Application of a marine Streptomyces strain and its oligomycin products in combating agricultural pathogens

Abstract

The present invention provides a strain of marine streptomyces and its oligomycin products for use in resisting agricultural pathogens. The marine streptomyces Streptomyces sp.FXY-T5 is deposited in the General Microbiology Center (CGMCC) of the China Microbiological Culture Collection Administration, with a deposit number of CGMCC No: 26908. The present invention separates and prepares oligomycin compounds I to V from the liquid culture fermentation product of marine streptomyces Streptomyces sp.FXY-T5, and the streptomyces crude extract and compounds I to V have inhibitory effects on a variety of agricultural pathogens (pathogenic fungi). The marine streptomyces Streptomyces sp.FXY-T5 and its oligomycin metabolites can be used to prevent and control plant fungal diseases, providing an effective way to find new, efficient and low-toxic biological drugs for preventing and controlling plant diseases.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, and in particular to application of a marine streptomyces strain and oligomycin products thereof in resisting agricultural pathogenic bacteria. Background Art

[0002] The ocean covers more than 70% of the earth's surface, and has environmental characteristics such as low temperature, high salt, high pressure, and oligotrophy. Compared with terrestrial microorganisms, marine microorganisms have lived in such a special environment for a long time, gradually forming their own unique metabolic pathways, and the secondary metabolites they produce are not only novel in structure and diverse in variety, but also have significant biological activity, providing an important basis for the research and development of agricultural drugs.

[0003] Plant fungal diseases not only reduce crop yields, but also endanger the health of humans and animals. At present, the main method for preventing and controlling plant fungal diseases is to use broad-spectrum fungicides, but this method brings problems such as environmental pollution, toxicity to the body, and drug resistance in some strains. In addition, the unscientific use method has led to an urgent need to find new high-efficiency and low-toxic biological pesticides for preventing and controlling plant diseases.

[0004] Most antimicrobial drugs in agriculture and clinics come from secondary metabolites of Streptomyces and their derivatives. Marine Streptomyces exist in special marine habitats and have been proven to be an important source of new active natural products. Therefore, there is great potential in finding natural products with anti-agricultural pathogenic bacteria activity from marine Streptomyces. The oligomycin family of natural products belongs to the 26-membered macrolide compound with a bicyclic spiroketal structural unit, which is mainly produced by Streptomyces. This type of molecular skeleton is specific and has biological activities such as antifungal, antitumor and insecticidal, showing great potential for drug development and worthy of the attention of pharmacologists.

[0005] In summary, it is of great research value and significance to explore Streptomyces and its secondary metabolites that are resistant to agricultural pathogens from the ocean for the prevention and control of plant diseases. Summary of the invention

[0006] In view of this, the present invention proposes the use of a marine streptomyces strain and its oligomycin products in resisting agricultural pathogens.

[0007] The technical solution of the present invention is achieved in this way:

[0008] A marine streptomyces strain, wherein the marine streptomyces is marine streptomyces sp. FXY-T5, and the preservation center is the General Microbiological Center of China Microorganism Culture Collection Administration, and the preservation number is CGMCC No: 26908.

[0009] Furthermore, the strain is preserved at the General Microbiology Center of China Culture Collection Administration, the preservation address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and the preservation time is March 24, 2023.

[0010] Application of a marine streptomyces strain, and application of the marine streptomyces strain Streptomyces sp.FXY-T5 in the preparation of oligomycin compounds.

[0011] An oligomycin compound is prepared using the above-mentioned marine streptomyces, and the oligomycin compound includes compound I, compound II, compound III, compound IV, and compound V; the structural formulas of compound I, compound II, compound III, compound IV, and compound V are shown in formula I to formula V respectively:

[0012]

[0013] Among them, compound I was named 4-lumooligomycin B, compound II was named 24-lumooligo mycin B, compound III was named 40-homooligomycin B, compound IV was named 15-hydroxy-oligomycin B, and compound V was named 6-lumooligomycin B.

[0014] Furthermore, the oligomycin compounds I to V are separated from the fermentation product of the above-mentioned marine Streptomyces sp. FXY-T5.

