Biochar for reducing resistance genes in soil and preparation method thereof

Abstract

The invention provides biochar capable of reducing resistance genes in soil and a preparation method of the biochar, the preparation method comprises the following steps: (1) crushing rape straws, then carrying out pre-fermentation treatment by adopting clostridium butyricum, then incubating by using a potassium sulfate aqueous solution, and then removing moisture; and (2) mixing the product obtained in the step (1) with sepiolite powder according to a weight ratio of 20: (1-3), and then treating the mixture in a closed oxygen-deficient environment at 600-650 DEG C for 2-2.5 hours, thereby obtaining the product, the Latin name of the clostridium butyricum is Clostridium butyricum, and the preservation number of the clostridium butyricum is CICC (China General Microbiological Culture Collection Center) 20036. The raw materials are simple and easy to obtain, and the obtained biochar has a remarkable reduction effect on the abundance of main resistance genes and the total abundance of the resistance genes in soil and has the application value for soil improvement.

Description

Technical Field

[0001] The present invention belongs to the technical field of biochar, and in particular relates to a biochar capable of eliminating resistance genes in soil and a preparation method thereof. Background Art

[0002] my country's economy ranks second in the world, with agriculture as a key pillar industry, of which livestock and poultry farming is a crucial component. Limited by current livestock and poultry husbandry and medical care, farms often administer various antibiotics to livestock. This increases the selective pressure of antibiotics on the microorganisms in the animals' guts, prompting the development of drug resistance in these microorganisms. This in turn induces the production of drug-resistant bacteria and antibiotic resistance genes in the animals. These intestinal microorganisms carrying these genes are excreted into the soil through feces and urine, leading to their accumulation and spread. Therefore, how to eliminate these genes in the soil is a crucial research topic.

[0003] Currently, commonly used technologies for reducing resistance genes include biocomposting and biochar application. While composting is effective in reducing resistance genes, it is often time-consuming and prone to producing other metabolites that can cause secondary soil contamination. While traditional biochar application is relatively simple, it is less effective in reducing resistance genes.

[0004] Therefore, developing a new type of biochar to overcome the aforementioned defects of traditional biochar is an urgent problem to be solved in this field. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a biochar that can efficiently reduce the absolute abundance of major resistance genes and total resistance genes in soil.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for preparing biochar for eliminating resistance genes in soil, the preparation method comprising the following steps:

[0008] (1) crushing rapeseed straw and performing pre-fermentation with Clostridium butyricum, then incubating with a potassium sulfate aqueous solution, and then removing moisture;

[0009] (2) mixing the product obtained in step (1) with sepiolite powder in a weight ratio of 20:1 to 3, and then treating the mixture in a closed oxygen-deficient environment at 600 to 650° C. for 2 to 2.5 hours to obtain;

[0010] The Latin name of the Clostridium butyricum is Clostridium butyricum, and the preservation number is CICC 20036.

[0011] Preferably, during the pre-fermentation treatment, water is added to the crushed rape straw to control the water content at 30% w / w, and then Clostridium butyricum is inoculated at a 5% inoculum amount, and fermented at 38° C. under anaerobic conditions for 4 to 6 hours.

[0012] Preferably, the concentration of the potassium sulfate aqueous solution is 10-15% w / w.

[0013] Preferably, during the incubation, the incubation temperature is 25-30° C., and the incubation time is 1.5-2 hours.

[0014] Preferably, when removing moisture, first drain the surface moisture of the rape straw and then dry it in an oven at 60°C.

[0015] Preferably, the rape straw has a particle size distribution of 1 to 2 mm after crushing; and the sepiolite powder is a powder that passes through a 200-mesh sieve.

[0016] Preferably, the weight ratio of the product obtained in step (1) to the sepiolite powder is 10:1.

[0017] Preferably, when the high temperature treatment is performed, the treatment is performed at 650° C. for 2 hours.

[0018] A biochar for eliminating resistance genes in soil, wherein the biochar is prepared by the above-mentioned preparation method.

[0019] The aforementioned application of biochar in eliminating resistance genes in soil.

