Method for preparing leather from superficial layer fermentation mycelium
The preparation of mushroom mycelium leather through shallow fermentation solves the pollution problems of wastewater and waste materials in traditional leather production, and realizes the preparation of biodegradable and low-cost leather with excellent mechanical properties.
Patent Information
- Application Number
- CN202310909752.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-21
- Publication Date
- 2025-01-21
AI Technical Summary
Traditional animal leather production processes generate large amounts of wastewater and solid waste that are difficult to degrade and pollute the environment. In addition, traditional leather-making methods are costly and time-consuming.
Mushroom mycelium was prepared using a shallow fermentation method. Through the cultivation, cross-linking, and plasticizing treatment of the aerial mycelium, biodegradable leather was produced.
It significantly increases mycelial length, with mechanical properties comparable to animal leather, and features a short production cycle, low cost, and minimal environmental pollution.
Smart Images
Figure CN119332514A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for preparing leather from shallow fermentation mycelium, belonging to the technical field of new materials. Background Art
[0002] Traditional animal leather will produce a lot of wastewater and solid waste during the production process, which pollutes the environment. Moreover, these animal leathers are difficult to degrade or reuse after being discarded. Therefore, environmentally friendly and sustainable leather processing is of great significance.
[0003] For more than a century, filamentous fungi have been widely used due to their high yield and multifunctionality. They are often used to produce enzymes and small molecule compounds such as antibiotics and organic acids, and their mycelium can also be used to make packaging materials, building materials, etc.
[0004] Shallow fermentation culture has the characteristics of short growth cycle, easy control of the growth process, and convenience for extraction and separation. Summary of the invention
[0005] In order to solve the above problems, the present invention prepares mushroom mycelium through shallow fermentation for making plain leather.
[0006] The present invention provides a method for preparing leather by shallow fermentation, the method comprising the following steps:
[0007] (1) Preparation of aerial mycelium:
[0008] The activated fungal strains are inoculated into a fermentation medium for static culture, so that the aerial hyphae are suspended upward, and after static culture for 24 to 36 hours, the culture is shaken at 20 to 30° C. and a speed of 100 to 150 r / min for 120 hours;
[0009] After the shaking culture, the mixture is placed in a static state and cultured at 22-34°C, 40-90% humidity, and 2000-100000ppm CO2 concentration until aerial mycelium grows, and then a viscose felt is laid on the mycelium film, and an electric field and a magnetic field are applied to make the aerial mycelium grow, and 460nm blue light is irradiated for 2-10 hours every 20 hours, and the culture is continued for 120 hours to obtain aerial mycelium;
[0010] (2) Preparation of leather:
[0011] The aerial mycelium obtained in step (1) is taken out, compressed and immersed in a 1-5% genipin solution, reacted at 25-75° C. for 4-12 hours, taken out and immersed in a 2-14% DES solution; the DES solution is prepared by adding choline chloride and urea in a mass ratio of (2-0.5):1 to an aqueous solution; taken out, dried, and squeezed to obtain leather.
[0012] In one embodiment of the present invention, the fungi include oyster mushroom, shiitake mushroom, straw mushroom, oregano, enoki mushroom, hericium erinaceus, white jade mushroom, king oyster mushroom, Agaricus bisporus, auricularia auricula, tremella fuciformis, chanterelle, morel, north wind mushroom or bamboo fungus.
[0013] In one embodiment of the present invention, the activation step of the fungal strain is: inoculating 1 cm2 of mushroom fruiting bodies on PDA culture medium, culturing at 28°C for 5 days, picking colonies and inoculating fresh PDA, and repeating multiple times to obtain pure strains.
[0014] In one embodiment of the present invention, the preparation of aerial mycelium is as follows: first, the activated pure strain is inoculated on PDA medium and cultured at 28° C. for 6 days;
[0015] Then cut four 4cm 2 The mushroom fruiting bodies are inoculated into a 500mL shaking flask filled with 100mL culture medium, and the aerial hyphae are suspended upward. After static cultivation for 24 hours, they are placed in an oscillating incubator and cultured at 28°C with a rotation speed of 130r / min. After oscillating cultivation for 5 days, they are taken out and placed in a constant temperature and humidity incubator with a temperature of 22-34°C, a humidity of 40-90%, and a CO2 concentration of 2000-10000ppm. They are irradiated with red light (650nm), blue light (460nm), natural light, ultraviolet light (260nm), and infrared light (800nm) for 2-10 hours per day, respectively. The culture time is: after the aerial hyphae grow out after 24-36 hours, an electric field and a magnetic field are applied to make the aerial hyphae grow.