[0015] Furthermore, the marine Streptomyces sp. FXY-T5 or the oligomycin compounds are used in the prevention and treatment of agricultural pathogens.

[0016] Further, the pathogenic bacteria include Colletotrichum musae ACCC 31244, Colletotrichum coccodes ACCC 36067, Colletotrichum asianum, Fusarium oxysporum f.sp.cubense, Fusarium oxysporum f.sp.phaseoli, Fusarium foetens, Fusarium graminearum, Fusarium mangiferae, Alternaria solani and Nectria sp.

[0017] Furthermore, the pathogenic bacteria include: Colletotrichum coccodes ACCC36067, Colletotrichum asianum, and Fusarium mangiferae.

[0018] Furthermore, the marine Streptomyces sp. FXY-T5 is used in preventing and controlling Colletotrichum musae ACCC 31244, Colletotrichum coccodes ACCC36067, Colletotrichum asianum, Fusarium oxysporumf.sp.cubense, Fusarium oxysporum f.sp.phaseoli, Fusarium foetens, Fusarium graminearum, Fusarium mangiferae, and Alternaria solani.

[0019] Furthermore, the compound I is used in preventing and controlling Colletotrichum coccodes ACCC36067, Colletotrichum asianum, and Fusarium mangiferae.

[0020] Furthermore, the compound II is used in preventing and controlling Colletotrichum musae ACCC31244, Colletotrichum coccodes ACCC 36067, Colletotrichum asianum, Fusarium oxysporum f.sp.cubense, Fusarium oxysporum f.sp.phaseoli, Fusarium foetens, and Fusarium mangiferae.

[0021] Furthermore, the compound III is used in preventing and controlling Colletotrichum musae ACCC31244, Colletotrichum coccodes ACCC 36067, Colletotrichum asianum, Fusarium oxysporum f.sp.cubense, Fusarium oxysporum f.sp.phaseoli, Fusarium foetens, Fusarium graminearum, Fusarium mangiferae and Nectria sp.

[0022] The preparation method of oligomycin compounds comprises the following steps:

[0023] (1) inoculating marine Streptomyces sp. FXY-T5 into SGCY liquid culture medium for fermentation to obtain a liquid fermentation product;

[0024] (2) adding an equal volume of ethyl acetate to the liquid fermentation product obtained in (1), firstly performing ultrasonic extraction, then leaching with ethyl acetate, and distilling the obtained extract under reduced pressure to obtain a crude extract;

[0025] (3) The crude extract obtained in (2) was separated by silica gel column chromatography, and the eluted fraction Fr.6 was collected according to TLC thin layer chromatography and HPLC analysis;

[0026] (4) The eluted fraction Fr.6 obtained in the above (3) is separated by medium pressure rapid preparative liquid chromatography, and the eluted fraction Fr.66 is collected. The eluted fraction Fr.66 is then prepared by HPLC and distilled under reduced pressure to obtain oligomycin compounds with structural formulas I to V.

[0027] Furthermore, in the above step (1), the formula of the SGCY liquid culture medium is: sucrose 20g, glucose 10g, casamino acid 0.1g, yeast powder 5g, propanesulfonic acid 5g, trace element minerals 0.1mL, K2SO4 0.25g, MgCl2·6H2O1g, tap water 1000mL; the pH value is naturally not adjusted.

[0028] Furthermore, in the above step (3), the silica gel column chromatography is normal pressure silica gel column chromatography; the silica gel column chromatography adopts gradient elution, and the gradient elution conditions are: using petroleum ether-ethyl acetate as the elution solvent and performing gradient elution in a volume ratio of 100:0, 99:1, 80:1, 50:1, 20:1, 10:1, 5:1, 2:1, 1:1 and 0:1 in sequence.

[0029] Furthermore, in the above step (3), the collection interval of the elution fraction Fr.6 is: the elution fraction obtained by eluting with petroleum ether-ethyl acetate at an elution volume ratio of 2:1.

[0030] Furthermore, the present invention has no particular limitation on the thin layer analysis method, and an analysis method known to those skilled in the art may be selected.