[0020] Beneficial effects of the present invention:

[0021] The raw materials of the present invention are simple and easy to obtain, and the obtained biochar has a significant reducing effect on the abundance of major resistance genes and the total abundance of resistance genes in the soil, and has application value for soil improvement. DETAILED DESCRIPTION

[0022] The following descriptions of the specific embodiments are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0023] Example 1

[0024] 1. Raw materials:

[0025] Clostridium butyricum (Latin name: Clostridium butyricum, accession number: CICC 20036), originally from Sichuan Food Fermentation Industry Research and Design Institute (1.265); purchased from Beijing Yuwei Technology Co., Ltd.

[0026] Rapeseed straw: collected locally;

[0027] Sepiolite powder: purchased from Merck Life Science, 200 mesh;

[0028] Potassium sulfate aqueous solution: prepared in the laboratory.

[0029] 2. Preparation of Biochar

[0030] (1) Crush rape straw to a particle size of 1 to 2 mm; add water to the crushed rape straw to control the water content at 30% w / w; then inoculate Clostridium butyricum at a 5% inoculum rate, and ferment at 38°C under anaerobic conditions for 6 hours; then incubate with a 15% w / w potassium sulfate aqueous solution at 30°C for 1.5 hours; then drain the surface moisture of the rape straw, and then dry it in an oven at 60°C.

[0031] (2) The product obtained in step (1) and sepiolite powder were mixed in a weight ratio of 10:1, and the mixture was then treated at 650° C. for 2 hours in a closed oxygen-deficient environment to obtain a product.

[0032] Example 2

[0033] 1. Raw materials:

[0034] Clostridium butyricum (Latin name: Clostridium butyricum, accession number: CICC 20036), originally from Sichuan Food Fermentation Industry Research and Design Institute (1.265); purchased from Beijing Yuwei Technology Co., Ltd.

[0035] Rapeseed straw: collected locally;

[0036] Sepiolite powder: purchased from Merck Life Science, 200 mesh;

[0037] Potassium sulfate aqueous solution: prepared in the laboratory.

[0038] 2. Preparation of Biochar

[0039] (1) Crush rape straw to a particle size of 1 to 2 mm; add water to the crushed rape straw to control the water content at 30% w / w; then inoculate Clostridium butyricum at a 5% inoculum rate, and ferment at 38°C under anaerobic conditions for 4 hours; then incubate with a 10% w / w potassium sulfate aqueous solution at 25°C for 2 hours; then drain the surface moisture of the rape straw, and then dry it in an oven at 60°C.

[0040] (2) The product obtained in step (1) and sepiolite powder were mixed in a weight ratio of 20:1, and the mixture was then treated at 600° C. for 2 hours in a closed oxygen-deficient environment to obtain a product.

[0041] Example 3

[0042] 1. Raw materials:

[0043] Clostridium butyricum (Latin name: Clostridium butyricum, accession number: CICC 20036), originally from Sichuan Food Fermentation Industry Research and Design Institute (1.265); purchased from Beijing Yuwei Technology Co., Ltd.

[0044] Rapeseed straw: collected locally;

[0045] Sepiolite powder: purchased from Merck Life Science, 200 mesh;

[0046] Potassium sulfate aqueous solution: prepared in the laboratory.

[0047] 2. Preparation of Biochar

[0048] (1) Crush rape straw to a particle size of 1 to 2 mm; add water to the crushed rape straw to control the water content at 30% w / w; then inoculate Clostridium butyricum at a 5% inoculum rate, and ferment at 38°C under anaerobic conditions for 5 hours; then incubate with a 12% w / w potassium sulfate aqueous solution at 30°C for 1.75 hours; then drain the surface moisture of the rape straw, and then dry it in an oven at 60°C.

[0049] (2) The product obtained in step (1) and sepiolite powder were mixed in a weight ratio of 20:3, and the mixture was then treated at 650° C. for 2 hours in a closed oxygen-deficient environment to obtain a product.

[0050] Comparative Example 1

[0051] Compared with Example 1, except that step (1) is not adopted and the crushed rape straw and sepiolite powder are directly mixed, the rest is the same as Example 1.

