Streptomycete and application thereof

Abstract

The invention relates to the technical field of agricultural biotechnology and plant protection, and particularly discloses streptomyces and application thereof. The streptomyces is preserved in the China General Microbiological Culture Collection Center (CGMCC) on July 10, 2025, and the preservation number is CGMCC No.35178. The streptomyces has the advantages that the streptomyces is preserved in the China General Microbiological Culture Collection Center (CGMCC); the invention also provides a culture, a fermentation broth, a bacterial suspension, a bacterial agent and bacterial powder of the strain. The invention also discloses application of the strain and the culture, the fermentation liquor, the bacterial suspension, the bacterial agent and the bacterial powder thereof in the aspects of preventing and treating pathogenic bacteria of crops and promoting plant growth. The streptomyces provided by the invention has relatively high acid resistance, IAA production, nitrogen fixation and protease production capabilities, and can promote plant growth and inhibit growth of various pathogenic bacteria and plant diseases.

Description

Technical Field

[0001] This application relates to the technical fields of agricultural biotechnology and plant protection, and more specifically, to a Streptomyces and its applications. Background Technology

[0002] Global agricultural production continues to face severe challenges in meeting the growing population's demand for food, feed, and fiber. However, crop production is severely constrained by a variety of biological stresses, including devastating plant diseases caused by fungi, oomycetes, bacteria, viruses, and nematodes. Traditionally, these pathogens have been controlled using chemically synthesized pesticides. However, the long-term and excessive use of these pesticides has led to a series of serious problems. Therefore, there is an urgent need to develop safer, more environmentally friendly, and more sustainable alternative strategies to manage plant diseases and promote crop health.

[0003] Biological control, which utilizes beneficial microorganisms or their metabolites to control pests, has become one of the most promising alternatives or supplements to chemically synthesized pesticides. Similarly, utilizing plant growth-promoting microorganisms (PGPMs) can improve crop yield and quality, reducing reliance on chemical fertilizers. Microbial solutions have gained widespread attention due to their environmental friendliness, (typically) target specificity, low residue risk, minimal impact on beneficial organisms, and contribution to soil health restoration.

[0004] Among the many microorganisms with agricultural application potential, Streptomyces occupies an extremely important position due to their extraordinary metabolic capacity and ecological functions. Streptomyces are a group of Gram-positive, aerobic, filamentous bacteria belonging to the phylum Actinobacteria. They are widely distributed in various environments such as soil, compost, marine sediments, and plant rhizosphere, playing a central role, especially in soil microbial communities.

[0005] Streptomyces are best known for their ability to synthesize complex and bioactive secondary metabolites. They are the leading producers of known natural antibiotics (more than two-thirds of clinical and agricultural antibiotics are derived from Streptomyces), but their metabolite repertoire extends far beyond this. Since the mid-20th century, when Streptomyces-produced antibiotics achieved great success in medicine and agriculture, research into the agricultural applications of Streptomyces has continued unabated. Many commercially available agromicrobial preparations are based on Streptomyces strains or their metabolites for the control of soil-borne diseases (such as damping-off, root rot), foliar diseases, and as plant growth promoters.

[0006] Despite the great potential of Streptomyces in agricultural biological control and plant growth promotion, existing technologies and products still have the following key limitations:

[0007] (1) Strain specificity and efficacy stability: The bioactivity of different Streptomyces strains varies greatly. The efficacy of existing commercial strains may be unstable due to environmental factors, application methods, crop varieties, and field microbial communities.

[0008] (2) The need for the discovery of novel active substances: In the face of the continuous evolution of pathogen resistance and the challenge of emerging diseases, it is crucial to continuously explore novel strains or active compounds with unique mechanisms of action from the huge resource pool of Streptomyces.

[0009] (3) Multifunctional integration: Ideal strains or products that simultaneously possess multiple functions such as efficient biological control, significant plant growth promotion and soil improvement are still relatively scarce.

[0010] Therefore, the isolation, identification, and development of novel or improved agricultural Streptomyces strains and their active products that are novel, broad-spectrum, highly efficient, environmentally adaptable, multifunctional, or have unique mechanisms of action are of great significance for overcoming the shortcomings of existing technologies and promoting sustainable agricultural development.

[0011] Most existing agricultural streptomyces strains are isolated from neutral or slightly alkaline soils (pH 6.0-8.0). They are easily inactivated in acidic soils (pH < 5.5) and cannot stably exert their growth-promoting or disease-resistant functions. Summary of the Invention

[0012] This application provides a Streptomyces and its application.

