Method for decomposing straw and application of decomposed straw

Abstract

The application provides a straw decomposition treatment method and application of decomposed straw, and the straw decomposition treatment method comprises the following steps: S1, crushing the straw; S2, mixing and filtering the crushed straw and thymol methanesulfonate to obtain filter residue; and S3, mixing and filtering the filter residue and ethanol to obtain colorless powder, which is the decomposed straw. Thymol reacts with methanesulfonic acid through the hydroxyl group to form thymol methanesulfonate, the thymol methanesulfonate can produce supramolecular interaction between the delignification medium and the lignin, and can quickly remove almost all the lignin under the condition of close to normal temperature, so that the decomposition is convenient and fast.

Description

Technical Field

[0001] This invention belongs to the field of straw treatment technology, specifically relating to a method for decomposing straw and the application of the decomposed straw. Background Technology

[0002] There is a regional, seasonal, and structural surplus of straw, with a large amount of straw resources going unused and resulting in significant waste. The indiscriminate dumping and burning of straw is rampant, causing not only resource waste but also a series of environmental problems. Its complex cross-linked structure and other characteristics pose significant obstacles to its utilization, as the lignocellulose components are almost impossible to separate under mild conditions. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for decomposing straw and the application of the decomposed straw. The addition of mesylate-thymol enables the rapid removal of almost all lignin under near-room temperature conditions, making the decomposition convenient and quick.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] On the one hand, the present invention provides a method for decomposing and processing straw, comprising the following steps:

[0006] S1. Crush the straw;

[0007] S2. After mixing and filtering the crushed straw and methanesulfonic acid-thymol, filter residue is obtained.

[0008] S3. Mix the filter residue and ethanol and filter to obtain a colorless powder, which is the decomposed straw.

[0009] Preferably, in step S1, the straw is crushed to 30-80 mesh.

[0010] Preferably, in step S2, the molar ratio of methanesulfonic acid to thymol in the methanesulfonic acid-thymol mixture is 1:(1.5-3).

[0011] Preferably, in step S2, the ratio of straw to methanesulfonic acid-thymol is 1:(2.2-10).

[0012] Preferably, in step S2, after mixing the crushed straw and methanesulfonic acid-thymol, the reaction temperature is 30-80℃ and the reaction time is 0.5-10 min.

[0013] Preferably, in step S3, the filter residue and ethanol are mixed and washed until colorless, then filtered to obtain a colorless powder.

[0014] On the other hand, the present invention provides the application of the decomposed straw obtained by the aforementioned treatment method in the preparation of a culture medium for culturing Bifidobacteria.

[0015] Preferably, the specific preparation steps of the carbon source in the culture medium for culturing Bifidobacteria are as follows: the colorless powder obtained in step S3 is mixed with water, cellulase and xylanase and concentrated to obtain the carbon source for Bifidobacteria fermentation.

[0016] Preferably, the ratio of colorless powder to water is 1:(2.2-10); and / or,

[0017] The mass ratio of cellulase to colorless powder is (0.1-10):100; and / or,

[0018] The mass ratio of xylanase to colorless powder is (0.1-1):100.

[0019] Preferably, the colorless powder obtained in step S3 is mixed with water, cellulase, and xylanase, and then 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 the carbon source for Bifidobacterium fermentation.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] (1) In this invention, thymol reacts with methanesulfonic acid through its hydroxyl group to form methanesulfonic acid-thymol. Methanesulfonic acid-thymol can generate supramolecular interactions between the lignin-de-lignin medium and lignin, and can quickly remove almost all lignin under near room temperature conditions, making decomposition convenient and fast.

[0022] (2) In this invention, cellulase and xylanase are added to the colorless powder obtained after straw decomposition to enzymatically remove lignin solids and obtain glucose, xylose and oligosaccharides, which can be used as carbon sources to cultivate high-density bifidobacteria. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can more clearly understand the present invention.

