Method for promoting cutinase to hydrolyze polyester by using triton

Abstract

The invention belongs to the technical field of polyester surface modification, and relates to a method for promoting cutinase to hydrolyze polyester by using triton. The method comprises the following steps: adding triton into a Tris-HCl buffer solution, uniformly mixing, and adjusting the pH value with hydrochloric acid to obtain a triton buffer solution; and immersing the refined terylene into a triton buffer solution, adding a cutinase preparation for hydrolysis reaction, inactivating cutinase, taking out the terylene, washing and drying. Triton is used as an additive to improve the activity and stability of cutinase, promote the hydrolysis effect of cutinase on polyester, and increase the hydrolysis release product by 229.8%, so that cutinase can hydrolyze polyester with higher crystallinity.

Description

TECHNICAL FIELD

[0001] The application relates to a method for promoting hydrolysis of polyester by cutinase with Triton, and belongs to the technical field of polyester surface modification. BACKGROUND

[0002] Polyester (polyester fiber) is one of the largest synthetic fibers in the world, and has high fiber strength and good wear resistance, and is widely used in the fields of clothing and home textiles. However, polyester fabric also has problems such as poor moisture absorption and air permeability, easy generation of static electricity, poor dyeing performance and the like, and further application is thus limited. In order to solve these problems, surface modification of polyester fabric is usually selected to enrich hydrophilic groups, so as to improve the hydrophilicity of polyester fabric.

[0003] There are many methods for modifying the surface of polyester, such as oxidation method (including radiation oxidation and oxidant oxidation), alkali treatment method, coating method and surface grafting modification, but these methods all have respective shortcomings such as high equipment requirement, large amount of wastewater pollution, insufficient air permeability and chemical residue and the like. The biological enzyme method is energy-saving and environment-friendly, meets the durability, and does not affect the performance of polyester itself, and becomes an ideal method for surface modification of polyester. However, due to the enzyme activity (activity and stability) and the high crystallinity of polyester and the accessibility between the two, the biological enzyme method has problems of low efficiency and long period. SUMMARY

[0004]

Technical problem

[0005] When the biological enzyme method is used to catalyze the hydrolysis of polyester, due to the enzyme activity (activity and stability) and the high crystallinity of polyester and the accessibility between the two, the hydrolysis effect is poor.

[0006]

Technical solution

[0007] Triton is a non-ionic surfactant, and the effective ingredient is octyl phenol polyoxyethylene ether, the molecular formula is C8H 17 C6H4(OCH2CH2) n OH, and different types can be divided according to the number of ethylene oxide (EO), and is widely used in the fields of biotechnology and textile industry. In the application, the activity and stability of cutinase are improved by using Triton, the hydrolysis effect of cutinase on polyester is enhanced, the hydrolysis product is increased by 229.8%, and cutinase can hydrolyze polyester with higher crystallinity.

[0008] The first object of the application is to provide a method for promoting hydrolysis of polyester by cutinase with Triton, comprising the following steps:

[0009] S1, Triton is added to Tris-HCl buffer solution, and after being uniformly mixed, hydrochloric acid is used to adjust the pH value, so as to obtain a Triton buffer solution;

[0010] S2, the polyester is immersed in Triton buffer, and a cutinase preparation is added for hydrolysis reaction, the cutinase is inactivated, the polyester is taken out and washed and dried, and the hydrolyzed polyester is obtained.

[0011] In an embodiment of the present application, in step S1, the Triton is a Triton X series nonionic surfactant, the number of ethylene oxide units is 1-70, and the molecular weight is 250-3300; the Triton is selected from one or more of Triton X-15, Triton X-35, Triton X-45, Triton X-114, Triton X-100, Triton X-102, Triton X-165, Triton X-305, Triton X-405, and Triton X-705.

[0012] In an embodiment of the present application, in step S1, the number of ethylene oxide units of the Triton is preferably 1-8.

[0013] In an embodiment of the present application, in step S1, the Triton is preferably one or more of Triton X-15, Triton X-35, Triton X-45, and Triton X-114.

[0014] In an embodiment of the present application, in step S1, the Triton is preferably Triton X-45.

