Method for extracting canescent wikstroemia natural fibers in one step by using compound enzyme and application thereof

Abstract

The invention provides a method for extracting natural fibers of wikstroemia canescens in one step by using a compound enzyme and application of the natural fibers. Through optimization of enzyme treatment conditions, dissociation extraction of wikstroemia wikstroemia bast fibers and removal of impurities are realized, and the quality and yield of the fibers are ensured. And carrying out fiber analysis and characterization on the obtained primary pulp. Compared with a traditional soaking degumming treatment method, the method has the advantages that the dissociation efficiency is high, the consumed time is short, and meanwhile, the property of the obtained dissociated fiber is not changed. Compared with paper pulp obtained by a chemical method or a mechanical method, the property of the fiber is obviously reduced due to external force or chemical treatment, and the fiber obtained by enzyme dissociation has excellent fiber length-diameter ratio and fiber polymerization degree, and can be used for preparing high-strength silk and satin paper.

Description

Technical Field

[0001] The invention relates to the field of enzyme engineering, and in particular to a method for extracting natural fiber of clematis odorifera by one step using a composite enzyme and application thereof. Background Art

[0002] The genus of the genus Wisconsin is a tree, shrub or subshrub. Its bast fiber is well developed, the fiber is slender, soft and tough. Wisconsin is often used as a raw material for handmade paper making and is an important raw material for the production of Yunnan Dongba paper. However, the bast fiber of Wisconsin fiber contains a lot of glue and impurities in the original bark. The presence of glue and impurities makes the fibers tightly bound to each other, and the fiber bundles need to be dissociated and the impurities removed before extraction.

[0003] Fiber dissociation refers to the process of separating or dispersing fiber materials from their structure. Chemical treatment, mechanical crushing, high temperature treatment, etc. may all be means to achieve fiber dissociation. The purpose of dissociation is usually to obtain an independent state of the fiber for further extraction. In traditional technical methods, acid pretreatment has low efficiency, high energy consumption, and strong corrosiveness; alkaline pretreatment of high-lignin biomass produces intermediates such as salts that have side effects on subsequent enzymatic hydrolysis and fermentation, and the economic cost is high, making it difficult to promote sustainably. At present, there are patents reporting new ideas for fiber dissociation. For example, Chinese patent application CN202311507731.0 (publication number CN117449115A, publication date November 13, 2023) discloses a pulping method, slurry and application of iron-manganese-loaded cerium oxide / carbon nanodots catalyzing straw fiber dissociation. The pulping method separates the straw into straw bundles, disperses the iron-manganese-loaded cerium oxide / carbon nanodots in ethanol, adds water, and then sprays the surface of the straw bundles. The product is immersed and catalyzed for 24 to 48 hours to obtain a dissociated straw product. Then, sodium hydroxide is added, steamed at 120 to 160°C for 15 to 30 minutes, and the straw is homogenized to obtain a separated fiber slurry. This process can obtain a slurry with excellent performance, but the process is too complicated and the cost is high. Another patent CN202211463957.0 (publication number CN115748134A) discloses a method for preparing bamboo single fibers, which uses a gradient heating method in a reactor to achieve the dissociation and dispersion of bamboo fibers. This process can obtain bamboo fibers with strong performance and uniform distribution, but the method uses high temperatures and consumes a lot of energy. Therefore, for handmade paper with high fiber performance requirements, a preparation method with advantages such as green, environmentally friendly and mild conditions is urgently needed. Summary of the invention

[0004] The object of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a method for extracting natural fibers from sedge vine by using a composite enzyme in one step. By optimizing the enzyme treatment conditions, the dissociation and extraction of sedge vine bast fibers and the removal of impurities are achieved, and the quality and yield of the fibers are guaranteed. The obtained raw pulp is then subjected to fiber analysis and characterization. Compared with the traditional immersion degumming treatment method, this method has high dissociation efficiency and short time, and the properties of the dissociated fibers obtained have not changed. Compared with pulp obtained by chemical or mechanical methods, the properties of the fibers are significantly reduced due to external force or chemical treatment, while the fibers obtained by enzyme treatment dissociation have excellent aroma aspect ratio and fiber polymerization degree, and can be used for the preparation of high-strength handmade paper.

[0005] Another object of the present invention is to provide the natural fiber of water chestnut flower prepared by the above preparation method.

[0006] Another object of the present invention is to provide an application of the above-mentioned natural fiber.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A method for extracting natural fiber from sedge flower in one step by using a composite enzyme comprises the following steps:

[0009] (1) Cut the bark of the sedge tree into pieces and steam it under high pressure;

[0010] (2) The steamed sedge bark is mixed with the compound enzyme solution, the pH is adjusted, the reaction is carried out, and the liquid is filtered out. The bark obtained after the reaction is defibrated by a fiber defibrator to obtain sedge natural fiber.

