A type of Mucor mold and its application

Abstract

This invention discloses a species of *Mucor* and its applications, wherein the *Mucor* ( Mucor moelleri The strain number, JSAFC 2483, was deposited on May 6, 2025, at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 41980. The biocontrol bacteria provided by this invention... Mucor moelleri JSAFC 2483 can effectively inhibit Fusarium equisetifolium ( Fusarium equiseti The growth of *Fusarium equisetifolium* was inhibited by 54.90% in plate confrontation culture, and its secreted extracellular metabolites also significantly reduced the growth of *Fusarium equisetifolium*. When the concentration of JSAFC 2483 extracellular metabolites was 10 mL / 100 mL, it significantly reduced the growth of *Fusarium equisetifolium*. F. equiseti The inhibition rate reached 53.98%. When the extracellular metabolite concentration of JSAFC 2483 was 100 mL / 100 mL, it had a significant inhibitory effect on... F. equiseti The inhibition rate reached 56.64%. At the same time, it promoted the growth of pepper plants.

Description

Technical Field

[0001] This invention belongs to the field of microbial technology and relates to a type of Mucor mold and its applications. Background Technology

[0002] Chili peppers are the most widely planted vegetable in my country, with an annual planting area of ​​32-34 million mu (approximately 2.8-2.6 million hectares), accounting for 10% of the country's total vegetable planting area. Their output accounts for nearly half of the global total, and in 2024, the total output value exceeded 270 billion yuan, firmly establishing China as the world's largest producer and consumer of chili peppers. However, root rot disease seriously threatens this advantageous industry. This disease is caused by *Fusarium oxysporum* (a type of fungus). Fusarium equiseti This disease, caused by [unspecified pathogen], is distributed in major chili-producing provinces. Although the incidence rate is low in general fields, it can reach 30%-50% in fields with continuous cropping. The disease overwinters in diseased plant debris in the soil through mycelium and chlamydospores, and spreads by rain splash. It invades through root wounds, leading to typical symptoms such as browning of vascular bundles, wilting and death of the plant, while the leaves remain green.

[0003] Currently, for the control of chili root rot, agricultural control methods cannot completely eliminate the pathogen and are prone to recurrence; chemical control methods easily produce pesticide residues and may also lead to disease resistance; biological control can effectively kill pathogens without damaging the environment, and is the future direction and trend of disease control. Biocontrol bacteria have significant advantages: First, they are highly specific; the chitinases and antimicrobial peptides they secrete target only the root rot pathogen, without affecting beneficial microorganisms such as nitrogen-fixing bacteria and phosphate-solubilizing bacteria in the soil, maintaining ecological balance. Compared with chemical agents, they can significantly increase the number of beneficial soil bacteria. Second, they improve the soil; biocontrol bacteria can decompose diseased plant debris and activate nutrients. After application in continuously cropped fields, the soil organic matter content increases by 15%-20%, alleviating continuous cropping obstacles. Third, they are safe and residue-free; the pesticide residue test pass rate for chili fruits treated with biocontrol bacteria reaches 100%, meeting export standards and helping to enhance the international competitiveness of the product.

[0004] In summary, current technologies lack a green and highly effective probiotic for preventing root rot in chili peppers. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a *Mucor* species (…). Mucor moelleri ), and its effect on inhibiting Fusarium equisetifolium ( Fusarium equiseti Applications in the growth and promotion of chili pepper growth.

[0006] Technical solution: This invention provides a *Mucor* species (… Mucor moelleri The *Mucor* species ( Mucor moelleri The strain number is JSAFC 2483, which was deposited at the China General Microbiological Culture Collection Center on May 6, 2024, with accession number CGMCC No. 41980.

[0007] Furthermore, the *Mucor* oosporium ( Mucor moelleri The nucleotide sequence of the ITS gene is shown in SEQ ID NO.1.

[0008] The present invention also provides a biocontrol agent, wherein the active ingredient of the biocontrol agent is the above-mentioned *Mucor* sp. Mucor moelleri ).

