Straw decomposition treatment method and application of decomposed straw

Abstract

The invention provides a straw decomposition treatment method and application of decomposed straw. The straw decomposition treatment method comprises the following steps: S1, crushing the straw; s2, mixing and filtering the crushed straws and methanesulfonic acid-thymol to obtain filter residues; s3, the filter residues and ethyl alcohol are mixed and filtered, colorless powder is obtained, and the colorless powder is decomposed straw. According to the method, the thymol reacts with the methanesulfonic acid through the hydroxyl of the thymol to form methanesulfonic acid-thymol, the methanesulfonic acid-thymol can generate supramolecular interaction between a delignification medium and the lignin, almost all the lignin can be rapidly removed under the condition close to the normal temperature, and decomposition is convenient and rapid.

Description

Technical Field

[0001] The invention belongs to the technical field of straw processing, and in particular relates to a straw decomposition processing method and application of the decomposed straw. Background Art

[0002] There is a regional, seasonal and structural surplus of straw, and a large amount of straw resources are not used, resulting in serious waste. Straw is often discarded and burned at random, which not only wastes resources but also brings about a series of environmental problems. Its complex cross-linked structure and other characteristics pose a huge obstacle to its utilization, as it is almost impossible to separate the lignocellulose components under mild conditions. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a straw decomposition treatment method and application of the decomposed straw, by adding methanesulfonic acid-thymol, which can quickly remove almost all lignin under conditions close to room temperature, and the decomposition is convenient and fast.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: In one aspect, the present invention provides a method for decomposing and treating straw, comprising the following steps: S1, crushing the straw; S2, mixing and filtering the crushed straw and methanesulfonic acid-thymol to obtain a filter residue; S3. Mix the filter residue and ethanol and filter to obtain a colorless powder, which is the decomposed straw.

[0005] Preferably, in step S1, the straw is crushed to 30-80 meshes.

[0006] Preferably, in step S2, in methanesulfonic acid-thymol, the molar ratio of methanesulfonic acid to thymol is 1:(1.5-3).

[0007] Preferably, in step S2, the solid-liquid ratio of straw to methanesulfonic acid-thymol is 1:(2.2-10).

[0008] Preferably, in step S2, after the crushed straw and methanesulfonic acid-thymol are mixed, the reaction temperature is 30-80° C. and the reaction time is 0.5-10 min.

[0009] Preferably, in step S3, the filter residue and ethanol are mixed and washed until colorless, and then filtered to obtain a colorless powder.

[0010] In another aspect, the present invention provides a use of the decomposed straw obtained by the treatment method in preparing a culture medium for culturing bifidobacteria.

[0011] Preferably, the specific preparation step of the carbon source in the culture medium for culturing bifidobacteria is: the colorless powder obtained in step S3 is mixed and concentrated with water, cellulase and xylanase to obtain the bifidobacterium fermentation carbon source.

[0012] Preferably, the solid-liquid ratio of the colorless powder to water is 1:(2.2-10); and / or, The mass ratio of cellulase to colorless powder is (0.1-10):100; and / or, The mass ratio of xylanase to colorless powder is (0.1-1):100.

[0013] Preferably, the colorless powder obtained in step S3 is mixed with water, cellulase and xylanase, and heated and stirred in a water bath at 30-80° C. for 3-48 hours. After the reaction is completed, the mixture is concentrated to obtain a bifidobacterium fermentation carbon source.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The thymol of the present invention reacts with methanesulfonic acid through its hydroxyl group to form methanesulfonic acid-thymol. Methanesulfonic acid-thymol can generate supramolecular interaction between the delignification medium and lignin, and can quickly remove almost all lignin under conditions close to room temperature, and the decomposition is convenient and fast.

[0015] (2) In the present invention, cellulase and xylanase are added to the colorless powder obtained after decomposition of straw to remove lignin solids to obtain glucose, xylose and oligosaccharides, which can be used as carbon sources to cultivate high-density bifidobacteria. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can understand the present invention more clearly.