[0015] In an embodiment of the present application, in step S1, the concentration of the Triton in the Triton buffer is 0.1-1.0 g / L.

[0016] In an embodiment of the present application, in step S1, the concentration of the Triton in the Triton buffer is preferably 0.3-0.6 g / L.

[0017] In an embodiment of the present application, in step S1, the concentration of the Triton in the Triton buffer is preferably 0.4 g / L.

[0018] In an embodiment of the present application, in step S1, the Tris-HCl buffer is a trimethylaminomethane hydrochloride aqueous solution; the pH of the Tris-HCl buffer is 9-10; and the concentration of the trimethylaminomethane hydrochloride in the Tris-HCl buffer is 5-50 mmol / L.

[0019] In an embodiment of the present application, in step S1, the pH is adjusted to 7.5-9.5.

[0020] In an embodiment of the present application, in step S1, the pH is preferably adjusted to 9.0.

[0021] In an embodiment of the present application, the polyester used in step S2 is refined polyester; the method for refining polyester comprises the steps of: dissolving soap flakes and anhydrous sodium carbonate in water to obtain a refining solution, immersing the polyester fabric, treating in a constant temperature water bath, washing, and drying to obtain the refined polyester.

[0022] In an embodiment of the present application, in the method for refining polyester, the concentration of soap flakes in the refining solution is 3-7 g / L; the concentration of anhydrous sodium carbonate is 2-6 g / L; and the bath ratio (mass ratio of polyester to treatment solution) is 1:20-40.

[0023] In an embodiment of the present application, in the method for refining polyester, the temperature of the constant temperature water bath treatment is 95-100℃; and the time of the constant temperature water bath treatment is 25-35 min.

[0024] In an embodiment of the present application, in the method for refining polyester, the drying is drying to constant weight; and the temperature of the drying is 80-120℃.

[0025] In an embodiment of the present application, in the method for refining polyester, the obtained polyester is equilibrated at a temperature and humidity of 25±1℃ and 65±2% for 36-60 h after drying.

[0026] In an embodiment of the present application, in step S2, the amount of cutinase added relative to the Triton buffer is 300-600 U / mL.

[0027] In an embodiment of the present application, in step S2, the amount of cutinase added relative to the Triton buffer is preferably 500 U / mL.

[0028] In an embodiment of the present application, in step S2, the cutinase is Novozym 51032 cutinase; and the enzyme activity of the cutinase preparation is 10000-16000 U / mL.

[0029] In an embodiment of the present application, in step S2, the conditions of the hydrolysis reaction are: temperature 50-70℃; time 6-72 h; and bath ratio 1:30-50.

[0030] In an embodiment of the present application, in step S2, the conditions of the hydrolysis reaction are preferably: temperature 65℃; time 72 h; and bath ratio 1:40.

[0031] In an embodiment of the present application, in step S2, the washing is washing with deionized water and ethanol.

[0032] In an embodiment of the present application, in step S2, the method for inactivation is heating in a 100℃ constant temperature water bath for 25-40 min.

[0033] In one embodiment of the present application, in step S2, the drying is to a constant weight; the drying temperature is 80-120°C.

[0034] In one embodiment of the present application, in step S2, the obtained polyester fabric is equilibrated at a temperature and humidity of 25±1°C and 65±2% for 36-60h after drying.

[0035] In one embodiment of the present application, the polyester is hydrolyzed twice, i.e. the polyester used in step S2 is a polyester treated by keratinase hydrolysis.

[0036] In one embodiment of the present application, the polyester is hydrolyzed twice, i.e. refined or unrefined polyester is put into an aqueous solution containing keratinase at 300-600U / mL, hydrolyzed at 50-70°C for 6-72h, bath ratio 1:30-50, keratinase enzyme activity 10000-16000U / mL, and after enzyme inactivation, the polyester is taken out and then sequentially treated by steps S1 and S2.

[0037] A second object of the present application is to provide the hydrolyzed polyester fabric prepared by the above method.

[0038] A third object of the present application is to provide the use of the above hydrolyzed polyester fabric in the field of textiles.

