A method of using a surfactant (tween)

Abstract

The application relates to a surfactant (tween) application method, in particular a method for improving holocellulose enzymolysis efficiency by using a surfactant (tween), which comprises the following steps: S1: mixing a surfactant with a mixed solution containing holocellulose to obtain an enzymolysis system, wherein the surfactant is selected from tween and / or glycerol; S2: adding an enzyme solution to the enzymolysis system, so that holocellulose is subjected to enzymolysis in the presence of an enzymolysis promoter and an enzyme. The method provided by the application can effectively reduce the invalid adsorption of cellulase in the enzymolysis process by adding the surfactant tween and / or glycerol in the holocellulose enzymolysis system with high solid concentration, and the enzymolysis efficiency of holocellulose is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cellulase enzymatic hydrolysis, in particular to a method for applying a surfactant (Tween), and more particularly to a method for improving the enzymatic hydrolysis efficiency of holocellulose by using a surfactant (Tween). BACKGROUND

[0002] With the high development of society, the consumption of fossil fuels is becoming larger and larger. Due to the non-renewable nature of fossil fuels, finding alternative energy sources has become the focus of attention. The preparation of cellulosic ethanol from corn stalks, corn cobs, rice straws and other crop straws, wood chips, tree branches and other agricultural and forestry wastes and other lignocellulosic biomass is called "second-generation fuel ethanol", which is of great significance in increasing the added value of agricultural and forestry wastes, reducing environmental pollution and promoting rural economic development.

[0003] The mainstream technology for preparing cellulosic ethanol includes pretreatment, enzymatic hydrolysis and fermentation. The efficient extraction of sugar products from lignocellulosic biomass is the most critical technical difficulty in the process of cellulosic ethanol. The extraction of sugar products mainly comes from pretreatment and enzymatic hydrolysis. However, the cost of cellulase used in the current enzymatic hydrolysis is high, and the concentration of generated sugar products is low, resulting in low enzymatic hydrolysis efficiency. Enzymatic hydrolysis of high-concentration raw materials is a very effective method to increase the concentration of output sugar products, but when the concentration of pretreated lignocellulosic solid raw materials is high, it will inevitably cause high viscosity and uneven mixing, which will also inhibit the smooth progress of enzymatic hydrolysis. SUMMARY

[0004] In order to solve the above technical problems existing in the prior art, the present application provides a method for improving the enzymatic hydrolysis efficiency of holocellulose, especially at high solid concentration. The method provided by the present application can effectively reduce the invalid adsorption of cellulase in the enzymatic hydrolysis process by adding Tween and / or glycerol to the holocellulose enzymatic hydrolysis system at high solid concentration, thereby improving the enzymatic hydrolysis efficiency of holocellulose.

[0005] The method for improving the enzymatic hydrolysis efficiency of holocellulose provided by the present application comprises the following steps:

[0006] S1: mixing a surfactant with a mixed solution containing holocellulose to obtain an enzymatic hydrolysis system, wherein the surfactant is selected from Tween and / or glycerol;

[0007] S2: adding enzyme solution to the enzymatic hydrolysis system to make the holocellulose undergo enzymatic hydrolysis in the presence of the surfactant and the enzyme.

[0008] In some embodiments, the mass content of the holocellulose is 10% to 20%, for example 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or any value therebetween, based on the mass of the enzymatic hydrolysis system.

[0009] In some embodiments, the mass content of the surfactant is 0.1%-1.5% based on the mass of the enzymatic system. In some embodiments, the mass content of the surfactant is 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, or any value therebetween. In some embodiments, the mass content of the surfactant is 0.5%-1.0%. When the concentration of the surfactant is too low, the effect of promotion is not obvious, and when the concentration of the surfactant is too high, the effect of promotion does not increase substantially.

[0010] In some embodiments, the Tween is selected from one or more of Tween 20, Tween 40, Tween 60, and Tween 80.

[0011] In some embodiments, the surfactant is Tween 80 and glycerol.

