Non-decarboxylated lactobacillus strain mha-2-f1 and applications thereof

Abstract

The present application relates to the field of microbial technology, in particular to a non-decarboxylation Leclercia strain MHA-2-F1 and its application, the non-decarboxylation Leclercia strain Leclerciaadecarboxylata MHA-2-F1 of the present application has good growth promotion and anthracnose inhibition effect on mango, and is a rhizosphere growth promoting bacteria with good effect on mango growth, in addition, through in-depth study, it is found that the strain can also promote IAA synthesis, can produce iron carrier, has good phosphorus solubilization and calcium solubilization effect, at the same time, the strain can significantly improve the content of soil organic matter, available nitrogen, available phosphorus and available potassium, has obvious soil improvement effect, is a multifunctional strain with wide application field, has good prospect in the fields of later biological control, biological bacterial fertilizer, soil conditioner processing and the like.

Description

[Technical Field]

[0001] This invention relates to the field of microbial technology, and in particular to the non-decarboxylated Luxembryophyte strain MHA-2-F1 and its applications. [Background Technology]

[0002] Rhizosphere bacteria (PGPR) have the ability to improve plant growth, enhance soil fertility, increase yield, and reduce pathogens or abiotic stress. Existing reports indicate that several PGPR strains have demonstrated good growth-promoting, disease-resistant, and soil-improving effects, making them a green and safe raw material for the production of biopesticides, biofertilizers, and soil conditioners. However, in practical applications, we have found significant physiological differences among different strains of the same genus and species. Some strains can inhibit the growth of a particular pathogen, but other strains of the same genus may not have the same antibacterial effect. A growth-promoting effect on one crop may not have the same effect on another. Moreover, some strains may even exhibit the opposite effect. Therefore, the screening and development of rhizosphere bacteria strains is an ongoing research field. The discovery of new strains and their applications will provide a solid foundation for subsequent plant protection, biofertilizers, and other related biological protection fields. This application focuses on screening microorganisms based on mango plantations, primarily to identify microorganisms that have good growth-promoting, disease-resistant, and soil-enhancing effects on mangoes. [Summary of the Invention]

[0003] In view of the above, it is necessary to continuously screen strains to obtain microorganisms that have good effects on promoting growth, resisting disease, and improving the soil environment of mango planting sites. Such strains can be applied to many fields such as bio-fertilizers, bio-pesticides, and soil improvement.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] The non-decarboxylating Leclercia adecarboxylata MHA-2-F1, with accession number GDMCC NO: 63336, is deposited at Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, on April 7, 2023.

[0006] The present invention also includes a bacterial agent comprising the non-decarboxylated Leclercia adecarboxylata strain MHA-2-F1.

[0007] The present invention also includes the application of the non-decarboxylated Leclercia adecarboxylata strain MHA-2-F1 or an agent containing the non-decarboxylated Leclercia adecarboxylata strain MHA-2-F1 in inhibiting the growth of Colletotrichum glocosporioides (Penz.) Penz. & Sacc.

[0008] The present invention also includes the application of the non-decarboxylated Leclercia adecarboxylata strain MHA-2-F1 or the bacterial agent containing the non-decarboxylated Leclercia adecarboxylata strain MHA-2-F1 in the inhibition of mango anthracnose.

[0009] The present invention also includes the application of the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 or the bacterial agent containing the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 in promoting mango growth.

[0010] The present invention also includes the application of the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 or the microbial agent containing the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 in soil remediation.

[0011] This invention also includes the application of the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 or the microbial agent containing the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 in the preparation of biofertilizers, biopesticides and / or soil remediation agents.

[0012] The present invention has the following beneficial effects:

[0013] The non-decarboxylating Leclercia adecarboxylata MHA-2-F1 strain of this invention has a good effect on promoting growth and inhibiting anthracnose in mangoes. It is a rhizosphere growth-promoting bacterium with good effects on mango growth. In addition, through in-depth research, it has been found that this strain can also promote IAA synthesis, produce siderophores, and has good phosphorus solubilization and calcium dissolution effects. At the same time, this strain significantly increases the content of soil organic matter, available nitrogen, available phosphorus, and available potassium, and has a significant soil improvement effect. It is a multifunctional strain with a wide range of applications and has good prospects in the fields of biological control, bio-fertilizer, and soil conditioner processing. [Attached Image Description]

[0014] Figure 1 This is a morphological image of the MHA-2-F1 strain of the present invention on a petri dish;

[0015] Figure 2 This is a phylogenetic tree diagram of the MHA-2-F1 strain of the present invention;

[0016] Figure 3 Figure 1 shows the experimental results of the study on the plant growth promotion effect of strain MHA-2-F1. In the figure, figure a shows the results of inorganic phosphorus degradation by strain MHA-2-F1; figure b shows the results of calcium carbonate degradation by strain MHA-2-F1; figure c shows the results of siderophore production by strain MHA-2-F1; and figure d shows the results of IAA production by strain MHA-2-F1.

