Regenerated cellulose fiber containing melanin and preparation method thereof

Abstract

The invention discloses a regenerated cellulose fiber containing melanin and a preparation method thereof. The regenerated cellulose fiber internally contains melanin which is uniformly dispersed, and the mass ratio of the melanin to the cellulose is preferably (0.005-0.2): 1. The melanin is creatively dispersed and firmly combined in the fiber, and the technical problem that the color fastness of the melanin coating and the color master batch is gradually lost along with use and washing in the prior art is solved for the first time. The anti-ultraviolet performance of the fiber is not gradually lost along with the use process, and meanwhile, the influence of a dielectric material on the appearance, color and texture of the fiber is also avoided. The regenerated cellulose fiber disclosed by the invention is particularly suitable for preparing a high-performance biomass fiber material with anti-ultraviolet and anti-radiation effects.

Description

Technical Field

[0001] The invention relates to the field of biotechnology, and in particular to a regenerated cellulose fiber containing melanin and a preparation method thereof. Background Art

[0002] In daily life, the ubiquitous ultraviolet rays in the sun and the potential radiation in the environment threaten human health. The turbulent international situation and the potential threat of nuclear war in recent years have led to an increasing demand for radiation protection for the military and the public. Technological progress has also accelerated human exploration of the space environment, making astronauts' resistance to ultraviolet rays and high-energy rays in space and environmental adaptation one of the main challenges of manned spaceflight and space exploration. There is a common demand in these scenarios, that is, a new type of clothing material that can resist radiation by simply wearing it, while meeting the performance expectations of biocompatibility, comfort, environmental friendliness, and sustainable development.

[0003] In most organisms in nature, there is a class of molecules that resist ultraviolet and high-energy radiation - melanin. It is a polymer compound formed by the polymerization of monomer molecules such as tyrosine or 3'4'-dihydroxyamphetamine, and is widely found in animals (such as human skin, hair, cephalopod cuttlefish ink, etc.), plants and microorganisms. Melanin molecules can absorb ultraviolet and other high-energy rays, and convert the energy into heat energy (rather than free radicals) and release it, so that living organisms are not damaged by free radicals frequently generated by high-energy rays. Black fungi that can resist nuclear radiation have been found in the ruins of the Chernobyl Nuclear Power Plant. It is precisely because of the secretion of high concentrations of melanin molecules that life can survive in high-intensity radiation. At the same time, melanin has many beneficial material properties. For example, as the process and final link of electron transfer in organisms, it has the characteristics of absorbing free electrons and scavenging free radicals. Therefore, it has strong potential applications in the fields of sun protection, skin care, industrial chemistry, electrochemistry and electronic products. Melanin is also a type of natural pigment ranging from brown to black. It has extremely low solubility in water and is often used as a black color enhancer in food additives (such as the use of cuttlefish ink in the food industry). As a biomacromolecule, it is naturally degradable in the natural environment.

[0004] However, melanin is rarely used in textile materials at present, which may be related to the fact that melanin molecules have large polymer molecular chains and more complex tertiary structures. The academic community has not yet formed a unified understanding of the complex structure of melanin molecules. Since melanin molecules have extremely low solubility in neutral aqueous solutions and are difficult to dissolve in common organic solvents, conventional fabric dyeing processes make it difficult for large melanin particles to enter the interior of the fiber and for melanin molecules to attach and bind. When preparing conventional chemical fibers, it is difficult to mix and prepare raw fibers with this material because the natural melanin particles are too large to be dispersed in the spinning system. Conventional methods require the use of other materials combined with melanin to disperse it before use. For example, the natural melanin extracted from yaks is compounded with polydimethylsiloxane (PDMS) to modify the surface of wool fabrics. The coating enhances the wool's UV protection function (UV protection factor level 198.48), photothermal performance, and hydrophobicity (hydrophobic angle 164°). There is also a method of first preparing a melanin / titanium dioxide composite material, and then compounding the material on the wool surface as a coating, which significantly improves the fabric's UV resistance. Obviously, using melanin plus a medium as a fabric coating or preparing a masterbatch is an existing conventional technical path for utilizing melanin. However, the coating structure or masterbatch requires a medium to carry the melanin molecules, and the color fastness of the coating and masterbatch will gradually disappear with use and washing. In addition, when adding melanin by coating, the coating thickness on the fiber surface is difficult to control, which will greatly affect the appearance, color and texture of the fiber. Summary of the invention

[0005] The object of the present invention is to provide a regenerated cellulose fiber containing melanin to enhance the performance of the regenerated cellulose fiber.

[0006] A regenerated cellulose fiber containing melanin, wherein the interior of the regenerated cellulose fiber contains uniformly dispersed melanin.

[0007] Optionally, the melanin is at least one of melanin extracted from cuttlefish ink, melanin extracted from mammalian hair, and melanin fermented by microorganisms.

[0008] Optionally, in the regenerated cellulose fiber containing melanin, the mass ratio of melanin to cellulose is 0.005 to 0.2:1

[0009] Preferably, in the regenerated cellulose fiber containing melanin, the mass ratio of melanin to cellulose is 0.01 to 0.2:1.

[0010] Optionally, the regenerated cellulose fiber further contains uniformly dispersed protein; the protein contains a carbohydrate binding domain.

[0011] Optionally, the protein comprises a natural animal protein amino acid sequence; the N-terminus and the C-terminus of the natural animal protein amino acid sequence are respectively connected to a carbohydrate binding domain;

[0012] Optionally, the natural animal protein amino acid sequence comprises at least one of a spider silk protein amino acid sequence, a squid beak protein amino acid sequence, and a bee silk protein amino acid sequence;

[0013] Optionally, the amino acid sequence of the protein containing the amino acid sequence of the squid beak protein is shown in SEQ ID NO.1, the amino acid sequence of the protein containing the amino acid sequence of the spider silk protein is shown in SEQ ID NO.3, and the amino acid sequence of the protein containing the amino acid sequence of the bee silk protein is shown in SEQ ID NO.5.

[0014] Optionally, in the regenerated cellulose fiber containing melanin, the mass ratio of protein to cellulose is 0.001 to 1:1;

[0015] Preferably, in the regenerated cellulose fiber containing melanin, the mass ratio of protein to cellulose is 0.01 to 0.2:1.