[0039] In one embodiment of the present application, the use in the field of textiles includes the use in garment fabrics, sports fabrics, functional textiles, and home textile fabrics.

[0040] Advantages:

[0041] (1) The present application uses Triton X-100 to promote the hydrolysis of polyester by enzymes, which is simple to operate and low in cost, and is suitable for large-scale use.

[0042] (2) The present application uses Novozym 51032 keratinase to catalyze the hydrolysis of ester bonds on the surface of polyester to produce terephthalic acid (TPA) and terephthalic acid mono(2-hydroxyethyl) ester (MHET), and generate hydroxyl and carboxyl groups on the surface of polyester, thereby improving the hydrophilicity of polyester.

[0043] (3) The present application uses Triton X-100 to improve the activity and stability of keratinase.

[0044] (4) The present application uses Triton X-100 to promote the hydrolysis of polyester by keratinase; promotes more keratinase protein molecules to be adsorbed on the surface of polyester to participate in the hydrolysis reaction; and increases the release of hydrolysis products by 229.8%, and more deeply etches the polyester.

[0045] (5) The present application uses Triton X-100, which enables keratinase to hydrolyze polyester with higher crystallinity. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 Figure 1 is a high performance liquid chromatogram of the reaction residue in Example 1 and Comparative Example 1.

[0047] Figure 2 Figure 2 is a water contact angle test diagram of the fabric treated in Example 1 and Comparative Example 1, wherein (a) is Comparative Example 1 and (b) is Example 1.

[0048] Figure 3 Figure 3 is a scanning electron microscope diagram of the fabric treated in Example 1 and Comparative Example 1, wherein (a) is Comparative Example 1 and (b) is Example 1.

[0049] Figure 4 Figure 4 is a result diagram of the effect of the buffer on the stability of the enzyme.

[0050] Figure 5 Figure 5 is a result diagram of the release amount of the secondary enzymatic hydrolysis product of Example 4 and Comparative Example 4. DETAILED DESCRIPTION

[0051] The polyester fabric used in the examples and comparative examples of the present application is: polyester filament plain fabric.

[0052] Test method:

[0053] 1. Quantitative test of hydrolysis product

[0054] The keratinase catalyzed polyester hydrolysis product has the same absorption intensity at 240 nm, so a standard curve is drawn using TPA solution. The specific method is as follows: prepare TPA solutions with concentrations of 0 mg / L, 4 mg / L, 8 mg / L, 12 mg / L, 16 mg / L and 20 mg / L using deionized water, adjust the pH of the above TPA solutions with different concentrations to about 8 using 0.1 mol / L NaOH solution, set deionized water to zero, and measure the absorbance values of the above TPA solutions at 240 nm using a double-beam ultraviolet spectrophotometer. Draw a standard curve with the concentration of the TPA standard solution as the abscissa and the absorbance value as the ordinate. The standard curve measured in the present application is Y = 0.0083X + 0.0051, R 2 = 0.9998. After centrifugation of the inactivated reaction residue, the supernatant is measured for absorbance value, and the hydrolysis product concentration is obtained by substituting the standard curve. The blank sample is a sample treated under the same conditions without containing polyester substrate.

[0055] 2. Qualitative test of hydrolysis product

[0056] The hydrolysis products were qualitatively analyzed using high performance liquid chromatography (HPLC). The instrument was a Shimadzu LC-20AD series high performance liquid chromatograph equipped with an Ultimate XB-C18 (4.6 x 250 mm, 5 μm) chromatographic column and an ultraviolet detector. The mobile phase was 1% glacial acetic acid:methanol = 35:65, the sample size was 5 μL, the flow rate was 0.5 mL / min, the column temperature was 33°C, and the detection wavelength was 240 nm. The hydrolysis products of the polyester included terephthalic acid (TPA), terephthalic acid mono(2-hydroxyethyl) ester (MHET), and terephthalic acid bis(2-hydroxyethyl) ester (BHET), which were distinguished by different peak times.