[0016] In one embodiment of the present invention, in step (2), compressing the obtained mycelium means: drying the aerial mycelium film obtained by shallow fermentation to make its moisture content less than 50%, and then compressing it to 5 mm using a hot press.
[0017] In one embodiment of the present invention, the fermentation medium is prepared by adding water to bran to make its mass fraction 1.5-3%, boiling it, adding 1.5-3% corn flour according to a mass ratio, continuing to boil it, cooling and filtering it, and adding 0.75-1.5% sucrose, 0.5-1% glucose, 0.075-0.15% soy peptone, 0.0375-0.075% potassium dihydrogen phosphate, and 0-2% calcium chloride to the obtained filtrate according to a mass ratio.
[0018] In one embodiment of the present invention, the culture medium is PDA culture medium: take 200g of fresh potatoes, boil for 15min and filter, add 20g of glucose and 20g of agar, add water to 1000ml after dissolution, and dispense into 250ml conical flasks, sterilize and put into sterile culture dishes while hot, and cool for use.
[0019] Shallow fermentation medium: 3% bran, 3% corn flour, 1.5% sucrose, 0.75% glucose, 0.15% soy peptone, 0.075% potassium dihydrogen phosphate. Preparation: Boil bran for 20 minutes, add corn flour and cook for 5 minutes, filter and add the remaining ingredients, dilute and sterilize for later use.
[0020] In one embodiment of the present invention, the strengths of the applied electric field and magnetic field are 20-80 kV / m and 20-50 mT, respectively.
[0021] In one embodiment of the present invention, in step (1), the activated fungal strain is inoculated into a fermentation medium, the aerial hyphae are suspended upward at 28°C, and after static culture for 24 hours, the culture is placed in a shaking incubator and shaken at 28°C and a rotation speed of 130 r / min.
[0022] In one embodiment of the present invention, in step (1), after shaking culture, the culture is placed in a constant temperature and humidity incubator and cultured statically at 28°C, 60% humidity, and 6000 ppm CO2 concentration for 24 to 36 hours, so that a layer of aerial mycelium grows on its surface.
[0023] In one embodiment of the present invention, in step (1), 460 nm blue light is irradiated for 4 hours every 20 hours, and the culture is continued for 120 hours to obtain aerial mycelium.
[0024] In one embodiment of the present invention, the strength of the externally applied electric field is 40 kV / m; the strength of the externally applied magnetic field is 30 mT.
[0025] In one embodiment of the present invention, in step (2), the mass fraction of the genipin solution is 4%; the mass fraction of the DES solution is 10%.
[0026] In one embodiment of the present invention, the harvested mycelium with a thickness of more than 5 cm is compressed to 1 to 5 mm, then immersed in an aqueous solution of a plasticizer and a cross-linking agent for 24 hours, and then dried to obtain plain leather.
[0027] The invention also provides leather prepared by the method.
[0028] Beneficial Effects
[0029] The length of mycelium grown under external conditions is greatly increased, increasing by 350.6% compared with the original mycelium. In addition, the mechanical properties of the mycelium leather obtained after a series of treatments such as cross-linking and plasticization are the same as those of animal leather, and compared with the raw skins of pigs, cattle, sheep, etc. used in traditional leather making, the mycelium leather has a short production cycle, low cost, is degradable, and has little pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 : Schematic representation of the method for shallow fermentation of mycelium leather.
[0031] Figure 2 : Thickness of aerial hyphae layer at different culture temperatures.
[0032] Figure 3 : Thickness of aerial hyphae layer under different CaCl2 addition amounts.
[0033] Figure 4 : Thickness of aerial hyphae layer under different electric field strengths.
[0034] Figure 5 : Thickness of aerial hyphae layer under different magnetic field intensities.