[0017] Example 1 The method of producing bifidobacterium cells by chemically treating straw comprises the following steps: (1) Crush the corn stalks to control the moisture content of the raw materials to less than 10%; remove impurities and iron from the stalks (using screens and electromagnetic impurities and iron removal), and then crush to 30-80 mesh; (2) adding the raw material obtained in step (1) to a mixture of methanesulfonic acid-thymol (molar ratio 1:1.5) at a material-liquid ratio of 1:2.2, mixing well, reacting at a temperature of 30°C for a reaction time of 0.5 min; (3) filtering the residue after the reaction in step (2) and washing it with ethanol until it becomes a colorless powder; (4) Add water to the dried colorless powder in step (3) at a material-water ratio of 1:2.2, add 0.1% of the mass of the colorless powder in step (4) with cellulase, and 0.1% of the mass of the colorless powder with xylanase, heat and stir in a 30°C water bath for 3 hours, and concentrate the solution to a 50% solid sugar solution for use as a carbon source for bifidobacterium fermentation after the reaction is completed; (5) Inoculate 5% (v / v) of Bifidobacterium seed solution into the fermentation tank for fermentation.

[0018] The fermentation medium was composed of 1000 mL of distilled water, 20 g of soy peptone, 20 g of yeast powder, 20 g of sugar solution, 1 g of sodium chloride, 1 g of potassium dihydrogen phosphate, 1 g of potassium dihydrogen phosphate, 0.01 g of FeSO4·7H2O, 0.005 g of MnSO4, 0.2 g of MgSO4, 0.5 g of L-cysteine, and the pH was adjusted to 6.8 using a 50 g / L sodium hydroxide solution. L-cysteine ​​was prepared at a concentration of 50 g / L, sterilized by membrane filtration, and L-cysteine ​​was added at 1 / 100 (v / v) after the fermentation medium was sterilized. Nitrogen was introduced into the vent of the fermentation tank to reduce the dissolved oxygen to below 1 mg / L; fermentation parameters were set: fermentation temperature was set to within 37.0°C, stirring speed was 200 r / min, after the culture medium temperature reached 37.0°C, seed solution was added at an inoculation rate of 5% (v / v) under the sterile environment of the flame circle, and 3 drops of defoaming agent were added at the same time; fermentation tank agitator was turned on, the current pH value of the culture medium after the seed solution was added was set to 6.6 as the fermentation set pH value, concentrated sugar solution was used for feeding, pH was adjusted with sodium hydroxide solution, and fermentation was carried out for 16 hours.

[0019] (6) Adding the fermentation liquid obtained in step (5) to a carrier and performing spray drying to obtain a live bifidobacterium product.

[0020] Example 2 The method of producing bifidobacterium cells by chemically treating straw comprises the following steps: (1) Crush the corn stalks to control the moisture content of the raw materials to less than 10%; remove impurities and iron from the stalks, and then crush them to 40 mesh; (2) adding the raw material obtained in step (1) to a mixture of methanesulfonic acid-thymol (methanesulfonic acid and thymol are uniformly mixed, the molar ratio of methanesulfonic acid to thymol is 1:2), with a material-liquid ratio of 1:5, and after uniform mixing, the reaction temperature is 60° C. and the reaction time is 4 min; (3) filtering the residue after the reaction in step (2) and washing it with ethanol until it becomes a colorless powder; (4) Add water to the dried colorless powder in step (3) at a material-water ratio of 1:5, add 3% of the mass of the colorless powder to the cellulase, and 0.3% of the mass of the colorless powder to the xylanase, heat and stir in a 50°C water bath for 24 hours, and concentrate the solution to a 50% sugar solution for use as a carbon source for bifidobacterium fermentation after the reaction is completed; (5) Inoculate 5% (v / v) of Bifidobacterium seed solution into the fermentation tank for fermentation.

[0021] The fermentation medium was composed of 1000 mL of distilled water, 20 g of soy peptone, 20 g of yeast powder, 20 g of sugar solution, 1 g of sodium chloride, 1 g of potassium dihydrogen phosphate, 1 g of potassium dihydrogen phosphate, 0.01 g of FeSO4·7H2O, 0.005 g of MnSO4, 0.2 g of MgSO4, 0.5 g of L-cysteine, and the pH was adjusted to 6.8 using a 50 g / L sodium hydroxide solution. L-cysteine ​​was prepared at a concentration of 50 g / L, sterilized by membrane filtration, and L-cysteine ​​was added at 1 / 100 (v / v) after the fermentation medium was sterilized. Nitrogen was introduced into the vent of the fermenter to reduce the dissolved oxygen to below 1 mg / L. Fermentation parameters were set: the fermentation temperature was set to 37.0°C, the stirring speed was 200 r / min, and after the culture medium temperature reached 37.0°C, seed solution was added at an inoculation rate of 5% (v / v) under the sterile environment of the flame circle. At the same time, 3 drops of defoaming agent were added. The fermenter agitator was turned on, and the current pH value of the culture medium after the seed solution was added was set to 6.6 as the fermentation set pH value. Concentrated sugar solution was used for feeding, and the pH was adjusted with sodium hydroxide solution. The fermentation was continued for 25 hours.