[0057] 3. Water contact angle test of polyester fabric

[0058] The sample to be tested was conditioned for 48 h at a temperature of 25 ± 1°C and a relative humidity of 65 ± 2%, and four samples from different positions were cut. The samples were attached to a glass slide, and a DSA25 contact angle measuring instrument was used for testing, with deionized water as the test solution. The injection liquid volume was set to 10 μL, and the injection head was 10 mm from the surface of the sample to be tested. The contact angle was measured and photographed, and the contact angle was averaged.

[0059] 4. Characterization of the apparent morphology of polyester

[0060] The sample was subjected to gold spraying conductive treatment, and the apparent morphology of the polyester was observed using a Hitachi scanning electron microscope SU1510. The acceleration voltage was set to 5 kV, and the magnification was 4k.

[0061] 5. Protein adsorption test

[0062] A 5.0 mg / mL bovine serum protein solution (BSA) stock solution was prepared, and appropriate dilution was performed to obtain 1.50 mg / mL, 1.0 mg / mL, 0.75 mg / mL, 0.50 mg / mL, 0.25 mg / mL, and 0.125 mg / mL BSA standard solutions. Five μL of each prepared standard solution was added to a 96-well plate, 250 μL of G-250 dye solution was added, and after mixing, the mixture was incubated at 37°C for 10 min. Finally, the absorbance value of the standard sample at 595 nm was measured using a microplate reader, and a protein standard curve was plotted with the protein concentration as the abscissa and the absorbance value as the ordinate. Y = 0.5755X + 0.053 (R 2 = 0.99)

[0063] Five μL of the supernatant of the reacted sample was taken and the absorbance value was measured according to the above method to obtain the protein concentration of the sample from the standard curve.

[0064] 6. Fabric crystallinity test

[0065] The treated fabric was subjected to crystallinity test using Mettler DSC3+ differential scanning calorimeter. The test temperature was 10-300℃, and the temperature rising rate was 10℃ / min. The crystallinity (%)=(melting enthalpy / 100% crystalline melting enthalpy)×100%, and the 100% crystalline melting enthalpy of terylene was 125.5 J / g.

[0066] 7. Enzyme activity determination

[0067] The keratinase enzyme activity was determined by continuous spectrophotometry. A standard solution of p-nitrophenol (pNP) was prepared in Tris-HCl buffer at different concentrations, and the absorbance value at 405 nm was determined to draw a standard curve. The total volume of the enzyme activity test reaction was 1.5 mL, including 1440 μL of Tris-HCl buffer (10 mmol / L, pH=8), 30 μL of pNPB (50 mmol / L) dissolved in acetonitrile, and 30 μL of diluted enzyme solution. The absorbance value change at 405 nm within one minute was detected, and the amount of generated pNP was calculated. The definition of enzyme activity: the amount of enzyme that catalyzes the hydrolysis of p-nitrophenyl butyrate to generate 1 μmol of p-nitrophenol per minute at 37℃ is one enzyme activity unit.

[0068] Example 1

[0069] A method for promoting terylene hydrolysis by keratinase using Triton X-100, comprising the steps of:

[0070] S1. Dissolve soap flakes and anhydrous sodium carbonate in deionized water to obtain a refining solution, the soap flakes concentration of the refining solution is 5 g / L, and the anhydrous sodium carbonate concentration is 4 g / L; immerse the terylene fabric, the bath ratio is 1:30, treat in a constant temperature water bath at 98℃ for 30 min, wash, dry at 105℃, and balance for 48 h under the conditions of temperature 25±1℃ and relative humidity 65±2%, to obtain refined terylene.

[0071] S2. Add Triton X-45 to Tris-HCl buffer with a concentration of 20 mmol / L, mix uniformly, and adjust the pH to 9.0 with hydrochloric acid to obtain a Triton X-45 buffer; the Triton X-45 concentration of the Triton X-45 buffer is 0.4 g / L.

[0072] S3. Immerse the refined terylene in the Triton X-45 buffer, the bath ratio is 1:40, and add Novozym 51032 keratinase preparation (enzyme activity is 12400 U / mL), so that the addition amount of Novozym 51032 keratinase relative to the Triton X-45 buffer is 500 U / mL; place in a constant temperature shaker for hydrolysis reaction for 72 h, the temperature is set to 65℃, and the rotation speed is 150 r / min; heat in a constant temperature water bath at 100℃ for 30 min to inactivate the keratinase, take out the terylene fabric, wash with deionized water and ethanol respectively, dry at 105℃, and balance for 48 h under the conditions of temperature 25±1℃ and relative humidity 65±2%.

