High-efficiency corn straw degrading bacterial agent as well as preparation method and application of high-efficiency corn straw degrading bacterial agent

Abstract

The invention relates to a corn straw efficient degradation bacterial agent and a preparation method and application thereof, Poroporus sp 111999 is preserved in the China General Microbiological Culture Collection Center on October 28, 2024, the preservation date is October 28, 2024, and the preservation number is CGMCC No.41584. The corn straw efficient degradation bacterial agent can be used for degrading corn straws. The invention discloses application of the corn straw degradation accelerating agent in the aspects of accelerating corn straw degradation and improving soil properties. And compared with a control group without inoculation, the corn straw is obviously degraded. Meanwhile, the fungicide has a certain improvement effect on soil nutrients, and the content of rapidly available potassium and rapidly available phosphorus is remarkably increased; the growth rate of soil organic matters is 2.8%; the DOC (dissoluble organic carbon) growth rate of the soil is 134.1%; the growth rate of the total carbon content of the soil is 6.0%; the growth rate of the total nitrogen content of the soil is 3%; the invention provides a strain resource and technical support for increasing the degradation rate of corn straws and improving soil properties.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms and relates to a high-efficiency corn stalk degradation bacterial agent and a preparation method and application thereof. Background Art

[0002] my country is a large agricultural country with abundant straw resources. According to relevant data, China's straw production has increased year by year for several consecutive years, among which corn straw production accounts for the largest proportion. Returning straw to the field is the main way to utilize straw resources, which is much higher than other resource utilization methods. This measure has the advantages of improving soil structure, improving soil properties, reducing the amount of fertilizer application, and reducing environmental pollution. However, this measure has not achieved the desired expected results in the above aspects. The main reasons are: after returning the straw to the field, it cannot be quickly and fully degraded, and the straw residue remains in the soil, with a low nutrient release rate, which hinders farming, easily increases pests and diseases, and affects the growth of crops in the next year. Therefore, how to improve the degradation rate of corn straw and increase soil nutrients has become a major problem restricting agricultural development.

[0003] The development of agriculture is inseparable from the use of chemical fertilizers. However, the unscientific use of chemical fertilizers will cause soil pollution. The long-term and large-scale use of chemical fertilizers will lead to soil degradation and loss of production capacity. A survey shows that the use of traditional chemical fertilizers has not achieved the expected results in increasing crop yields and improving soil fertility. For this reason, agricultural development urgently needs a new type of fertilizer to replace traditional agricultural fertilizers. Microbial fertilizers have attracted much attention for their green, environmentally friendly and efficient characteristics, and their application in agriculture has become more and more extensive. Among them, the way microorganisms degrade straw has been generally recognized. Improving the degradation rate of corn straw and improving soil nutrients is inseparable from the screening and development of strains. Summary of the invention

[0004] Technical problem to be solved: The present invention aims to screen out strains that can quickly degrade corn straw in nature and prepare them into bacterial agents, so as to provide a corn straw efficient degradation bacterial agent and its preparation method and application in order to increase the degradation rate of corn straw and improve soil properties.

[0005] Technical solution: Polyporales sp. 111999, the colony of this strain is flocculent, with white hyphae and white spores. After Gram staining, it is observed under an optical microscope that the bacteria are Gram-negative bacteria, belonging to the order Aglajiales, class Agaricales, phylum Basidiomycetes. It is currently deposited in the General Biological Center of the China Microbiological Culture Collection Administration, with a deposit date of October 28, 2024, and a deposit number of CGMCC No.41584.

[0006] The above-mentioned Polyporales sp. 111999 is used for degrading corn stalks.

[0007] The application of the above-mentioned Polyporales sp. 111999 in the preparation of corn straw degradation bacterial agent.

[0008] A method for preparing a high-efficiency corn stalk degradation microbial agent is prepared by the following steps: step 1, strain activation: inoculating Polyporales sp. 111999 stored at -80 DEG C on a malt agar medium, and culturing at 28 DEG C until a large number of hyphae grow; step 2, spore liquid preparation: in a sterile environment, using sterile distilled water to treat fungal colonies, using a physical method to release spores and disperse them in liquid, then performing centrifugation to separate spores, remove impurities, and finally resuspending the spores with sterile distilled water to obtain the desired microbial agent.

[0009] The composition of the malt agar medium is as follows: 20 g of malt extract powder, 20 g of agar powder, 1000 mL of deionized water, pH 7.1-7.3.