[0013] To date, there are few Streptomyces strains with acid-resistant capabilities. The Streptomyces strain provided in this application possesses high acid resistance, IAA production, nitrogen fixation, and protease production capabilities, and can promote plant growth while inhibiting the growth of various pathogens and the occurrence of plant diseases.

[0014] In a first aspect, this application provides a Streptomyces strain, employing the following technical solution:

[0015] The Streptomyces andamanensis provided in this application was deposited on July 10, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 35178. The deposit address is: Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing.

[0016] This strain was isolated from the rhizosphere soil of a tomato planting base in Wuyishan City, Fujian Province (27°45'N, 118°02'E), with a soil pH of 4.6, in a plot of land that had been continuously planted with tomatoes for more than 5 years and was also affected by disease. Functional verification of the strain showed that it produces IAA, fixes nitrogen, is acid-tolerant, produces protease, and also possesses growth-promoting and disease-preventing functions.

[0017] Secondly, this application provides a culture comprising the aforementioned Streptomyces.

[0018] Thirdly, this application provides a fermentation broth. The fermentation broth includes the aforementioned Streptomyces.

[0019] Fourthly, this application provides a bacterial suspension. The bacterial suspension includes the aforementioned Streptomyces.

[0020] Fifthly, this application provides a microbial agent. This microbial agent includes the aforementioned Streptomyces.

[0021] Sixthly, this application provides a bacterial powder. The bacterial powder includes the aforementioned Streptomyces.

[0022] Seventhly, this application provides the application of the above-mentioned Streptomyces culture, fermentation broth, bacterial suspension, bacterial agent or bacterial powder in the control of crop pathogens and the promotion of plant growth.

[0023] In summary, this application has the following beneficial effects:

[0024] 1. This application provides a Streptomyces strain that was deposited on July 10, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 35178.

[0025] 2. The Streptomyces provided in this application has high acid resistance, IAA production, nitrogen fixation, and protease production capabilities, and can promote plant growth and inhibit the growth of various pathogens and the occurrence of plant diseases. Attached Figure Description

[0026] Figure 1 The colony morphology of the strains isolated and purified in this application is shown.

[0027] Figure 2 The image shows the microscopic morphology of the strain isolated and purified in this application.

[0028] Figure 3 This is a phylogenetic tree of the strains isolated and purified in this application.

[0029] Figure 4 The results show the IAA production capacity of the strain isolated and purified in this application.

[0030] Figure 5 The results show the protease production ability of the strains isolated and purified in this application.

[0031] Figure 6 The results of nitrogen fixation activity detection of the strains isolated and purified in this application are shown in A. 7-day culture results; B. 14-day culture results; C. 21-day culture results.

[0032] Figure 7 The results of confrontation culture experiments on the strains isolated and purified in this application are shown (for each pathogen, the left side shows the results of the blank control group, the middle side shows the results of the positive control group, and the right side shows the results of the Streptomyces isolated and purified in this application).

[0033] Figure 8 The results of tomato pot experiments conducted on the strains isolated and purified in this application are shown (the left side shows the results of the blank control group, the middle side shows the results of the positive control group, and the right side shows the results of the Streptomyces isolated and purified in this application).

[0034] Figure 9 The results of the germination test of the strains isolated and purified in this application.

[0035] Figure 10 The results of a rapeseed pot experiment were conducted on the strains isolated and purified in this application. Detailed Implementation

[0036] Before describing the embodiments of this application in detail, it should be understood that the terminology used herein is for the purpose of describing a particular embodiment only. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the term pertains.

[0037] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values, and such ranges or values ​​should be understood to include values ​​close to such ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0038] In this application, the terms "comprising" or "including" are open-ended expressions, meaning they include the content specified in this application but do not exclude other aspects.

[0039] This application provides a Streptomyces andamanensis strain, which is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 35178. Furthermore, this application provides methods for the isolation, purification, and cultivation of this strain. It also provides cultures, fermentation broths, bacterial suspensions, bacterial powders, and bacterial agents containing this strain.

[0040] This application also provides the application of the Streptomyces strain and its cultures, fermentation broths, suspensions, powders, and agents for the control of crop pathogens and the promotion of plant growth.

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0042] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0043] The present application will be further described in detail below with reference to the embodiments and test results.