[0012] In some embodiments, the mass ratio of Tween 80 to glycerol is 1:(0.1-10), for example, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.3, 1:1.5, 1:1.7, 1:1.9, 1:2, 1:2.1, 1:2.3, 1:2.5, 1:2.7, 1:2.9, 1:3, 1:3.1, 1:3.3, 1:3.5, 1:3.7, 1:3.9, 1:4, 1:4.1, 1:4.3, 1:4.5, 1:4.7, 1:4.9, 1:5, 1:5.1, 1:5.3, 1:5.5, 1:5.7, 1:5.9, 1:6, 1:6.1, 1:6.3, 1:6.5, 1:6.7, 1:6.9, 1:7, 1:7.1, 1:7.3, 1:7.5, 1:7.7, 1:7.9, 1:8, 1:9, or any value therebetween. When Tween and glycerol are added together in a certain ratio in the enzymatic system, they have a synergistic effect.

[0013] In some embodiments, the raw material for preparing the holocellulose is selected from wheat straw.

[0014] In some embodiments, the method for preparing the holocellulose comprises crushing the raw material for preparing the holocellulose, mixing the crushed raw material with an alkali solution, and then performing heat treatment, and then washing and drying the heat-treated material to obtain the holocellulose.

[0015] In some embodiments, the particle size of the crushed raw material is 20-40 mesh.

[0016] In some embodiments, the alkali solution is selected from a sodium hydroxide solution. In some embodiments, the sodium hydroxide solution has a concentration of 2-6%, for example 3%, 4% or 5%.

[0017] In some embodiments, the mass ratio of the alkali solution to the mass of the broken raw material is (2.5-3): 1.

[0018] In some embodiments, the temperature of the heat treatment is 95-110°C. In some embodiments, the time of the heat treatment is 2-4h, for example 2.5-3.5h.

[0019] In some embodiments, the enzyme solution comprises a cellulase solution, a cellobiase solution and a xylanase solution.

[0020] In some embodiments, the cellulase solution is added in an amount of 10-35wt% based on the dry mass of holocellulose, for example 13wt%, 15wt%, 17wt%, 20wt%, 23wt%, 25wt%, 27wt%, 30wt% or 33wt%.

[0021] In some embodiments, the cellobiase solution is added in an amount of 40-60wt% based on the dry mass of holocellulose, for example 43wt%, 45wt%, 47wt%, 50wt%, 53wt%, 55wt% or 57wt%.

[0022] In some embodiments, the xylanase solution is added in an amount of 5-15wt% based on the dry mass of holocellulose, for example 6wt%, 8wt%, 10wt%, 12wt% or 14wt%.

[0023] In some embodiments, the cellulase has a filter paper activity of 100-300IU / g, for example 150IU / g, 200IU / g or 250IU / g.

[0024] In some embodiments, the cellobiase has a standard enzyme activity of 100-400IU / g, for example 150IU / g, 200IU / g, 250IU / g, 300IU / g or 350IU / g.

[0025] In some embodiments, the xylanase has an enzyme activity of 800-1200IU / g, for example 850IU / g, 900IU / g, 950IU / g, 1000IU / g, 1050IU / g, 1100IU / g or 1150IU / g.

[0026] In some embodiments, the pH of the enzymatic system is 4.5-5.5. In some embodiments, the pH of the enzymatic system is adjusted by using sulfuric acid and sodium hydroxide solution.

[0027] In some embodiments, the temperature of the enzymatic reaction is 45-52℃, for example, 46℃, 47℃, 48℃, 49℃, 50℃ or 51℃. In some embodiments, the time of the enzymatic reaction is 72-96h, for example, 76h, 80h, 84h, 88h or 92h.

[0028] In some embodiments, the enzymatic reaction is carried out in a shaker. In some embodiments, the speed of the shaker is 150-230rpm.