[0073] The reaction residual liquid after step S3 was centrifuged at 8000 r / min for 10 min, and the supernatant was taken for standby use.

[0074] Comparative Example 1

[0075] The difference from Example 1 is that no Triton X-45 is added in step S2, and the Triton buffer in step S3 is replaced by 20 mmol / L Tris-HCl buffer with pH = 9.0.

[0076] Comparative Example 2

[0077] The difference from Example 1 is that no cutinase is added in step S3.

[0078] Performance determination

[0079] 1. Quantitative test of the release amount of the polyester hydrolysis product in the reaction residual liquid, and the test results are as follows:

[0080] Table 1 Release amount of hydrolysis product of Example 1 and Comparative Examples 1 and 2

[0081] Example 1 Comparative Example 1 Comparative Example 2 TPA release (mg / L) 388.7 117.8 3.85

[0082] As can be seen from Table 1, in Comparative Example 2, only the Triton buffer is used without adding cutinase, which does not produce effective hydrolysis effect on polyester. In Comparative Example 1, no Triton is used and only cutinase is used, and the release amount of the hydrolysis product of Example 1 is increased by 229.8% compared with Comparative Example 1, indicating that the increase in the release amount of the product is the result of the joint action of the enzyme and Triton.

[0083] 2. Qualitative test of the release amount of the polyester hydrolysis product in the reaction liquid, and the test results are as follows:

[0084] The high performance liquid chromatography test results are shown in Figure 1 As can be seen, compared with the single action of the cutinase in Comparative Example 1, the types of the hydrolysis products in Example 1 with the addition of Triton do not change, and the release amounts of the products TPA and MHET are obviously increased. It is indicated that the addition of Triton does not change the mechanism of the cutinase hydrolyzing polyester.

[0085] 3. Test of the water contact angle of the polyester fabric, and the test results are as follows:

[0086] The water contact angle test results are shown in Figure 2 As can be seen, the contact angle of the cutinase alone in Comparative Example 1 is 81.6°, and the contact angle of Example 1 with the addition of Triton is 76.1°, and the hydrophilicity of the polyester fabric is further enhanced, indicating that under the action of Triton, the cutinase hydrolyzing polyester makes more hydrophilic groups generated on the fabric surface.

[0087] 4. The apparent morphology of the polyester fiber was tested, and the test results were as follows:

[0088] The scanning electron microscope results are shown in Figure a for Comparative Example 1 and b for Example 1. As can be seen, after the cutinase hydrolysis of Comparative Example 1, the surface of the polyester fiber was etched and became rough. The etching of the polyester fiber of Example 1 was deeper and the surface was rougher due to the addition of Triton, indicating that the hydrolysis of the cutinase was stronger under the action of Triton. Figure 3 5. The protein content in the reaction liquid was tested, and the test results were as follows:

[0089] Table 2 Protein content in the reaction residual liquid of Example 1 and Comparative Example 1

[0090]

[0091] Example 1 Comparative Example 1 Protein content (mg / mL) 0.50 0.64

[0092] As can be seen from Table 2, the protein content in the reaction residual liquid decreased from 0.64 mg / mL to 0.50 mg / mL after the addition of Triton, indicating that more cutinase protein molecules were adsorbed on the surface of the polyester to participate in the hydrolysis reaction under the action of Triton, and thus the hydrolysis effect was stronger.