[0009] The present invention also provides the above-mentioned *Mucor* species ( Mucor moelleri ) or its extracellular metabolites, biocontrol agents, in inhibiting Fusarium equisetifolium ( Fusarium equiseti Applications during growth.

[0010] The present invention also provides the above-mentioned *Mucor* species ( Mucor moelleri Application of biocontrol agents in promoting chili pepper growth.

[0011] Furthermore, the method involves planting chili peppers in an environment containing *Mucor* fungus (…). Mucor moelleri In the substrate of JSAFC2483 mycelium.

[0012] Furthermore, the substrate is peat moss.

[0013] Furthermore, the promotion of chili pepper growth includes increasing plant height and leaf size.

[0014] The present invention also provides the above-mentioned *Mucor* species ( Mucor moelleri Application of biocontrol agents in the preparation of drugs for controlling root rot of pepper.

[0015] Furthermore, the root rot of the pepper is caused by Fusarium equisetifolium (… Fusarium equiseti )cause.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following outstanding advantages: the biocontrol bacteria provided by the present invention Mucor moelleri JSAFC 2483 can effectively inhibit Fusarium equisetifolium ( Fusarium equiseti The growth of *Fusarium equisetifolium* was inhibited by 54.90% in plate confrontation culture, and its secreted extracellular metabolites also significantly reduced the growth of *Fusarium equisetifolium*. When the concentration of JSAFC 2483 extracellular metabolites was 10 mL / 100 mL, it significantly reduced the growth of *Fusarium equisetifolium*. F. equiseti The inhibition rate reached 53.98%. When the extracellular metabolite concentration of JSAFC 2483 was 100 mL / 100 mL, it had a significant inhibitory effect on... F. equiseti The inhibition rate reached 56.64%. At the same time, it promoted the growth of pepper plants. Attached Figure Description

[0017] Figure 1 :Mucor moelleri Phylogenetic tree of JSAFC 2483.

[0018] Figure 2 The biocontrol bacteria of this invention Mucor moelleri JSAFC 2483 and Fusarium equiseti Confrontation fosters development.

[0019] Figure 3 The biocontrol bacteria of this invention Mucor moelleri JSAFC 2483 secretes extracellular metabolites on Fusarium equiseti The impact.

[0020] Figure 4 The biocontrol bacteria of this invention Mucor moelleri The effect of JSAFC 2483 on the plant height of chili peppers. Detailed Implementation

[0021] The following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0022] As described in this invention, the term "biocontrol bacteria" refers to beneficial microorganisms that can prevent and control plant diseases.

[0023] Example 1: Mucor moelleri Separation and identification of JSAFC 2483

[0024] 1. Mucor moelleri Separation of JSAFC 2483

[0025] Healthy chili pepper plants with good growth were selected from the fields in Yunnan, China. Root tissue was taken from these plants, and JSAFC 2483 was isolated from them. The colony characteristics are as follows: when cultured on PDA plates, the growth rate is rapid, forming round colonies with no pigment production; the mycelium grows vigorously, appearing as cotton wool, and adheres to the surface of the culture medium.

[0026] 2. Mucor moelleri JSAFC 2483 Molecular Biological Identification

[0027] (1) Genomic DNA of strain JSAFC 2483 was extracted using a kit from TIANGEN.

[0028] (2) Amplification of the ITS gene of genomic DNA. DNA amplification was performed using a 30 μL reaction volume, containing 15 µL of 2×EasyTaq PCR SuperMix (+dye), 1 μL (10 μM) each of primer pairs ITS1 (SEQ ID NO.2: 5'-CTTGGTCATTTAGAGGAAGTAA-3') & ITS4 (SEQ ID NO.3: 5'-TCCTCCGCTTATTGATATGC-3'), 2 μL of template DNA, and 11 μL of ddH2O. The PCR amplification program conditions were as follows: 94℃ pre-denaturation for 5 min; 94℃ denaturation for 30 s, 54℃ annealing for 45 s, 72℃ extension for 1 min, for a total of 35 cycles; and a final extension at 72℃ for 10 min.