[0031] Furthermore, in the above step (4), the elution procedure of the medium-pressure rapid preparative liquid chromatography is: 5% methanol-100% methanol (linear elution, 0-76 min), 100% methanol (linear elution 76-95 min).

[0032] Furthermore, in the above step (4), the collection condition of the eluted fraction Fr.66 is: the volume concentration of methanol is in the range of 80% to 90%.

[0033] Furthermore, in the above step (4), the HPLC preparation conditions are: water and methanol as mobile phases, 81% methanol volume concentration as purification conditions, and the mobile phase flow rate is 2 mL / min.

[0034] Furthermore, in the above step (4), the retention times of the fractions prepared by HPLC are 15.1 min, 16.7 min, 22.4 min, 26.7 min and 35.5 min.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The marine streptomyces provided by the invention and five oligomycin compounds prepared from the marine streptomyces have certain inhibitory effects on various agricultural pathogens, especially on Colletotrichum musae ACCC31244, Colletotrichum coccodes ACCC 36067, Colletotrichum asianum, Fusarium oxysporum f.sp.cubense, Fusarium oxysporum f.sp.phaseoli, Fusarium foetens, Fusarium graminearum, Fusarium mangiferae, Alternaria solani, Lasiodiplodia pseudotheobromae and Nectria spp. sp.) has a certain inhibitory effect, which has important research value and significance for the excavation of Streptomyces and its secondary metabolites that are resistant to agricultural pathogens from the ocean for the prevention and control of plant fungal diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Growth morphology of marine Streptomyces sp.FXY-T5 on ISP4 medium.

[0038] Figure 2 Phylogenetic tree analysis of marine Streptomyces sp.FXY-T5.

[0039] Figure 3 HPLC analysis chromatogram of the fermentation product of Streptomyces sp.FXY-T5, wherein area A represents other compounds; area B represents oligomycin compounds (oligomycins).

[0040] Figure 4 HRESI-MS spectrum of oligomycin compound Ⅰ (4-lumooligomycin B).

[0041] Figure 5 Oligomycin compounds Ⅰ (4-lumooligomycin B) 1 H-NMR (600 MHz, DMSO-d6) spectrum.

[0042] Figure 6Oligomycin compound I (4-lumooligomycin B) 13 C-NMR (150 MHz, DMSO-d6) spectrum.

[0043] Figure 7 HRESI-MS spectrum of oligomycin compound II (24-lumooligomycin B).

[0044] Figure 8 Oligomycin compound Ⅱ (24-lumooligomycin B) 1 H-NMR (600 MHz, DMSO-d6) spectrum.

[0045] Fig. 9 Oligomycin compound Ⅱ (24-lumooligomycin B) 13 C-NMR (150 MHz, DMSO-d 6z ) spectrum.

[0046] Fig.10 HRESI-MS spectrum of oligomycin compound III (40-homooligomycin B).

[0047] Fig.11 Oligomycin compound Ⅲ (40-homooligomycin B) 1 H-NMR (600 MHz, DMSO-d6) spectrum.

[0048] Fig.12 Oligomycin compound Ⅲ (40-homooligomycin B) 13 C-NMR (150 MHz, DMSO-d6) spectrum.

[0049] Fig.13 HRESI-MS spectrum of oligomycin compound IV (15-hydroxy-oligomycin B).

[0050] Fig.14 Oligomycin compound Ⅳ (15-hydroxy-oligomycin B) 1 H-NMR (600 MHz, DMSO-d6) spectrum.

[0051] Fig.15 Oligomycin compound Ⅳ (15-hydroxy-oligomycin B) 13 C-NMR (150 MHz, DMSO-d6) spectrum.

[0052] Fig.16 HRESI-MS spectrum of oligomycin compound V (6-lumooligomycin B).

[0053] Fig.17 Oligomycin compound V (6-lumooligomycin B) 1 H-NMR (600 MHz, DMSO-d6) spectrum.