[0093] 6. Novozym 51032 cutinase preparation (enzyme activity of 12400 U / mL) was added to the Triton buffer prepared in step S2 of Example 1 and the Tris-HCl buffer (pH = 9.0, 20 mmol / L) prepared in step S2 of Comparative Example 1, respectively, so that the addition amount of Novozym 51032 cutinase relative to the Triton buffer was 500 U / mL, and the enzyme activity was measured after incubation for 0-288 h. The test results were as follows:

[0094] The enzyme activity after incubation for 0 h in the Tris-HCl buffer was defined as the initial enzyme activity, which was 100% of the enzyme activity, and the relative enzyme activity of the other samples was calculated, and the results are shown in Figure a. As can be seen, although the cutinase activity decreased rapidly within the first 48 h, the decrease rate of the cutinase activity in the Triton buffer was significantly lower than that in the Tris-HCl buffer. After 120 h, the enzyme activity in the Triton buffer remained 74.6%, while the enzyme activity in the Tris-HCl buffer remained only 53.8%. This indicates that the use of the Triton buffer in Example 1 greatly enhances the stability of the cutinase activity, and the half-life of the enzyme activity is extended from 137 h to 272 h. Figure 4 Comparative Example 3

[0095]

[0096] ​​The comparative example explores the influence of the buffer concentration on the product release amount. The difference from Example 1 is that step S2 does not add Triton X-45, and the Triton buffer in step S3 is replaced with 5, 10, 20, 50 mmol / L Tris-HCl buffer with pH = 9.0. A series of hydrolyzed fabrics and reaction residues are obtained.

[0097] The hydrolyzed polyester product release amount in the reaction residue is tested, and the test results are as follows:

[0098] Table 3 Hydrolysis product release amount at different buffer concentrations

[0099] Buffer concentration (mmol / L) 5 10 20 50 TPA release (mg / L) 107.6 113.2 117.8 118.1

[0100] As can be seen from Table 3, the buffer concentration will affect the product release amount, because the product TPA dissolved in water will ionize H + , reducing the pH of the reaction system and affecting the activity of cutinase to some extent, thereby reducing the product release amount. Increasing the buffer concentration will improve its buffering capacity and weaken the pH change. From the results, the product release amount does not change significantly when the buffer concentration is higher than 20 mmol / L, indicating that this concentration is sufficient to buffer the H + ionized by the product.

[0101] Example 2

[0102] This example explores the influence of the Triton chain length on the product release amount. The Triton X-45 in step S2 of Example 1 is replaced with Triton X-15, Triton X-35, Triton X-114, Triton X-100, Triton X-102, Triton X-165, Triton X-305, Triton X-405, or Triton X-705, obtaining a series of hydrolyzed polyester fabrics and reaction residues.

[0103] The hydrolyzed polyester product release amount in the reaction residue is tested, and the test results are as follows:

[0104] Table 4 Hydrolysis product release amount at different Triton chain lengths

[0105]

[0106]

[0107] As can be seen from Table 4, the different chain lengths of Triton all increase the release of hydrolysis products to different extents, among which the release of hydrolysis products under the condition of Triton X-45 is the most increased, and the enzymatic hydrolysis is the strongest. The surfactant is connected with two phases by the hydrophilic group and the hydrophobic group at both ends, so the chain length will affect the accessibility between Triton and enzyme and polyester, thereby affecting the enzymatic hydrolysis effect. As can be seen from Table 4, both too long and too short chain lengths will weaken the enhancement effect of Triton, and the effect of Triton X-45 is the best.

[0108] Example 3

[0109] This example investigates the effect of Triton concentration on the release of products. The concentration of Triton X-45 in the Triton buffer in step S2 of Example 1 is replaced by 0.2 g / L, 0.4 g / L, 0.6 g / L, 0.8 g / L and 1.0 g / L, to obtain a series of hydrolyzed polyester fabrics and reaction residues.

[0110] The release of hydrolyzed polyester products in the reaction residue is tested, and the test results are as follows:

[0111] Table 5 Product release amount under different concentrations of Triton

[0112] Triton concentration (g / L) 0.2 0.4 0.6 0.8 1.0 TPA release (mg / L) 359.4 388.7 389.1 386.4 387.2

[0113] As can be seen from Table 5, when the concentration of Triton is higher than 0.4 g / L, the release of hydrolysis products does not increase significantly with the increase of the concentration of Triton, indicating that the increase of the concentration of Triton is limited for the enhancement of the effect of enzyme hydrolysis on polyester. The hydrophilic end and the hydrophobic end of Triton will connect the enzyme and the polyester substrate on the one hand, and change the accessibility between the enzyme and the polyester on the other hand. Therefore, when the concentration of Triton increases to a certain value, the hydrolysis effect of the enzyme will not be further enhanced.

