Method for preparing leather by submerged fermentation of mycelium
Preparing Ganoderma lucidum mycelium through deep fermentation technology and performing cross-linking and plasticizing treatment solves the problems of environmental pollution and resource waste in the traditional animal leather production process, and realizes the production of high-performance degradable leather.
Patent Information
- Application Number
- CN202310899254.0
- 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
A large amount of wastewater and solid waste are generated during the production of traditional animal leather, causing environmental pollution and difficult to degrade or reuse, and lacking environmentally friendly and sustainable leather processing technology.
Ganoderma lucidum mycelium is prepared through deep fermentation technology, mixed with cotton fiber or PU, and subjected to cross-linking and plasticizing treatment to prepare degradable leather.
Biodegradable leather with mechanical properties equivalent to those of animal leather has been achieved, with short production cycle, low cost and little environmental pollution.
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Figure CN119332513A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for preparing leather from deep 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] Submerged 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 Ganoderma lucidum mycelium for making leather through deep fermentation.
[0006] The present invention provides a method for preparing leather by deep fermentation, the method comprising the following steps:
[0007] (1) Preparation of mycelium:
[0008] Inoculate the fungal seed liquid into a fermentation tank containing a fermentation medium at an inoculum rate of 6-12%, apply a magnetic field with a magnetic field strength of 10-60 mT, and ferment for 6 days at a temperature of 24-30° C., a rotation speed of 150-300 r / min, and a ventilation volume of 2-10 L / min; obtain a culture liquid, and obtain mycelium after filtering;
[0009] (2) Preparation of leather:
[0010] The mycelium is mixed with cotton fiber or PU in a ratio of 1: (0.5-2.5), a film is laid, and after static culture at 28°C for 4-5 days, a tyrosinase / PEG solution is added and soaked for 24 hours, and then dried and squeezed to obtain leather; the tyrosinase / PEG solution is obtained by mixing PEG with a mass fraction of 2-10% and 5-10% tyrosinase.
[0011] 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, chanterelle, morel, north wind mushroom, bamboo fungus.
[0012] In one embodiment of the present invention, the fermentation medium is prepared by adding water to bran to obtain a mass fraction of 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 to the obtained filtrate according to a mass ratio.
[0013] The fermentation medium is prepared by adding water to bran to make its mass fraction 3%, boiling, adding 3% corn flour according to a mass ratio, continuing to boil, cooling, filtering, and adding 1.5% sucrose, 0.75% glucose, 0.15% soy peptone, 0.075% potassium dihydrogen phosphate, and 0.02% calcium chloride to the obtained filtrate according to a mass ratio.
[0014] In one embodiment of the present invention, the external magnetic field has a magnetic field strength of 40 mT.
[0015] In one embodiment of the present invention, in step (1), the fungal seed liquid is inoculated into a fermentation tank containing a fermentation medium at an inoculation rate of 8%.
[0016] In one embodiment of the present invention, in step (1), the culture medium is obtained by fermenting for 6 days at a temperature of 28° C., a rotation speed of 150 r / min, and a ventilation volume of 8 L / min.
[0017] In one embodiment of the present invention, in step (2), mycelium is mixed with cotton fiber or PU in a ratio of 1:1.
[0018] The invention also provides leather prepared by the method.
[0019] In one embodiment of the present invention, the preparation of the mycelium:
[0020] The activated strain is inoculated into a culture medium for cultivation, and the aerial hyphae are suspended upward. After being statically cultured for 24 hours at 28° C., the strain is placed in an oscillating culture box and oscillated at 24-30° C. and a rotation speed of 150-300 r / min. After oscillating culture for 5 days, a seed liquid is obtained, and the seed liquid is taken out and inoculated into a 5L fermentation tank containing a fermentation medium. A magnetic field is applied, and the magnetic field strength is 10-60 mT. The liquid volume of the fermentation medium is 50%-60%, and the seed liquid inoculation amount is 8%-10%. Deep fermentation is carried out at a temperature of 24-30° C. and a rotation speed of 150-300 r / min. The fermentation is carried out for 6 days to obtain a deep fermentation culture liquid.