[0024] Example 1

[0025] The production of Bifidobacterium cells by chemically treating straw includes the following steps:

[0026] (1) Crush corn stalk raw material and control the moisture content of the raw material to <10%; remove impurities and iron from the stalk (use a sieve and electromagnetic removal to remove impurities and iron), and then crush to 30~80 mesh;

[0027] (2) Add the raw material obtained in step (1) to the methanesulfonic acid-thymol mixture (molar ratio 1:1.5), the material-liquid ratio is 1:2.2, mix evenly, the reaction temperature is 30℃, and the reaction time is 0.5min;

[0028] (3) Filter the residue from step (2) after the reaction is complete and wash it with ethanol until it becomes a colorless powder;

[0029] (4) Add water to the dried colorless powder in step (3) with a material-to-water ratio of 1:2.2. Add cellulase at a rate of 0.1% of the mass of the colorless powder in step (4) and xylanase at a rate of 0.1% of the mass of the colorless powder. Heat and stir in a water bath at 30°C for 3 hours. After the reaction is complete, concentrate the solution to a sugar solution containing 50% solids for use as a carbon source for Bifidobacterium fermentation.

[0030] (5) Inoculate 5% (v / v) of Bifidobacterium seed solution into the fermenter for fermentation.

[0031] The fermentation medium consisted of the following: 1000 mL distilled water, 20 g soybean peptone, 20 g yeast extract, 20 g sugar solution, 1 g sodium chloride, 1 g dipotassium hydrogen phosphate, 1 g potassium dihydrogen phosphate, 0.01 g FeSO4·7H2O, 0.005 g MnSO4, 0.2 g MgSO4, and 0.5 g L-cysteine. The pH was adjusted to 6.8 using a 50 g / L sodium hydroxide solution. The L-cysteine ​​concentration was 50 g / L, sterilized by membrane filtration, and added at a 1 / 100 (v / v) ratio after the fermentation medium was sterilized. Nitrogen gas was introduced into the vent of the fermenter to reduce dissolved oxygen to below 1 mg / L. Fermentation parameters were set as follows: fermentation temperature was set within the range of 37.0℃, stirring speed was 200 r / min, and after the culture medium temperature reached 37.0℃, seed liquid was added at an inoculum rate of 5% (v / v) under aseptic conditions in a flame ring, along with 3 drops of defoamer. The fermenter agitator was turned on, and the current pH value of the culture medium after the addition of seed liquid 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. Fermentation was carried out for 16 hours.

[0032] (6) Add the fermentation broth obtained in step (5) to the carrier and spray dry to obtain the live Bifidobacterium product.

[0033] Example 2

[0034] The production of Bifidobacterium cells by chemically treating straw includes the following steps:

[0035] (1) Crush corn stalks as raw material, control the moisture content of the raw material to <10%; remove impurities and iron from the stalks, and then crush them to 40 mesh;

[0036] (2) Add the raw material obtained in step (1) to the mixture of methanesulfonic acid and thymol (methanesulfonic acid and thymol are mixed evenly and the molar ratio of methanesulfonic acid and thymol is 1:2), the material-liquid ratio is 1:5, after mixing evenly, the reaction temperature is 60℃ and the reaction time is 4min.

[0037] (3) Filter the residue from step (2) after the reaction is complete and wash it with ethanol until it becomes a colorless powder;

[0038] (4) Add water to the dried colorless powder in step (3) at a ratio of 1:5. Add 3% of the mass of the colorless powder with cellulase and 0.3% of the mass of the colorless powder with xylanase. Heat and stir in a water bath at 50°C for 24 hours. After the reaction is complete, concentrate the solution to a sugar solution containing 50% sugar for use as a carbon source for Bifidobacterium fermentation.

[0039] (5) Inoculate 5% (v / v) of Bifidobacterium seed solution into the fermenter for fermentation.

[0040] The fermentation medium consisted of the following: 1000 mL distilled water, 20 g soybean peptone, 20 g yeast extract, 20 g sugar solution, 1 g sodium chloride, 1 g dipotassium hydrogen phosphate, 1 g potassium dihydrogen phosphate, 0.01 g FeSO4·7H2O, 0.005 g MnSO4, 0.2 g MgSO4, and 0.5 g L-cysteine. The pH was adjusted to 6.8 using a 50 g / L sodium hydroxide solution. The L-cysteine ​​concentration was 50 g / L, sterilized by membrane filtration, and added at a 1 / 100 (v / v) ratio after the fermentation medium was sterilized. Nitrogen gas was introduced into the vent of the fermenter to reduce dissolved oxygen to below 1 mg / L. Fermentation parameters were set as follows: fermentation temperature was set within the range of 37.0℃, stirring speed was 200 r / min, and after the culture medium temperature reached 37.0℃, seed liquid was added at an inoculation rate of 5% (v / v) under aseptic conditions in a flame ring, along with 3 drops of defoamer. The fermenter agitator was turned on, and the current pH value of the culture medium after the addition of seed liquid was set to 6.6 as the fermentation set pH value. Concentrated sugar solution was used for feeding, and sodium hydroxide solution was used to adjust the pH. Fermentation was carried out for 25 hours.