[0044] Example

[0045] Example 1

[0046] This embodiment provides the process for isolating and purifying new bacterial strains.

[0047] Specifically as follows:

[0048] (1) Soil sample collection: Using a multi-point soil collection method, rhizosphere soil samples were collected from tomato planting bases in Wuyishan City, Fujian Province (27°45'N, 118°02'E), with soil pH 4.6, and from plots that have been continuously planted with tomatoes and have been affected by diseases (more than 5 years of continuous cropping). Samples were collected from a depth of 5-10 cm using a sterile shovel, placed in sterile bags, and stored at 4°C or processed immediately.

[0049] (2) Separation test: Soil samples were heated in an oven at 55-60℃ for 30 min to kill some non-actinomycetes (heat-resistant Streptomyces spores survived). Then, a 1% CaCO3 suspension was used: shaken for 30 min, and the supernatant was collected after sedimentation (to reduce bacterial interference). The supernatant was then treated with 0.1% phenol for 10 min using the phenol dilution method to inhibit some bacteria and fungi. The treated liquid was spread on ISP-2 yeast malt extract agar (formulation: yeast extract 4 g / L, malt extract 10 g / L, glucose 4 g / L, agar 15 g / L, pH 7.2-7.4) and incubated in a 28℃ incubator for 7 days.

[0050] (3) Morphological identification: such as Figure 1 and Figure 2 The images show the colony morphology and microscopic morphology of the strain isolated and purified in this application.

[0051] The strain was cultured on ISP-2 yeast malt extract agar for 7 days. The colonies were gray, thick, difficult to pick up, and elastic. The center of the colony was darker, and the edges were neat, sometimes wavy. The surface of the colony had white or light gray hyphae or spores. Based on the colony morphology, it was preliminarily identified as *Streptomyces*.

[0052] Based on the microscopic morphology of the strain, after culturing for 7 days using the slide insertion method, the coverslip was removed, placed on a slide, and observed under an oil immersion microscope. It was found that the spore filaments of strain LMJ-06 were slender and highly branched; Gram staining was positive; the spores were oblong, smooth, and sized (0.6–0.8) μm × (0.5–0.7) μm.

[0053] (4) Molecular biological identification:

[0054] The strain was identified using 16S rDNA sequencing technology, and its 16S rDNA sequence (as shown in SEQ ID NO: 1) was obtained. This sequence was then BLAST-aligned with GenBank. A phylogenetic tree was constructed using MEGA 5.0 software using the neighbor-joining method (e.g., ...). Figure 3 As shown in the figure, the strain's position in the phylogenetic tree was determined by comparing relevant sequences in the NCBI gene database. The identification and comparison results indicated that the strain was *Streptomyces andamanensis*, and it was named *Streptomyces LMJ-06*.

[0055] Streptomyces andamanensis was deposited on July 10, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 35178. The deposit address is: Institute of Microbiology, Chinese Academy of Sciences, No. 1 Beichen West Road, Chaoyang District, Beijing.

[0056] Example 2

[0057] This embodiment provides a fermentation broth of Streptomyces.

[0058] The specific method for preparing the above fermentation broth is as follows:

[0059] The strain obtained by isolation and purification in Example 1 was activated and transferred to ISP-2 yeast malt extract liquid medium (formulation: yeast extract 4g / L, malt extract 10g / L, glucose 4g / L) at pH 7.2-7.4 to obtain the fermentation broth of Streptomyces.

[0060] Example 3

[0061] This embodiment provides a fermentation supernatant of Streptomyces.

[0062] The specific method for preparing the above-mentioned fermentation supernatant is as follows:

[0063] The strains isolated and purified in Example 1 were activated and transferred to ISP-2 yeast malt extract liquid medium with pH 7.2-7.4. The medium was cultured at 28°C for 7 days to obtain the fermentation broth of Streptomyces, with a bacterial count of 4 billion / ml. The fermentation broth was centrifuged and the supernatant was collected as the fermentation supernatant of Streptomyces.

[0064] Example 4

[0065] This embodiment provides a Streptomyces bacterial suspension.

[0066] The specific method for preparing the above-mentioned bacterial suspension is as follows:

[0067] The strain obtained by isolation and purification in Example 1 was activated and transferred to ISP-2 yeast malt extract liquid medium with pH 7.2-7.4. It was cultured at 28°C for 7 days to obtain the fermentation broth of Streptomyces. The fermentation broth was centrifuged, the precipitate was retained, and the precipitate was resuspended with sterile water to obtain the bacterial suspension of Streptomyces.