[0021] In one embodiment of the present invention, the preparation of leather:
[0022] The deep fermentation culture liquid is filtered and washed with a small amount of clean water to obtain a large amount of mycelium. The mycelium is filtered and mixed with cotton fiber, film-made and placed in a 28°C incubator for static culture. After five days, a cross-linking agent and a plasticizer are added respectively and soaked for 24 hours. The mixture is filtered and film-made, and the mixture is dried at 90-120°C for 20 minutes. Finally, the leather is obtained after drying and hot pressing.
[0023] In one embodiment of the present invention, step (1) is specifically: inoculating 1 cm 2 After culturing mushroom fruiting bodies at 28°C for 5 days, pick colonies and inoculate them into fresh PDA. Repeat this process several times to obtain pure strains.
[0024] In one embodiment of the present invention, step (2) is specifically:
[0025] 1) The method for preparing the seed solution is as follows: Select the strain obtained in step (1) to prepare the seed solution: 2 The strain was inoculated into a 2 / 5 liquid (PDA medium) shake flask, allowed to stand at 28°C for 24 hours, and then placed in a shaking incubator. After culturing at 28°C and 150 r / min for 5 days, 4 to 5 mycelial balls were selected and inoculated into a 2 / 5 liquid (PDA medium) shake flask. After allowing to stand at 28°C for 24 hours, the flask was placed in a shaking incubator. After culturing at 28°C and 150 r / min for 5 days, seed solution was obtained.
[0026] 2) The seed liquid obtained in step 1) is inoculated into a 5L fermentation tank, a magnetic field is applied, the magnetic field strength is 10-60mT, the liquid volume is 50%-60%, the seed liquid inoculation amount is 8%-10%, the temperature is 24-30°C, the rotation speed is 150-300r / min, and the fermentation is carried out for 6 days.
[0027] In one embodiment of the present invention, the fermentation medium comprises: 3% bran, 3% corn flour, 1.5% sucrose, 0.75% glucose, 0.15% soy peptone, and 0.075% potassium dihydrogen phosphate. Preparation: Boil the bran for 20 minutes, add corn flour and cook for 5 minutes, filter and add the remaining ingredients, dilute and sterilize for later use.
[0028] In one embodiment of the present invention, the plasticizer includes one or more of formamide, urea, sodium nitrate, salicylic acid, dicyandiamide, thiocyanate, glycerol, sorbitol, ethylene glycol, diisooctyl sebacate, dibutyl phthalate, and DES.
[0029] In one embodiment of the present invention, the cross-linking agent includes one or more of KH550, formaldehyde, tyrosinase, linseed oil, acetic anhydride, glutaraldehyde, genipin, sodium tripolyphosphate or tannic acid.
[0030] In one embodiment of the present invention, the added amount of the plasticizer is 2-10%.
[0031] In one embodiment of the present invention, the amount of the cross-linking agent added is 5-10%.
[0032] In one embodiment of the present invention, the fermentation conditions are: magnetic field intensity 10-60 mT, 24-28° C., ventilation volume 2-10 L / min, and rotation speed 150-300 r / min.
[0033] In one embodiment of the present invention, the tyrosinase / PEG solution is prepared by taking 8 g of PEG and 6 g of tyrosinase, dissolving them in 100 mL of water to obtain a tyrosinase / PEG solution.
[0034] The present invention also provides a method for preparing degradable leather, wherein the method uses the mycelium obtained by the deep fermentation as a raw material, and obtains the degradable leather through a series of treatments such as filtration, cross-linking and plasticization.
[0035] The present invention also provides an application of the deep fermentation method for preparing leather.
[0036] In one embodiment of the present invention, the mycelium fermentation time is short and the yield is large; in addition to the mycelium, additional products such as fungal polysaccharides and triterpenes can be obtained;
[0037] The invention also provides leather and by-products prepared by the method.
[0038] In one embodiment of the present invention, the leather is made from mycelium, which is affected by the culture medium formulation and external conditions.
[0039] Beneficial Effects
[0040] The mycelium leather obtained by the present invention after a series of treatments such as cross-linking and plasticization has the same mechanical properties as animal leather. Compared with the raw skins of pigs, cattle, sheep, etc. used in traditional leather making, the deep fermentation mycelium leather has a short production cycle, low cost, is degradable, and has little pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] Figure 1 : Schematic diagram of the deep fermentation process for preparing mycelium leather.
[0042] Figure 2 : Effect of temperature on mycelial biomass.
