A type of Bacillus rumeli and its application
The fermentation broth of Bacillus rumeli JY-2-4R solved the problem of postharvest disease control in kiwifruit and aconite plants, achieving green and efficient disease control, and has broad application prospects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHWEAT UNIV OF SCI & TECH
- Filing Date
- 2026-04-01
- Publication Date
- 2026-06-30
Smart Images
Figure CN122303088A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of microorganisms, and particularly relates to a Bacillus rummeliensis and its application. Background Art
[0002] Kiwi (Actinidia spp) is a perennial deciduous vine fruit tree native to China. Its fruit is rich in nutrients, containing vitamin C, dietary fiber, potassium, folic acid and various antioxidant substances, and is known as the "king of fruits". Kiwi fruits are prone to pathogen infection during transportation and storage after harvest, leading to the occurrence of diseases such as canker, soft rot and black spot, increasing post-harvest losses and affecting fruit quality. Chemical agents and low-temperature preservation are currently common strategies for kiwi preservation and disease prevention and control, but they have disadvantages such as food safety, pathogen drug resistance and high energy consumption. Therefore, there is an urgent need for green and safe post-harvest disease control technologies for kiwi.
[0003] Aconitum carmichaelii Debx is a perennial herbaceous medicinal plant of the genus Aconitum in the family Ranunculaceae. The processed product of its lateral roots is called aconite tuber, which is one of the 40 famous large-scale Chinese medicinal materials in China. The soil-borne diseases of Aconitum are serious, especially Sclerotium rolfsii, root rot and soft rot, which most severely restrict the sustainable production of Aconitum. In production, the application of chemical pesticides such as carbendazim, kasugamycin and tetracycline is the main method for farmers to control Sclerotium rolfsii, root rot and soft rot of Aconitum. However, the overuse of pesticides is extremely likely to cause problems such as environmental pollution and pathogen drug resistance. The green and efficient control of Sclerotium rolfsii, root rot and soft rot of Aconitum is extremely urgent.
[0004] The genus Bacillus rummeliensis is a relatively newly established genus of Gram-positive bacteria with a unique position in phylogeny. It belongs to the phylum Firmicutes and is one of the core members of the class Bacilli. The genus Bacillus rummeliensis is closely related to the genera Virgibacillus, Paenibacillus, Brevibacillus, etc., but is genetically and phenotypically distinct enough to be defined as an independent genus. One of its most remarkable characteristics is its ability to grow at 65 °C or higher temperatures, and most members are thermophilic or heat-resistant bacteria. The sources of the genus Bacillus rummeliensis are very diverse, including soil, plants, compost, etc., but only 7 species have been identified so far. The genus Bacillus rummeliensis has a certain inhibitory effect on some pathogens such as Alternaria solani and Botrytis cinerea on the plate, and there are few reports on its inhibitory effect on other pathogens and its application in disease control. Exploring and developing the antibacterial and disease-resistant functions of the genus Bacillus rummeliensis is of great significance for deeply understanding the functions of microorganisms and developing new microbial agents. Summary of the Invention
[0005] The purpose of this invention is to provide a Bacillus rumeli and its application. Bacillus rumeli JY-2-4R is a potential biological agent that combines stress resistance, growth promotion and broad-spectrum antibacterial activity, and has broad development space and good development and application prospects, in order to solve the problem of the lack of functional microorganisms for the biological control of diseases in kiwifruit and aconite.
[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A Rummeliibacillus sp. is provided, named Rummeliibacillus JY-2-4R, which was deposited on February 11, 2026 at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCC No: 67853.
[0007] Furthermore, the 16S rRNA gene sequence of Bacillus rumeli JY-2-4R is shown in SEQ ID No. 1.
[0008] Furthermore, Bacillus rumeli JY-2-4R was grown under conditions of 4-65 ℃, pH 4.0-9.0, and NaCl concentration of 0.5%-8.0%.
[0009] Furthermore, Bacillus rumeli JY-2-4R exhibits strong tolerance to temperature and NaCl, thrives in a weakly acidic environment, and possesses the ability to produce proteases, cellulases, and indoleacetic acid.
[0010] The present invention also provides the application of the above-mentioned Bacillus rumeli in the preparation of preparations antagonistic to kiwifruit black spot fungus, kiwifruit soft rot fungus, aconite white rot fungus, aconite soft rot fungus or aconite root rot fungus.
[0011] Furthermore, the preparation is a fermentation broth.
[0012] The present invention also provides a fermentation broth comprising the above-mentioned Bacillus rumeli.