[0041] (6) Add the fermentation broth obtained in step (5) to the carrier and spray dry to obtain the live Bifidobacterium product.

[0042] Example 3

[0043] The production of Bifidobacterium cells by chemically treating straw includes the following steps:

[0044] (1) Crush corn stalks as raw material, control the moisture content of the raw material to <10%; remove impurities and iron from the stalks, and then crush them to 80 mesh;

[0045] (2) Add the raw material obtained in step (1) to the methanesulfonic acid-thymol (molar ratio 1:3) mixture, the material-liquid ratio is 1:10, mix evenly, the reaction temperature is 80℃, and the reaction time is 10min.

[0046] (3) Filter the residue from step (2) after the reaction is complete and wash it with ethanol until it becomes a colorless powder;

[0047] (4) Add water to the dried colorless powder in step (3) at a ratio of 1:10. Add 10% of the mass of the colorless powder and 1% of the mass of the colorless powder with cellulase. Heat and stir in a water bath at 50°C for 48 hours. After the reaction is complete, concentrate the solution to a sugar solution containing 50% sugar for use as a carbon source for Bifidobacterium fermentation.

[0048] (5) Inoculate 5% (v / v) of Bifidobacterium seed solution into the fermenter for fermentation.

[0049] The fermentation medium consisted of the following: 1000 mL distilled water, 20 g soybean peptone, 20 g yeast extract, 20 g sugar solution, 1 g sodium chloride, 1 g dipotassium hydrogen phosphate, 1 g potassium dihydrogen phosphate, 0.01 g FeSO4·7H2O, 0.005 g MnSO4, 0.2 g MgSO4, and 0.5 g L-cysteine. The pH was adjusted to 6.8 using a 50 g / L sodium hydroxide solution. The L-cysteine ​​concentration was 50 g / L, sterilized by membrane filtration, and added at a 1 / 100 (v / v) ratio after the fermentation medium was sterilized. Nitrogen gas was introduced into the vent of the fermenter to reduce dissolved oxygen to below 1 mg / L. Fermentation parameters were set as follows: fermentation temperature was set within the range of 37.0℃, stirring speed was 200 r / min, and after the culture medium temperature reached 37.0℃, seed liquid was added at an inoculum rate of 5% (v / v) under aseptic conditions in a flame ring, along with 3 drops of defoamer. The fermenter agitator was turned on, and the current pH value of the culture medium after the addition of seed liquid was set to 6.6 as the fermentation set pH value. Concentrated sugar solution was used for feeding, and sodium hydroxide solution was used to adjust the pH. Fermentation was carried out for 36 hours.

[0050] (6) Add the fermentation broth obtained in step (5) to the carrier and spray dry to obtain the live Bifidobacterium product.

[0051] Example 4

[0052] The production of Bifidobacterium cells by chemically treating straw includes the following steps:

[0053] (1) Crush corn stalks as raw material, control the moisture content of the raw material to <10%; remove impurities and iron from the stalks, and then crush them to 80 mesh;

[0054] (2) Add the raw material obtained in step (1) to the methanesulfonic acid-thymol (molar ratio 1:2) mixture, the material-liquid ratio is 1:10, mix evenly, the reaction temperature is 60℃, and the reaction time is 4min.

[0055] (3) Filter the residue from step (2) after the reaction is complete and wash it with ethanol until it becomes a colorless powder;

[0056] (4) Add water to the dried colorless powder in step (3) at a ratio of 1:5. Add 3% of the mass of the colorless powder with cellulase and 1% of the mass of the colorless powder with xylanase. Heat and stir in a water bath at 50°C for 24 hours. After the reaction is complete, concentrate the solution to a sugar solution containing 50% sugar for use as a carbon source for Bifidobacterium fermentation.