[0035] Figure 6 : Thickness of aerial hyphae layer under different CO2 concentrations.
[0036] Figure 7 : Thickness of aerial hyphae layer under different blue light irradiation time.
[0037] Figure 8 : Tensile strength and elongation at break after treatment with different plasticizer concentrations.
[0038] Fig. 9 : Tensile strength and elongation at break after treatment with different cross-linker concentrations.
[0039] Fig.10 : Growth diagram of aerial hyphae layer on viscose felt, where (1) to (6) are growth diagrams for 1 to 6 days respectively. DETAILED DESCRIPTION
[0040] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not used to limit the present invention. The mushrooms involved in the following embodiments were purchased from a local supermarket.
[0041] The culture medium involved in the following examples is as follows:
[0042] PDA culture medium: Take 200g fresh potatoes, boil for 15min and filter, add 20g glucose and 20g agar, add water to 1000ml after dissolving, divide into 250ml conical flasks, sterilize and put into sterile culture dishes while hot, cool and set aside.
[0043] Shallow fermentation medium: 3% bran, 3% corn flour, 1.5% sucrose, 0.75% glucose, 0.15% soy peptone, 0.075% potassium dihydrogen phosphate. Preparation: Boil bran for 20 minutes, add corn flour and cook for 5 minutes, filter and add the remaining ingredients, dilute and sterilize for later use.
[0044] The detection methods involved in the following embodiments are as follows:
[0045] Biomass test:
[0046] The aerial mycelium layer was fished out, dried to constant weight, and its mass was measured.
[0047] Thickness test:
[0048] Measure the height of the aerial hyphae layer.
[0049] Tensile strength test:
[0050] Cut the mycelium leather into 8cm samples, clamp the two ends of the sample in the upper and lower clamps of the tensile machine, keep the sample vertical and not too tight or too loose. The distance between the two clamps is 60mm, and the test speed is 500mm / min.
[0051] Folding performance test:
[0052] Refer to the standard "QB / T2714-2005 Determination of folding fastness of leather in physical and mechanical tests" and make appropriate improvements. Cut the sample into a square with a side length of 3 cm, fold it repeatedly, observe the creases and fractures of the leather, and record the number of folds when the leather shows obvious fracture marks.
[0053] Example 1: Preparation of leather
[0054] Method for shallow fermentation of mycelium leather Figure 1 The specific steps are as follows:
[0055] (1) Preparation of fermentation medium:
[0056] Take 15g bran and add it to 500mL boiling water and cook for 10min, then add 15g corn flour and continue to cook for 20min, filter, and add (by mass fraction) 2% sucrose, 1% glucose, 0.2% peptone, 0.01% potassium dihydrogen phosphate, and 1% calcium chloride to the filtrate. Stir to dissolve and continue filtering, and add water to 500mL.
[0057] (2) Activation of fungal species;
[0058] Inoculate 1 cm2 of mushroom fruiting bodies on PDA medium. After culturing at 28°C for 5 days, pick colonies and inoculate them into fresh PDA medium. Repeat the above steps three times to obtain pure strains.
[0059] (3) Preparation of aerial mycelium:
[0060] 1) Take four 4 cm 2, inoculated into a 500 mL shake flask containing 100 mL of the fermentation medium obtained in step (1), so that the aerial hyphae are suspended upward, and placed in a shaking incubator for 24 h, and shaken at 28° C. and 130 r / min;
[0061] 2) After 5 days of shaking culture, take out and place in a constant temperature and humidity incubator, and culture at 28°C, 60% humidity, and 6000ppm CO2 concentration for 24 to 36 hours, so that a layer of aerial mycelium grows on the surface;
[0062] 3) After static culture, lay a piece of viscose felt on the mycelium film ( Fig.10 ), apply electric field and magnetic field with intensities of 40 kV / m and 30 mT respectively, to make aerial hyphae grow, and irradiate with blue light (460 nm) for 4 hours every 20 hours, and continue to culture for 120 hours; aerial hyphae are obtained.