[0022] (6) Adding the fermentation liquid obtained in step (5) to a carrier and performing spray drying to obtain a live bifidobacterium product.

[0023] Example 3 The method of producing bifidobacterium cells by chemically treating straw comprises the following steps: (1) Crush corn stalks to control the moisture content of the raw materials to less than 10%; remove impurities and iron from the stalks, and then crush them to 80 mesh; (2) adding the raw material obtained in step (1) to a mixture of methanesulfonic acid-thymol (molar ratio 1:3) at a material-liquid ratio of 1:10, mixing evenly, reacting at a temperature of 80°C for 10 min; (3) filtering the residue after the reaction in step (2) and washing it with ethanol until it becomes a colorless powder; (4) Add water to the dried colorless powder in step (3) at a material-water ratio of 1:10, add 10% of the mass of the colorless powder to the cellulase, and 1% of the mass of the colorless powder to the xylanase, and heat and stir in a 50°C water bath for 48 hours. After the reaction is completed, concentrate the solution to a 50% sugar solution for use as a carbon source for bifidobacterium fermentation; (5) Inoculate 5% (v / v) of Bifidobacterium seed solution into the fermentation tank for fermentation.

[0024] The fermentation medium was composed of 1000 mL of distilled water, 20 g of soy peptone, 20 g of yeast powder, 20 g of sugar solution, 1 g of sodium chloride, 1 g of potassium dihydrogen phosphate, 1 g of potassium dihydrogen phosphate, 0.01 g of FeSO4·7H2O, 0.005 g of MnSO4, 0.2 g of MgSO4, 0.5 g of L-cysteine, and the pH was adjusted to 6.8 using a 50 g / L sodium hydroxide solution. L-cysteine ​​was prepared at a concentration of 50 g / L, sterilized by membrane filtration, and L-cysteine ​​was added at 1 / 100 (v / v) after the fermentation medium was sterilized. Nitrogen was introduced into the vent of the fermenter to reduce the dissolved oxygen to below 1 mg / L. Fermentation parameters were set: the fermentation temperature was set within 37.0°C, the stirring speed was 200 r / min, and after the culture medium temperature reached 37.0°C, seed solution was added at an inoculation rate of 5% (v / v) under the sterile environment of the flame circle. At the same time, 3 drops of defoaming agent were added. The fermenter agitator was turned on, and the current pH value of the culture medium after the seed solution was added was set to 6.6 as the fermentation set pH value. Concentrated sugar solution was used for feeding, and the pH was adjusted with sodium hydroxide solution. The fermentation was continued for 36 hours.

[0025] (6) Adding the fermentation liquid obtained in step (5) to a carrier and performing spray drying to obtain a live bifidobacterium product.

[0026] Example 4 The method of producing bifidobacterium cells by chemically treating straw comprises the following steps: (1) Crush corn stalks to control the moisture content of the raw materials to less than 10%; remove impurities and iron from the stalks, and then crush them to 80 mesh; (2) adding the raw material obtained in step (1) to a mixture of methanesulfonic acid-thymol (molar ratio 1:2) with a material-liquid ratio of 1:10, mixing evenly, reacting at 60°C for 4 min; (3) filtering the residue after the reaction in step (2) and washing it with ethanol until it becomes a colorless powder; (4) Add water to the dried colorless powder in step (3) at a material-water ratio of 1:5, add 3% of the mass of the colorless powder to the cellulase, and 1% of the mass of the colorless powder to the xylanase, heat and stir in a 50°C water bath for 24 hours, and concentrate the solution to a 50% sugar solution for use as a carbon source for bifidobacterium fermentation after the reaction is completed; (5) Inoculate 5% (v / v) of Bifidobacterium seed solution into the fermentation tank for fermentation.