[0054] Fig.18 Oligomycin compound V (6-lumooligomycin B) 13 C-NMR (150 MHz, DMSO-d6) spectrum. DETAILED DESCRIPTION

[0055] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0056] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0057] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0058] Example 1: Isolation, solid culture and preservation of marine Streptomyces sp. FXY-T5 strain

[0059] 1. Isolation and solid culture of strains

[0060] The formula of ISP4 solid culture medium (i.e., ISP culture medium 4) is: soluble starch 10.0 g, K2HPO4 1.0 g, MgSO4·7H2O 1.0 g, NaCl 1.0 g, (NH4)2SO4 2.0 g, CaCO3 2.0 g, FeSO4·7H2O 0.001 g, MnCl2·7H2O0.001 g, ZnSO4 0.001 g, agar 20.0 g, tap water 1000 mL; pH value is not adjusted naturally. The solid culture medium preparation process is: weigh, dissolve and stir the ingredients in the formula according to the above formula, and sterilize in an autoclave.

[0061] Marine Streptomyces sp.FXY-T5 was isolated from the soil around the marine plant Limonium sphaerocephalum collected from the sea area near 002 Township, Tugang Road, Laoshan District, Qingdao City (120.472°E, 36.091°N). The marine Streptomyces sp.FXY-T5 was inoculated into a plate containing ISP4 solid culture medium and cultured in a constant temperature incubator at 30°C. The marine Streptomyces sp.FXY-T5 grew well in the constant temperature incubator at 30°C. After culturing for 2-5 days, the colony turned white, without spores, and had wrinkled surface. Its growth morphology is shown in the figure below. Figure 1 shown.

[0062] 2. Preservation of strains

[0063] The marine Streptomyces sp. FXY-T5 grown on the ISP4 solid culture medium plate was stored in a -80°C refrigerator using 20% ​​sterile glycerol at a volume concentration. The storage time was March 24, 2023, the storage address was General Microbiology Center of China Microbiological Culture Collection Administration (CGMCC), and the storage number was CGMCC No: 26908.

[0064] Example 2: Identification of marine Streptomyces sp. FXY-T5 strain

[0065] A single colony of Streptomyces sp.FXY-T5 purified and cultured in Example 1 was picked and placed on an ISP4 solid culture medium plate for secondary purification. After culturing for 5 days, the plate with bacteria was sent to a sequencing company for 16S rDNA gene sequence determination. The 16S rDNA gene sequence was compared by BLAST on the National Center for Biotechnology Information (NCBI) website, and the phylogenetic tree (such as Figure 2 As shown in the figure, it can be seen that the strain Streptomyces sp.FXY-T5 is on the same evolutionary branch as Streptomyces luteogriseus GCF_014205055.1, and it is determined to be a Streptomyces sp.

[0066] Example 3: Preparation of oligomycin compounds

[0067] (1) First, 200 mL of SGCY liquid culture medium was prepared in a 500 mL conical flask and placed in an autoclave for sterilization. Then, the marine Streptomyces FXY-T5 that grew well in the ISP4 solid culture medium plate in Example 1 was inoculated into the sterilized SGCY liquid culture medium. Finally, the culture medium was fermented in a shaker at 30° C. and 180 RPM for 9 days to obtain a liquid fermentation product. The formula of the SGCY liquid culture medium was as follows: 20 g of sucrose, 10 g of glucose, 0.1 g of casamino acids, 5 g of yeast powder, 5 g of propanesulfonic acid, 0.1 mL of trace elements and minerals, 0.25 g of K2SO4, 1 g of MgCl2·6H2O, and 1000 mL of tap water. The pH value was not adjusted naturally.

[0068] (2) adding an equal volume of ethyl acetate to the liquid fermentation product obtained in (1), firstly subjecting it to ultrasonic extraction for 15 min, then subjecting it to ethyl acetate extraction for 3 times, and subjecting the obtained extract to vacuum distillation to obtain a crude extract;

[0069] (3) The crude extract obtained in (2) was mixed by dry method and loaded on a column by wet method, and then eluted on a 300-400 mesh silica gel column, using petroleum ether-ethyl acetate as the elution solvent and performing gradient elution in a volume ratio of 100:0, 99:1, 80:1, 50:1, 20:1, 10:1, 5:1, 2:1, 1:1 and 0:1, respectively. According to the results of TLC thin layer chromatography and HPLC chromatogram analysis, 7 fractions (Fr.1-Fr.7) were obtained, and the elution fraction Fr.6 with a volume ratio of petroleum ether-ethyl acetate of 2:1 was collected;