[0043] Figure 3 : Effect of inoculum size on mycelial biomass.
[0044] Figure 4 :Effect of rotation speed on mycelial biomass.
[0045] Figure 5 : Effects of magnetic field on mycelial biomass.
[0046] Figure 6 : Effect of plasticizer concentration on mechanical properties of plain leather.
[0047] Figure 7 : Effect of cross-linking agent concentration on the mechanical properties of plain leather.
[0048] Figure 8 : Effect of cotton fiber content on mechanical properties of plain leather. DETAILED DESCRIPTION
[0049] 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 intended to limit the present invention. The mushrooms involved in the following embodiments were purchased from a supermarket.
[0050] The culture medium involved in the following examples is as follows:
[0051] 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.
[0052] Submerged 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.
[0053] The detection methods involved in the following embodiments are as follows:
[0054] Biomass test: Take a certain volume of fermentation liquid, dry it to constant weight, and weigh the mass.
[0055] Tensile strength test: Cut the mycelium leather into 8cm samples, clamp the two ends of the sample in the upper and lower clamps of the tensile machine, and keep the sample vertical and neither tight nor loose. The distance between the two clamps is 60mm, and the test speed is 500mm / min.
[0056] Degradability test: Take a piece of leather and dry it to constant weight, record the mass, and bury the leather in the soil 20cm to 30cm below the surface under natural conditions. Take it out after 50 days, wash it with clean water, dry it to constant weight, and calculate the weight loss rate W.
[0057] Folding performance test: refer to the standard "QB / T2714-2005 Determination of folding fastness of leather 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 membrane material, and record the number of folds when the membrane material shows obvious fracture marks.
[0058] Example 1: Preparation of leather
[0059] Deep fermentation process for preparing mycelium leather Figure 1 As shown, the specific steps are as follows:
[0060] (1) Preparation of fermentation medium:
[0061] Take 75g bran and add it to 2500mL boiling water and cook for 10min, then add 75g 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 2500mL.
[0062] (2) Activation of fungal species;
[0063] Inoculate 1 cm on PDA medium 2 After culturing mushroom fruiting bodies 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.
[0064] (3) Preparation of mycelium:
[0065] 1) Take 1 cm 2 The strain was inoculated into a 2 / 5 liquid (PDA medium) shake flask, allowed to stand at 28°C for 24 hours, then placed in a shaking incubator, and cultured at 28°C, 150 r / min for 5 days. Then, 4 to 5 mycelial balls were selected and inoculated into a 2 / 5 liquid (PDA medium) shake flask, allowed to stand at 28°C for 24 hours, then placed in a shaking incubator, and cultured at 28°C, 150 r / min for 5 days to obtain seed solution.
[0066] 2) inoculating the obtained seed liquid into a 5L fermentation tank containing the fermentation medium obtained in step (1) at an inoculum amount of 8% (v / v), applying a magnetic field with a magnetic field strength of 40mT, a liquid filling volume of 50%, and fermenting for 6 days at a temperature of 28°C, a rotation speed of 150r / min, and a ventilation volume of 8L / min; and obtaining a culture solution.
[0067] The deep fermentation culture solution is filtered and washed with a small amount of clean water to obtain mycelium.
[0068] (4) Preparation of leather:
[0069] Preparation of tyrosinase / PEG solution: 8 g of PEG and 6 g of tyrosinase were dissolved in 100 mL of water to obtain a tyrosinase / PEG solution.
[0070] The mycelium prepared in step (3) is filtered, and the mycelium and cotton fiber are mixed in a mass ratio of 1:1. After film laying, the mycelium is placed in a 28°C incubator for static culture. After 5 days, tyrosinase / PEG solution is added and soaked for 24 hours, and then baked at 100°C for 20 minutes. Finally, the leather is dried and squeezed to obtain leather.
[0071] Example 2: Preparation of leather
[0072] The specific implementation method is the same as that of Example 1, except that the temperature of the deep fermentation in step (3) (28°C) is adjusted to 24°C, 26°C, 28°C, and 30°C respectively; and the leather is prepared in the manner of Example 1.
[0073] The results show:
[0074] The mycelium biomass in step (3) is tested. Figure 2 As shown: as the temperature rises, the biomass increases. When the temperature is 28℃, the biomass reaches 16.1g / L. When the temperature exceeds 28℃, the biomass begins to decrease.