[0016] A method for preparing regenerated cellulose fibers containing melanin, comprising:

[0017] Step 1) adding melanin into an alkaline solution and mixing the mixture evenly to obtain a melanin dispersion;

[0018] Step 2) uniformly mixing a spinning solution raw material comprising cellulose, a solvent and the melanin dispersion to obtain a spinning solution;

[0019] Step three) using the spinning solution to perform spinning, and using an acidic solution as a coagulation bath to coagulate the fibers during the spinning process to obtain the regenerated cellulose fibers containing melanin.

[0020] Optionally, in the step 1), the melanin is first dissolved in a NaOH solution with a pH of 10-14, impurities are removed, and then dried to obtain a melanin powder; the melanin is then added to an alkaline solution and mixed evenly to obtain a melanin dispersion.

[0021] Optionally, the solvent of the spinning solution in step 2) is at least one of lithium chloride / DMAc and imidazole chloride.

[0022] Optionally, the pH of the acidic solution used in step 3) is 1-5. The acidic solution can be any one of strong acids such as sulfuric acid and hydrochloric acid, or one of organic acids or weak acid solutions such as formic acid and acetic acid, or one of strong acid and weak base salts.

[0023] Preferably, the acidic solution is a sulfuric acid solution with a pH range of 2-3.

[0024] Optionally, the spinning solution raw material further comprises protein; the protein comprises a carbohydrate binding domain;

[0025] Preferably, the protein comprises a natural animal protein amino acid sequence; the N-terminus and the C-terminus of the natural animal protein amino acid sequence are respectively connected to carbohydrate binding domains.

[0026] Optionally, the protein is synthesized by microorganisms;

[0027] Preferably, the protein is synthesized by the following method:

[0028] The nucleic acid sequence encoding the protein is transferred into a microorganism for cultivation to synthesize the protein and obtain a strain culture solution; the strain culture solution is then subjected to ultrasonic and centrifugal treatment, and the supernatant is taken for protein purification using a nickel column to obtain the protein;

[0029] Preferably, the nucleic acid sequence encoding the protein is shown in any one of SEQ ID NO.2, SEQ ID NO.4, and SEQ ID NO.6.

[0030] The invention also proposes the application of the above-mentioned regenerated cellulose fiber containing melanin in textile materials.

[0031] The invention also provides a textile material having anti-ultraviolet and anti-radiation effects, namely the above-mentioned regenerated cellulose fiber containing melanin.

[0032] The present invention has the following beneficial effects:

[0033] The present invention disperses and combines melanin inside the fiber, solving the problem in the prior art that the color fastness of melanin coating and masterbatch will gradually lose with use and washing. The fiber's anti-ultraviolet performance will not be gradually lost during use, and the influence of the medium material on the fiber's feel can also be avoided.

[0034] In the existing cellulose-based composite material system, most of them are composite solutions of protein combined with cellulose, but the combination effect of protein and cellulose is not ideal, and the reinforcing effect of protein on composite materials cannot be fully exerted. The present invention utilizes the solubility property of melanin molecules to disperse the melanin, making it easy to prepare fibers and other chemical materials. At the same time, the present invention is inspired by the beak structure of cephalopods (cuttlefish, squid or octopus)-this structure is composed of polysaccharide chains (chitosan), polyphenol chains (polytyrosine or polytea polyphenols), and proteins (squid beak proteins, etc.). The three-phase structure has good stability and gives the beak structure excellent mechanical strength and toughness. The present invention introduces melanin (polyphenol) into cellulose (polysaccharide) and protein fiber systems, and these materials exert forces on each other and thus combine with each other, creating soft or hard structural materials through differences in proportion.

[0035] The present invention realizes a solvent system suitable for combining cellulose, melanin and protein, and can prepare these natural materials into excellent bio-based fibers by compounding them. The present invention creatively compounds melanin with cellulose, or adds recombinant animal proteins (modified spider silk protein, squid beak protein, bee silk protein, etc.) that interact with melanin and cellulose on the basis of the melanin and cellulose compound, and firmly combines melanin in the fiber. Such fiber can be used to prepare high-performance biomass fiber materials with anti-ultraviolet and anti-radiation effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 Stretching curves of samples with different concentrations of melanin;

[0038] Figure 2 The stretching curves of spider silk protein samples with different concentrations;

[0039] Figure 3 Tensile curves of samples with different melanin / protein contents;

[0040] Figure 4 Tensile curves of samples with different spider silk protein contents;

[0041] Figure 5 Sample tensile curve of honeycomb silk protein

[0042] Figure 6 Tensile curves of samples with different squid beak protein / melanin content;

[0043] Figure 7 Comparison of melanin dissolution in different solutions;

[0044] Figure 8 Comparison of spinning solutions after dissolving melanin in different solutions;

[0045] Fig. 9 Fiber diagram with different melanin addition amounts;

[0046] Fig.10 The results of the fiber antioxidant test of composite melanin; A is the free radical scavenging experiment photo, and B is the free radical scavenging efficiency;

[0047] Fig.11 SDS-page electrophoresis of recombinant protein;

[0048] Fig.12 Actual photo of industrially produced composite melanin / spider silk protein fibers. DETAILED DESCRIPTION

[0049] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0050] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0051] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0052] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0053] First, the present invention utilizes the fact that melanin molecules can be dissolved or dispersed into extremely small aggregates in an alkaline aqueous solution (pH>10), and when the pH returns to neutral or acidic, they aggregate and precipitate. The present invention utilizes this property to directly freeze-dry or spray-dry the alkaline solution of melanin, thereby maintaining its nanoscale dispersion effect. The treated melanin can remain dissolved in the aqueous solution or be uniformly dispersed at the nanoscale.

[0054] The present invention utilizes the characteristic that melanin is soluble in alkaline aqueous solution, and can use the spinning system of alkaline viscose fiber to uniformly mix the dissolved melanin with the alkaline cellulose system dissolved by carbon disulfide, and obtain black viscose fiber through wet spinning. Since the spinning coagulation bath is an acidic solution such as sulfuric acid, the melanin molecules can be solidified while solidifying the cellulose, and the phenolic hydroxyl groups of the melanin molecules can generate hydrogen bonds with the hydroxyl groups of the cellulose sugar chain, thereby firmly binding to the cellulose chain.