[0029] (3) After the amplified PCR products were electrophoresed by 1% agarose gel, they were observed under UV light. The PCR products with the target band were sent to Nanjing Qingke Biotechnology Co., Ltd. for sequencing. The sequencing results were: the ITS gene sequence of strain JSAFC 2483 was SEQ ID NO.1.

[0030] (4) Compare SEQ ID NO.1 on the NCBI database website. The comparison results are shown in Table 1. Construct a phylogenetic tree based on SEQ ID NO.1. See [link to citation]. Figure 1 .according to Figure 1 Based on the results in Table 1, it can be inferred that the biocontrol bacterium JSAFC2483 of the present invention is... Mucor moelleri Named Mucor moelleri JSAFC 2483, and the strain was deposited on May 6, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC NO.41980, and classified as *Mucor*. Mucor moelleriThe address for the collection is No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0031] Table 1. Sequence alignment results of SEQ ID NO.1

[0032]

[0033] Example 2: Mucor moelleri JSAFC 2483 pairs Fusarium equiseti Inhibition effect

[0034] (1) On the clean bench, F. equiseti A 4 mm diameter mycelial disc was inoculated onto one side of a PDA medium plate, while simultaneously... Mucor moelleri JSAFC 2483 mycelial discs with a diameter of 4 mm were inoculated onto one symmetrical side of PDA medium as the experimental group; and only inoculated with... F. equiseti The culture medium plates were used as the control group.

[0035] (2) The experimental group and control group of step (1) were cultured upside down in a constant temperature incubator at 25°C. The culture conditions were 8 hours of light and then 16 hours of dark culture.

[0036] (3) After culturing the experimental and control culture media from step (2) under the above culture conditions for 7 days, measure the results using the plate confrontation method. F. equiseti Colony radius, and observation Mucor moelleri JSAFC 2483 pairs F. equiseti The inhibitory effect.

[0037] The results are as follows Figure 2 As shown, the blank control group F. equiseti The colony radius was 1.53 cm; in the experimental group, the colony radius was determined using the plate confrontation method. F. equiseti The pathogen's average radius was only 0.69 cm, and the inhibition rate reached 54.90%, indicating that... Mucor moelleri JSAFC 2483 pairs F. equiseti The inhibitory effect is significant.

[0038] Example 3: Mucor moelleri JSAFC 2483 extracellular metabolite pairs F. equiseti Impact

[0039] (1) Use a hole punch to take holes with a diameter of 5 mm. F. equiseti and Mucor moelleri JSAFC 2483 mycelial blocks were inoculated into 9 cm diameter petri dishes containing 15 mL of PDA medium and incubated at 25°C in the dark for 5 days. F. equisetiOnce the strain has fully grown in the culture dish, holes are punched at the edge of the colony using a punch (5 mm in diameter) to prepare the culture dish.

[0040] (2) Cut 3 mm × 3 mm hyphal blocks from the edge of JSAFC 2483 colonies that have grown for 5 days. Under aseptic conditions, transfer 30 hyphal blocks to 200 ml of PDB liquid medium and incubate for 7 days at 25°C, in the dark, and at 160 rpm. First, filter out the hyphal blocks in the culture medium with two layers of sterile gauze. After centrifugation at 10,000 rpm for 30 min at room temperature, collect the supernatant. Filter the supernatant once with a 0.45 µm bacterial filter and then filter it again with a 0.22 µm bacterial filter to completely remove the JSAFC2483 cells. Obtain sterile filtrate.

[0041] (3) Measure 10 mL and 100 mL of the above sterile filtrate respectively, pour them into 100 mL of PDA medium (cooled to about 50°C), mix quickly, and prepare plates containing JSAFC 2483 sterile filtrate with concentrations of 10 mL / 100 mL and 100 mL / 100 mL. Use sterile water instead of sterile filtrate for the control and prepare sterile horizontal plates of the corresponding concentrations respectively.

[0042] (4) Pick up the inoculation needle in the clean bench. F. equiseti The mycelial discs were inoculated onto the plates prepared above, with the mycelial side facing down. Three replicates were set for each concentration (sterile filtrate and sterile water).