[0010] The spore concentration in the above-mentioned bacterial agent is not less than 1×10 8 Pieces / mL.

[0011] The spore solution of Polyporales sp. 111999 was inoculated into potted plants buried with corn stalks at 30 wt.% of the amount of stalks returned to the field.

[0012] The mass ratio of the above soil to straw is 50:1.

[0013] A method for improving farmland soil fertility comprises using the prepared corn stalk degrading bacterial agent to treat the farmland, thereby accelerating the decomposition of the corn stalks, increasing the soil organic matter content, and improving the soil structure.

[0014] The Polyporales sp. 111999 strain of the present invention was sequenced and analyzed, and the results showed that it was closely homologous to Polyporales sp. ZP-4D-1 (OL471316.1). The strains with high similarity to it were used to construct a phylogenetic tree (see Figure 2 ), phylogenetic tree analysis showed that the strain belonged to the phylum Basidiomycetes, and it was named Polyporales sp 111999.

[0015] Beneficial effect: The present invention provides a fungal agent for improving the degradation rate of corn stalks. The fungal agent is applied to corn stalks to effectively degrade the corn stalks and improve soil properties to a certain extent. In terms of the degradation effect of corn stalks, the degradation rate of corn stalks can reach 39.98% ( Figure 3). In terms of improving soil properties, after being treated with the fungal strain, the average growth rate of soil available potassium was 65.4%, the average growth rate of soil available phosphorus was 16.3%, the soil organic matter increased from 14.65g / kg to 15.06g / kg, with a growth rate of 2.80%, the soil DOC (soluble organic carbon) growth rate was 134.1%, the soil total carbon content increased from 19.86g / kg to 21.05g / kg, with a growth rate of 6.0%; the soil total nitrogen content increased from 1.01g / kg to 1.05g / kg, with a growth rate of 3% ( Figure 4 ). BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Figure 2 shows the colony of Polyporales fungi on malt medium plate (A) and the schematic diagram of Gram staining results (B).

[0017] Figure 2 This is a phylogenetic tree diagram of the Polyporales fungal strains provided by the present invention.

[0018] Figure 3 This is a schematic diagram of the degradation rate of corn stalks after being treated with a fungal agent provided by the present invention.

[0019] Figure 4 Schematic diagram of the changes in AK (a), AP (b), SOM (c), DOC (d), TC (e), and TN (f) in potted soil after being treated with the fungal agent provided by the present invention.

[0020] Figure 5 The present invention provides a schematic diagram of the scanning electron microscope comparison of corn stalks treated with fungal agents. Figure A is a schematic diagram of the scanning electron microscope of the stalk leaves of the control group, with the specific characteristics that the leaves are intact as a whole, the stomata are tightly closed, and there is no breakage; Figure B is a schematic diagram of the scanning electron microscope of the stalk leaves of the experimental group, with the specific characteristics that the leaves are obviously broken as a whole, the stomata are enlarged, and the degradation effect is obvious. DETAILED DESCRIPTION

[0021] The present invention discloses a preparation method and application of a highly efficient corn stalk degradation bacterial agent. To make the above invention clearer, the invention content will be described in more detail and completely below. Where the specific operation or conditions are not specified in the description, they shall be carried out according to conventional operations or conditions; where the manufacturers of the reagents or instruments used are not specified in detail, they can be purchased through conventional commercial channels. The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention. The present invention is further described below in conjunction with the embodiments.

[0022] Example 1: Fermentation of the bacterial agent of the present invention

[0023] 1) Source and type of bacteria:

[0024] The fungal strain was isolated from the soil of Fengqiu Agricultural Ecological Experimental Station of the Chinese Academy of Sciences;

[0025] The fungal strain belongs to the order Polyporales,

[0026] The Polyporales sp. 111999 is deposited in the General Biological Center of the China Microbiological Culture Collection Administration. The address of the depository is No. 3, Yard No. 1, Beichen West Road, Chaoyang City, Beijing. The deposit date is October 28, 2024. The classification name is Polyporales sp. 111999, and the deposit number is CGMCC No. 41584.

[0027] 2) Culture medium formula:

[0028] Malt agar medium: 20g malt extract powder, 20g agar, 1L distilled water;

[0029] 3) Bacteria activation:

[0030] The fungal strain stored at -80°C was taken out, inoculated into malt agar medium, and cultured in a 28°C incubator until the strain grew a large number of hyphae.