[0055] The present invention finds that the uniformly dispersed melanin molecules can be effectively dissolved in the NMMO solution, thus being suitable for the preparation of cellulose fibers in the Lyocell system. In addition, the "Preparation Method of Regenerated Cellulose Fibers Combined with Recombinant Proteins" (CN118835343A) proposed by the applicant shows that proteins with carbohydrate binding domains (CBM) can interact with cellulose in the NMMO system. Therefore, we use this system to add melanin molecules on the basis of cellulose-protein interaction to form a type of three-way interacting composite material: melanin can use phenolic hydroxyl groups to produce hydrogen bond interactions with cellulose chains, melanin can use aldehyde-ammonia condensation to form a Schiff base reaction to interact with the N-terminal amino residues of the protein chain, and protein and cellulose can interact through the combination of CBM and sugar chains.

[0056] The present invention prepares new recombinant spider silk protein, squid beak protein, bee silk protein and other animal proteins, which are used together with the spider silk protein reported in the aforementioned patent to further enhance the fiber effect. The present invention is based on the improvement and adjustment of regenerated cellulose fibers such as the Lyocell system, and replaces the coagulation bath with a weakly acidic solution with a pH of 2-3, thereby utilizing the change of pH on the solubility of the material to solidify and retain the silk protein and melanin inside the fiber.

[0057] Example 1 Design and expression of recombinant protein

[0058] In this example, the various recombinant proteins used in the various examples and comparative examples were prepared. The amino acid sequences and nucleic acid sequences of all the recombinant proteins in the present invention are:

[0059] The recombinant squid beak protein comprises a squid beak protein HBP-1 repeat region and is connected to CBM at both ends, wherein the amino acid sequence of CBM-HBP-1-CBM is SEQ ID NO.1, wherein positions 162-322 are the squid beak protein HBP-1 repeat region sequence;

[0060] The DNA sequence encoding the above CBM-HBP-1-CBM is SEQ ID NO.2.

[0061] A recombinant spider silk protein, comprising a MaSp2 spider silk protein repeat region and having CBMs connected at both ends, wherein the amino acid sequence of the recombinant spider silk protein is SEQ ID NO.3, wherein positions 160-353 are the sequence of the MaSp2 spider silk protein repeat region;

[0062] The DNA sequence encoding the above recombinant spider silk protein is SEQ ID NO.4.

[0063] Recombinant bee silk protein, comprising a bee silk protein AF3 repeat region and having CBM connected at both ends, the amino acid sequence of CBM-AF3-CBM is SEQ ID NO.5, wherein positions 164-498 are the sequence of the bee silk protein AF3 repeat region;

[0064] The DNA sequence encoding the above CBM-AF3-CBM is SEQ ID NO.6.

[0065] The above sequences were all synthesized by BGI and inserted into the pET28a commercial plasmid vector with the insertion site between BamHI and XhoI. The final plasmid was transferred into the Escherichia coli BL21 (DE3) strain by chemical transformation (completed by BGI service).

[0066] The constructed strain was cultured by fermentation, purified and freeze-dried to obtain recombinant protein dry powder, as follows:

[0067] (1) Shake flask fermentation

[0068] After the strain is constructed, take the preserved glycerol tube and streak it on a solid LB (containing 50ug / ml kanamycin Kana) plate, and culture it in a 37°C incubator overnight. Pick a single clone and grow it in 4-5mL LB (containing 50ug / ml kanamycin Kana) liquid culture medium at 37°C, 200rpm shaker overnight. The next day, transfer it to a 400mL shake flask for fermentation at 1%, and culture it at 200rpm, 37°C for 2-3h until OD600 = 0.6. Add isopropylthiogalactoside (IPTG) at a final concentration of 0.3mM and induce it at 20°C for 12-16h. Centrifuge at 12000rpm for 5min to collect the bacteria.

[0069] (2) Protein purification

[0070] Add 20mM Tris-HCl to the bacteria to make a concentrated bacterial solution, OD600 = about 20. Ultrasonication 25kHz, power 70-80%, each ultrasonication 3S, stop 6S, ultrasonication for a total of 30min, the solution changes from turbid to clear. Centrifuge at 12000rpm, 10-15min to take the supernatant. Repeat the supernatant through the loaded nickel column (Shenggong, product number NO.A600657) 2-3 times, collect the flow-through; wash the column material with 20mM Tris-HCl 3-5 times (1-3 times the volume of the column material each time) until the dripping solution is clear; wash the column material with 1-2 times the column volume of 0.5M imidazole solution at least 3 times, and collect the eluate in turn. Use 5 times the column volume of 20mM Tris-HCl to wash away the residual 0.5M imidazole solution, and finally save it with 20% alcohol. The washed column material can be reused. Mix the collected protein eluates and then dialyze in pure water.

[0071] (3) SDS-PAGE electrophoresis

[0072] Prepare 10% SDS-PAGE gel (Biyuntian, product number: P0012A)

[0073] Sample preparation and detection: Take 20uL of the protein purification sample and add 5uL of loading buffer for SDS-PAGE detection. The electrophoresis detection results are as follows: Fig.11 shown.

[0074] (4) Protein freeze-drying

[0075] The dialyzed protein solution was placed in a -80 refrigerator until the protein solution was completely solidified, and then placed in a freeze dryer to freeze-dry the protein at a freezing temperature of -55°C and a vacuum degree of 5 Pa. The freeze-dried protein was weighed to finally obtain the purified recombinant spider silk protein powder.

[0076] Example 2 Pretreatment and dispersion of melanin molecules

[0077] The present embodiment involves a melanin molecule pretreatment and dispersion process, which specifically includes the following steps:

[0078] (1) Pretreatment of melanin: The melanin raw material of the present invention is purchased from the microbial fermentation melanin product of Shenzhen Lingzhu Technology Co., Ltd., and the melanin of the present invention also includes but is not limited to melanin extracted from cuttlefish ink extract, mammalian hair extract, microbial fermentation fungi and bacteria. The melanin raw material is added to a NaOH solution with a pH of 10-12 and stirred to dissolve, and then the insoluble impurities in the melanin raw material are removed by centrifugation, and the supernatant melanin solution is freeze-dried to obtain a purified melanin powder for standby use.

[0079] (2) Dispersion of melanin: Prepare a NaOH solution with a pH of 10-12 in advance, dissolve and disperse the melanin powder material purified in the above step in the NaOH solution, and stir and disperse overnight for 12 hours.