[0057] (5) Inoculate 5% (v / v) of Bifidobacterium seed solution into the fermenter for fermentation.

[0058] The fermentation medium consisted of the following: 1000 mL distilled water, 20 g soybean peptone, 20 g yeast extract, 20 g sugar solution, 1 g sodium chloride, 1 g dipotassium hydrogen phosphate, 1 g potassium dihydrogen phosphate, 0.01 g FeSO4·7H2O, 0.005 g MnSO4, 0.2 g MgSO4, and 0.5 g L-cysteine. The pH was adjusted to 6.8 using a 50 g / L sodium hydroxide solution. The L-cysteine ​​concentration was 50 g / L, sterilized by membrane filtration, and added at a 1 / 100 (v / v) ratio after the fermentation medium was sterilized. Nitrogen gas was introduced into the vent of the fermenter to reduce dissolved oxygen to below 1 mg / L. Fermentation parameters were set as follows: fermentation temperature was set within the range of 37.0℃, stirring speed was 200 r / min, and after the culture medium temperature reached 37.0℃, seed liquid was added at an inoculum rate of 5% (v / v) under aseptic conditions in a flame ring, along with 3 drops of defoamer. The fermenter agitator was turned on, and the current pH value of the culture medium after the addition of seed liquid was set to 6.6 as the fermentation set pH value. Concentrated sugar solution was used for feeding, and sodium hydroxide solution was used to adjust the pH. Fermentation was carried out for 30 hours.

[0059] (6) Add the fermentation broth obtained in step (5) to the carrier and spray dry to obtain the live Bifidobacterium product.

[0060] Comparative Example 1

[0061] Bifidobacterium cells were produced by chemically treating straw. The preparation method was the same as in Example 4, except that the culture medium in Example 4 was used directly to culture the Bifidobacterium, and glucose solution was used instead of sugar solution in the steps.

[0062] Comparative Example 2

[0063] Bifidobacterium cells were produced by chemically treating straw. The preparation method was the same as in Example 4, except that the methanesulfonic acid-thymol in step (2) was replaced with methanesulfonic acid.

[0064] Comparative Example 3

[0065] Bifidobacterium cells were produced by chemically treating straw. The preparation method was the same as in Example 4, except that the mesylate-thymol in step (2) was replaced with thymol.

[0066] Product Analysis and Testing

[0067] The analysis results are shown in Table 1.

[0068] Table 1. Nutritional composition analysis results of enzymatically hydrolyzed concentrated sugar solution

[0069]

[0070] As shown in Table 1, the addition of mesylate-thymol can effectively disrupt 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 and growth of Bifidobacteria.

[0071] All other raw materials or structures not specifically described in this invention already exist in the prior art and can be purchased directly from the market.

[0072] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for decomposing and processing straw, characterized in that, Includes the following steps: S1. Crush the straw; S2. After mixing and filtering the crushed straw and methanesulfonic acid-thymol, filter residue is obtained. S3. Mix the filter residue and ethanol and filter to obtain a colorless powder, which is the decomposed straw. In step S2, the molar ratio of methanesulfonic acid to thymol in the methanesulfonic acid-thymol mixture is 1:(1.5-3). In step S2, the crushed straw and methanesulfonic acid-thymol are mixed and reacted at a temperature of 30-80℃ for a time of 0.5-10 min.

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, the ratio of straw to methanesulfonic acid-thymol is 1:(2.2-10).

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

5. The use of the decomposed straw obtained by the treatment method according to any one of claims 1-4 in the preparation of a culture medium for culturing Bifidobacteria.

6. The application according to claim 5, characterized in that, The specific preparation steps for the carbon source in the culture medium used to cultivate Bifidobacteria are as follows: the colorless powder obtained in step S3 is mixed with water, cellulase and xylanase and concentrated to obtain the carbon source for Bifidobacteria fermentation.

7. The application according to claim 6, characterized in that, The 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.

8. The application according to claim 6, characterized in that, The colorless powder obtained in step S3 is mixed with water, cellulase, and xylanase, and then heated and stirred in a water bath at 30-80℃ for 3-48 hours. After the reaction is completed, the mixture is concentrated to obtain the carbon source for Bifidobacterium fermentation.

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