[0029] In some embodiments, the method for improving the efficiency of enzymatic hydrolysis of holocellulose provided by the present application comprises the following specific steps:

[0030] The raw material for preparing holocellulose, such as wheat straw, is crushed, then cooked with alkali, washed with water to pH 7-8, and dried to obtain holocellulose of wheat straw;

[0031] The holocellulose is mixed with surfactant Tween and / or glycerol to obtain a high solid enzymatic system;

[0032] Then, cellulase solution, cellobiase solution and xylanase solution are added to the system for enzymatic hydrolysis.

[0033] The present application has the following advantages:

[0034] (1) The addition of Tween and / or glycerol in the high solid concentration enzymatic system can increase the fluidity of the enzymatic system, which is conducive to the full contact reaction between enzyme protein molecules and holocellulose.

[0035] (2) Tween and / or glycerol can bind with part of the lignin in holocellulose, thereby reducing the irreversible binding of lignin and cellulase, alleviating enzyme poisoning, improving the utilization rate of enzyme and the efficiency of enzymatic hydrolysis, and reducing the cost. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with examples. The specific examples described herein are only used to explain the present application and do not constitute any limitation on the present application.

[0037] The enzymatic efficiency described in the present application is expressed by the hydrolysis rate of holocellulose of wheat straw, and the specific calculation formula is:

[0038] The enzymatic hydrolysis rate of holocellulose of wheat straw (%) = total reducing sugar content (g) / reducing sugar content of holocellulose of wheat straw (g) x 100%; wherein,

[0039] Total reducing sugar content is the total reducing sugar mass in the enzymatic hydrolysis system after the enzymatic hydrolysis is completed;

[0040] Wheat straw holocellulose reducing sugar content is the sum of the mass of cellulose converted into glucose and the mass of hemicellulose converted into xylose in the wheat straw holocellulose;

[0041] The enzymatic hydrolysis system is composed of wheat straw holocellulose substrate and mixed enzyme solution.

[0042] The particle size of the crushed wheat straw is preferably between 20 mesh and 40 mesh. The alkali solution used for alkali cooking is preferably a 2wt%-6wt% concentration of sodium hydroxide solution, and the amount used is 2.5 times to 3 times the mass of the straw powder. The cooking temperature is preferably 95°C-110°C, and the cooking time is preferably 2.5h-3.5h. After cooking, wash with pure water until the pH is 7-8, and dry at a constant temperature of 90°C. The following examples and comparative examples all use this method to pretreat the wheat straw.

[0043] Example One

[0044] (1) Prepare a surfactant aqueous solution: prepare 10wt% concentrations of Tween-20, Tween-40, Tween-60, Tween-80, and glycerol aqueous solution, numbered as A1, B1, C1, D1, and E1.

[0045] (2) Prepare a high-solid enzymatic hydrolysis system: take wheat holocellulose, determine the dry basis content to be 95wt%, divide it into 5 parts, each 31.58g (i.e. 30g of dry weight), add 100g of pure water and mix well, then add cellulase solution 10mL (specific enzyme activity is 100IU / g), cellobiase solution 15mL (specific enzyme activity is 200IU / g), and xylanase solution 3mL (specific enzyme activity is 1000IU / g), respectively, then add A1, B1, C1, D1, and E1 30mL, and then add pure water to make up to 300mL, to prepare a high-solid enzymatic hydrolysis system containing 10wt% wheat holocellulose and 1wt% of each surfactant, and adjust the pH to 4.5-5.5 using 0.05mol / mL sulfuric acid solution and 0.1mol / mL sodium hydroxide solution.

[0046] (3) Enzymatic hydrolysis reaction: place the enzymatic hydrolysis system in a water bath shaker, set the temperature to 50°C, and the rotation speed to 200rpm, control the pH of the enzymatic hydrolysis system to 4.8-5.0 using 0.05mol / mL sulfuric acid solution and 0.1mol / mL sodium hydroxide solution, and enzymatic hydrolysis for 96h. The enzymatic hydrolysis efficiency after the enzymatic hydrolysis is completed is shown in Table 1 below.