[0068] Example 5

[0069] This embodiment provides a Streptomyces inoculum agent.

[0070] The specific preparation process of the above-mentioned microbial agent is as follows:

[0071] Using activated strain plates, the Streptomyces isolated and purified in Example 1 was inoculated into a 500 mL Erlenmeyer flask containing liquid fermentation seed culture medium and cultured in a constant temperature shaker at 28°C and 200 rpm for 7 days to obtain a cultured seed culture for later use.

[0072] The cultured seed culture was inoculated into a 100L fermenter, with the fermentation liquid volume accounting for 70% of the total fermenter volume. The inoculum size was 1%, the rotation speed was 200 rpm, the temperature was 28℃, and the aeration rate was 1 vvm. After 7 days of cultivation, the culture was removed from the fermenter. This is the Streptomyces inoculum.

[0073] Example 6

[0074] This embodiment provides a Streptomyces powder.

[0075] The preparation process of the above-mentioned bacterial powder is as follows: The bacterial agent obtained in Example 6 is spray-dried to become bacterial powder, which is the bacterial powder of Streptomyces.

[0076] Example 7

[0077] This embodiment provides a microbial inoculant. The microbial inoculant includes an inoculant prepared using Streptomyces.

[0078] The specific preparation process of the above-mentioned microbial inoculant is as follows:

[0079] The bacterial agent prepared in Example 6 was compounded with zeolite powder and mixed evenly at a weight ratio of 1:40. The bacterial agent product after mixing contained 500 million bacteria per gram.

[0080] Performance Test Experiment 1

[0081] The performance of the isolated and purified Streptomyces was tested. Details are as follows:

[0082] (1) Produced by IAA

[0083] The ability of the strain to produce IAA was qualitatively determined by colorimetry. 200 μL of *Streptomyces* bacterial culture was transferred to IAA detection medium (formulation: IAA detection medium: glucose 20 g / L, yeast extract 10 g / L, peptone 20 g / L, L-tryptophan 0.5 g / L, distilled water 1000 mL, pH 7.0) and cultured at 28℃ and 200 rpm for 2 days. Then, the culture was centrifuged in 50 mL centrifuge tubes at 4000 rpm for 10 min. 2 mL of the supernatant was added to an equal volume of Salkowski colorimetric solution (35% perchloric acid and 0.5 mol / L FeCl3 solution mixed at a 50:1 ratio, stored in the dark). After standing in the dark for 30 min, a pink color change indicated the strain had IAA-producing ability. The absorbance was measured at 530 nm. A blank IAA detection medium was used as a control. Each treatment consisted of 3 bottles, with 3 replicates. A standard curve was plotted for the absorbance of pure IAA, and the IAA yield was calculated while observing its color change.

[0084] Test results as follows Figure 4 As shown. By Figure 4 It is known that the Streptomyces isolated and purified in this application has the ability to produce IAA, with an IAA yield of 54.16 mg / L.

[0085] (2) Protease production

[0086] Streptomyces were inoculated onto protease selection medium (formulation: glucose: 10.0 g, (NH4)2SO4 5.0 g / L, KH2PO4 1.0 g / L, MgSO4·7H2O 0.2 g / L, CaCl2 0.1 g / L, skim milk powder 10 g / L, agar 20.0 g / L, pH 7.0-7.2) and incubated at 28℃ for 7 days. Strains capable of producing protease will show a transparent hydrolysis zone around their colonies; if no hydrolysis zone appears, it indicates that the strain does not possess the ability to produce protease.

[0087] The Folin-Ciocalteu method was used to determine protease activity. After fermentation for 48 h and centrifugation at 10,000 rpm, 1 mL of protease solution was obtained. This solution was mixed with 1 mL of 2% casein solution (prepared with pH 8 borate buffer) and incubated at 55 °C for 10 min. Then, 0.5 mL of Folin-Ciocalteu reagent was added, and the absorbance was measured at 680 nm. One unit of protease activity was defined as the amount of enzyme that hydrolyzes 1 μg of tyrosine per minute.

[0088] Test results as follows Figure 5 As shown. By Figure 5 It is known that the Streptomyces isolated and purified in this application has the ability to produce protease, and the amount of protease produced is 278.35 U / mL.