[0080] (3) Preparation of spinning solution: A wood pulp board with a cellulose content of 99wt%, an ash content of 0.2wt% and an average degree of polymerization of 700 was used as the cellulose raw material. Recombinant spider silk protein raw material was purchased from Shenzhen Lingzhu Technology Co., Ltd. 120g of 50% NMMO solution, 0.128g of propyl gallate, a certain mass of spider silk protein powder and melanin dispersion (concentration of 2.5g / L) were added to the spinning material tank, and sodium hydroxide was added dropwise to make the pH of the solution between 10-12. Stir evenly until there is no obvious insoluble matter, and then add 7.5g of cellulose raw material, wherein the melanin solid content is controlled to be 5wt% of the mass fraction of the cellulose raw material, and the spider silk protein dry powder content is controlled to be consistent with the melanin solid content. The above-mentioned mixed solution was stirred and dissolved at 95°C and 90KPa for 2-3h until a transparent spinning solution was obtained.

[0081] The dissolution and dispersion state of the composite melanin / recombinant spider silk protein lyocell fiber spinning solution was observed under a microscope. The dispersion effects of the spinning solutions of different dissolution processes were compared, and the optimal dissolution process was selected.

[0082] Comparative Example 2

[0083] The difference between this comparative example and Example 2 is that in the (2) melanin dispersion step of a melanin molecule pretreatment and dispersion process, an aqueous solution with pH = 7 is used to disperse the melanin powder, and the other preparation processes and testing methods are exactly the same as those in Example 2.

[0084] Comparative Example 3

[0085] The difference between this comparative example 3 and example 2 is that in the melanin dispersion step (2) of the melanin molecule pretreatment and dispersion process, a NaOH solution with a pH of 10-12 is used to dissolve the melanin, but the overnight dispersion operation for 12 hours is not performed. The other preparation processes and testing methods are exactly the same as those of example 2.

[0086] Figure 7 and Figure 8 The following are the actual pictures of Example 2, Comparative Examples 2 and 3 and the pictures of their spinning solutions under a microscope. Figure 7 As can be seen from the actual picture, in Comparative Example 2, after using a PH=7 aqueous solution to disperse the melanin powder, a mixed solution with obvious stratification was obtained, indicating that a PH=7 aqueous solution is not conducive to the dispersion of melanin; in Example 2, after using a PH=10-12 NaOH solution to dissolve the melanin, a uniformly dispersed mixed solution was obtained, indicating that the alkaline solution used in the present invention is more conducive to the dispersion of melanin. Figure 8 The microscopic image of the spinning solution shows that after the dispersion used in Comparative Example 2 is made into spinning solution, there are a large number of obvious large particle aggregates under the microscope; in Comparative Example 3, a NaOH solution with a pH of 10-12 is used to dissolve the melanin but is not stirred and dispersed overnight. After the dispersion is made into spinning solution, there are still a small amount of particles under the microscope; in Example 2, a NaOH solution with a pH of 10-12 is used to dissolve the melanin and is stirred and dispersed overnight. The spinning solution under the microscope is transparent and has no particles. Example 2, Comparative Examples 2 and 3 illustrate that the present invention uses the method of alkali solution + overnight stirring and dispersion to obtain a uniformly dispersed melanin solution, which is very beneficial to the subsequent preparation of spinning solution and spinning.

[0087] Example 3 Preparation of composite microbial melanin molecule lyocell fiber

[0088] The present embodiment relates to a preparation process of a composite microbial melanin molecule lyocell fiber, which specifically includes the following steps:

[0089] (1) Microbial fermentation extraction of melanin: The melanin raw material is derived from microbial synthesis. Bacillus megaterium ACCC 11107 (purchased from Beijing Biological Collection Center) was cultured in 200 ml LB medium (yeast powder 5 g / L, peptone 10 g / L and sodium chloride 10 g / L, pH 7.0) in a 1L shake flask for 48 h, and the pH was adjusted to 2-3 with 30% sulfuric acid. After ultrasonic disruption, the melanin precipitate was collected by centrifugation at 10000 rpm for 2 min, and the precipitate was soaked in sulfuric acid solution with pH = 3 for 2 h, and the supernatant was removed by centrifugation at 10000 rpm for 2 min. The melanin precipitate was freeze-dried to obtain the melanin raw material used for the test.

[0090] (2) Dispersion of melanin: see Example 2 for the method.

[0091] (3) Preparation of spinning solution: A wood pulp board with a cellulose content of 99 wt%, an ash content of 0.2 wt% and an average degree of polymerization of 700 was used as the cellulose raw material. 120 g of 50% NMMO solution, 0.128 g of propyl gallate and the above melanin dispersion were added to the spinning material tank, and 7.5 g of cellulose raw material was added after stirring evenly, wherein the melanin solid content was controlled to be 1, 5, 10 and 20 wt% of the mass fraction of the cellulose raw material, respectively. The above mixed solution was stirred and dissolved at 95°C and 90 KPa for 2-3 h until the spinning solution had no obvious particles under a microscope, thereby obtaining the spinning solution.

[0092] (4) Preparation of composite melanin molecule Lyocell fiber: Add the spinning solution to the spinning system, and filter and degassing at high temperature, then transport the spinning solution to the spinneret through a metering pump for dry-jet wet spinning. The spinning needle aperture is 0.3 mm, the spinning speed is controlled to be 30 m / min, the air gap is 20 mm, and the coagulation bath is a sulfuric acid solution with a pH of 3 at room temperature. The high-viscosity spinning solution is vertically pulled and stretched into the coagulation bath after passing through the air section. As the NMMO in the spinning solution is displaced to form a fiber bundle, the melanin molecules in the fiber encounter the acidic coagulation bath and are solidified inside the fiber, and the composite melanin Lyocell fiber is initially obtained. The fiber is immersed in an acetic acid solution with a pH of 3 at room temperature for 10 minutes to further solidify the melanin, and then repeatedly washed with cold and hot water to remove the residual NMMO and acetic acid, followed by oiling, drying and cutting to obtain the final composite melanin Lyocell fiber.

[0093] The obtained composite melanin lyocell fiber was subjected to mechanical property tests, and its dry breaking strength, dry breaking elongation and other properties were tested in accordance with GB / T14337-2022.

[0094] Comparative Example 4

[0095] The difference between Comparative Example 4 and Example 3 is that no melanin is added during the preparation process of the composite melanin lyocell fiber, and the other preparation processes and testing methods are exactly the same as those of Example 3.