[0017] Figure 4 Figure 1 shows the results of a plate antagonism experiment between strain MHA-2-F1 and the pathogen causing mango anthracnose.

[0018] Figure 5 The figure shows the results of the inhibition experiment of strain MHA-2-F1 on mango anthracnose.

[0019] Figure 6 Figure showing the effect of strain MHA-2-F1 on the roots of mango seedlings;

[0020] Figure 7 The figure shows the experimental results of the effect of strain MHA-2-F1 on soil organic matter content;

[0021] Figure 8 The figure shows the experimental results of the effect of strain MHA-2-F1 on the available nitrogen content in soil.

[0022] Figure 9 The figure shows the experimental results of the effect of strain MHA-2-F1 on the available phosphorus content in soil.

[0023] Figure 10 The figure shows the experimental results of the effect of strain MHA-2-F1 on the available potassium content in soil.

[0024] Figure 11 The figure shows the experimental results of the effect of strain MHA-2-F1 on soil pH.

Detailed Implementation Methods

[0025] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0026] Unless otherwise stated, each feature disclosed in this specification (including any appended claims and abstract) is merely one example of a series of equivalent or similar features.

[0027] Example 1:

[0028] Screening of strain Leclercia adecarboxylata MHA-2-F1:

[0029] The non-decarboxylating Leclercia strain MHA-2-F1, with accession number GDMCCNO: 63336, is deposited at Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, on April 7, 2023.

[0030] The strain was isolated from mango-growing soil in Baise City, Guangxi Zhuang Autonomous Region on December 21, 2021.

[0031] The isolated strains were morphologically classified and molecularly identified, as follows:

[0032] 1. Morphological classification of strains

[0033] Morphological classification of strains:

[0034] like Figure 1 As shown, the colony morphology of strain MHA-2-F1 on LB medium is as follows: white colonies with rough edges, oval shape, and wrinkles in the middle and at the edges.

[0035] 2. Molecular biological identification

[0036] Sequencing of the above strains and multiple sequence alignment with sequences of other strains were performed to construct a phylogenetic tree of the strains: the results are as follows. Figure 2As shown, strain MHA-2-F1 has 99.99% similarity to non-decarboxylating Leclercia sp. and belongs to the genus Leclercia sp. After morphological identification, it is believed that its appearance is closer to the species Leclercia adecarboxylata. Therefore, it is named Leclercia adecarboxylata.

[0037] Example 2:

[0038] This embodiment mainly studies the growth-promoting effect of strain MHA-2-F1 on plants.

[0039] I. The antagonistic experiment between strain MHA-2-F1 and Colletotrichum glocosporioides (Penz.) Penz. & Sacc. is described in detail below:

[0040] (1) Observation of whether strain MHA-2-F1 has phosphate-solubilizing activity: The activated strain MHA-2-F1 was inoculated onto a phosphate-solubilizing bacterial plate and cultured upside down at 37℃ for 1-2 days. The phosphate-solubilizing zone was observed to determine whether it had phosphate-solubilizing ability. The results are as follows: Figure 3 As shown in Figure a, a phosphate-solubilizing zone forms near the bacterial spot, and the zone is 8 mm in size, indicating that the strain has phosphate-solubilizing function.

[0041] (2) Observation of whether strain MHA-2-F1 has calcium-dissolving ability: The activated strain MHA-2-F1 was inoculated onto a calcium-dissolving plate and incubated upside down at 37℃ for 1-2 days. The calcium-dissolving zone was observed to determine whether it has calcium-dissolving ability. The results are as follows: Figure 3 As shown in Figure b, a calcium-dissolving zone forms near the bacterial spot, and the zone is 5 mm in size, indicating that the strain has calcium-dissolving function.