[0011] The Wikstroemi described in step (1) is a shrub of the genus Wikstroemi of the family Thymelaeaceae.

[0012] The high-pressure steaming in step (1) is steaming in a high-temperature pressure cooker in a water bath for 0.5 to 2 hours, preferably 1 hour.

[0013] The solid-to-liquid ratio of the schisandra chinensis bark to the composite enzyme solution in step (2) is 1 g:10-50 mL, based on the mass of the absolutely dry schisandra chinensis bark; preferably 1 g:20 mL.

[0014] The compound enzyme solution in step (2) comprises at least one of lipase, pectinase and xylanase; preferably pectinase, lipase and xylanase.

[0015] The pectinase concentration in the composite enzyme solution is 50-200 U / mL, preferably 100 U / mL.

[0016] The lipase concentration in the composite enzyme solution is 20-100 U / mL, preferably 50 U / mL.

[0017] The xylanase concentration in the composite enzyme solution is 50-200 U / mL, preferably 100 U / mL.

[0018] The xylanase is deep-sea xylanase, and its amino acid sequence is shown in SEQ ID NO.1.

[0019] The lipase is the deep-sea enzyme Vm disclosed in patent ZL 202310516302.3.

[0020] The pH adjustment in step (2) is to adjust the pH to 4-8; preferably to adjust the pH to 7.

[0021] The reaction conditions of step (2) are 40-60° C. for 5-15 h; preferably 50° C. for 10 h.

[0022] The filtration in step (2) is vacuum filtration.

[0023] The conditions for the decomposition in step (2) are 7000-10000 rpm for 3-10 min, preferably 9000 rpm for 5 min.

[0024] The method for extracting natural fiber from calendula by one step using the composite enzyme is applied in the papermaking industry.

[0025] A kind of natural fiber of sedge flower is prepared according to the method.

[0026] The application of the above-mentioned natural fiber of water chestnut flower in the preparation of paper.

[0027] The paper is satin paper.

[0028] The papermaking method is a rapid Kaesai papermaking method.

[0029] Compared with the prior art, the present invention has the following advantages and effects:

[0030] (1) The present invention adopts the bio-enzyme method for the first time to catalyze the dissociation of the bast fiber of the taro. Compared with chemical and mechanical treatment methods, it ensures the process efficiency while also ensuring the properties of the fiber, and ultimately improves the quality of the finished paper.

[0031] (2) The present invention uses fresh bark of the sedge tree as raw material. The outer bark does not need to be peeled off by any mechanical treatment before processing, and the dissociated bast fiber can be directly obtained from the bark.

[0032] (3) Compared with the mechanical method, the bio-enzyme treatment process adopted in the present invention has lower energy consumption and higher long fiber yield, while compared with the chemical method, the waste liquid pollution is lower and the fiber properties are protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the dissociation morphology of bark fiber after being treated in Examples 1 to 3 and Comparative Examples 1 to 2.

[0034] Figure 2 Schematic diagram of the steps of Example 1.

[0035] Figure 3 This is a photograph of the satin paper made from the water chestnut fiber obtained in Example 1. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0037] If no specific experimental conditions are specified in the following embodiments, conventional experimental conditions or experimental conditions recommended by the reagent company are generally followed. The materials and reagents used, unless otherwise specified, are all reagents and materials obtained from commercial sources.

[0038] The raw material of the water chestnut flower used in the present invention comes from the mountainous area of ​​Quzhou, Zhejiang.

[0039] The pectinase was purchased from Xiasheng Enzyme Technology Co., Ltd., with a pectinase activity of 3000U / mL and a product number of S3100. Lipase was made by South China University of Technology. The specific sequence can be found in patent ZL 202310516302.3, i.e. the deep-sea enzyme Vm in the patent. Deep-sea xylanase was obtained by extracting genes from the deep-sea organism Verrucosispora maris AB-18-032 and purifying them after prokaryotic expression (the specific preparation method can be found in the literature Expression of the Thermobifida fusca xylanase Xyn11Ain Pichia pastoris and its characterization), and its amino acid sequence is shown in SEQ ID NO.1. McLean xylanase was purchased from Shanghai McLean Reagent Co., Ltd., with an enzyme activity of 100,000 U / mL and a product number of X832362. CaO and K2CO3 were both analytically pure and purchased from Shanghai McLean Reagent Co., Ltd.

[0040] The neutral deionized water was prepared by the laboratory of South China University of Technology.