[0013] Furthermore, the fermentation broth was prepared by the following method: Bacillus rumeli JY-2-4R was inoculated into 1 L LB medium and cultured at 28 ℃ and 120 rpm for one week until the bacterial count in the solution was greater than 1×10⁻⁶. 9 CFU / mL was used to obtain the fermentation broth.
[0014] The present invention has the following beneficial effects:
[0015] 1. The Bacillus rumeli JY-2-4R of the present invention can grow under conditions of temperature of 4-65 °C, pH of 4.0-9.0, and NaCl concentration of 0.5%-8.0%. This bacterium has good resistance to temperature, acid, alkali and salt.
[0016] 2. The Bacillus rumelius JY-2-4R of the present invention has the ability to produce protease, cellulase and indoleacetic acid, etc.
[0017] 3. The Bacillus rumelius JY-2-4R strain and its fermentation broth of this invention can significantly inhibit the growth of kiwifruit black spot fungus and soft rot fungus, aconite white mold fungus, soft rot fungus and root rot fungus, and reduce the incidence of diseases. The JY-2-4R strain is derived from healthy aconite plants, does not pollute the environment, leaves no residue, and is harmless to humans and animals. It possesses broad-spectrum antibacterial, growth-promoting, and stress-resistant properties, and has broad application prospects. Attached Figure Description
[0018] Figure 1 Figure 1 shows the colony morphology and Gram staining results of Bacillus rumeli JY-2-4R on LB medium in Example 1; Figure A shows the colony morphology, and Figure B shows the Gram staining results.
[0019] Figure 2 This is a phylogenetic tree of Bacillus rumeli JY-2-4R constructed based on the 16S rRNA gene in Example 2;
[0020] Figure 3 The following is a graph showing the effect of Bacillus rumelii JY-2-4R in producing degrading enzymes in Example 3; Figure A shows the clear zone produced by JY-2-4R in a protein-containing medium, and Figure B shows the clear zone produced by JY-2-4R in a cellulose-containing medium.
[0021] Figure 4 The antagonistic effect of Bacillus rumelius JY-2-4R fermentation broth on pathogenic fungi in Example 6;
[0022] Figure 5 The antagonistic effect of Bacillus rumelius JY-2-4R fermentation broth on pathogenic bacteria in Example 6;
[0023] Figure 6 The control effect of Bacillus rumelius JY-2-4R fermentation broth in Example 7 on black spot and soft rot of kiwifruit;
[0024] Figure 7 The image shows the control effect of Bacillus rumeli JY-2-4R fermentation broth on aconite white rot, root rot and soft rot in Example 7. Detailed Implementation
[0025] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.
[0026] Example 1: Isolation of Bacillus rumeli JY-2-4R
[0027] Healthy Aconitum plants were collected from Laopingba Village, Sanhe Town, Jiangyou City, Sichuan Province (31°53'20'' N, 104°47'31'' E, altitude 570 m), the authentic producing area of Aconitum. Five healthy Aconitum plants were randomly collected using a five-point sampling method, taking care to avoid mechanical damage during sampling. After removing the soil from the plants, they were placed in sterile bags and brought back to the laboratory for processing. The collected Aconitum plants were washed with sterile water and then surface-sterilized. The sterilization steps were as follows: the Aconitum plants were cut into small pieces and placed in a sterile beaker, 75% alcohol was added, and the mixture was soaked for 2 minutes. The alcohol was then poured out, and the mixture was rinsed once with ddH2O. Then, 2% NaClO was added, and the mixture was soaked for 10 minutes. The NaClO was then poured out. Finally, the mixture was soaked in ddH2O for 1 minute. This step was repeated 5 times. After surface sterilization, plant samples were inoculated onto LB agar medium. 100 μL of the final soaking ddH2O was spread onto LB agar medium as a control. After incubation at 28 ℃ for 7 days, if no colonies formed in the control, sterilization was considered complete, and endophytic bacteria could be isolated from the samples. Finally, a white, opaque, smooth-surfaced, moist, viscous, raised bacterial strain was selected and named JY-2-4R (e.g., ...). Figure 1 (As shown). After three purifications, the purity of the strain was tested and it was stored in 25% glycerol at -80 ℃. The strain was stained with a Gram staining kit and observed under a microscope. The results showed that JY-2-4R was rod-shaped and showed a purple Gram staining result, indicating that it was a Gram-positive bacterium.