[0096] Table 1 Mechanical data of Example 3 and Comparative Example 4

[0097]

[0098] The mechanical properties test results of Example 3 and Comparative Example 4 are shown in Tables 1 and Figure 1 As shown in the figure, the strength and elongation of Lyocell fibers compounded with melanin have been significantly improved to varying degrees. The strength of 20% melanin fiber has increased by 48.97% compared to the control fiber. This is because the multi-hydroxy structure of melanin interacts with the hydroxyl group of cellulose polysaccharide, thus providing the fiber with excellent mechanical properties. Fig. 9 shown.

[0099] Example 4 Preparation of Lyocell Fiber Composited with Cuttlefish Ink Melanin and Recombinant Spider Silk Protein

[0100] The present embodiment relates to a preparation process of a lyocell fiber composited with cuttlefish ink melanin and recombinant spider silk protein, which specifically comprises the following steps:

[0101] (1) Melanin extraction: Melanin is extracted from cuttlefish ink powder, which is purchased from Henan Zhongda Hengyuan Biotechnology Co., Ltd. 5 g of ink powder was placed in 30 mL of concentrated hydrochloric acid and reacted at 48-50°C for 30 min. Then, the melanin precipitate was collected by centrifugation at 10,000 rpm for 2 min, and the precipitate was soaked in a sulfuric acid solution with a pH of 3 for 2 h. The supernatant was removed by centrifugation at 10,000 rpm for 2 min, and the melanin precipitate was freeze-dried to obtain the melanin raw material used in the test.

[0102] (2) Dispersion of melanin: The preparation steps of melanin dispersion are the same as those in Example 3.

[0103] (3) Preparation of spinning solution: The steps for preparing the spinning solution are the same as those in Example 3, except that the solid content of melanin added is controlled to be 1, 5, 10 and 20 wt% of the mass fraction of the cellulose raw material, and recombinant spider silk protein dry powder is added at a ratio consistent with the solid content of melanin, i.e., 1, 5, 10 and 20 wt% of recombinant spider silk protein.

[0104] (4) Preparation of lyocell fiber containing composite melanin and recombinant spider silk protein: The spinning steps are the same as those in Example 3, except that the spinning solution is a mixed spinning solution of melanin / recombinant spider silk protein.

[0105] The obtained composite melanin and recombinant spider silk protein lyocell fibers were subjected to mechanical property tests, and their dry breaking strength, dry breaking elongation and other properties were tested in accordance with GB / T14337-2022.

[0106] Comparative Example 5

[0107] The only difference between Comparative Example 5 and Example 4 is that no melanin is added during the preparation process of a composite melanin and recombinant spider silk protein lyocell fiber, the added amount of recombinant spider silk protein is 1, 5, 10 and 20wt%, and the other preparation processes and testing methods are exactly the same as those in Example 4.

[0108] Table 2 Mechanical data of Example 4 and Comparative Example 5

[0109]

[0110]

[0111] The mechanical properties test results of Example 4 and Comparative Examples 4 and 5 are shown in Tables 2 and Figure 2 , Figure 3As shown in the figure, compared with single melanin or spider silk protein composite fibers, the strength of Lyocell fibers double-compounded with melanin and recombinant spider silk protein has a very obvious performance improvement, among which the strength of 10% melanin + 10% spider silk protein composite fibers is 95.17% higher than that of the control fibers. This is because melanin, cellulose, and spider silk protein have a binding force with each other, and the three-phase structure formed by the combination of the three provides the fiber with more excellent mechanical properties.

[0112] Example 5 Preparation of wool melanin composite lyocell fibers with different contents of recombinant spider silk protein

[0113] The present embodiment relates to a preparation process of wool melanin composite lyocell fiber with different contents of recombinant spider silk protein, which specifically includes the following steps:

[0114] (1) Melanin extraction: Melanin is extracted from black wool. 5 g of black wool was placed in 30 mL of concentrated hydrochloric acid and reacted at 48-50°C for 30 min. The melanin precipitate was then collected by centrifugation at 10,000 rpm for 2 min, and the precipitate was soaked in a sulfuric acid solution with a pH of 3 for 2 h. The supernatant was removed by centrifugation at 10,000 rpm for 2 min, and the melanin precipitate was freeze-dried to obtain the melanin raw material used for the test.

[0115] (2) Dispersion of melanin: The preparation steps of melanin dispersion are the same as those in Example 3.

[0116] (3) Preparation of spinning solution: The steps for preparing the spinning solution are the same as those in Example 3, except that the solid content of melanin added is controlled to be 10 wt % of the mass fraction of the cellulose raw material, and recombinant spider silk protein is added at 1, 2, 5 and 10 wt % of the mass fraction of the cellulose raw material.

[0117] (4) Preparation of lyocell fiber containing composite melanin and recombinant spider silk protein: The spinning steps are the same as those in Example 3, except that the spinning solution is a melanin / recombinant spider silk protein spinning solution of different concentrations.

[0118] The obtained composite melanin and recombinant spider silk protein lyocell fibers were subjected to mechanical property tests, and their dry breaking strength, dry breaking elongation and other properties were tested in accordance with GB / T14337-2022.

[0119] Comparative Example 6

[0120] The only difference between Comparative Example 6 and Example 5 is that, in the preparation process of melanin-compounded Lyocell fibers with different contents of recombinant spider silk protein, no spider silk protein is added, and only melanin with a mass fraction of 10 wt% of the cellulose raw material is added. The other preparation processes and testing methods are exactly the same as those in Example 5.

[0121] Table 3 Mechanical data of Example 5 and Comparative Example 6

[0122]

[0123] The mechanical data of Example 5 and Comparative Example 6 are shown in Tables 3 and Figure 4 As shown in the figure, melanin fibers with different amounts of spider silk protein added have different degrees of improvement in strength and elongation compared with pure melanin fibers. Among them, the improvement in strength of spider silk protein is more obvious. When the amount of spider silk protein added is 2%, the strength is increased by 77.13% compared with the control group.