[0089] (3) Nitrogen fixation activity

[0090] The activated Streptomyces strains were inoculated onto Ashby medium (formulation: KH2PO4 0.2 g / L, NaCl 0.2 g / L, MgSO4·7H2O 0.2 g / L, mannitol 10 g / L, CaSO4·2H2O 0.1 g / L, CaCO3 5 g / L, agar 20.0 g / L, pH 6.8-7.0) and cultured at 28℃ for 7 days. This was repeated three times. If the strains grew normally on Ashby medium, it indicated that the strains had nitrogen-fixing activity.

[0091] Test results as follows Figure 6 As shown.

[0092] Depend on Figure 6 It is known that the Streptomyces isolated and purified in this application has nitrogen-fixing activity.

[0093] Performance Test 2

[0094] The disease-preventive function of the isolated and purified Streptomyces strain was verified. The positive control was a commercially available Streptomyces strain GDMCC No:63885, which exhibits strong and broad-spectrum antibacterial activity. Details are as follows:

[0095] (I) Confrontation Cultivation Experiment

[0096] (1) Test methods

[0097] The isolated and purified Streptomyces strain GDMCC No:63885 was activated and cultured at 28℃ on ISP-2 yeast malt extract agar (formulation: yeast extract 4g / L, malt extract 10g / L, glucose 4g / L, agar 15g / L, pH 7.2-7.4) for 7 days. The pathogens of Fusarium wilt, gray mold, tomato gray mold, corn leaf spot, tobacco red spot, wheat scab, tomato leaf mold, and potato late blight were inoculated on PDA medium (formulation: peel 200g potatoes, cut into 1cm squares, add 1L distilled water, boil, filter with gauze, add 20g glucose and 20g agar) and cultured for 7 days. Streptomyces, strain GDMCC No:63885, and pathogens of Fusarium wilt, gray mold, tomato gray mold, corn short spot, tobacco red spot, wheat scab, tomato leaf mold, and potato late blight were isolated and purified and cultured for more than 7 days to prepare mycelial cakes with a diameter of 8 mm using a punch. The pathogens were inoculated into the center of PDA medium, and the isolated and purified Streptomyces and strain GDMCC No:63885 were inoculated at a distance of 2 cm from the pathogens using a cross-cutting method. After 7 days of culture, the inhibition rate was calculated. Inhibition rate (%) = (colon diameter of blank control group - colony diameter of treatment group) / colony diameter of control group × 100%.

[0098] In this experiment, the isolated and purified Streptomyces strain was used as the treatment group. A group containing strain GDMCC No:63885 was set up as the positive control group. A group without Streptomyces strain was used as the blank control group.

[0099] (2) Test Results

[0100] The test results are shown in Table 1 and Figure 7 As shown.

[0101] Table 1 Results of the confrontation cultivation experiment

[0102]

[0103] Combining Table 1 and Figure 7 It is known that the Streptomyces isolated and purified in this application has antagonistic effects on the growth of all eight pathogens, and the inhibition rate is higher than that of the positive control, showing higher antibacterial activity than strain GDMCC No:63885.

[0104] (II) Pot Experiment

[0105] (1) Test methods

[0106] Tomato seedlings with 5 or 6 leaves and uniform growth were selected, and different treatment solutions were sprayed on the leaves until the leaf surface was completely wetted. The experiment used water as a blank control, GDMCC No:63885 as a positive control, and Streptomyces isolated and purified in this application as the treatment group.

[0107] The plants were naturally cultivated in a greenhouse. After 24 hours, tomato gray mold spores were sprayed until the leaf surface was completely soaked. Once the tomato plants showed symptoms, the disease leaf rate, disease index, and disease control effect were calculated.

[0108] Disease incidence rate (%) = (number of diseased leaves / total number of leaves) × 100%.

[0109] Disease index = ∑(number of diseased leaves at each level × representative value of each level) / (total number of leaves × highest representative level) × 100%.

[0110] Prevention efficacy (%) = (Control disease index - Treatment disease index) / Control disease index × 100%.

[0111] Disease severity is classified into 5 levels (based on leaf infection area):

[0112] 1) Grade 0: Leaves are not infected or the infected area is <1%;

[0113] 2) Level 1: Leaf infection area is 1%-25%;

[0114] 3) Level 2: Leaf infection area is 26%-50%;

[0115] 4) Level 3: Leaf infection area is 51%-75%;

[0116] 5) Level 4: Leaf infection area is 76%-90%;

[0117] 6) Level 5: Leaf infection area >90%.