[0042] (3) Observation of whether strain MHA-2-F1 has the ability to produce siderophores: The activated strain MHA-2-F1 was inoculated onto CAS plates and cultured upside down at 37℃ for 1-2 days. Observe whether a yellow-green halo appears. If it does, it indicates that it has the ability to produce siderophores. The results are as follows. Figure 3 As shown in Figure c, a yellow-green halo forms near the bacterial spot, and the size of the halo is 20 mm, indicating that the strain has the function of producing siderophores.

[0043] (4) Observation of whether strain MHA-2-F1 produces IAA: The activated strain MHA-2-F1 was inoculated into 5 mL of LB medium in a straight bottle and cultured at 37℃ with shaking at 220 r / min for 24 h. 2 mL of fermentation broth was centrifuged at 12000 r / min for 5 min, and 1 mL of supernatant was collected. An equal volume of Salkowski colorimetric reagent was added and mixed well. After standing in the dark for 30 min, the color change was observed. If it turned red, it indicated that it had the ability to produce IAA. The results are as follows: Figure 3 As shown in Figure d, the color development of the test tube before standing is shown in the left image of Figure d, and the color development of the test tube after standing for 30 minutes is shown in the right image of Figure d. As can be seen in the figure, the color of the test tube changes from yellow to red, indicating that the strain has the function of producing IAA.

[0044] Example 3:

[0045] This embodiment mainly studies the effect of strain MHA-2-F1 on mango anthracnose.

[0046] Using *Colletotrichum glocosporioides* (Penz.) Penz. & Sacc., the pathogen of mango anthracnose, as an indicator bacterium, the effect of strain MHA-2-F1 on this pathogen was studied using the plate confrontation method. Specifically, the pathogen was spotted at the center of a PDA plate, and a straight line was drawn 3 cm away from the spot. Strain MHA-2-F1 was then inoculated, with a plate uninoculated as a control. After incubation at 30°C upside down for 5-7 days, the inhibitory effect was observed. Results are as follows: Figure 4 As shown in the figure, the left side represents the experimental group inoculated with MHA-2-F1, and the right side represents the control group not inoculated with MHA-2-F1. It can be seen from the figure that the MHA-2-F1 strain in the experimental group has a significant antagonistic effect on the pathogen, while the pathogen mycelium in the control group completely covers the plate. This indicates that strain MHA-2-F1 has a significant inhibitory effect on the pathogen causing mango anthracnose.

[0047] To further verify this, the applicant also investigated the inhibitory effect of strain MHA-2-F1 on anthracnose in mango plants, as detailed below:

[0048] Select healthy, disease-free mangoes of uniform ripeness and similar size. Rinse them thoroughly with tap water, disinfect the surface with 75% ethanol, wash with sterile water, and air dry. Under sterile conditions, puncture the mango skin with a toothpick and inoculate with 20 μL of pathogenic fungal spore suspension (spore concentration of 10). 6 20 μL of antagonistic bacterial fermentation broth (number of bacteria / mL) was used as a control. The fermentation broth was inoculated once a day, with mango fruits inoculated with an equal volume of LB medium as a control. The culture was carried out at room temperature for 5-7 days, and the disease incidence was recorded.

[0049] Leclercia adecarboxylata MHA-2-F1 showed a control effect against Leclercia adecarboxylata infection in mango fruit. Two days later, the control group began to be infected, while the experimental group remained uninfected. Infection gradually appeared in the experimental group on the fourth day, with black spots developing. Six days later, the control effect of MHA-2-F1 against anthracnose pathogen infection in mango was as follows: Figure 5 As shown, there was a significant difference in the degree of infection between the experimental group and the control group. The control group had obvious lesions, larger black spots, and depressions, and orange conidia were generated at the site of infection. In contrast, the lesions in the experimental group were significantly weaker, indicating that MHA-2-F1 has a good control effect on mangoes infected with Colletotrichum gloeosporioides.

[0050] Example 4:

[0051] This example studies the growth-promoting effect of strain MHA-2-F1 on mango, and the specific method is as follows:

[0052] Take sufficiently ripe mangoes, remove the seeds, wash them clean, and soak them in water for one week, changing the water daily. Peel off the seed coat, select germinated seeds of similar shape and size, and bury them in flowerpots (each pot containing 1.5 kg of fertile, loose, and well-drained soil). The experimental group was given 200 mL of probiotic fermentation liquid diluted 20 times, bringing the final probiotic concentration to 10. 7 / g, the control group was given the same amount of LB medium diluted with the same ratio, applied once every 15 days, and placed in a warm, humid and sunny place for maintenance. The germination and growth of mangoes were observed. After 3 months, the fresh weight and dry weight of mango plants were compared. Each treatment group was performed in 3 replicates.