[0070] (4) The eluted fraction Fr.6 obtained in (3) above was separated by medium pressure rapid preparative liquid chromatography, with methanol-water as the elution solvent and the elution procedure being: 5% methanol-100% methanol (linear elution, 0-76 min), 100% methanol (linear elution, 76-95 min), and the eluted fraction Fr.66 with a methanol volume concentration between 80% and 90% was collected; the eluted fraction Fr.66 was then prepared by HPLC, with water and methanol as the mobile phase, The volume concentration of 81% methanol was used as the purification condition, and the mobile phase flow rate was 2 mL / min for elution. Fractions I (6.47 mg), II (8.30 mg), III (5.16 mg), IV (5.34 mg), and V (9.11 mg) with retention times of 15.1 min, 16.7 min, 22.4 min, 26.7 min, and 35.5 min were collected, and finally distilled under reduced pressure to obtain five oligomycin compounds with structural formulas I to V.

[0071] Example 4: HPLC spectral analysis of crude extract and structural identification of oligomycin compounds

[0072] 1. HPLC spectrum analysis of crude extract

[0073] The crude extract obtained in step (2) of Example 3 was dissolved in chromatographic methanol and transferred to a 1.5 mL centrifuge tube. The extract was centrifuged at 16000 RPM for 5 min. The supernatant was placed in a liquid phase vial for HPLC analysis. The instrument model used for HPLC analysis was Agilent HPLC 1260Ⅱ, the mobile phase was phase A-methanol, phase B-double distilled water + 1% formic acid, the detection wavelengths were 210 nm, 254 nm and 290 nm, the elution program was: 10% A-100% A (linear elution, 0-20 min), 100% A (linear elution, 20-30 min), 100% A-10% A (30-35 min), the flow rate was 1 mL / min, and the HPLC fingerprint of the liquid fermentation product was obtained as shown in FIG. Figure 3 shown.

[0074] 2. Structural identification of oligomycin compounds

[0075] (1) Structural identification of compound Ⅰ

[0076] The physicochemical properties and spectral data of compound Ⅰ are as follows:

[0077] White amorphous solid. HRESI(–)MS spectrum ( Figure 4 ) shows m / z [MH] - 789.4799, [M+Cl] - 825.4575, [M+HCOOH-H] - 835.4857 and [M+CH3COOH-H] - 849.5010, it is inferred that the molecular formula of compound I is C 44 H 70 O 12 Compound I 1 H NMR (600 MHz) and 13 C NMR (150MHz) spectra are shown in Figure 5 and Figure 6 .

[0078] Analysis of Compound I 1 H-NMR and 13 C-NMR spectrum data ( Figure 5-Figure 6 ), it was found that compound I and oligomycin B isolated at the same time had similar structures, the difference being that compound I 1 A methyl signal is missing in the H-NMR spectrum. 13 In the C-NMR spectrum, there is a loss of a methyl signal and a C-4 (δ C36.9) chemical shift values. Combined with the HMBC spectrum, C-4 and 5-OH (4.79, br s), C-3 (δ C 145.6) has a long-distance coupling relationship, so it is speculated that the methyl group at position 4 in compound I is missing.

[0079] According to the above physical and chemical properties combined 1 H-NMR, 13 The C-NMR spectrum and 2D-NMR confirmed the structure of compound I. After searching, the compound was found to be a new structure, named: 4-lumooligomycin B, and the structure is shown in the following formula I:

[0080]

[0081] (2) Structural identification of compound II

[0082] White amorphous solid; HRESI(–)MS spectrum ( Figure 7 ) shows m / z [MH] - 789.4784, [M+Cl] - 825.4557, [M+HCOOH-H] - 835.4841 and [M+CH3COOH-H] - 849.4991, it is inferred that the molecular formula of compound II is C 44 H 70 O 12 Compound 662 1 H NMR (600 MHz) and 13 C NMR (150MHz) spectra are shown in Figure 8 and Fig. 9 .

