Application of a microorganism bacteria for repairing soil pollution

Abstract

This invention relates to the field of microbial technology, specifically to the application of a microbial strain for remediating soil pollution. The strain used in this invention is *Trichoderma harzianum* 124D, which is not only a broad-spectrum biocontrol agent but also significantly reduces the accumulation of copper in the soil, alleviating the stress on wheat growth.

Description

Technical Field

[0001] This invention belongs to the field of microbial technology, specifically the application of a microbial bacterium for remediating soil pollution. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] In recent decades, the extensive use of copper-based pesticides and copper-containing fertilizers has increased the copper ion content in the soil environment. The copper content in many soils that have been treated with copper-based pesticides for a long time has seriously exceeded the standard, which has seriously affected the soil's physical and chemical properties, microbial populations and biomass, and excessive copper has led to plant death.

[0004] Current methods for remediating copper-contaminated environments all have limitations to varying degrees. Many traditional methods rely on chemical agents, which often produce unpleasant odors, are costly, and have adverse environmental impacts. Therefore, copper pollution is a pressing environmental issue that urgently needs to be addressed. Consequently, biological and ecological technologies, such as phytoremediation and microbial remediation, hold particularly promising prospects.

[0005] Trichoderma, a widespread soil-dwelling fungus, is also widely used as an active ingredient in biopesticides and fertilizers. When used in combination with chemical pesticides and fertilizers, it requires good environmental tolerance. This is especially true when used in copper-contaminated soils or in combination with copper-based pesticides, where good copper tolerance is essential. Patent CN112501033A discloses a strain of Trichoderma harzianum 124D (accession number CGMCC No. 21030). Antagonistic experiments showed that Trichoderma harzianum 124D has good antagonistic effects against various pathogens, including Phytophthora harzianum, Pythium cerevisiae, wheat powdery mildew, and Fusarium graminearum. It also promotes wheat yield per acre and increases the protein and amino acid content of wheat caryopsis, thereby enhancing wheat's resistance. However, further research is needed to explore its functional properties and expand its application scope. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides an application of a microbial agent for remediating soil pollution. This invention further enhances the functionality of *Trichoderma harzianum* 124D, which can alleviate the stress effects of copper on wheat growth, improve wheat resistance, and promote copper absorption and translocation. This is of great significance for remediating copper-contaminated environments.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the invention provides the application of Trichoderma harzianum 124D in the remediation of soil pollution, wherein the accession number of Trichoderma harzianum 124D is CGMCC No. 21030.

[0009] In some embodiments, the remediation of soil pollution includes: mitigating the stress effects of copper on plant growth, and / or reducing the accumulation of copper in the soil.

[0010] In some embodiments, the plant is wheat.

[0011] In some implementations, growth indicators include: wheat germination characteristics and wheat seedling growth characteristics.

[0012] In some embodiments, the wheat germination characteristics include: germination rate, germination potential, shoot length, and root length.

[0013] In some embodiments, the wheat seedling growth characteristics include: dry weight biomass, plant height, total SOD activity, POD activity, and malondialdehyde content.

[0014] In some embodiments, the copper content in the soil is greater than 500 mg / kg.

[0015] In a second aspect, the present invention provides a microbial agent for remediating soil pollution, comprising: Trichoderma harzianum 124D spore liquid.

[0016] In some embodiments, the preparation method of the Trichoderma harzianum 124D spore solution includes: picking Trichoderma harzianum 124D and inoculating it into a sterile culture medium, and then culturing it on a shaker to obtain a Trichoderma harzianum 124D suspension.

[0017] In some embodiments, the spore count in the Trichoderma harzianum 124D spore solution is ≥1×10⁻⁶. 6 CFU / mL.

[0018] Beneficial effects of the present invention

[0019] (1) The biocontrol bacteria used in this invention is Trichoderma harzianum 124D, which is a broad-spectrum biocontrol agent that can also significantly reduce the accumulation of copper in the soil and alleviate the stress on wheat growth.

[0020] (2) The method of the present invention is simple, practical and easy to promote. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Figure 1This invention provides a statistical analysis of wheat germination rate and germination potential under copper stress.

[0023] Figure 2 This invention relates to the shoot and root lengths of wheat during germination under copper stress.

[0024] Figure 3 This illustrates the changes in wheat biomass under copper stress in this invention.

[0025] Figure 4 This invention illustrates the effect of copper stress on wheat plant height.

[0026] Figure 5 The total activity of superoxide dismutase (SOD) in wheat seedlings under copper stress in this invention;

[0027] Figure 6 This invention relates to the activity of peroxidase (POD) in wheat seedlings under copper stress.

[0028] Figure 7 This invention describes the changes in malondialdehyde (MDA) content in wheat under copper stress.

[0029] Figure 8 This invention relates to the changes in copper content in copper-contaminated soil under copper stress. Detailed Implementation

[0030] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0031] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0032] Example 1

[0033] Seed pretreatment: Select a number of uniform, healthy and undamaged wheat seeds, disinfect their surfaces, rinse them several times with sterile water, and then conduct a seed germination test on a portion of them in a petri dish and a seedling planting test on the other portion in an incubator.