[0075] Example 3: Preparation of leather
[0076] The specific implementation method is the same as Example 1, except that the inoculation amount of the seed solution in step (3) (2) (8%) is adjusted to 6%, 8%, 10%, and 12% respectively; and the leather is prepared in the manner of Example 1.
[0077] The results show:
[0078] The mycelium biomass in step (3) is tested. Figure 3 The results show that the biomass increases with the increase of inoculation amount. When the inoculation amount is 8%, the biomass reaches 16.1g / L. When the inoculation amount exceeds 8%, the mycelium grows too fast, the viscosity of the nutrient solution increases, and the dissolved oxygen is insufficient, which is not conducive to fermentation, and the biomass decreases.
[0079] Example 4: Preparation of leather
[0080] The specific implementation method is the same as that of Example 1, except that the rotation speed of the deep fermentation in step (3) (2) is adjusted from 150 r / min to 150 r / min, 200 r / min, 250 r / min, and 300 r / min respectively; and the leather is prepared in the manner of Example 1.
[0081] The results show:
[0082] The mycelium biomass in step (3) is tested. Figure 4 Display: When the rotation speed is 150r / min, the biomass reaches 16.1g / L. When the rotation speed increases, the large mechanical stirring shear force destroys the mycelium, which is not conducive to mycelium growth and the biomass decreases.
[0083] Example 5: Preparation of leather
[0084] The specific implementation method is the same as that of Example 1, except that the magnetic field strength in step (2) of step (3) is adjusted to 10mT, 20mT, 30mT, 40mT, 50mT, and 60mT respectively; and leather is prepared in the manner of Example 1.
[0085] The results show:
[0086] The mycelium biomass in step (3) is tested. Figure 5 Display: When the magnetic field strength is 40mT, the biomass is the largest (biomass: 16.1g / L).
[0087] Example 6: Preparation of leather
[0088] The specific implementation method is the same as that of Example 1, except that the PEG concentration of 8% in step (4) is adjusted to 2%, 4%, 6%, 8%, and 10% respectively; and the leather is prepared in the manner of Example 1.
[0089] The results show:
[0090] Test the performance of leather, the results are as follows Figure 6 It shows that the increase of plasticizer PEG makes the leather tensile strength decrease and the elongation at break increase, and the best effect is achieved when the concentration of plasticizer PEG is 8%.
[0091] Example 7: Preparation of leather
[0092] The specific implementation method is the same as Example 1, except that the tyrosinase concentration of 6% in step (4) is adjusted to 5%, 6%, 7%, 8%, 9%, and 10% respectively; and leather is prepared in the manner of Example 1.
[0093] The results show:
[0094] Test the performance of leather, the results are as follows Figure 7 It shows that tyrosinase and protein undergo cross-linking reaction. As the amount of cross-linking agent tyrosinase increases, the number of cross-linking points increases, showing that the membrane strength gradually increases. When the concentration of cross-linking agent tyrosinase exceeds 6%, the over-cross-linked leather feels hard, the flexibility decreases, and the elongation at break decreases significantly; therefore, a tyrosinase concentration of 6% has the best effect.
[0095] Example 8: Preparation of leather
[0096] The specific implementation method is the same as that of Example 1, except that the mass ratio of mycelium to cotton fiber in step (4) is changed from 1:1 to 1:0.5, 1:1.5, 1:2, and 1:2.5; and the leather is prepared in the manner of Example 1.
[0097] The results show:
[0098] Test the performance of leather, the results are as follows Figure 8 It shows that when the cotton fiber accounts for a small proportion, it cannot play a role in increasing strength. When the cotton fiber content is too high, there are too few mycelium to bond the cotton fiber well, so the mechanical properties decrease. The best mixture is the mycelium and cotton fiber in a mass ratio of 1:1.
[0099] Example 9: Preparation of leather
[0100] The specific implementation method is the same as that of Example 1, except that the mixing with cotton fiber in step (4) is changed to: the mycelium obtained by filtration is evenly spread on cotton cloth with a thickness of 2 cm, placed in a 28°C incubator for static culture for 5 days, and after five days, tyrosinase / PEG solution is added and soaked for 24 hours, filtered, and after film spreading, baked at 100°C for 20 minutes, and finally dried and squeezed to obtain leather.