[0031] 4) Spore liquid preparation:

[0032] Under sterile conditions, sterile distilled water is used to cover the fungal colony, and the surface of the fungal colony is scraped with a sterile inoculation loop. The operation is repeated in small amounts and multiple times to allow the spores to be fully mixed into the liquid. The liquid containing the spores is centrifuged at a low speed, and the centrifuge parameters are set to: 4000r / min, centrifuged for 5 minutes to precipitate the spores and remove the colony fragments and culture medium residues, the supernatant is discarded, and the spore precipitate is resuspended with sterile distilled water to prepare a spore liquid.

[0033] Use a blood cell counting plate to adjust the concentration of the spore solution. Observe under a microscope and count the total number of spores in the top left, bottom left, center, top right, and bottom right squares of the counting plate. Calculate according to the formula to ensure that the concentration of the spore solution is approximately 1×10 8 Pieces / mL.

[0034] Example 2: Study on the effect of microbial agent application in potted plants

[0035] 1) Corn stalk preparation:

[0036] Take the corn stalks after harvest, cut them into blocks about 3 cm in length, and sterilize them under high pressure and high temperature to eliminate interference from miscellaneous bacteria.

[0037] 2) Implementation method:

[0038] Two treatments were set up: blank control and corn straw + invented microbial agent, with three replicates for each treatment. During the implementation, the external conditions of the blank control group and the experimental group were kept consistent, with the ratio of soil mass to straw mass being 50:1 and the ratio of straw mass to microbial agent application being 1:3. No other substances were applied to the experimental potted plants. The straw was shallowly buried in the soil surface, and the degradation time was 30 days.

[0039] 3) Determination of soil physical and chemical properties: The determination of AK, AP, SOM, DOC, TC, and TN indicators were all carried out in accordance with national standard methods.

[0040] The implementation results are as follows Figure 3 As shown: The degradation rate of corn straw in the experimental group was 39.98%.

[0041] The implementation results are as follows Figure 4 As shown: Comparison between the experimental group and the blank group: the average growth rate of soil available potassium was 65.4%; the average growth rate of soil available phosphorus was 16.3%; soil organic matter increased from 14.65g / kg to 15.06g / kg, with a growth rate of 2.80%; soil DOC (soluble organic carbon) growth rate was 134.1%; soil total carbon content increased from 19.86g / kg to 21.05g / kg, with a growth rate of 6.0%; soil total nitrogen content increased from 1.01g / kg to 1.05g / kg, with a growth rate of 3.0%.

Claims

1. Polypore Polyporales sp )111999, deposited in the General Biological Center of China Microbiological Culture Collection Administration, the deposit date is October 28, 2024, and the deposit number is CGMCC No.41584.

2. The polypore fungus according to claim 1 ( Polyporales sp )111999 application in the degradation of corn straw.

3. The polypore fungus according to claim 1 ( Polyporales sp )111999 is used in the preparation of corn straw degradation bacterial agent.

4. A method for preparing a highly efficient corn stalk degradation agent, characterized in that: The preparation was carried out by the following steps: Step 1, strain activation: the polypore bacteria ( Polyporales sp )111999 is inoculated on malt agar medium and cultured at 28°C until a large number of hyphae grow; Step 2, preparation of spore liquid: in a sterile environment, the fungal colony is treated with sterile distilled water, the spores are released and dispersed in the liquid by physical methods, and then centrifuged to separate the spores and remove impurities, and finally the spores are resuspended with sterile distilled water to obtain the desired bacterial agent.

5. The preparation method according to claim 4, characterized in that: The malt agar medium is composed of: 20 g malt extract powder, 20 g agar powder, 1000 mL deionized water, and pH 7.1-7.3 according to the following proportions.

6. The preparation method according to claim 4, characterized in that: The spore concentration in the bacterial agent is not less than 1×10 8 Pieces / mL.

7. The use according to claim 2, characterized in that: The polypore bacteria ( Polyporales sp )111999 spore liquid was inoculated into potted plants buried with corn straw at 30wt.% of the amount of straw returned to the field.

8. The use according to claim 7, characterized in that: The mass ratio of the soil to the straw is 50:

1.

9. A method for improving farmland soil fertility, characterized in that: The method comprises using the corn stalk degrading bacterial agent prepared as claimed in claim 3 to treat farmland, thereby accelerating the decomposition of corn stalks, increasing the soil organic matter content and improving the soil structure.

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