[0047] Comparative Example One

[0048] (1) Preparation of high solid enzyme hydrolysis system: wheat holocellulose was taken, and the dry basis content was determined to be 95wt%, 10mL of cellulase solution (specific enzyme activity was 100IU / g), 15mL of cellobiase solution (specific enzyme activity was 200IU / g), and 3mL of xylanase solution (specific enzyme activity was 1000IU / g) were added, and pure water was added to make up to 300mL to prepare a high solid enzyme hydrolysis system containing 10wt% wheat holocellulose. The pH was adjusted to 4.5-5.5 using 0.05mol / mL sulfuric acid solution and 0.1mol / mL sodium hydroxide solution.

[0049] (2) Enzymatic hydrolysis: the enzyme hydrolysis system was placed in a water bath shaker, the temperature was 50°C, the rotation speed was 200rpm, and the pH of the enzyme hydrolysis system was controlled at 4.8-5.0 using 0.05mol / mL sulfuric acid solution and 0.1mol / mL sodium hydroxide solution, and the enzyme hydrolysis was carried out for 96h. The enzyme hydrolysis efficiency after the specific enzyme hydrolysis was completed is shown in Table 1 below.

[0050] In Table 1, the enzyme hydrolysis efficiency improvement rate = (enzyme hydrolysis efficiency of Example 1 - enzyme hydrolysis efficiency of Comparative Example 1) / enzyme hydrolysis efficiency of Comparative Example 1 x 100%.

[0051] Table 1

[0052]

[0053] From the data in Table 1, it can be seen that when Tween or glycerol is added to the wheat straw holocellulose enzyme hydrolysis system at a concentration of 10wt%, the ineffective adsorption of lignin on cellulase during the enzyme hydrolysis process can be effectively reduced, thereby improving the enzyme hydrolysis efficiency of wheat straw holocellulose, and the highest improvement rate can reach 12.5%.

[0054] Example Two

[0055] (1) Preparation of surfactant aqueous solution: 10wt% concentrations of Tween-20, Tween-40, Tween-60, Tween-80, and glycerol aqueous solution were prepared, numbered as A2, B2, C2, D2, and E2.

[0056] (2) Preparation of high solid enzymatic hydrolysis system: wheat holocellulose was taken, and the dry basis content was determined to be 95wt%, which was divided into 5 parts, each of which was 31.58g (i.e. 30g of dry weight), and then 100g of pure water was added and mixed, and then 10mL of cellulase liquid (specific enzyme activity was 100IU / g), 15mL of cellobiase liquid (specific enzyme activity was 200IU / g), and 3mL of xylanase liquid (specific enzyme activity was 1000IU / g) were added, and then 20mL of A2, B2, C2, D2, and E2 liquids were added respectively, and then pure water was added to make up to 200mL, so as to prepare a high solid enzymatic hydrolysis system containing 15wt% of wheat holocellulose and 1wt% of each surfactant, and the pH was adjusted to 4.5-5.5 by using 0.05mol / mL of sulfuric acid solution and 0.1mol / mL of sodium hydroxide solution.

[0057] (3) Enzymatic hydrolysis reaction: the enzymatic hydrolysis system was placed in a water bath shaker, the temperature was 50°C, the rotation speed was 200rpm, the pH of the enzymatic hydrolysis system was controlled to be 4.8-5.0 by using 0.05mol / mL of sulfuric acid solution and 0.1mol / mL of sodium hydroxide solution, and the enzymatic hydrolysis was carried out for 96h. The enzymatic hydrolysis efficiency after the enzymatic hydrolysis was completed was shown in Table 2.

[0058] Comparative Example Two

[0059] (1) Preparation of high solid enzymatic hydrolysis system: wheat holocellulose was taken, and the dry basis content was determined to be 95wt%, and then 10mL of cellulase liquid (specific enzyme activity was 100IU / g), 15mL of cellobiase liquid (specific enzyme activity was 200IU / g), and 3mL of xylanase liquid (specific enzyme activity was 1000IU / g) were added, and then pure water was added to make up to 200mL, so as to prepare a high solid enzymatic hydrolysis system containing 15wt% of wheat holocellulose, and the pH was adjusted to 4.5-5.5 by using 0.05mol / mL of sulfuric acid solution and 0.1mol / mL of sodium hydroxide solution.

