination with the embodiments.

[0031] Example 1 The present example provides a method for preparing mycelium leather by liquid mycelium fermentation of Ganoderma, which specifically comprises the following steps: (I) Experimental materials 1. Strains: Common edible fungus strains (available in the market) such as Ganoderma (Guoling 1, Hunan 1, rubber, HZ) are preliminarily selected.

[0032] 2. Basic medium: 2.1 Potato plate medium: 200 g of peeled potato (cut into blocks, boiled in water for 20 min, and filtered with gauze to obtain the filtrate), 20 g of glucose (in other embodiments, it can be any value between 20-22 g), 18 g of agar powder (in other embodiments, it can be any value between 18-20 g), 5 g of mulberry branch powder (in other embodiments, it can be any value between 5-8 g), and distilled water are added to make up to 1 L, the pH is natural, and sterilization is performed at 121 ℃ for 20-25 min.

[0033] 2.2 Liquid medium: 20 g of glucose, 2 g of wheat bran powder, 2 g of yeast powder, 2 g of peptone, 1 g of potassium dihydrogen phosphate, 1 g of magnesium sulfate, and 1 L of distilled water are added, the pH is natural, and sterilization is performed at 121 ℃ for 20-25 min.

[0034] 3. Preparation of tanning solution: Tannin solution: 6% (w / v) tannin (plant source such as gallnut, chestnut extract) in deionized water, pH adjusted to 3-4 (adjusted with citric acid).

[0035] Pre-treatment solution: 3% (w / v) sodium carbonate solution (for degreasing, opening the fiber structure) (in other embodiments, it can be any value between 2-4%).

[0036] Post-treatment solution: composite post-treatment solution containing 5% (w / v) glycerol (plasticizer) (in other embodiments, it can be any value between 5-6%), 3% (w / v) collagen (in other embodiments, it can be any value between 3-5%), and 2% (w / v) sorbitol (in other embodiments, it can be any value between 2-5%).

[0037] (II) Experimental equipment Electric heating pressure steam sterilizer; electric heating air drying oven; shaking incubator; biological fermentation bottle; fermentation box; constant temperature and humidity box; pH meter; ultrasonic cleaner; gauze II. Preparation steps (I) Activation and culture of strains 1. In a sterile clean bench, transfer each strain to a potato plate culture medium respectively; 2. Place Ganoderma lucidum at 24-27°C, 65-70% relative humidity for 9-15 days; 3. Select strains with dense mycelium and no contamination for standby use.

[0038] The culture appearance results of each Ganoderma lucidum strain on the potato plate culture medium are shown in Figure 1 .

[0039] (II) Inoculation and expansion culture of liquid medium Prepare the liquid expansion culture medium according to the above formula, sterilize at 121°C for 20 minutes, and after cooling, inoculate an equal amount of fungus cake (600mL of culture medium / 20 fungus cakes) in the liquid culture medium, place it in a 25°C, 150rpm shaking incubator, and culture for 7 days. Select the fermentation bottles with uniform and suspended state of mycelial balls for standby use.

[0040] The culture appearance results of each Ganoderma lucidum strain on the liquid expansion culture medium at day 0 and day 7 of culture are shown in Figure 2 .

[0041] (III) Static fermentation culture of liquid strains The selected liquid strain fermentation bottle is transferred to a sterilized fermentation box container in a sterile clean bench without preparing new culture medium, spread, and static fermentation culture is carried out. The mouth is sealed and placed in a culture room with a temperature of 25°C and a relative humidity of 70% (in other embodiments, it can be any value between 65-70%). The culture is carried out for 25 days (in other embodiments, it can be any value between 22-26 days). When the mycelium skin is relatively thick and not easy to break, it is taken out and placed in a 40°C electric heating air drying oven for 4 hours for use.

[0042] The appearance of the mycelium skin obtained from each Ganoderma strain after fermentation in the fermentation box is shown in Figure 3 ; the mycelium is dense, and the front surface has a touch of velvet.

[0043] The mycelium leather obtained from the HZ strain has the following appearance characteristics: the color is white to light yellow, and the color is relatively uniform; in terms of texture, the back surface is smoother than the front surface, the front surface has a silk feel, and the back surface has a clear gloss; in terms of texture, the material is soft, the thickness is greater than that of the leather obtained from the Hunan 1, XJ and Guoling 1 strains, the front surface has a relatively dense touch, and the back surface has a smooth touch.