[0101] Example 10: Preparation of leather
[0102] The specific implementation method is the same as that of Example 1, except that the mixing with cotton fiber in step (4) is changed to: the mycelium obtained by filtration is mixed with PU, the mass ratio of mycelium to PU is 1:1, dried at 80°C, then added with tyrosinase / PEG solution and soaked for 24h, filtered, baked at 100°C for 20min, and finally dried and squeezed to obtain leather.
[0103] Comparative Example 1:
[0104] The magnetic field in step (3) of Example 1 is omitted, and the rest is the same.
[0105] The biomass test results are shown in Table 1 below:
[0106] Table 1: Biomass of Example 1 and Comparative Example 1
[0107] Biomass Example 1 16.1g / L Comparative Example 1 10.3g / L
[0108] The magnetic field can improve the permeability of the cell membrane to a certain extent, which is beneficial to the transfer of substances between cells and more conducive to the growth of hyphae.
[0109] Comparative Example 2:
[0110] The cotton fiber in step (4) of Example 1 was omitted, and the rest was the same as Example 1.
[0111] The test results are shown in Table 2 below:
[0112] Table 2: Mechanical properties of leather in Examples 1, 9-10 and Comparative Example 2
[0113] Folding performance / times Tensile strength / MPa Elongation at break / % Weight loss rate / % Example 1 3708 26.3 72.1 98.6 Example 9 2190 38.4 56.9 96.3 Example 10 5021 35.2 119.4 49.6 Comparative Example 2 4798 19.2 33.1 99.2
[0114] The mechanical properties of the leather in Example 9 were affected by the mechanical properties of the cotton cloth, but the mycelium and the cotton cloth were not firmly bonded, so the folding resistance was poor. The addition of PU in Example 10 improved the performance of the leather in all aspects, but since PU was not degradable, the weight loss rate was poor. Comparative Example 2 lacked cotton fiber as a skeleton, and the mechanical properties were greatly reduced.
[0115] 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 deep fermentation, characterized in that: The method comprises the following steps: (1) Preparation of mycelium: Inoculating the fungal seed liquid into a fermentation tank containing a fermentation medium at an inoculum rate of 6-12%, fermenting for 6 days at a temperature of 24-30° C., a rotation speed of 150-300 r / min, a ventilation volume of 2-10 L / min, and a magnetic field strength of 10-60 mT; obtaining a culture liquid, and filtering to obtain mycelium; (2) Preparation of leather: The mycelium is mixed with cotton fiber or PU in a ratio of 1: (0.5-2.5), a film is laid, and after static culture at 28°C for 5 days, a tyrosinase / PEG solution is added and soaked for 24 hours, and then dried and squeezed to obtain leather; the tyrosinase / PEG solution is obtained by mixing a PEG solution with a mass fraction of 2-10% and a tyrosinase with a mass fraction of 5-10%.
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, 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 magnetic field strength is 40 mT.
5. The method according to any one of claims 1 to 4, characterized in that: In step (1), the fungal seed liquid is inoculated into a fermentation tank containing a fermentation medium at an inoculation rate of 8%.
6. The method according to any one of claims 1 to 5, characterized in that: In step (1), the culture medium is obtained by fermenting for 6 days at a temperature of 28° C., a rotation speed of 150 r / min, and a ventilation volume of 8 L / min.
7. The method according to any one of claims 1 to 6, characterized in that: In step (2), mycelium is mixed with cotton fiber or PU in a ratio of 1:
1.
8. The method according to any one of claims 1 to 7, characterized in that: The fermentation medium is prepared by adding water to bran to make its mass fraction 3%, boiling, adding 3% corn flour according to a mass ratio, continuing to boil, cooling, filtering, and adding 1.5% sucrose, 0.75% glucose, 0.15% soy peptone, 0.075% potassium dihydrogen phosphate, and 0.02% calcium chloride to the obtained filtrate according to a mass ratio.
9. The method according to any one of claims 1 to 8, characterized in that: In step (2), the tyrosinase / PEG solution is prepared by taking 8 g of PEG and 6 g of tyrosinase, dissolving them in 100 mL of water to obtain a tyrosinase / PEG solution.
10. Leather prepared by the method according to any one of claims 1 to 9.