[0053] Mango seeds were planted in soil mixed with Leclercia adecarboxylata MHA-2-F1 and placed in a warm, humid, and sunny location for one month before germination. Three months later, the above-ground parts and roots of the mango seedlings were collected. After weighing the above-ground parts, the experimental group of mango seedlings had a wet weight of (1.74±0.30) g and a dry weight of (0.37±0.22) g, which were 171% and 264% of the control group's (wet weight (1.02±0.37) g; dry weight (0.14±0.06) g), respectively. The underground parts... Figure 6 As shown, the control group mango seedlings had only one taproot, no lateral roots, and a very small number of fibrous roots, while the experimental group mango seedlings had a taproot, a small number of lateral roots, and a large number of fibrous roots. This not only enhances the root system's support for the above-ground parts but also effectively increases the absorption of water and mineral nutrients by the mango roots. In conclusion, MHA-2-F1 has a significant growth-promoting effect on mango plants.

[0054] Example 5:

[0055] This example studies the soil-improving effect of strain MHA-2-F1. The specific methods are as follows:

[0056] 1. Soil organic matter content:

[0057] The determination of soil organic matter content should refer to "Soil Testing - Determination of Soil Organic Matter Content (NY / T1121.6-2006)". Soil samples should be air-dried and passed through a 2.5mm sieve. Accurately weigh 0.2000g of soil sample and place it in a hard glass test tube. Accurately add 10.00mL of 0.4mol / L potassium dichromate-sulfuric acid solution. Insert a glass funnel into the mouth of the test tube, shake well, and heat in a 230℃ digestion furnace for 15 minutes. After cooling, transfer the digestion solution and soil residue from the test tube intact into a 100mL beaker. Rinse the test tube and funnel with water, and transfer the solution to the beaker to a total volume of approximately 50mL. Add 3 drops of o-phenanthroline indicator and titrate the remaining potassium dichromate with ferrous sulfate standard solution. The color change of the solution should be orange-yellow to blue-green to brown-red. For each batch of analysis, perform two blank tests and three replicate tests, and take the average value.

[0058] Formula for calculating soil organic matter content:

[0059]

[0060] Where: c: concentration of ferrous sulfate standard solution, mol / L; V0: volume of ferrous sulfate standard solution consumed in blank test, mL; V: volume of ferrous sulfate standard solution consumed in sample determination, mL; 0.003: millimolecular mass of 1 / 4 carbon atom, g; 1.724: coefficient for converting organic carbon to organic matter; 1.10: oxidation correction coefficient; m: mass of air-dried sample, g; 1000: content converted to per kg.

[0061] Organic matter, composed of organic residues, soil organisms, and humus, is one of the important standards for directly measuring soil fertility. It contains almost all the nutrients needed by microorganisms and crops, promoting nutrient cycling, improving soil physical properties, enhancing water and fertilizer retention capacity, and even reducing soil pesticide and heavy metal pollution. A mango-growing soil inoculated with Leclercia decarboxylata MHA-2-F1 bacterial solution was used as the experimental group, while mango-growing soil inoculated with an equal amount of water served as the control group. The organic matter content of soil at different locations was tested and compared. The results are as follows: Figure 7 As shown, the organic matter content of the soil in the experimental group was significantly higher than that in the control group, indicating that the MHA-2-F1 strain has a significant effect on increasing the organic matter content of the soil.

[0062] 2. Available nitrogen content in soil:

[0063] The nitrogen content in soil effectively reflects soil fertility. Nitrogen that can be directly absorbed and utilized by plants is called available nitrogen, including nitrate nitrogen and ammonium nitrogen. Available nitrogen is generally determined using the alkaline hydrolysis-diffusion method, but this method is cumbersome and time-consuming. Therefore, referring to "Water Quality—Determination of Ammonia Nitrogen—Nessler's Reagent Spectrophotometric Method (HJ 535-2009)," the available nitrogen content in soil was determined using the Nessler colorimetric spectrophotometric method. Soil samples were air-dried, passed through a 40-mesh sieve, and 1.00 g was accurately weighed into a 50 mL straight-sided bottle. 10 mL of 20% NaCl solution was added, and the sample was ultrasonically cleaned for 1 hour. After filtration, 5 mL of the available nitrogen extract was placed in a straight-sided bottle, 2 mL of 50% potassium sodium tartrate solution and 1.5 mL of Nessler's reagent were added, and water was added to a final volume of 25 mL. The sample was shaken well, and the absorbance at 420 nm was measured after 10 minutes. A soil-free sample under the same treatment conditions was used as a blank sample. Calculate the available nitrogen content based on the standard curve, repeat the experiment three times, and take the average value.