[0052] Comparative Example 2

[0053] Compared with Example 1, except that Clostridium butyricum was not used for pre-fermentation, the rest was the same as Example 1.

[0054] Comparative Example 3

[0055] Compared with Example 1, except that the potassium sulfate aqueous solution is not used for incubation, the rest is the same as Example 1.

[0056] Experimental Example 1

[0057] Soil from a local chicken farm was used as the experimental subject. The soil was placed in several experimental pots (50 cm x 50 cm x 50 cm square pots), and samples were taken from each pot to test resistance based on abundance. Biochar from each example and comparative example was applied to the soil at a volume ratio of 10:1, and the soil was tilled to mix evenly. After one month, soil samples from each pot were taken and tested for resistance based on abundance. The experimental results are shown in Tables 1 and 2.

[0058] Table 1

[0059]

[0060] Note: “Before the experiment” refers to the soil without adding biochar, and “after the experiment” refers to the soil after adding biochar.

[0061] As shown in Table 1, pre-fermentation of rapeseed straw with Clostridium butyricum and incubation with potassium sulfate are crucial for biochar's ability to eliminate resistance genes. This may be because fermentation of rapeseed straw with Clostridium butyricum changes the morphology of the straw, facilitating easier entry of potassium sulfate salt crystals into the interstices within the straw, thereby enhancing the resulting biochar's ability to remove resistance genes. Comparative Examples 1-3 show that the biochar obtained by the present invention is far superior to the traditional biochar shown in Comparative Example 1 in eliminating resistance genes. It also shows that pre-fermentation of rapeseed straw with Clostridium butyricum and incubation with a potassium sulfate aqueous solution are both essential for the performance of the resulting biochar.

[0062] Table 2

[0063]

[0064] Note: “Before the experiment” refers to the soil without adding biochar, and “after the experiment” refers to the soil after adding biochar.

[0065] As shown in Table 2, the present invention has a significant effect on reducing the major antibiotic resistance genes. In contrast, the traditional biochar used in Comparative Example 1 and the biochar obtained by not fully using the present invention, as shown in Comparative Examples 2 and 3, have limited effects on reducing the major antibiotic resistance genes listed in Table 2.

Claims

1. A method for preparing biochar for eliminating resistance genes in soil, characterized in that: The preparation method comprises the following steps: (1) crushing rapeseed straw and performing pre-fermentation with Clostridium butyricum, then incubating with a potassium sulfate aqueous solution, and then removing moisture; (2) mixing the product obtained in step (1) with sepiolite powder in a weight ratio of 20:1 to 3, and then treating the mixture in a closed oxygen-deficient environment at 600 to 650° C. for 2 to 2.5 hours to obtain; The Latin name of the Clostridium butyricum is Clostridium butyricum, and the preservation number is CICC 20036.

2. The preparation method according to claim 1, characterized in that During the pre-fermentation treatment, water is added to the crushed rape straw to control the water content at 30% w / w, and then Clostridium butyricum is inoculated at a 5% inoculum amount and fermented at 38° C. under anaerobic conditions for 4 to 6 hours.

3. The preparation method according to claim 1, characterized in that The concentration of the potassium sulfate aqueous solution is 10-15% w / w.

4. The preparation method according to claim 3, characterized in that During the incubation, the incubation temperature is 25-30° C. and the incubation time is 1.5-2 hours.

5. The preparation method according to claim 1, characterized in that When removing moisture, first drain the surface moisture of the rape straw and then dry it in an oven at 60°C.

6. The preparation method according to claim 1, characterized in that The rape straw is crushed to have a particle size distribution of 1 to 2 mm; the sepiolite powder is a powder that passes through a 200-mesh sieve.

7. The preparation method according to claim 1, characterized in that The weight ratio of the obtained product of step (1) to the sepiolite powder is 10:

1.

8. The preparation method according to claim 1, characterized in that When the high temperature treatment is performed, the treatment is performed at 650° C. for 2 hours.

9. A biochar for eliminating resistance genes in soil, characterized in that: The biochar is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the biochar according to claim 9 in eliminating resistance genes in soil.

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