[0044] The mycelium leather obtained from the Hunan 1 strain has the following appearance characteristics: the color is white to light yellow; in terms of texture, the back surface is relatively smooth than the front surface, the front surface has irregular concentric ring texture, and the back surface has a gloss; in terms of texture, the material is soft, the thickness is less than that of the leather obtained from the HZ strain but greater than that of the XJ and Guoling 1 strains, the front surface has a relatively rough touch, and the back surface has a smooth touch.

[0045] The mycelium leather obtained from the XJ strain has the following appearance characteristics: the color is white to light yellow; in terms of texture, the front surface and the back surface are relatively smooth, the front surface has a strong and dense silk feel, and the back surface has a strong gloss; in terms of texture, the material is brittle, the thickness is less than that of the leather obtained from the HZ, Hunan 1 and Guoling 1 strains, and the front surface and the back surface have a fine and smooth touch.

[0046] The mycelium leather obtained from the Guoling 1 strain has the following appearance characteristics: the color is white to light yellow; in terms of texture, the back surface is relatively smooth than the front surface, the front surface has a silk feel, and the back surface has a gloss; in terms of texture, the material is brittle, the thickness is less than that of the leather obtained from the HZ and Hunan 1 strains but greater than that of the XJ strain, the front surface has a relatively rough touch, and the back surface has a relatively smooth touch.

[0047] (Four) Tannic acid tanning of mycelium leather 1. Pretreatment of the above mycelium skin for use: Cleaning: remove the surface matrix with a toothbrush and ultrasonic cleaning for 10 minutes (40 kHz).

[0048] Defatting: Soaking in 3% (w / v) sodium carbonate solution (50℃) for 3h to remove hydrophobic proteins.

[0049] 2. Tannin tanning: Pretanning: Mycelial pellicle immersed in tannin solution (liquid ratio 1:20, i.e. 20L of tannin solution with concentration of 6% (w / v) per kg of mycelial material), constant temperature oscillation (60rpm) at 40℃ for 24h.

[0050] Retanning: New tanning solution was replaced and the treatment was prolonged for 24h (to increase cross-linking density).

[0051] pH control: pH was monitored every 2h and maintained at 3.5±0.2 (too low would degrade mycelium, too high would reduce tanning efficiency).

[0052] 3. Post-treatment: Water washing: rinsed with flowing deionized water until pH neutral.

[0053] Plasticizing: 5% (w / v) glycerol + 3% (w / v) collagen solution + 2% (w / v) sorbitol (50℃) soaking for 6h to improve flexibility.

[0054] Drying: air-dried at room temperature for 24h, and then hot-air dried at 50℃ until the moisture content was 10-12%.

[0055] 4. Post-finishing: Mechanical pressing: hot-pressed by calender (80℃, 10MPa) for 5min to improve surface gloss.

[0056] The appearance of the front and back of the mycelial leather product of each Ganoderma strain after tanning and finishing of the mycelial pellicle is shown in Figure 4 , and the treated Ganoderma mycelial leather is characterized in that the front thereof presents a uniform light brown to dark brown color and a tough and supple leather-like texture, and the back thereof presents a non-uniform brown tone with natural texture and a solidified matrix grain texture.

[0057] III. Performance parameter detection of mycelial leather: The mycelium leather material prepared from the four strains of HZ, XJ, Hunong 1 and Guoling 1 provided by the application shows significant comprehensive performance advantages after being treated by the tanning process of tannic acid, especially in mechanical properties, lightweight and structural consistency, far exceeding untreated samples and existing mycelium leather materials. The hardness of the material after processing is significantly improved, for example, the average hardness of the HZ strain after processing reaches 2308.57 gf, which is more than doubled compared with the unprocessed state (1112.19 gf), and the breaking performance is also greatly enhanced, for example, the average breaking of HZ after processing is 2044.60 gf, which is increased by about 142%, indicating that the compression resistance and breaking resistance are excellent, and the durability is significantly better than existing mycelium leather. At the same time, the thickness of the material is generally reduced after processing (for example, HZ from 2.20 mm to 1.84 mm), but the mechanical properties per unit thickness and per unit weight are significantly improved, showing high specific strength and lightweight characteristics, suitable for application scenarios sensitive to weight. In addition, the processed sample performs more stably in terms of internal structural consistency, with Gumminess and Cohesiveness parameters tending to be balanced, indicating that the material is more dense and uniform, which is conducive to subsequent cutting, compounding and surface treatment processing. Compared with the prior art, the material of the application not only achieves a good balance between hardness and toughness, but also has the outstanding advantages of strong controllability, environmental protection, no pollution, wide application field, etc., and can be widely used in shoe materials, bags, clothing and automotive interiors, etc. field, has significant industrial application potential.