[0034] Example 2

[0035] Preparation of Trichoderma harzianum spore suspension: Trichoderma harzianum 124D was inoculated into 150 mL of sterile PDB culture medium and cultured on a shaker at 25℃ / 150 rpm for 4 days to obtain a suspension of Trichoderma harzianum 124D. The spore count was adjusted to 1×10⁻⁶. 6 CFU / mL available for use.

[0036] Example 3

[0037] Seed germination experiment: Two treatment groups were set up. The control group used no Cu solution, and the treatment group used sterilized wheat seeds soaked in Trichoderma harzianum spore suspension for 30 min. Each treatment was replicated 5 times, with 5 ml of 0.5 mol / L Cu solution added to each petri dish. Germination was marked when the sprout length reached half the seed length. Root length and sprout length were then measured, and germination potential and germination rate were calculated on days 3 and 5.

[0038] Example 4

[0039] Seedling stage experiment: Wheat seeds without Trichoderma harzianum served as the control group; the treatment group consisted of wheat seeds soaked in Trichoderma harzianum spore solution, with each seed having 1×10⁻⁶ Trichoderma harzianum spores attached. 6 CFU. Both the control and treatment groups were kept at a copper concentration of 0.5 g / kg in the soil, with each treatment replicated five times. Physiological and biochemical parameters were measured after four weeks of wheat cultivation.

[0040] Experimental Example 1

[0041] Methods for determining physiological indicators of wheat:

[0042] After the wheat has grown for 4 weeks, fresh samples of some leaves are taken for the determination of physiological indicators, and the remaining leaves are stored in a refrigerator at 4°C. The physiological indicators of this invention are determined using the nitroblue tetrazolium photochemical reduction method to measure the activity of superoxide dismutase; the guaiacol method to measure peroxidase; the trichloroacetic acid method to determine malondialdehyde content; and the sodium diethyldithiocarbamate-ammonium citrate spectrophotometric method to determine copper content.

[0043] Experimental results:

[0044] (1) Effects of copper stress on wheat germination characteristics

[0045] from Figure 1 It can be seen that under copper stress, the germination potential and germination rate of wheat seeds showed a decreasing trend, and copper stress also inhibited the sprout and root length of wheat. After adding Trichoderma harzianum 124D, the germination potential and germination rate were both higher than those of the control group, and it also increased the sprout and root length of wheat. Figure 2 ).

[0046] (2) Effects of copper stress on wheat seedling growth characteristics

[0047] Biomass can reflect the growth status of wheat under heavy metal copper stress, by Figure 3 It can be seen that copper stress has a certain inhibitory effect on the growth of wheat seedlings. Compared with the control group without any fungal agent, Trichoderma harzianum 124D can alleviate the damage of copper stress to wheat and increase the dry weight biomass of wheat seedlings.

[0048] according to Figure 4 It was found that under copper stress, the wheat seedlings were significantly shorter than those in the control group treated with Trichoderma harzianum 124D, indicating that the Trichoderma harzianum 124D treatment had a relatively significant effect on promoting wheat growth.

[0049] according to Figure 5 It was found that the total SOD activity in wheat seedlings was higher with the addition of Trichoderma harzianum 124D than that in the control group. This indicates that Trichoderma harzianum 124D can enhance the stress resistance of wheat.

[0050] from Figure 6 It can be seen that the treatment group with added Trichoderma harzianum exhibited higher POD activity, indicating that adding Trichoderma harzianum 124D can increase the POD enzyme content in wheat, thereby enhancing antioxidant activity.

[0051] according to Figure 7 It can be observed that under the influence of Trichoderma harzianum 124D, the malondialdehyde content in wheat is much lower than that in the control group, indicating that Trichoderma harzianum 124D can alleviate the damaging effects of copper on wheat.

[0052] Depend on Figure 8 It can be seen that in copper-contaminated soil, both the treatment group and the experimental group reduced the total copper content of the soil, indicating that wheat itself has a certain adsorption effect on copper-contaminated soil. However, compared with the Trichoderma harzianum 124D treatment group, Trichoderma harzianum 124D has a more obvious effect on the remediation of copper pollution in the soil, reducing the soil copper content to 355.27 mg / kg, and the remediation effect is more obvious.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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. The application of Trichoderma harzianum 124D in the remediation of soil pollution, characterized in that, The accession number of Trichoderma harzianum 124D is CGMCC No. 21030; The soil remediation includes: mitigating the stress effects of copper on plant growth and reducing the accumulation of copper in the soil; the copper content in the soil is greater than 500 mg / kg; The plant in question is wheat; Trichoderma harzianum 124D specifically refers to Trichoderma harzianum 124D spore solution, wherein the spore count in the Trichoderma harzianum 124D spore solution is ≥1×10⁻⁶. 6 CFU / mL.

2. The application as described in claim 1, characterized in that, Growth indicators include: wheat germination characteristics and wheat seedling growth characteristics.

3. The application as described in claim 2, characterized in that, The wheat germination characteristics include: germination rate, germination potential, shoot length, and root length.

4. The application as described in claim 2, characterized in that, The wheat seedling growth characteristics include: dry weight biomass, plant height, total SOD activity, POD activity, and malondialdehyde content.

Images