[0027] The fermentation medium was composed of 1000 mL of distilled water, 20 g of soy peptone, 20 g of yeast powder, 20 g of sugar solution, 1 g of sodium chloride, 1 g of potassium dihydrogen phosphate, 1 g of potassium dihydrogen phosphate, 0.01 g of FeSO4·7H2O, 0.005 g of MnSO4, 0.2 g of MgSO4, 0.5 g of L-cysteine, and the pH was adjusted to 6.8 using a 50 g / L sodium hydroxide solution. L-cysteine ​​was prepared at a concentration of 50 g / L, sterilized by membrane filtration, and L-cysteine ​​was added at 1 / 100 (v / v) after the fermentation medium was sterilized. Nitrogen was introduced into the vent of the fermenter to reduce the dissolved oxygen to below 1 mg / L. Fermentation parameters were set: the fermentation temperature was set to 37.0°C, the stirring speed was 200 r / min, and after the culture medium temperature reached 37.0°C, seed solution was added at an inoculation rate of 5% (v / v) under the sterile environment of the flame circle. At the same time, 3 drops of defoaming agent were added. The fermenter agitator was turned on, and the current pH value of the culture medium after the seed solution was added was set to 6.6 as the fermentation set pH value. Concentrated sugar solution was used for feeding, and the pH was adjusted with sodium hydroxide solution. The fermentation was continued for 30 hours.

[0028] (6) Adding the fermentation liquid obtained in step (5) to a carrier and performing spray drying to obtain a live bifidobacterium product.

[0029] Comparative Example 1 The bifidobacterium cells were produced by chemically treating straw, and the preparation method was the same as that in Example 4, except that the culture medium in Example 4 was directly used to culture the bifidobacteria, and the sugar solution in the step was replaced by glucose solution.

[0030] Comparative Example 2 The bifidobacterium cells were produced by chemically treating straw, and the preparation method was the same as that in Example 4, except that the methanesulfonic acid-thymol in step (2) was replaced by methanesulfonic acid.

[0031] Comparative Example 3 The preparation method of producing bifidobacterium cells by chemically treating straw is the same as that in Example 4, except that methanesulfonic acid-thymol in step (2) is replaced by thymol.

[0032] Product analysis and testing The analysis results are shown in Table 1.

[0033] Table 1 Analysis results of nutrient components of enzymatic concentrated sugar solution

[0034] Combined with Table 1, it can be seen that the addition of methanesulfonic acid-thymol can effectively destroy the structure of lignocellulose, promote the action of cellulase and xylanase on cellulose sites, and promote enzymatic hydrolysis to obtain monosaccharides and oligosaccharides, which is beneficial to the fermentation growth of bifidobacteria.

[0035] Other raw materials or structures not specifically described in the present invention already exist in the prior art and can be directly purchased from the market.

[0036] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for decomposing and treating straw, characterized in that: The following steps are involved: S1, crushing the straw; S2, mixing and filtering the crushed straw and methanesulfonic acid-thymol to obtain a filter residue; S3. Mix the filter residue and ethanol and filter to obtain a colorless powder, which is the decomposed straw.

2. The processing method according to claim 1, characterized in that: In step S1, the straw is crushed to 30-80 mesh.

3. The processing method according to claim 1, characterized in that: In step S2, in methanesulfonic acid-thymol, the molar ratio of methanesulfonic acid to thymol is 1:(1.5-3).

4. The processing method according to claim 1, characterized in that: In step S2, the solid-liquid ratio of straw to methanesulfonic acid-thymol is 1:(2.2-10).

5. The processing method according to claim 1, characterized in that: In step S2, after the crushed straw and methanesulfonic acid-thymol are mixed, the reaction temperature is 30-80° C. and the reaction time is 0.5-10 min.

6. The processing method according to claim 1, characterized in that: In step S3, the filter residue is mixed with ethanol and washed until colorless, and then filtered to obtain a colorless powder.

7. Use of the decomposed straw obtained by the treatment method according to any one of claims 1 to 6 in preparing a culture medium for culturing bifidobacteria.

8. The use according to claim 7, characterized in that: The specific preparation step of the carbon source in the culture medium for culturing bifidobacteria is: the colorless powder obtained in step S3 is mixed and concentrated with water, cellulase and xylanase to obtain the bifidobacterium fermentation carbon source.

9. The use according to claim 8, characterized in that: The solid-liquid ratio of colorless powder to water is 1:(2.2-10); and / or, The mass ratio of cellulase to colorless powder is (0.1-10):100; and / or, The mass ratio of xylanase to colorless powder is (0.1-1):

100.

10. The use according to claim 8, characterized in that: The colorless powder obtained in step S3 is mixed with water, cellulase and xylanase, and heated and stirred in a water bath at 30-80° C. for 3-48 hours. After the reaction is completed, the mixture is concentrated to obtain a bifidobacterium fermentation carbon source.

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