[0058] Example 2 The method for preparing the mycelium leather of this example is basically the same as that of the example, the difference is that the expansion culture medium formula used is as follows: glucose 22g, wheat bran powder 1g, yeast powder 3g, peptone 1g, potassium dihydrogen phosphate 2g, magnesium sulfate 1g, distilled water 1L, pH natural, 121℃ sterilization for 20-25min.

[0059] The performance of the obtained mycelium leather is similar to that of example 1.

[0060] Example 3 The method for preparing the mycelium leather of this example is basically the same as that of the example, the difference is that the expansion culture medium formula used is as follows: glucose 18g, wheat bran powder 3g, yeast powder 1g, peptone 3g, potassium dihydrogen phosphate 1g, magnesium sulfate 2g, distilled water 1L, pH natural, 121℃ sterilization for 20-25min.

[0061] The performance of the obtained mycelium leather is similar to that of example 1.

[0062] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing mycelium leather, characterized by, It comprises the following steps: The strain activation step: inoculate the strain into the activation culture medium; wherein, the activation culture medium is potato plate culture medium; the strain is Ganoderma lucidum; The expansion culture step: inoculate the activated strain into the expansion culture medium; wherein, the expansion culture medium comprises, by weight: 18-22 parts of glucose, 1-3 parts of wheat bran powder, 1-3 parts of yeast powder, 1-3 parts of peptone, 1-2 parts of potassium dihydrogen phosphate, 1-2 parts of magnesium sulfate, and 1000 parts of water; The fermentation culture step: ferment the expanded culture strain liquid to obtain mycelium skin.

2. The production method according to claim 1, characterized by, The preparation method further comprises a mycelium skin pretreatment step; The mycelium skin pretreatment step comprises placing the mycelium skin obtained from the fermentation culture step in a sodium carbonate solution for degreasing treatment.

3. The production method according to claim 2, characterized by, The concentration of the sodium carbonate solution is 2-4%, the degreasing treatment temperature is 48-52℃, and the time is 2-4h.

4. The preparation method according to claim 2, characterized in that, The preparation method further comprises a preliminary tanning step; The preliminary tanning step comprises placing the mycelium skin treated in the pretreatment step in a tannin acid solution for preliminary tanning treatment.

5. The production method according to claim 4, characterized by, The concentration of the tannin acid solution is 6-8%; the conditions for preliminary tanning treatment are: pH is maintained at 3-4, constant temperature oscillation at 38-42℃ for 22-26h.

6. The preparation method according to claim 4, characterized in that, The preparation method further comprises a retanning step; The retanning step comprises replacing the fresh tannin acid solution for retanning treatment; the conditions for retanning treatment are: pH is maintained at 3-4, constant temperature oscillation at 38-42℃ for 22-26h.

7. The method of any one of claims 4-6, wherein, The preparation method further comprises a post-treatment step; The post-treatment step comprises: after washing the kneaded mycelium skin, immersing it in a plasticizing solution for plasticizing treatment; wherein, the plasticizing solution comprises: 5-6% glycerol, 3-5% collagen protein, and 2-5% sorbitol.

8. The preparation method according to claim 7, characterized in that, The conditions for plasticizing treatment are: 48-52℃ soaking for 5-7h.

9. The preparation method according to claim 7, characterized in that, The preparation method further comprises a post-finishing step; The post-finishing step comprises: pressing the mycelium skin treated in the post-treatment step to obtain finished mycelium leather; the pressing conditions are: hot pressing at 78-82℃, 9-11Mpa for 5-10 minutes.

10. A mycelium leather, characterized in that, It is made by the preparation method of any one of claims 1-9.

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