[0060] (2) Enzymatic hydrolysis reaction: the enzymatic hydrolysis system was placed in a water bath shaker, the temperature was 50°C, the rotation speed was 200rpm, the pH of the enzymatic hydrolysis system was controlled to be 4.8-5.0 by using 0.05mol / mL of sulfuric acid solution and 0.1mol / mL of sodium hydroxide solution, and the enzymatic hydrolysis was carried out for 96h. The enzymatic hydrolysis efficiency after the enzymatic hydrolysis was completed was shown in Table 2.

[0061] In Table 2, the enzymatic hydrolysis efficiency improvement rate = (enzymatic hydrolysis efficiency of Example Two - enzymatic hydrolysis efficiency of Comparative Example Two) / enzymatic hydrolysis efficiency of Comparative Example Two x 100%.

[0062] Table 2

[0063]

[0064] As can be seen from the data in Table 2, when Tween or glycerol is added to the wheat straw holocellulase enzymolysis system at a concentration of 15wt%, the ineffective adsorption of lignin to cellulase during enzymolysis can be effectively reduced, thereby improving the enzymolysis efficiency of wheat straw holocellulose, and the highest increase rate can reach 12.85%.

[0065] Example Three

[0066] (1) Preparation of surfactant aqueous solution: prepare 10wt% concentration of Tween-20, Tween-40, Tween-60, Tween-80, glycerol aqueous solution, respectively, numbered as A3, B3, C3, D3, E3 liquid.

[0067] (2) Preparation of high solid enzymolysis system: take wheat holocellulose, determine the dry basis content to be 95wt%, divide into 5 parts, each 31.58g (i.e. dry weight 30g), add 100g pure water and mix well, then add cellulase liquid 10mL (specific enzyme activity 100IU / g), cellobiase liquid 15mL (specific enzyme activity 200IU / g), xylanase liquid 3mL (specific enzyme activity 1000IU / g), respectively, then add A2, B2, C2, D2, E2 liquid 15mL respectively, then add pure water to make up to 150mL, prepare a high solid enzymolysis system containing 20wt% wheat holocellulose and 1wt% of each surfactant, adjust the pH to 4.5-5.5 using 0.05mol / mL sulfuric acid solution and 0.1mol / mL sodium hydroxide solution.

[0068] (3) Enzymolysis reaction: place the enzymolysis system in a water bath shaker, temperature 50℃, rotation speed 200rpm, control the pH of the enzymolysis system to 4.8-5.0 using 0.05mol / mL sulfuric acid solution and 0.1mol / mL sodium hydroxide solution, and enzymolysis for 96h. The enzymolysis efficiency after specific enzymolysis is shown in Table 3 below.

[0069] Comparative Example Three

[0070] (1) Preparation of high solid enzymolysis system: take wheat holocellulose, determine the dry basis content to be 95wt%, add cellulase liquid 10mL (specific enzyme activity 100IU / g), cellobiase liquid 15mL (specific enzyme activity 200IU / g), xylanase liquid 3mL (specific enzyme activity 1000IU / g), add pure water to make up to 150mL, prepare a high solid enzymolysis system containing 20wt% wheat holocellulose, adjust the pH to 4.5-5.5 using 0.05mol / mL sulfuric acid solution and 0.1mol / mL sodium hydroxide solution.

[0071] (2) Enzymatic hydrolysis reaction: The enzymatic hydrolysis system was placed in a water bath shaker, the temperature was 50°C, the rotation speed was 200 rpm, the pH of the enzymatic hydrolysis system was controlled by 0.05 mol / mL sulfuric acid solution and 0.1 mol / mL sodium hydroxide solution at 4.8-5.0, and the enzymatic hydrolysis was performed for 96 h. The enzymatic hydrolysis efficiency after the enzymatic hydrolysis was completed was shown in Table 3.