[0114] Example 4

[0115] The secondary hydrolysis polyester is prepared by the steps of treating the polyester prepared in Comparative Example 1 by steps S2 and S3 of Example 1.

[0116] Comparative Example 4

[0117] The secondary hydrolysis polyester is prepared by the steps of treating the polyester prepared in Comparative Example 1 by steps S2 and S3 of Example 1.

[0118] Table 6 Crystallinity of hydrolyzed polyester fabric

[0119] Untreated polyester fabric Example 1 Comparative Example 1 Crystallinity (%) 35.8 36.2 38.6

[0120] As can be seen from Table 6, the crystallinity of the polyester fabric is increased from 35.8% to 38.6% after hydrolysis by using cutinase only, and the crystallinity of the polyester fabric is 36.2% after hydrolysis by using cutinase and Triton X-100 together. The reason is that, when Triton X-100 is not used, the hydrolysis of cutinase mainly occurs in the amorphous region of polyester, and with the progress of hydrolysis, the crystallinity of polyester is increased. The structure of the crystalline region is compact, and the steric hindrance is large, so it is difficult for cutinase to approach and combine with the ester bond therein, and the hydrolysis reaction is difficult to occur in this region. When the crystallinity is increased to a certain extent, cutinase cannot continue to hydrolyze. However, the addition of Triton X-100 can make the hydrolysis proceed to part of the crystalline region, so the crystallinity of the hydrolyzed polyester is lower.

[0121] In order to explore the influence of crystallinity on the effect of enzymatic hydrolysis, the enzymatic hydrolysis fabric prepared in Comparative Example 1 was subjected to secondary enzymatic hydrolysis (Example 4 and Comparative Example 4), and the product release amount was measured, and the results are shown in Table 8. Figure 5 As can be seen, the product release amount is only 4.8 mg / L after 24 h of secondary enzymatic hydrolysis by using cutinase only (Comparative Example 4), and there is no obvious increasing trend of product release amount during the period of 6-24 h of secondary enzymatic hydrolysis, which indicates that cutinase cannot further hydrolyze the polyester with such crystallinity. In contrast, when cutinase and Triton X-100 are used simultaneously for secondary enzymatic hydrolysis (Example 4), although the product release amount is also low at the initial stage of secondary enzymatic hydrolysis, it shows a sustained increasing trend, and reaches a product release amount of 32.5 mg / L at 24 h of secondary enzymatic hydrolysis, which is 6.7 times that of Comparative Example 4. This is because, after the initial enzymatic hydrolysis, the increased crystallinity of the polyester fabric leads to the reduced accessibility of cutinase to the polyester, and the secondary enzymatic hydrolysis process becomes extremely difficult or even impossible. However, the addition of Triton X-100 significantly improves this situation, so that cutinase can effectively act on the polyester fabric with higher crystallinity, and thus cutinase can effectively hydrolyze the polyester for a long time.

[0122] Example 5

[0123] In this example, the influence of the chain length of Triton X-100 on the product release amount of secondary enzymatic hydrolysis was explored. In the secondary hydrolysis of polyester, the Triton X-45 in the Triton X-100 buffer in step S2 of Example 4 was replaced by Triton X-15, Triton X-35, Triton X-114, Triton X-100, Triton X-102, Triton X-165, Triton X-305, Triton X-405 or Triton X-705, to obtain a series of hydrolyzed polyester fabrics and reaction residues.

[0124] The product release amount of the hydrolyzed polyester in the reaction residue was tested, and the test results are as follows:

[0125] Table 7 Product release amount of secondary enzymatic hydrolysis under different chain lengths of Triton X-100

[0126] Triton class Chain length (EO number) 6h product release (mg / L) 24h product release (mg / L) Triton X-15 1～2 10.4 29.5 Triton X-35 3 10.6 29.1 Triton X-45 4～5 11.3 32.5 Triton X-114 7～8 8.7 24.8 Triton X-100 9～10 7.5 15.2 Triton X-102 12 6.8 11.6 Triton X-165 16 5.3 6.3 Triton X-305 30 4.4 5.3 Triton X-405 40 4.2 5.1 Triton X-705 70 4.1 5.0