[0041] Example 1

[0042] A method for extracting natural fiber from sedge flower in one step by using a composite enzyme comprises the following steps:

[0043] (1) collecting 1-2 year old twigs of ...

[0044] (2) steaming the treated bark of the sedge tree in a high-temperature and high-pressure sterilizer for 1 hour and then cooling it to room temperature;

[0045] (3) The steamed bark of the sedge tree (1 g, based on absolute dry mass) was mixed with the composite enzyme solution (10 mL) at a solid-liquid ratio of 1:10, and reacted at a pH of 7 and a temperature of 50°C for 10 h, wherein the concentration of pectinase in the composite enzyme was 100 U / mL, the concentration of lipase was 50 U / mL, and the concentration of deep-sea xylanase was 100 U / mL, and stirring was continued during the reaction;

[0046] (4) The bark fibers and the solution after the reaction are filtered, and the outer layer of the bark is picked out from the filter residue to obtain the coarse wattle fiber, which is then washed with clean water (5 to 10 times) and then deflated by a fiber deflagrator (9000 rpm, 5 min) to obtain wattle fiber slurry.

[0047] (5) Using a fiber quality analyzer, the properties of the safflower fiber obtained in step (4) are measured.

[0048] (6) Using the mulberry fiber obtained in step (4) to prepare pulp for papermaking, and testing the properties of the obtained paper.

[0049] Example 2

[0050] A method for extracting natural fiber from sedge flower in one step by using a composite enzyme comprises the following steps:

[0051] The method of Example 1 was used to catalyze the dissociation of sedge fiber, except that in step (2), the xylanase in the composite enzyme solution was replaced with MacLean xylanase at a concentration of 100 U / mL, and the concentrations of other enzymes were the same.

[0052] Example 3

[0053] A method for extracting natural fiber from sedge flower in one step by using a composite enzyme comprises the following steps:

[0054] The method of Example 1 is used to catalyze the dissociation of water chestnut fiber, except that in step (2), the composite enzyme solution does not contain deep-sea xylanase, and the concentrations of other enzymes are the same.

[0055] Example 4

[0056] A method for extracting natural fiber from sedge flower in one step by using a composite enzyme comprises the following steps:

[0057] The method of Example 1 is used to catalyze the dissociation of the sedge fiber, except that in step (2), the compound enzyme solution does not contain lipase, and the concentrations of other enzymes are the same.

[0058] Example 5

[0059] A method for extracting natural fiber from sedge flower in one step by using a composite enzyme comprises the following steps:

[0060] The dissociation of the sedge fiber was catalyzed by the method of Example 1, except that in step (2), the compound enzyme solution did not contain pectinase, and the concentrations of other enzymes were the same.

[0061] Comparative Example 1

[0062] (1) collecting 1-2 year old twigs of ...

[0063] (2) steaming the treated bark of the spatholobi tree in a high temperature and high pressure sterilizer for 1 hour and then cooling it to room temperature;

[0064] (3) The steamed bark of the spatholobiaceae tree (absolutely dry, 1 g) was mixed with an aqueous solution (10 mL) at a solid-liquid ratio of 1:10, and reacted at a pH of 7 and a temperature of 50° C. for 5 h with continuous stirring during the reaction;

[0065] (4) filtering the bark fibers and the solution after the reaction, separating the outer layer of the bark from the dissociated bast fibers, and obtaining the bast fibers.

[0066] Comparative Example 2

[0067] (1) collecting 1-2 year old twigs of ...

[0068] (2) soaking the mixture at room temperature for 24 hours and manually peeling off the outer skin of the flower;

[0069] (3) The peeled inner bark of the hyacinthus annuus was boiled with a 5% CaO solution at a solid-liquid ratio of 1:10 at 110° C. for 12 h, and the inner bark was washed with running water after boiling;

[0070] (4) steaming the leather material again according to step (3), and then washing it with running water until it becomes neutral;

[0071] (5) soaking the slurry in a 5% K2CO3 aqueous solution for 15 days to achieve bleaching;

[0072] (6) The bleached pulp is separated and cleaned by a pulp bag to obtain sedge fiber, and its properties are measured by a fiber quality analyzer.

[0073] (7) The obtained pulp is used to make paper.

[0074] Test Case

[0075] The fiber quality obtained above was analyzed by using the MorFi Compact fiber quality analyzer of Techpap of France, with specific reference to ISO 16065-2:2014 Pulp. Determination of fiber length by automated optical analysis. Part 2: Unpolarized light method.

[0076] Satin papermaking and performance measurement: Take pulp (1g of absolute dryness) and make sheets by the rapid Kaesai papermaking method. The specific method can refer to GB / T 24326-2009. After drying, measure the paper weight in the national standard constant temperature and humidity laboratory, and test the physical indicators at the same time. The pulp tensile index is measured according to GB / T453-2002, and the pulp softness is measured according to GB / T8942-2016.