[0083] Analysis of Compound II 1 H-NMR and 13 C-NMR spectrum data ( Figure 8-Figure 9 ), it was found that compound II and oligomycin B isolated at the same time had similar structures, the difference was that compound II 1 A methyl signal is missing in the H-NMR spectrum. 13 In the C-NMR spectrum, there is a loss of a methyl signal and a C-24 (δ C 37.3), C-23(δ C 67.3), C-25(δ C 71.8) chemical shift values, combined with the HMBC spectrum, C-24 and C-25 (δ C 71.8) has a long-distance coupling relationship, so it is speculated that the methyl group at position 24 in compound II is missing.

[0084] According to the above physical and chemical properties, combined with 1 H-NMR, 13 The structure of compound II was confirmed by C-NMR spectrum and 2D-NMR. The compound was found to be a new structure and named as 24-lumooligomycin B. The structure is shown in the following formula II:

[0085]

[0086] (3) Structural identification of compounds III, IV and V

[0087] The above strategies of HRMS and NMR structure identification (e.g. Figure 5 , Figure 6 as well as Figure 8 , Fig. 9 As shown), according to the spectrum ( Figure 10-Figure 18 ) analysis, the structures of compounds III, IV and V were determined. Compound III was named 40-homooligomycin B, compound IV was named 15-hydroxy-oligomycin B, and compound V was named 6-lumooligomycin B.

[0088]

[0089] Example 5: Evaluation of the activity of crude extract of marine Streptomyces sp. FXY-T5 and oligomycin compounds against agricultural pathogens

[0090] Colletotrichum musae ACCC 31244, Colletotrichum coccodes ACCC 36067, Colletotrichum asianum, Fusarium oxysporum f.sp.cubense, Fusarium oxysporumf.sp.phaseoli, Fusarium foetens, Fusarium graminearum, Fusarium mangiferae, Alternaria solani and Nectria sp. were used as test strains for evaluating the activity against agricultural pathogens. The test was carried out with reference to the drug sensitivity diffusion method. The specific experimental steps are as follows:

[0091] (1) Cultivation of seed solution of agricultural pathogenic bacteria: The above agricultural pathogenic bacteria were inoculated into potato dextrose agar (PDA) medium, cultured in a constant temperature incubator at 28°C for 2-4 days, and then the 10 cultivated agricultural pathogenic bacteria were inoculated into 200 mL potato dextrose water (PDB) medium respectively, cultured in a shaker at 28°C and 180RPM for 2-3 days to obtain seed solution of agricultural pathogenic bacteria. The formula of potato dextrose agar (PDA) medium is: 200 g potato flour, 20 g glucose, 15 g agar, 1000 mL tap water, natural pH; the formula of potato dextrose water (PDB) medium is: 300 g potato flour, 20 g glucose, 1000 mL tap water, natural pH; the medium preparation process is: weigh, stir and dissolve the ingredients in the formula according to the above formula, and sterilize in an autoclave.

[0092] (2) Preparation of samples and positive drugs: The crude extract obtained by fermentation of marine Streptomyces sp. FXY-T5 and the oligomycin compounds of formula I to V were dissolved in methanol to form a sample solution with a concentration of 4 mg / mL, and the positive drug cycloheximide was dissolved in methanol to form a solution with a concentration of 4 mg / mL. A methanol solution with the same concentration was selected as a blank control.

[0093] (3) Activity evaluation test: Pour a certain amount of agricultural pathogen seed liquid into a mortar and grind it, take 200 μL of the ground seed uniform liquid and apply it to the PDA plate, then take 10 μL of the sample solution with a concentration of 4 mg / mL and place it in the center of the drug-sensitive paper, evaporate it, and finally place it on the above PDA plate, and use the plates containing only methanol solution and cycloheximide as positive and negative controls. Similarly, the crude extract obtained by fermentation of marine Streptomyces sp. FXY-T5 and the oligomycin compounds Formula I to V are prepared into samples and placed on PDA plates containing corresponding agricultural pathogens, and incubated in a constant temperature incubator at 28°C for 2-5 days to observe the size of the inhibition zone. The above operations are all performed in a clean bench, and the items and reagents used must be sterilized in advance. The above activity evaluation operations are repeated three times in parallel, and the antibacterial effects are recorded as shown in Tables 1, 2, 3, and 4 below.