[0127] As can be seen from Table 7, the promotion effects of different chain lengths of Triton on secondary enzymatic hydrolysis are also different. In primary enzymatic hydrolysis, different chain lengths of Triton all showed different degrees of promotion effect on enzymatic hydrolysis, but in secondary enzymatic hydrolysis, due to the decrease of amorphous region and the increase of crystallinity, part of the larger chain length Triton (Triton X-705, Triton X-305, Triton X-405) can no longer effectively promote keratinase to hydrolyze polyester, while the smaller chain length Triton maintains the promotion effect on hydrolysis, and is relatively more prominent. For example, the product release amount of Triton X-114 in primary enzymatic hydrolysis is close to that of Triton X-45, but in secondary enzymatic hydrolysis, Triton X-45 is 31.0% higher than Triton X-114. This may be because the smaller chain length Triton is easier to enter the tightly arranged crystal region for adsorption, while the larger chain length Triton is blocked outside, so it can no longer continue to promote keratinase to hydrolyze polyester.

[0128] The above provided examples are not intended to limit the scope covered by the present application, and the described steps are not intended to limit the execution order thereof. The improvements of the present application made by those skilled in the art in combination with the existing common knowledge are also within the protection scope defined by the claims of the present application.

Claims

1. A method for promoting the hydrolysis of polyester by cutinase using Triton, characterized in that: Including steps: S1, adding Triton to Tris-HCl buffer, mixing well and adjusting the pH with hydrochloric acid to obtain Triton buffer; S2. Immerse the polyester in a Triton buffer solution, add a cutinase preparation to carry out a hydrolysis reaction, inactivate the cutinase, take out the polyester, wash it, and dry it to obtain a hydrolyzed polyester.

2. The method according to claim 1, characterized in that In step S1, Triton is a Triton X series nonionic surfactant, the number of ethylene oxide units is 1 to 70, and the molecular weight is 250 to 3300.

3. The method according to claim 1, characterized in that In step S1, the Triton concentration of the Triton buffer is 0.1 to 1.0 g / L; the Tris-HCl buffer is a tris(hydroxymethyl)aminomethane hydrochloride aqueous solution; the pH of the Tris-HCl buffer is 9 to 10; the tris(hydroxymethyl)aminomethane hydrochloride concentration of the Tris-HCl buffer is 5 to 50 mmol / L; and the pH is adjusted to 7.5 to 9.

5.

4. The method according to claim 1, wherein In step S2, the polyester used is refined polyester; the method for refining polyester includes the steps of: dissolving soap flakes and anhydrous sodium carbonate in water to obtain a refining solution, immersing the refined solution in the polyester fabric, treating the solution in a constant temperature water bath, washing the solution with water, and drying the solution to obtain the refined polyester.

5. The method according to claim 4, characterized in that The soap flake concentration of the refining liquid is 3-7 g / L; the anhydrous sodium carbonate concentration is 2-6 g / L; the refining bath ratio is 1:20-40; the temperature of the constant temperature water bath treatment is 95-100° C.; and the constant temperature water bath treatment time is 25-35 minutes.

6. The method according to claim 4, characterized in that The drying step is to dry the polyester fabric to a constant weight; after drying, the obtained polyester fabric is balanced at a temperature and humidity of 25±1° C. and 65±2% for 36 to 60 hours.

7. The method according to claim 1, characterized in that In step S2, the amount of cutinase added relative to the Triton buffer is 300-600 U / mL; the cutinase is Novozym 51032 cutinase; the hydrolysis reaction conditions are: temperature 50-70°C, time 6-72 hours, bath ratio 1:30-50; the inactivation method is heating in a constant temperature water bath at 100°C for 25-40 minutes; and the drying is drying to constant weight.

8. The method according to claim 1, characterized in that In step S2, the polyester used is polyester that has been hydrolyzed by cutinase.

9. The hydrolyzed polyester fabric prepared by the method according to any one of claims 1 to 8.

10. Use of the hydrolyzed polyester fabric according to claim 9 in the field of textiles.

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