[0118] (2) Test Results

[0119] The test results are shown in Table 2 and Figure 8 As shown.

[0120] Table 2. Disease incidence, disease index, and control efficacy of tomato plants under each treatment.

[0121] Diseased leaf rate (%) Disease index Preventive efficacy (%) Blank control group 88.18±8.09 64.08±5.17 / Strain CGMCC No.63885 60.07±5.96 35.02±3.10 45.35 Streptomyces obtained by isolation and purification 41.75±3.12 18.44±2.86 71.22

[0122] Combine Table 2 and Figure 8 It is known that the Streptomyces isolated and purified in this application can reduce the disease rate and disease index of plants, and can effectively prevent and control tomato gray mold, and the effect is better than that of the comparative strain GDMCC No:63885.

[0123] Performance Test 3

[0124] The growth-promoting function of the isolated and purified Streptomyces strain was verified. The positive control was a commercially available Streptomyces strain GDMCC No:63885 with strong and broad-spectrum antibacterial properties. Details are as follows:

[0125] (a) Germination test

[0126] (1) Test methods

[0127] Thirty plump rapeseed seeds were selected and placed in a petri dish containing sterile filter paper. 10 mL of the *Streptomyces* strain isolated and purified in this application, along with strain GDMCC No:63885, was added to the petri dish at different dilution gradients (10, 100, and 1000 times). Sterile water was added as a blank control. Each treatment was repeated three times. The petri dishes were placed in a 25°C incubator, and the petri dishes were kept moist throughout the germination period. Germination rate, plant height, root length, and photographs were recorded on the third day of the germination experiment.

[0128] (2) Test Results

[0129] The test results are shown in Table 3 and Figure 9 As shown.

[0130] Table 3 Germination Experiment Data

[0131]

[0132] Combined with Table 3 and Figure 9 It is evident that the Streptomyces metabolites isolated and purified in this application exhibit a phenomenon where high concentrations inhibit germination while low concentrations promote germination. Regardless of whether the dilution is 10, 100, or 1000 times, the Streptomyces isolated and purified in this application shows superior effects on germination rate, plant height, and root length compared to strain GDMCC No:63885.

[0133] (II) Pot Experiment

[0134] (1) Test methods

[0135] Choose a loose, fertile, and well-drained commercial cultivation substrate (peat:perlite:vermiculite = 6:3:1) and fill the cultivation pots with the substrate.

[0136] Ten rapeseed seeds were sown in each cultivation pot, and then covered with a thin layer of soil, just enough to cover the seeds, and kept slightly moist. Each treatment was set up in triplicate. On days 1, 8, and 15 after planting, 10 mL of the purified Streptomyces strain GDMCC No:63885 obtained in this application and its metabolites were applied. Sterile water was added as a blank control. The plant height, root length, and plant weight of rapeseed plants were measured after 22 days.

[0137] (2) Test Results

[0138] The test results are shown in Table 4 and Figure 10 As shown.

[0139] Table 4. Rapeseed biomass in pot experiments

[0140]

[0141]

[0142] Combine Table 4 and Figure 10 It is known that the Streptomyces isolated and purified in this application can improve the growth of rapeseed plant height, root length and plant weight, and the effect is better than that of GDMCC No:63885.

[0143] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A Streptomyces species, characterized in that, The Streptomyces ( Streptomyces and amanensis It is deposited at the China General Microbiological Culture Collection Center, with accession number CGMCC No. 35178.

2. A culture, characterized in that, The culture comprises the Streptomyces as described in claim 1.

3. A fermentation broth, characterized in that, The fermentation broth includes the Streptomyces strain described in claim 1.

4. A bacterial suspension, characterized in that, The bacterial suspension includes the Streptomyces as described in claim 1.

5. A microbial agent, characterized in that, The microbial agent includes the Streptomyces as described in claim 1.

6. A bacterial powder, characterized in that, The bacterial powder includes the Streptomyces as described in claim 1.

7. The application of the Streptomyces of claim 1, the culture of claim 2, the fermentation broth of claim 3, the bacterial suspension of claim 4, the bacterial agent of claim 5, and the bacterial powder of claim 6 in the control of crop pathogens and the promotion of plant growth.

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