[0124] Example 6 Preparation of Lyocell Fiber Catalyzed by Complex Enzyme to Synthesize Melanin and Recombinant Honeybee Silk Protein

[0125] The present embodiment relates to a preparation process of lyocell fiber catalyzed by a composite enzyme to synthesize melanin and recombinant bee silk protein, which specifically includes the following steps:

[0126] (1) Enzyme catalytic extraction of melanin: The melanin raw material is derived from enzyme catalytic synthesis. Tyrosinase (purchased from Hunan Wokai Biotechnology Co., Ltd.) was used to prepare a 0.01% (w / v) tyrosinase solution with pH 8.0 pure water, and then 0.01% copper sulfate was added to the enzyme solution and stirred evenly. Prepare 1L of tyrosine solution (2.5g / L), add 0.1L of tyrosinase solution, stir at room temperature for ~24h to catalyze the reaction, then adjust the pH to 2-3 with 30% sulfuric acid, centrifuge at 10000rpm for 2min to collect the melanin precipitate, and freeze-dry the melanin precipitate to be the melanin raw material used in the test.

[0127] (2) Dispersion of melanin: The preparation steps of melanin dispersion are the same as those in Example 3.

[0128] (3) Preparation of spinning solution: The steps for preparing the spinning solution are the same as those in Example 3, except that the solid content of melanin added is controlled to be 1 and 5 wt% of the mass fraction of the cellulose raw material, and recombinant honeybee silk protein dry powder is added at a ratio consistent with the solid content of melanin, i.e., 1 and 5 wt% of recombinant honeybee silk protein.

[0129] (4) Preparation of lyocell fiber containing composite melanin and recombinant bee silk protein: The spinning steps are the same as those in Example 3, except that the spinning solution is a mixed spinning solution of melanin / recombinant bee silk protein.

[0130] The obtained composite melanin and recombinant bee silk protein lyocell fiber were subjected to mechanical property tests, and its dry breaking strength, dry breaking elongation and other properties were tested in accordance with GB / T14337-2022.

[0131] Comparative Example 7

[0132] The difference between this comparative example 7 and Example 6 is that no melanin is added in the preparation process of a composite melanin and honeycomb protein lyocell fiber, the added amount of honeycomb protein is 0, 1 and 5wt%, and the other preparation processes and testing methods are exactly the same as those in Example 6.

[0133] Table 4 Mechanical data of Example 6 and Comparative Examples 2 and 7

[0134]

[0135] The mechanical data of Example 6 and Comparative Example 7 are shown in Tables 4 and Figure 5 As shown. Compared with the comparative example 2, the sample with 5% bees silk protein added has a strength increase of 64.14% and an elongation increase of 33.17%, indicating that there is an interaction between bees silk protein and cellulose. Compared with the comparative example 2, the sample of Example 6 with 5% melanin and 5% bees silk protein added has a strength increase of 166.90% and an elongation increase of 26.30%. This shows that there is a binding force between melanin, bees silk protein and cellulose, which further improves the mechanical strength of the fiber.

[0136] Example 7 Preparation of Lyocell Fiber Composite Melanin and Recombinant Squid Beak Protein

[0137] The present embodiment relates to a preparation process of a lyocell fiber containing composite melanin and recombinant squid beak protein, which specifically includes the following steps:

[0138] (1) Dispersion of melanin: The preparation steps of melanin dispersion are the same as those in Example 3.

[0139] (2) Preparation of spinning solution: The steps for preparing the spinning solution are the same as those in Example 3, except that the solid content of melanin added is controlled to be 0, 1 and 5 wt% of the mass fraction of the cellulose raw material, and recombinant squid beak protein powder is added at the same ratio as the solid content of melanin, i.e., 0, 1 and 5 wt% of recombinant squid beak protein.

[0140] (3) Preparation of Lyocell Fibers Composited with Melanin and Recombinant Squid Beak Protein: The spinning steps are the same as those in Example 3, except that the spinning solution is a mixed spinning solution of melanin / recombinant squid beak protein.

[0141] The obtained composite melanin and recombinant squid beak protein lyocell fiber were subjected to mechanical property tests, and its dry breaking strength, dry breaking elongation and other properties were tested in accordance with GB / T14337-2022.

[0142] Comparative Example 8

[0143] The only difference between Comparative Example 6 and Example 6 is that no melanin is added during the preparation process of a composite melanin and squid beak protein lyocell fiber, the added amounts of squid beak protein are all 0, 1 and 5 wt %, and the other preparation processes and testing methods are exactly the same as those of Example 6.

[0144] Table 5 Mechanical data of Example 7 and Comparative Examples 2 and 8

[0145]

[0146] The mechanical data of Example 7 and Comparative Example 8 are shown in Tables 5 and Figure 6 As shown, the strength of the comparative example 8 is increased by 35.86% compared with the control cellulose fiber, indicating that the recombinant squid beak protein and cellulose can generate interaction forces, thereby improving the mechanical properties. The strength of the sample in Example 7 is further improved compared with that in Comparative Example 8, among which the 5% melanin + 5% squid beak protein sample is increased by 29.44% compared with Comparative Example 8, and the strength is increased by 75.86% compared with the control cellulose.

[0147] Example 8 Factory-scale preparation process of lyocell fiber with composite melanin / recombinant spider silk protein

[0148] This embodiment involves an optimization of the preparation process of a composite melanin / recombinant spider silk protein lyocell fiber. Different from the previous embodiment, the preparation process of this embodiment is a factory-scaled process, which specifically includes the following steps:

[0149] (1) Dispersion of melanin: The preparation steps of melanin dispersion are the same as those in Example 3.

[0150] (2) The preparation process of a lyocell fiber spinning solution of composite melanin / recombinant spider silk protein is the same as that of Example 3. The melanin content is controlled to be 10wt% of the fiber content, and the spider silk protein content is controlled to be 1wt%.

[0151] (3) Preparation of composite melanin / recombinant spider silk protein Lyocell fiber: Add the spinning solution to the spinning system, and perform filtering and degassing operations at high temperature, then transport the spinning solution to the spinneret through a metering pump for dry-jet wet spinning. The spinneret hole diameter is 0.075 mm, the number of holes is 10,000 holes, the spinning speed is controlled to be 50 m / min, the air gap is 40 mm, and the coagulation bath is an ammonium chloride solution with a pH of 3 at room temperature. The spinning solution with high viscosity is vertically pulled and stretched into the coagulation bath by air, and the solvent is replaced by solidification to obtain the primary fiber bundle. The fiber is immersed in an ammonium chloride solution with a pH of 3 at room temperature for 10 minutes again, and then repeatedly washed with cold and hot water to remove the residual NMMO and ammonium chloride, followed by oiling, drying and cutting to obtain the final composite melanin / recombinant spider silk protein Lyocell fiber. The obtained composite melanin / recombinant spider silk protein Lyocell fiber is as follows Fig.12 shown.