[0064]

[0065] Where: ρ: nitrogen concentration in the colorimetric solution obtained from the standard curve, mg / L; ρ0: nitrogen concentration in the blank sample obtained from the standard curve, mg / L; V: volume of the colorimetric solution, mL; D: fractionation factor, the ratio of the sample extractant volume to the fractionation volume; m: sample mass, g; 1000: coefficient for converting mL to L and g to kg.

[0066] Available nitrogen in soil refers to nitrogen that can be directly absorbed and utilized by plants, including nitrate nitrogen and ammonia nitrogen, reflecting the soil's nitrogen supply capacity in the near term. Mango-growing soil treated with Leclercia adecarboxylata MHA-2-F1 bacterial solution was used as the experimental group, while mango-growing soil treated with an equal amount of water served as the control group. The available nitrogen content in soils at different locations was tested and compared. The results are as follows: Figure 8 As shown in the figure, the available nitrogen content in the experimental group soil was significantly higher than that in the control group soil, indicating that the MHA-2-F1 strain has a significant effect on increasing the available nitrogen content in the soil.

[0067] 3. Available phosphorus content in soil:

[0068] The determination of available phosphorus content in soil should refer to "Soil Testing - Determination of Available Phosphorus in Soil (NT / T 1121.7-2014)". Soil samples should be air-dried and passed through a 2mm sieve. For acidic soil (pH < 6.5), accurately weigh 1.00g and place it in a 50mL Erlenmeyer flask, add 10.00mL of ammonium fluoride-hydrochloric acid extraction solvent, and shake at 25℃ and 180r / min for 30min. After filtration, take 5 mL of the sample solution, add 5 mL of boric acid solution, shake well, add water to 15 mL, add 1 drop of dinitrophenol indicator, add 2.5 mL of molybdenum antimony colorimetric reagent, and dilute with water to 25 mL. Let it stand for 30 min at room temperature above 20℃. After zeroing with the zero point of the standard solution, measure its UV-Vis absorbance at a wavelength of 700 nm. Accurately weigh 0.50 g of neutral or calcareous soil (pH≥6.5) into a 50 mL Erlenmeyer flask, add 10.00 mL of sodium bicarbonate extractant, and shake at 25℃ and 180 r / min for 30 min. After filtration, take 5 mL of the sample solution, add 2.5 mL of molybdenum-antimony anti-colorimetric reagent, shake slowly to remove carbon dioxide, add 5 mL of water, shake thoroughly to remove carbon dioxide, and let stand for 30 min at room temperature above 20℃. After zeroing with the zero point of the standard solution, measure the absorbance of ultraviolet-visible light at a wavelength of 880 nm. Use a soil-free sample under the same treatment conditions as a blank sample. Calculate the available phosphorus content according to the standard curve. Perform three replicate experiments and take the average value.

[0069] Where: ρ: Phosphorus concentration in the colorimetric solution obtained from the standard curve, mg / L; ρ0: Phosphorus concentration in the blank sample obtained from the standard curve, mg / L; V: Volume of colorimetric solution, mL; D: Dispensing factor, the ratio of sample extractant volume to dispensed volume; m: Sample mass, g; 1000: Coefficient for converting mL to L and g to kg.

[0070] Available phosphorus in soil refers to the total amount of phosphorus that plants can absorb and utilize, including all water-soluble phosphorus, some adsorbed phosphorus, and some organic phosphorus. Some soils also contain some precipitated phosphorus. Its content is significant for guiding crop fertilization. Using mango-growing soil with an equal amount of water added as a control group, the available phosphorus content in soils at different locations was tested and compared. The results are as follows: Figure 9 As shown in the figure, the available phosphorus content in the experimental group soil was significantly higher than that in the control group soil, indicating that the MHA-2-F1 strain has a significant effect on increasing the available phosphorus content in the soil.