[0077] The fiber quality results are shown in Table 1, and the paper test results are shown in Table 2;

[0078] Table 1 Characterization properties of the sedge fiber prepared in different embodiments

[0079] Example 1 Example 2 Comparative Example 2 Average fiber length (mm) 4.039 3.837 3.252 Average fiber width (um) 14.7 15.3 14.2 Fiber polymerization degree 1441 1266 1051

[0080] Table 2 Characteristic properties of paper obtained after preparing paper in different embodiments

[0081] Example 1 Comparative Example 2 <![CDATA[Tensile strength (N / m 2 )]]> 1425 965 Softness(mN) 23.5 39.1

[0082] After different treatments, it was found that the bark of the sedge tree after the three enzyme treatments (Example 1) achieved the shedding of the cortex and the obvious dissociation of the fibers ( Figure 1 ), and the pulp of the water chestnut tree was directly obtained in one step. In Example 2, although the fiber cortex fell off after the treatment with the composite enzyme replaced with commercial xylanase, the fiber dissociation was not obvious, and it was impossible to achieve complete pulping in one step. In Example 3, due to the removal of xylanase, the connection between the fiber cells in the bark and the connection between the cortex and the phloem hemicellulose was not destroyed, so that the cortex on the surface of the water chestnut tree bark did not fall off obviously, and the dissociation between the fibers was not obvious. In Example 4 and Example 5, due to the lack of lipase and pectinase, the cortex did not fall off, and the fiber dissociation was not obvious. In Example 1, the treatment without enzymes resulted in no falling off of the cortex, and the fibers did not dissociate. In summary, the one-step shedding from bark to fiber can be achieved only by the combination of three enzymes and the use of homemade high-temperature resistant xylanase for xylanase.

[0083] From Table 1, it can be seen that after the three kinds of compound enzyme treatment, the fiber has a higher fiber length, reaching 4.039mm, while the fiber length after chemical cooking and bleaching is significantly reduced to only 3.252mm, which may be due to the damage of the fiber during the chemical cooking process. The fiber polymerization degree also confirms this. The fiber polymerization degree after biological enzyme treatment reaches 1441, while the fiber polymerization degree after chemical treatment is only 1051. The above results show that compound enzyme treatment can successfully achieve the dissociation and extraction of bast fiber, and the obtained bast fiber has higher properties.

[0084] It can be seen from Table 2 that the satin paper prepared by the fiber extracted by the compound enzyme has better tensile strength, which is due to its high-quality fiber quality. At the same time, since the enzymatic fiber has not been processed by steaming and bleaching, the obtained paper has a higher bulkiness, resulting in the paper having better softness.

[0085] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for extracting natural fiber from sedge flower in one step by using a composite enzyme, characterized in that The steps include: (1) Cut the bark of the sedge tree into pieces and steam it under high pressure; (2) The steamed sedge bark is mixed with the compound enzyme solution, the pH is adjusted, the reaction is carried out, and the liquid is filtered out. The bark obtained after the reaction is defibrated by a fiber defibrator to obtain sedge natural fiber.

2. The method according to claim 1, characterized in that: The high-pressure steaming in step (1) is steaming in a high-temperature pressure cooker in a water bath for 0.5 to 2 hours.

3. The method according to claim 1, characterized in that: The solid-to-liquid ratio of the schisandra chinensis bark to the composite enzyme solution in step (2) is 1 g:10-50 mL, based on the mass of the absolutely dry schisandra chinensis bark.

4. The method according to claim 1, characterized in that: The compound enzyme solution described in step (2) comprises at least one of lipase, pectinase and xylanase.

5. The method according to claim 2, characterized in that: The pectinase concentration in the compound enzyme solution is 50-200 U / mL; The lipase concentration in the composite enzyme solution is 20-100 U / mL; The xylanase concentration in the compound enzyme solution is 50-200 U / mL.

6. The method according to claim 1, characterized in that: The reaction conditions of step (2) are 40-60° C. for 5-15 hours.

7. The method according to claim 1, characterized in that: The pH adjustment in step (2) is to adjust the pH to 4-8; The filtration in step (2) is vacuum filtration; The conditions for the decomposition in step (2) are 7000-10000 rpm for 3-10 min.

8. Use of the method for extracting natural fiber from sedge flower by one step using a composite enzyme as claimed in any one of claims 1 to 7 in the papermaking industry.

9. A natural fiber of thuja serrata, prepared by the method according to any one of claims 1 to 7.

10. Use of the natural fiber of water chestnut flower according to claim 9 in preparing paper.

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