[0072] In Table 3, the enzymatic hydrolysis efficiency improvement rate = (the enzymatic hydrolysis efficiency of Example 3 - the enzymatic hydrolysis efficiency of Comparative Example 3) / the enzymatic hydrolysis efficiency of Comparative Example 3 x 100%.

[0073] Table 3

[0074]

[0075] As can be seen from the data in Table 3, when Tween or glycerol was added to the enzymatic hydrolysis system of wheat straw holocellulose at a concentration of 20 wt%, the ineffective adsorption of lignin to cellulase during the enzymatic hydrolysis process was effectively reduced, thereby improving the enzymatic hydrolysis efficiency of wheat straw holocellulose, and the highest improvement rate was up to 12.3%.

[0076] Example 4

[0077] (1) Preparation of surfactant aqueous solution: 10 wt% Tween-80 aqueous solution was prepared.

[0078] (2) Preparation of high solid enzymatic hydrolysis system: wheat holocellulose was taken, and the dry basis content was determined to be 95 wt%, which was divided into 6 parts, denoted as A4, B4, C4, D4, E4, F4, each part was 31.58 g (i.e. 30 g of dry weight), 100 g of pure water was added and mixed, then 10 mL of cellulase solution (specific enzyme activity was 100 IU / g), 15 mL of cellobiase solution (specific enzyme activity was 200 IU / g), and 3 mL of xylanase solution (specific enzyme activity was 1000 IU / g) were added, 2 mL, 4 mL, 8 mL, 12 mL, 16 mL, and 20 mL of 10 wt% Tween-80 solution were added to A4, B4, C4, D4, E4, and F4, respectively, and then pure water was added to make the volume to 200 mL, thereby preparing a high solid enzymatic hydrolysis system containing 15 wt% wheat holocellulose and 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, and 1% Tween-80, and the pH was adjusted to 4.5-5.5 by using 0.05 mol / mL sulfuric acid solution and 0.1 mol / mL sodium hydroxide solution.

[0079] (3) Enzymatic hydrolysis reaction: The enzymatic hydrolysis system was placed in a water bath shaker, the temperature was 50°C, the rotation speed was 200 rpm, the pH of the enzymatic hydrolysis system was controlled by 0.05 mol / mL sulfuric acid solution and 0.1 mol / mL sodium hydroxide solution at 4.8-5.0, and the enzymatic hydrolysis was performed for 96 h. The enzymatic hydrolysis efficiency after the enzymatic hydrolysis was completed was shown in Table 4.

[0080] In Table 4, the enzyme hydrolysis efficiency improvement rate = (enzyme hydrolysis efficiency of Example 4 - enzyme hydrolysis efficiency of Comparative Example 2) / enzyme hydrolysis efficiency of Comparative Example 2 x 100%.

[0081] Table 4

[0082]

[0083] Example Five

[0084] (1) Preparation of surfactant aqueous solution: prepare 10 wt% concentration glycerol aqueous solution and 10 wt% concentration Tween-80 aqueous solution.

[0085] (2) Preparation of high solid enzyme hydrolysis system: take wheat holocellulose, determine the dry basis content to be 95 wt%, divide into 3 parts, marked as A5, B5, C5, each 31.58 g (i.e. dry weight 30 g), add 100 g pure water and mix well, then add cellulase liquid 10 mL (specific enzyme activity 100 IU / g), cellobiase liquid 15 mL (specific enzyme activity 200 IU / g), xylanase liquid 3 mL (specific enzyme activity 1000 IU / g), add 10 wt% glycerol aqueous solution 4 mL and 10 wt% Tween-80 aqueous solution 16 mL to A5, add 10 wt% glycerol aqueous solution 10 mL and 10 wt% Tween-80 aqueous solution 10 mL to B5, add 10 wt% glycerol aqueous solution 16 mL and 10 wt% Tween-80 aqueous solution 4 mL to C5, then add pure water to make up to 200 mL, prepare high solid enzyme hydrolysis system containing 15 wt% wheat holocellulose and containing 0.2% glycerol and 0.8% Tween-80, 0.5% glycerol and 0.5% Tween-80, 0.8% glycerol and 0.2% Tween-80, and adjust pH to 4.5-5.5 using 0.05 mol / mL sulfuric acid solution and 0.1 mol / mL sodium hydroxide solution.