[0071]

[0072] 4. Available potassium content in the soil:

[0073] The determination of available potassium content in soil was performed according to the standard curve "Determination of Available and Slow-release Potassium Content in Soil (NY / T 889-2004)". Soil samples were air-dried and passed through a 1 mm sieve. 1.00 g of soil sample was accurately weighed and placed in a 50 mL Erlenmeyer flask. 10.00 mL of ammonium acetate solution was added (soil-to-solution ratio 1:10), the flask was sealed, and the mixture was shaken at 25℃ and 180 rpm for 30 min. After filtration, the sample was diluted with ammonium acetate solution to an appropriate concentration and measured using an atomic absorption spectrophotometer. A soil sample without soil under the same treatment conditions was used as a blank sample. The available potassium content was calculated based on the standard curve. Three replicate experiments were performed, and the average value was taken.

[0074]

[0075] In the formula: c: the concentration of potassium in the test solution obtained from the standard curve, mg / L; V: the volume of the extractant, mL; m: the mass of the sample, g; D: the dilution factor.

[0076] Available potassium in soil is potassium that is easily absorbed and utilized by plants, mainly in the form of exchangeable potassium, but also including water-soluble potassium. Although the content of available potassium is very low, accounting for only 0.1-0.2% of the total potassium content in the soil, it is one of the important indicators of soil potassium supply. Using mango-growing soil with an equal amount of water added as a control group, the available potassium content in soils at different locations was tested and compared. The results are as follows: Figure 10 As shown in the figure, the available potassium content in the experimental group soil was significantly higher than that in the control group soil, indicating that the MHA-2-F1 strain has a significant effect on increasing the available potassium content in the soil.

[0077] 5. Soil pH value:

[0078] Soil pH determination should refer to "Determination of Soil pH (NY / T 1377-2007)". Soil samples should be air-dried, passed through a 2mm sieve, and mixed with water at a ratio of 1:2.5 (the water should be boiled for 10 minutes and cooled to remove carbon dioxide before use). After sealing, the solution should be shaken vigorously for 5 minutes and allowed to stand for 1-3 hours. After thoroughly mixing the solution, the pH value should be measured using a pH meter. After the reading stabilizes, the pH value should be recorded. The experiment should be repeated 3 times, and the average value should be taken.

[0079] Soil pH is an important chemical indicator. Although not a direct nutrient, it affects soil structure, nutrient supply capacity, and the diversity and abundance of soil microorganisms. Excessive acidity or alkalinity can reduce available nutrients for plants, alter the microbial community, and consequently lead to poor plant growth and development or even disease. Using mango-growing soil with an equal amount of water added as a control group, the pH values ​​of soils at different locations were tested and compared. The results are as follows: Figure 11 As shown in the figure, the pH values ​​of the soil in the experimental groups did not differ significantly, indicating that the MHA-2-F1 strain could not affect the soil pH value.

[0080] In summary, the non-decarboxylating Leclercia adecarboxylata MHA-2-F1 strain and its inoculant of the present invention have a significant promoting effect on rhizosphere growth of mango and a significant inhibitory effect on mango anthracnose. This demonstrates that MHA-2-F1 has good growth-promoting and disease-resistant effects on mango. Furthermore, this strain can also be used to remediate contaminated soil. Therefore, the strain of this application can be widely used in various fields such as plant protection, growth promotion, and soil remediation, making it a widely applicable and excellent strain suitable for both plant protection and growth promotion.

[0081] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1, characterized in that... The strain has the accession number GDMCCNO:63336.

2. An agent containing the non-decarboxylated Leclercia adecarboxylata strain MHA-2-F1 as described in claim 1.

3. The application of the non-decarboxylated Leclercia adecarboxylata strain MHA-2-F1 as described in claim 1 or the bacterial agent containing the non-decarboxylated Leclercia adecarboxylata strain MHA-2-F1 as described in claim 2 in inhibiting the growth of Colletotrichum glocosporioides (Penz.) Penz. & Sacc.

4. The application of the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 as described in claim 1 or the bacterial agent containing the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 as described in claim 2 in the inhibition of mango anthracnose.

5. The application of the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 as described in claim 1 or the microbial agent containing the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 as described in claim 2 in promoting mango growth.

6. The application of the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 as described in claim 1 or the microbial agent containing the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 as described in claim 2 in soil remediation.

7. The application of the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 as described in claim 1 or the microbial agent containing the non-decarboxylating Leclercia adecarboxylata strain MHA-2-F1 as described in claim 2 in the preparation of biofertilizers, biopesticides and / or soil remediation agents.

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