[0043] (5) Place the inoculated petri dishes in a 25℃ incubator and incubate in the dark for 3-5 days, then measure the colony diameter. The inhibition rate is calculated according to the formula: Inhibition rate = (colon diameter of control group - colony diameter of treatment group) / colony diameter of control group × 100%.

[0044] The results are shown in Figure 3 and Table 2.

[0045] Table 2. Effects of extracellular metabolites secreted by strain JSAFC 2483 on... F. equiseti Inhibition rate

[0046]

[0047] The colony diameter in the table is expressed as: mean ± standard error.

[0048] from Figure 3 As shown in Table 2, the extracellular metabolites secreted by strain JSAFC 2483 have the effect on... F. equiseti The inhibitory effect was observed, and the inhibitory effect tended to increase with increasing extracellular metabolite concentration. When the extracellular metabolite concentration of JSAFC 2483 was 10 mL / 100 mL, the inhibitory effect on… F. equisetiThe inhibition rate reached 53.98%. When the extracellular metabolite concentration of JSAFC 2483 was 100 mL / 100 mL, it had a significant inhibitory effect on... F. equiseti The inhibition rate reached 56.64%.

[0049] Example 4: Mucor moelleri The effects of JSAFC 2483 on the growth of chili peppers

[0050] (1) Use a hole punch to cut a hole with a diameter of 5 mm. Mucor moelleri JSAFC 2483 mycelial blocks were inoculated into 9 cm diameter petri dishes (containing 15 ml of PDA medium) and cultured at 25°C in the dark for 7 days.

[0051] (2) Select a pot with a diameter of 15 cm and place the pots that have been cultivated for 7 days. Mucor moelleri JSAFC 2483 culture medium was cut into 0.5 cm × 0.5 cm flat plates. Two groups were set up for the experiment: the control group consisted of four 0.5 cm × 0.5 cm PDA flat plates per pot; the experimental group consisted of four 0.5 cm × 0.5 cm PDA flat plates per pot. Mucor moelleri JSAFC2483 flat plates. Various flat plates were thoroughly mixed with sterilized peat moss and added to pots until 1 / 3 full. One healthy, uniformly growing pepper seedling was transplanted into each pot, and then covered with peat moss. Each treatment was set up with 3 replicates.

[0052] (3) Irrigate each group of peppers with sterile water, and count the plant height of peppers after 30 days.

[0053] The results are shown in Table 3 and Figure 4 As shown.

[0054] Table 3. Statistical results of chili plant height

[0055]

[0056] The plant height in the table is expressed as: mean ± standard error.

[0057] From Table 3 and Figure 4 The data show that the plant height in the experimental group was significantly different from that in the control group. These results indicate that... Mucor moelleri JSAFC 2483 has a growth-promoting effect on chili pepper plants.

Claims

1. A type of Mucor (Oomycetes) Mucor moelleri ), characterized in that, The Mucor ( Mucor moelleri The strain number is JSAFC 2483, which was deposited at the China General Microbiological Culture Collection Center on May 6, 2025, with accession number CGMCC No. 41980.

2. A biocontrol agent, characterized in that, The active ingredient of the biocontrol agent is *Mucor* as described in claim 1 (…). Mucor moelleri ).

3. The *Mucor* species as described in claim 1 ( Mucor moelleri The biocontrol agent according to claim 2 inhibits Fusarium equisetifolium (…). Fusarium equiseti Applications during growth.

4. The *Mucor* species as described in claim 1 (… Mucor moelleri The application of the biocontrol agent described in claim 2 in promoting the growth of chili peppers.

5. The application according to claim 4, characterized in that, The method described involves planting chili peppers in an environment containing *Mucor* fungus (…). Mucor moelleri In the substrate of JSAFC 2483 mycelium.

6. The application according to claim 5, characterized in that, The substrate is peat moss.

7. The application according to claim 4, characterized in that, The promotion of chili pepper growth includes both plant height growth and root growth.

8. The *Mucor* species as described in claim 1 (… Mucor moelleri The application of the biocontrol agent according to claim 2 in the preparation of a drug for controlling pepper root rot, wherein the pepper root rot is caused by Fusarium equisetifolium (…). Fusarium equiseti )cause.

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