[0063] (4) Preparation of leather:
[0064] Preparation of DES solution: Choline chloride and urea are added into an aqueous solution in a mass ratio of 1:1.5 to prepare;
[0065] The aerial mycelium produced from shallow fermentation was taken out, compressed to 2 mm, immersed in a 4% genipin solution by mass, reacted at 50° C. for 4 hours, and then taken out and immersed in a 10% DES solution.
[0066] Soak for 24 hours, dry (dry), squeeze, and obtain leather.
[0067] Example 2: Preparation of leather
[0068] The specific implementation method is the same as Example 1, except that the temperature of the static culture in step (3) (28°C) is adjusted to 22°C, 24°C, 26°C, 28°C, 30°C, 32°C, and 34°C respectively; leather is prepared in the manner of Example 1. The height and biomass of aerial hyphae in step (3) are detected, and the results are as follows: Figure 2 shown.
[0069] The results showed that the higher the temperature, the faster the mycelium grew, but too high a temperature was not conducive to mycelium growth, causing it to start autolysis prematurely and reduce biomass. When the temperature was 28°C, the height of aerial mycelium reached 6.1 cm and the biomass was 1.8 g.
[0070] Example 3: Preparation of leather
[0071] The specific implementation method is the same as that of Example 1, except that the 1% calcium chloride in step (1) is adjusted to 0, 0.5%, 1.5%, and 2% respectively; and leather is prepared in the manner of Example 1.
[0072] The height and biomass of aerial hyphae in step (3) are tested. Figure 3 shown.
[0073] The results showed that after the 1% calcium chloride in step (1) was adjusted to 0, 0.5%, 1%, 1.5%, and 2%, the heights of the aerial mycelium were 2.1 cm, 3.8 cm, 6.0 cm, and 6.1 cm, respectively. When the concentration of calcium chloride was 1%, the height of the aerial mycelium was the highest and the biomass was the largest.
[0074] Example 4: Preparation of leather
[0075] The specific implementation method is the same as Example 1, except that the electric field strength of 40 kV / m in step (3) is adjusted to: 0 kV / m, 20 kV / m, 40 kV / m, 60 kV / m, 80 kV / m, 100 kV / m respectively; and the leather is prepared in the manner of Example 1.
[0076] The results show:
[0077] The height and biomass of aerial hyphae in step (3) are tested. Figure 4 As shown, when the electric field strength reaches 40 kV / m, the aerial hyphae layer is the thickest and has the largest biomass (6.1 cm).
[0078] Example 5: Preparation of leather
[0079] The specific implementation method is the same as that of Example 1, except that the magnetic field intensity in step (3) is changed to 10mT, 20mT, 30mT, 40mT, 50mT; and leather is prepared in the manner of Example 1.
[0080] The results show:
[0081] The height and biomass of aerial hyphae in step (3) are tested. Figure 5 As shown, when the magnetic field intensity reaches 30 mT, the aerial hyphae layer is the thickest and has the largest biomass (6.1 cm).
[0082] Example 6: Preparation of leather
[0083] The specific implementation method is the same as that of Example 1, except that the CO2 concentration of 6000 ppm in step (3) is adjusted to 2000 ppm, 4000 ppm, 8000 ppm, and 10000 ppm respectively; and the leather is prepared in the manner of Example 1.
[0084] The results show:
[0085] The height and biomass of aerial hyphae in step (3) are tested. Figure 6As shown, an appropriate amount of CO2 promotes the growth of mycelium, while excessive CO2 will cause mycelium to lack oxygen and stop growing. When the CO2 concentration reaches 6000ppm, it is most suitable for mycelium growth (6.1cm).
[0086] Example 7: Preparation of leather
[0087] The specific implementation method is the same as that of Example 1, except that the irradiation with blue light (460 nm) for 4 h in step (3) is adjusted to irradiation for 2 h, 4 h, 6 h, 8 h, and 10 h respectively; and the leather is prepared according to the method of Example 1.
[0088] The results show:
[0089] The height and biomass of aerial hyphae in step (3) are tested. Figure 7 As shown, blue light can inhibit the differentiation of fruiting bodies to a certain extent, which is beneficial to the growth of hyphae. Irradiation time of 4h promotes the growth of hyphae (6.1cm).