[0152] The obtained composite melanin / recombinant spider silk protein lyocell fiber was subjected to mechanical property tests, and its dry breaking strength, dry breaking elongation and other properties were tested in accordance with GB / T14337-2022.

[0153] The fiber was spun into 60-count fiber by Siro compact spinning to prepare plain woven fabric, and the anti-ultraviolet effect was tested according to national standards; the fiber was prepared into spunlace non-woven fabric with a gram weight of 50g / m 2 The anti-ultraviolet effect of fabrics was tested according to GB / T 18830-2009; the free radical scavenging function of fabrics was tested according to T / CCTA20102-2023 "Determination and evaluation of antioxidant capacity of textiles - DPPH and ABTS methods"; the color fastness to washing of fabrics was tested according to GB / T 3921-2008 "Textiles - Tests for color fastness".

[0154] Comparative Example 9

[0155] The difference between this comparative example 9 and example 8 is that no melanin and spider silk protein are added during the optimization of the preparation process of a composite melanin / recombinant spider silk protein lyocell fiber, and the other preparation processes and testing methods are exactly the same as those of example 8.

[0156] Table 6 Mechanical data of Example 8 and Comparative Example 9

[0157] sample Strong / cN Elongation at break / % Strength / cN / dtex Denier / dtex Example 8 5.71 11.59 4.39 1.30 Comparative Example 9 4.68 11.40 3.55 1.32

[0158] Table 7 Anti-ultraviolet performance data of woven fabrics and non-woven fabrics

[0159] sample UPF average T(UVA) / % T(UVB) / % Woven fabrics ≥2000 0.05 0.05 Non-woven fabrics 170 0.61 0.57

[0160] Table 8 Color fastness data of woven fabrics to soap washing

[0161]

[0162] The mechanical property data of Example 8 and Comparative Example 9 are shown in Table 6. The strength of Example 8 with the addition of 10% melanin and 10% spider silk protein is increased by 23.66% compared with Comparative Example 9, indicating that melanin, recombinant spider silk protein and cellulose have a binding force with each other, giving the fiber a significant mechanical enhancement effect.

[0163] like Fig.10 As shown in Figure A, the colors of the ABTS solution in the 10% melanin fiber and the 0% melanin control fiber are significantly different. The ABTS solution in the sample with added melanin is close to the color of distilled water, indicating that the fiber containing melanin has the ability to scavenge free radicals. The free radical scavenging efficiency was tested according to the ABTS method in the T / CCTA20102-2023 standard, as shown in Figure 1. Fig.10 As shown in Figure B, the free radical scavenging rate of the sample with 10% melanin added is 99.67%, while the free radical scavenging rate of the control fiber is only 12.7%. The free radical scavenging rate is increased by 684.80%, reaching the third level of antioxidant capacity in the standard (free radical scavenging rate ≥ 80%, the sample has extremely strong antioxidant capacity).

[0164] The anti-ultraviolet performance of woven fabrics and non-woven fabrics is shown in Table 7. According to the test method in GB / T 18830-2009 standard, the anti-ultraviolet performance evaluation standard is carried out. The average UPF of woven fabrics is ≥2000, and the average T (UVA) is 0.05%, which has strong anti-ultraviolet performance. The UPF of non-woven fabric samples is 170, and the average T (UVA) is 0.61%, which has anti-ultraviolet performance. The color fastness to soap washing of woven fabrics is shown in Table 8. According to the test method in GB / T 3921 standard, the color fastness of woven fabrics can reach level 4, and the color fastness to different media reaches level 4-5, indicating that the fabric has excellent color fastness.

[0165] Example 9 Preparation of a composite melanin / recombinant spider silk protein viscose fiber

[0166] The preparation process of a composite melanin / recombinant spider silk protein viscose fiber of this embodiment comprises the following steps:

[0167] (1) Preparation of spider silk protein dispersion: prepare 20 mM Tris-HCl solution, adjust the pH of the dispersant to 7, add recombinant spider silk protein and stir to dissolve until the solution is clear and transparent, and then degas and filter to obtain a recombinant spider silk protein dispersion.

[0168] (2) Dispersion of melanin: The preparation steps of melanin dispersion are the same as those in Example 3.

[0169] (3) Preparation of viscose spinning stock solution of composite melanin / recombinant spider silk protein: a wood pulp raw material with an average degree of polymerization of 700 is immersed in a sodium hydroxide solution with a temperature of 50°C and a mass fraction of 18% for 60 minutes, and the alkaline solution dissolves the hemicellulose with a low degree of polymerization, and the obtained insoluble matter is α-cellulose; the obtained α-cellulose is squeezed and crushed, and then aged at an aging temperature of 25°C and an aging time of 2.5 hours; carbon disulfide with a mass fraction of 35% of the total amount of α-cellulose is added for yellowing at a temperature of 15°C and a yellowing time of 65 minutes to obtain cellulose sulfonate; the cellulose sulfonate is dissolved in a 6% sodium hydroxide solution, and the cellulose spinning stock solution is obtained by dissolving, filtering, degassing and aging in sequence.

[0170] (4) Preparation of high-strength composite spider silk protein regenerated fibers: blending a melanin dispersion, a spider silk protein dispersion and a cellulose spinning stock solution, controlling the proportions of melanin and spider silk protein in the fibers to be 10 wt% and 1 wt% respectively, and then filtering and degassing the mixture to obtain a blended spinning solution; passing the blended spinning solution into a coagulation bath through a spinneret for spinning to obtain a primary filament bundle, wherein the coagulation bath comprises 80 g / L sulfuric acid, 90 g / L zinc sulfate, and 170 g / L sodium sulfate, the reaction temperature is 50°C, the spinning rate is 50 m / min, and the immersion time is 2 s; the obtained primary filament bundle is stretched to obtain a formed filament bundle, and the formed filament bundle is post-treated to obtain a composite melanin / recombinant spider silk protein viscose fiber.

[0171] The obtained viscose fiber of composite melanin / recombinant spider silk protein was subjected to mechanical testing, and its dry breaking strength, dry breaking elongation and other properties were tested in accordance with GB / T14337-2022.