[0094] Table 1 Effect of crude extract of marine Streptomyces sp.FXY-T5 on resistance to agricultural pathogens

[0095]

[0096] Table 2 Effect of oligomycin compound I on anti-agricultural pathogens

[0097]

[0098] Table 3 Effects of oligomycin compounds II on the resistance to agricultural pathogens

[0099]

[0100] Table 4 Effect of oligomycin compounds III on the resistance to agricultural pathogens

[0101]

[0102] From the data results in Tables 1 to 4, it can be found that the crude extract of the fermentation product of marine Streptomyces sp.FXY-T5 has a better antibacterial effect on banana anthracnose, hairy anthracnose, mango anthracnose, banana wilt, cowpea wilt, cucumber wilt, wheat fusarium, mango Fusarium, and tomato early blight than the positive drug actinomycin. After separating the fermentation product of marine Streptomyces sp.FXY-T5, it was found that oligomycin compound I mainly inhibited hairy anthracnose, mango anthracnose and mango Fusarium, and the antibacterial effect was weaker than that of positive drugs. Oligomycin compound II mainly inhibited banana anthracnose, hairy anthracnose, mango anthracnose, banana wilt, cowpea wilt, cucumber wilt, and mango Fusarium. The antibacterial effect of oligomycin compound III is mainly manifested in banana anthracnose, hairy-spined anthracnose, mango anthracnose, banana wilt, cowpea wilt, cucumber wilt, wheat fusarium, mango Fusarium, and clump red shell fungi. The antibacterial effect of oligomycin compound III on mango anthracnose, wheat fusarium and mango Fusarium is better than that of positive drugs, and the inhibitory effect on other pathogenic fungi is basically equivalent to that of positive drugs. The marine streptomyces Streptomyces sp. FXY-T5 and the fermentation product of the present invention can play a synergistic antibacterial effect, and the antibacterial effect is better. Compared with oligomycin compounds I to III, oligomycin compounds IV and V showed average inhibitory effects on banana anthracnose, hairy-spined anthracnose, mango anthracnose, banana wilt, cowpea wilt, cucumber wilt, wheat fusarium, mango Fusarium, tomato early blight and clustered red shell fungus, and the effects were not significant.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A marine Streptomyces strain, characterized in that: The marine streptomyces is marine streptomyces Streptomyces sp.FXY-T5, the preservation center is the General Microbiology Center of China Microorganism Culture Collection Administration, and the preservation number is CGMCCNo: 26908.

2. The use of marine streptomyces according to claim 1, characterized in that: Streptomyces marineus Streptomyces sp. Application of FXY-T5 in the preparation of oligomycin compounds; The oligomycin compounds include compound I, compound II, compound III, compound IV, and compound V; The structural formulas of the compound I, compound II, compound III, compound IV, and compound V are shown in Formula I to Formula V respectively: 。 3. The use of marine streptomyces according to claim 1, characterized in that: The application of the marine streptomyces in preventing and controlling agricultural pathogenic bacteria; the agricultural pathogenic bacteria include banana anthracnose Colletotrichum musae ACCC 31244, Colletotrichum trichomoniasis Colletotrichum coccodes ACCC 36067, Colletotrichum spp. Colletotrichum asianum )、Banana wilt fungus ( Fusarium oxysporum f. sp. cubense )、Vinepea wilt pathogen ( Fusarium oxysporum f. sp. phaseoli )、Cucumber wilt pathogen ( Fusarium foetens )、Triticum fusarium ( Fusarium graminearum )、Mango Fusarium ( Fusarium mangiferae )、Tomato early blight pathogen ( Alternaria solani ) and Echinococcus spp. Nectria sp.).

4. The use according to claim 3, characterized in that: The agricultural pathogenic bacteria include: Colletotrichum Colletotrichum coccodes ACCC 36067, Colletotrichum spp. Colletotrichum asianum )、Mango Fusarium spp.( Fusarium mangiferae ).

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