[0090] Example 8: Preparation of leather
[0091] The specific implementation method is the same as that of Example 1, except that the DES concentration in step (4) is adjusted from 10% to 2%, 4%, 6%, 8%, 10%, 12% and 14% respectively; and leather is prepared in the manner of Example 1.
[0092] The results show:
[0093] Testing the properties of leather, such as Figure 8 As shown in the figure, as the DES concentration increases, the tensile strength decreases and the elongation at break increases. There is a hydrogen bond between the hydrophilic plasticizer and chitin and dextran, which reduces the molecular forces between chitin and dextran and destroys their rigid structure, so the tensile strength decreases. At the same time, due to the reduction of intermolecular forces, the mobility and deformation ability of the molecular chains of the film are enhanced, so the toughness is enhanced and the elongation at break is also enhanced. However, too much plasticizer causes the strength to decrease quickly, the hand feels sticky, and the flexibility is poor. When the DES concentration is 10%, it is most suitable, with a tensile strength of 27MPa and an elongation at break of 71.2%.
[0094] Example 9: Preparation of leather
[0095] The specific implementation method is the same as Example 1, except that the concentration of genipin in step (4) is adjusted from 4% to: 0%, 1%, 2%, 3%, 4%, 5% respectively; and the leather is prepared in the manner of Example 1.
[0096] The results show:
[0097] Test the performance of leather, the results are as follows Fig. 9As shown in the figure, as the concentration of genipin increases, the number of crosslinking points increases, the tensile strength increases, and the elongation at break decreases. When the concentration is 4%, the tensile strength increases and the elongation at break decreases slightly, and the change in the feel is not obvious. When the concentration exceeds 4%, the elongation at break decreases significantly, and the feel is brittle and hard. Therefore, the optimal concentration is 4%.
[0098] Comparative Example 1:
[0099] The electric field in step (3) of Example 1 is omitted, and the rest remains the same as Example 1.
[0100] Comparative Example 2:
[0101] The magnetic field in step (3) of Example 1 is omitted, and the rest remains the same as Example 1.
[0102] The test results are shown in Table 1 below:
[0103] Table 1: Mycelium and biomass of Example 1 and Comparative Examples 1 to 2
[0104] Mycelium layer height / cm Biomass / g Example 1 6.1 1.8 Comparative Example 1 4.4 0.9 Comparative Example 2 4.9 1.2
[0105] Electric field and magnetic field promote the growth of aerial hyphae, and the hyphae height is the highest when both act simultaneously.
[0106] Comparative Example 3:
[0107] The viscose felt in step (3) of Example 1 was omitted, and the rest was kept the same as in Example 1; that is, after the static culture was completed, an electric field and a magnetic field were applied with intensities of 40 kV / m and 30 mT, respectively, to grow aerial mycelium, and blue light (460 nm) was irradiated for 4 h every 20 h, and the culture was continued for 120 h to obtain aerial mycelium.
[0108] The test results are shown in Table 2 below:
[0109] Table 2: Tensile strength and elongation at break of Example 1 and Comparative Example 3
[0110] Tensile strength / MPa Elongation at break / % Example 1 27.4 71.2 Comparative Example 3 22.9 45.4
[0111] In Comparative Example 3, there is a lack of viscose felt as support, and the mechanical properties are greatly reduced.
[0112] Comparative Example 4:
[0113] The blue light in step (3) of Example 1 was omitted, and the culture was carried out in dark conditions instead. The rest of the steps were the same as in Example 1.
[0114] Comparative Example 5:
[0115] The blue light in step (3) of Example 1 was omitted, and the culture was performed under red light (650 nm) instead. The rest of the steps were the same as in Example 1.
[0116] Comparative Example 6:
[0117] The blue light in step (3) of Example 1 was omitted, and the culture was carried out under natural light conditions instead. The rest of the steps were the same as in Example 1.
[0118] Comparative Example 7:
[0119] The blue light in step (3) of Example 1 was omitted, and the culture was performed under ultraviolet light (260 nm) instead. The rest was the same as in Example 1.
[0120] Comparative Example 8:
[0121] The blue light in step (3) of Example 1 was omitted, and the culture was performed under infrared light (800 nm) instead. The rest of the process remained the same as in Example 1.