[0172] Comparative Example 10

[0173] The difference between this comparative example 10 and Example 9 is that, in the preparation process of a composite melanin / recombinant spider silk protein viscose fiber, no melanin molecule and recombinant spider silk protein are added, and the other preparation processes and testing methods are exactly the same as those of Example 9.

[0174] Table 9 Mechanical data of Example 9 and Comparative Example 10

[0175]

[0176] The mechanical property data of Example 9 and Comparative Example 10 are shown in Table 9. The strength of the samples of Example 9 with the addition of melanin and spider silk protein compared with Comparative Example 10 shows different degrees of increase. Among them, when the amount of melanin added is 10% and the amount of spider silk protein added is 2%, the strength of the fiber reaches 3.03 cN / dtex, which is 48.53% higher than that of Comparative Example 10, indicating that the three-phase structure system of melanin, cellulose and spider silk protein has been formed, which greatly improves its strength.

[0177] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A regenerated cellulose fiber containing melanin, characterized in that: The regenerated cellulose fiber contains uniformly dispersed melanin.

2. The melanin-containing regenerated cellulose fiber according to claim 1, characterized in that The melanin is at least one of melanin extracted from cuttlefish ink, melanin extracted from mammal hair, melanin extracted from microbial fermentation, and melanin extracted by tyrosinase catalysis.

3. The melanin-containing regenerated cellulose fiber according to claim 1, characterized in that In the regenerated cellulose fiber containing melanin, the mass ratio of melanin to cellulose is 0.005-0.2:1; Preferably, in the regenerated cellulose fiber containing melanin, the mass ratio of melanin to cellulose is 0.01-0.2:

1.

4. The melanin-containing regenerated cellulose fiber according to claim 1, characterized in that The regenerated cellulose fiber also contains uniformly dispersed protein; the protein contains a carbohydrate binding domain.

5. The melanin-containing regenerated cellulose fiber according to claim 1, characterized in that The protein contains a natural animal protein amino acid sequence; the N-terminus and the C-terminus of the natural animal protein amino acid sequence are respectively connected to a carbohydrate binding domain; Preferably, the natural animal protein amino acid sequence comprises at least one of the amino acid sequence of spider silk protein, the amino acid sequence of cuttlefish beak protein, and the amino acid sequence of bee silk protein; Preferably, the amino acid sequence of the protein containing the amino acid sequence of the squid beak protein is shown in SEQ ID NO.1, the amino acid sequence of the protein containing the amino acid sequence of the spider silk protein is shown in SEQ ID NO.3, and the amino acid sequence of the protein containing the amino acid sequence of the bee silk protein is shown in SEQ ID NO.

5.

6. The melanin-containing regenerated cellulose fiber according to claim 1, characterized in that In the regenerated cellulose fiber containing melanin, the mass ratio of protein to cellulose is 0.001 to 1:1; Preferably, in the regenerated cellulose fiber containing melanin, the mass ratio of protein to cellulose is 0.01 to 0.2:

1.

7. The method for producing melanin-containing regenerated cellulose fibers according to any one of claims 1 to 6, characterized in that: include: Step 1) adding melanin into an alkaline solution and mixing the mixture evenly to obtain a melanin dispersion; Step 2) uniformly mixing a spinning solution raw material comprising cellulose, a solvent and the melanin dispersion to obtain a spinning solution; Step three) using the spinning solution to perform spinning, and using an acidic solution as a coagulation bath to coagulate the fibers during the spinning process to obtain the regenerated cellulose fibers containing melanin.

8. The preparation method according to claim 7, characterized in that: In the step 1), the melanin is first dissolved in a NaOH solution with a pH of 10-12, impurities are removed, and then dried to obtain a melanin powder; the melanin is then added to an alkaline solution and mixed evenly to obtain a melanin dispersion.

9. The preparation method according to claim 7, characterized in that: The solvent of the spinning solution in step 2) is at least one of NMMO solution, carbon disulfide alkaline solution or ionic liquid; Preferably, the spinning solution pH>10; Preferably, the ionic liquid is at least one of lithium chloride / DMAc and imidazole chloride; In the step 2), the spinning solution raw material including cellulose, solvent and the melanin dispersion is stirred and dissolved at 90-110° C. and 85-98 KPa for 2-3 hours; In the step 2), the spinning solution is stirred and dispersed for 10 to 15 hours.

10. The preparation method according to claim 7, characterized in that: The pH of the acidic solution used in step 3) is 2-3; the acidic solution is at least one of an inorganic acid solution, an organic acid solution, and a strong acid and weak base salt solution; Preferably, the acidic solution is at least one of a sulfuric acid solution, a hydrochloric acid solution, a formic acid solution, and an acetic acid solution; Preferably, the acidic solution is a sulfuric acid solution.

11. The preparation method according to claim 7, characterized in that: The spinning solution raw material also contains protein; the protein contains a carbohydrate binding domain; Preferably, the protein comprises a natural animal protein amino acid sequence; the N-terminus and the C-terminus of the natural animal protein amino acid sequence are respectively connected to carbohydrate binding domains.

12. The preparation method according to claim 7, characterized in that: The protein is synthesized by microorganisms; Preferably, the protein is synthesized by the following method: The nucleic acid sequence encoding the protein is transferred into a microorganism, and the microorganism is cultured to synthesize the protein to obtain a strain culture solution; the strain culture solution is then subjected to ultrasonic and centrifugal treatment, and the supernatant is taken and purified using a nickel column to obtain the protein; Preferably, the nucleic acid sequence encoding the protein is shown in any one of SEQ ID NO.2, SEQ ID NO.4, and SEQ ID NO.

6.

13. The preparation method according to claim 7, characterized in that: The spinning process adopts dry-jet wet spinning; the aperture of the spinning needle in the dry-jet wet spinning is 0.075-0.3 mm, the spinning speed is controlled to be 10-50 m / min, and the air gap is 10-40 mm.

14. Use of the melanin-containing regenerated cellulose fiber according to any one of claims 1 to 6 or the melanin-containing regenerated cellulose fiber prepared by the preparation method according to any one of claims 7 to 13 in textile materials.

15. A textile material with anti-ultraviolet and anti-radiation effects, characterized in that: The invention relates to a regenerated cellulose fiber containing melanin according to any one of claims 1 to 6 or a regenerated cellulose fiber containing melanin prepared by the preparation method according to any one of claims 7 to 13.

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