[0086] (3) Enzymatic hydrolysis reaction: place the enzyme hydrolysis system in a water bath shaker, temperature 50°C, rotation speed 200 rpm, control the pH of the enzyme hydrolysis system to 4.8-5.0 using 0.05 mol / mL sulfuric acid solution and 0.1 mol / mL sodium hydroxide solution, and hydrolyze for 96 h. The enzyme hydrolysis efficiency after the specific enzymatic hydrolysis is shown in Table 5 below.

[0087] In Table 5, the enzyme hydrolysis efficiency improvement rate = (enzyme hydrolysis efficiency of Example Five - enzyme hydrolysis efficiency of Comparative Example Two) / enzyme hydrolysis efficiency of Comparative Example Two x 100%.

[0088] Table 5

[0089]

[0090] From the data in Table 5, it can be seen that when Tween and glycerol are added together in a certain proportion into the wheat straw holocellulase hydrolysis system, the hydrolysis efficiency of the wheat straw holocellulase can be increased by 14.53%, and the two have a synergistic effect.

[0091] The technical solution of the present application is not limited to the above specific embodiments, and any technical transformation made according to the technical solution of the present application falls within the protection scope of the present application.

Claims

1. A method for applying a surfactant, comprising the following steps: S1: The surfactant is mixed with a mixture containing holocellulose to obtain an enzymatic hydrolysis system; S2: Add enzyme solution to the enzymatic hydrolysis system to allow holocellulose to undergo enzymatic hydrolysis in the presence of surfactant and enzyme; Based on the mass of the enzymatic hydrolysis system, the mass content of the surfactant is 0.5%-1.0%; The surfactant is Tween 80 and glycerol, and the mass ratio of Tween 80 to glycerol is 1:4; The enzyme solution includes cellulase solution, cellobiase solution, and xylanase solution.

2. The method according to claim 1, characterized in that, Based on the mass of the enzymatic hydrolysis system, the mass content of the holocellulose is 10% to 20%.

3. The method according to claim 1, characterized in that, The raw material for preparing holocellulose is selected from wheat straw.

4. The method according to claim 1, characterized in that, The method for preparing holocellulose includes crushing the raw materials for holocellulose preparation, mixing the crushed raw materials with an alkaline solution and then heat-treating them, and washing and drying the heat-treated material to obtain the holocellulose.

5. The method according to claim 4, characterized in that, The particle size of the crushed raw material is 20-40 mesh; and / or The alkaline solution is selected from sodium hydroxide solution; and / or The mass ratio of the alkaline solution to the crushed raw material is (2.5-3):1; and / or The heat treatment is performed at a temperature of 95℃-110℃ for 2-4 hours.

6. The method according to claim 5, characterized in that, The concentration of the sodium hydroxide solution is 2%-6%.

7. The method according to claim 1, characterized in that, Based on the dry weight of holocellulose, the amount of cellulase solution added is 10wt%-35wt%, the amount of cellobiase solution added is 40wt%-60wt%, and the amount of xylanase solution added is 5wt%-15wt%.

8. The method according to claim 1, characterized in that, The cellulase has a filter paper activity of 100-300 IU / g, the cellobiase has a standard activity of 100-400 IU / g, and the xylanase has an activity of 800-1200 IU / g.

9. The method according to claim 1, characterized in that, The pH value of the enzymatic hydrolysis system is 4.5-5.

5.

10. The method according to claim 1, characterized in that, The enzymatic hydrolysis temperature is 45℃-52℃, and the enzymatic hydrolysis time is 72h-96h; and / or The enzymatic hydrolysis is carried out in a shaker.

11. The method according to claim 10, characterized in that, The shaking speed is 150rpm-230rpm.

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