[0122] The results are shown in Table 3 below:
[0123] Table 3: Mycelium and biomass of Example 1 and Comparative Examples 4 to 8
[0124] Mycelium layer height / cm Biomass / g Example 1 6.1 1.8 Comparative Example 4 5.9 1.7 Comparative Example 5 4.3 1.1 Comparative Example 6 3.3 0.9 Comparative Example 7 3.5 1.2 Comparative Example 8 5.4 1.5
[0125] Compared with other monochromatic lights, blue light and dark conditions are more conducive to mycelium growth. The mycelium does not require light induction during the nutritional stage, but the stimulation of different light qualities can upregulate or downregulate multiple genes of the mycelium. The mycelium is sensitive to blue light, and blue light irradiation causes an increase in endogenous IAA in the mycelium, thereby promoting its growth.
[0126] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.
Claims
1. A method for preparing leather by shallow fermentation, characterized in that: The method comprises the following steps: (1) Preparation of aerial mycelium: The activated fungal strains are inoculated into a fermentation medium for static culture, so that the aerial hyphae are suspended upward, and after static culture for 24 to 36 hours, the culture is shaken at 20 to 30° C. and a speed of 100 to 150 r / min for 120 hours; After the shaking culture, the mixture is placed under the conditions of 22-34° C., 40-90% humidity, and 2000-100000 ppm CO2 concentration to grow aerial mycelium, and then a viscose felt is laid on the mycelium film, and an electric field and a magnetic field are applied to make the aerial mycelium grow, and 460 nm blue light is irradiated for 2-10 hours every 20 hours, and the culture time is 120 hours to obtain aerial mycelium; (2) Preparation of leather: The aerial mycelium obtained in step (1) is taken out, compressed and immersed in a 1-5% genipin solution, reacted at 25-75° C. for 4-12 hours, taken out and immersed in a 2-14% DES solution; the DES solution is prepared by adding choline chloride and urea in a mass ratio of (2-0.5):1 to an aqueous solution; taken out, dried, and squeezed to obtain leather.
2. The method according to claim 1, characterized in that: The fungi include oyster mushroom, shiitake mushroom, straw mushroom, mouth mushroom, enoki mushroom, hericium erinaceus, white jade mushroom, king oyster mushroom, Agaricus bisporus, auricularia auricula, tremella fuciformis, chanterelle, morel, north wind mushroom or bamboo fungus.
3. The method according to claim 1 or 2, characterized in that: The fermentation medium comprises the following steps: adding water to bran to make its mass fraction 1.5-3%, boiling, adding 1.5-3% corn flour according to a mass ratio, continuing to boil, cooling, filtering, and adding 0.75-1.5% sucrose, 0.5-1% glucose, 0.075-0.15% soy peptone, 0.0375-0.075% potassium dihydrogen phosphate, and 0-2% calcium chloride according to a mass ratio to the obtained filtrate.
4. The method according to any one of claims 1 to 3, characterized in that: The intensities of the applied electric field and magnetic field are 20-80 kV / m and 20-50 mT respectively.
5. The method according to any one of claims 1 to 4, characterized in that: In step (1), the activated fungal strain is inoculated into the fermentation medium, the aerial hyphae are suspended upward at 28° C., and after static culture for 24 hours, the culture is placed in a shaking incubator and shaken at 28° C. and a rotation speed of 130 r / min.
6. The method according to any one of claims 1 to 5, characterized in that: In step (1), after shaking culture, the mixture is placed in a constant temperature and humidity incubator and cultured at 28° C., 60% humidity, and 6000 ppm CO2 concentration for 24 to 36 hours, so that a layer of aerial mycelium grows on its surface.
7. The method according to any one of claims 1 to 6, characterized in that: In step (1), irradiate with 460 nm blue light for 4 hours every 20 hours, and continue culturing for 120 hours to obtain aerial mycelium.
8. The method according to any one of claims 1 to 7, characterized in that: The strength of the external electric field is 40 kV / m; the strength of the external magnetic field is 30 mT.
9. The method according to any one of claims 1 to 8, characterized in that: In step (2), the mass fraction of the genipin solution is 4%; the mass fraction of the DES solution is 10%.
10. Leather prepared by the method according to any one of claims 1 to 9.