[0028] Example 2: Identification of the 16S rRNA gene of Bacillus rumeli JY-2-4R
[0029] Total DNA was extracted from strain JY-2-4R, isolated and screened in Example 1, using a Rapid Bacterial Genomic DNA Isolation Kit, and the DNA concentration was checked by 1% agarose gel electrophoresis. After verifying the DNA concentration, 16S rDNA PCR amplification was performed using universal primers 27F (5'-AGAGTTTGATCCTGGCTCAG-3') and 1492R (5'-TACCTTGTTACGACTT-3'). The PCR amplification system consisted of 12.5 μL of 2×mix, 1 μL of 10 μmol / mL 27F, 1 μL of 10 μmol / mL 1492R, 1 μL of DNA, and 9.5 μL of ddH2O. The PCR amplification conditions were: 94 °C pre-denaturation for 5 min; 94 °C denaturation for 30 s, 50 °C annealing for 30 s, 72 °C extension for 2 min, for 30 cycles; and a final extension at 72 °C for 10 min. The amplified products were detected using a 1% agarose gel electrophoresis at 80 V for 80 min. The PCR products were sent to Beijing Qingke Biotechnology Co., Ltd. for sequencing. The obtained sequences were compared with the NCBI database. Reference strains were selected based on the comparison results, and a phylogenetic tree was constructed using MEGA X software (e.g., Figure 2 The taxonomic position of strain JY-2-4R is clearly defined as shown in SEQ ID NO.1. The 16S rRNA gene sequence of strain JY-2-4R is shown in SEQ ID NO.1. The phylogenetic tree results show that JY-2-4R is related to Rummeliibacillus pycnus NBRC 101231. T They cluster together and, together with Rummeliibacillus spp., form a stable and independent branch. JY-2-4R 16S rRNA was combined with R. pycnus NBRC 101231. T R. stabekisii NBRC 104870 T and R. suwonensis G20 T The 16S rRNA similarities were 99.30%, 98.2%, and 97.2%, respectively.
[0030] Total DNA was extracted from strain JY-2-4R, isolated and screened in Example 1, using a Rapid Bacterial Genomic DNA Isolation Kit. The total DNA quality was assessed by 1% agarose gel electrophoresis and then sent to Shanghai Paisenno Biotechnology Co., Ltd. for sequencing. Oxford Nanopore PromethION 48 and Illumina NovaSeq platforms were used, with Illumina NovaSeq data used to correct or supplement Oxford Nanopore PromethION 48 data. Therefore, two DNA libraries were constructed using genomic DNA: a 400-bp paired-end library from the Illumina NovaSeq platform and a standard library from the Oxford Nanopore PromethION 48 platform. Raw sequencing data were obtained from approximately 2.62 Gb from the Illumina NovaSeq platform and approximately 4.12 Gb from the Oxford Nanopore PromethION 48 platform. The raw data was then filtered using fastp (v0.23.1) to generate high-quality sequences. The third-generation sequencing data was processed using Flye (v2.9.1) and Unicycler (v0.5.0) to assemble the filtered reads into contig sequences. High-quality second-generation data was then used to correct the third-generation contig results using Pilon (v1.24) software. Finally, the complete sequences were assembled. Genome sequences, gene predictions, and non-coding RNA predictions were integrated into the standard GenBank format, and the genome was visualized using cgview (v2020) to generate pie charts.
[0031] Genome correlation analysis was performed on JY-2-4R and known strains, and the ANI and dDDH values were calculated online. The results of the correlation analysis are shown in Table 1. ANI analysis showed that JY-2-4R is related to R. pycnus DSM 15030. T The ANI value was the highest, at 80.50%, less than 95%; the dDDH analysis was similar to the ANI, and consistent with R. pycnus DSM 15030. T The dDDH value was the highest, at 22.50%, which is less than 70%. Therefore, JY-2-4R was identified as a new species of the genus Rummeliibacillus sp., and the strain was named Rummeliibacillus sp. JY-2-4R.
[0032] Table 1. Genomic correlation analysis between JY-2-4R and known bacterial species
[0033] Example 3: Detection of the ability of Bacillus rumeli JY-2-4R to produce degrading enzymes
[0034] Prepare the following culture media: Cellulose medium: sodium carboxymethyl cellulose 10 g / L, peptone 10 g / L, NaCl 10 g / L, yeast extract 5 g / L, agar 15 g / L, pH=7.0; Protein medium: tryptone 5 g / L, yeast extract 2.5 g / L, glucose 1 g / L, skim milk 7%, agar 15 g / L, pH=7.0.
[0035] JY-2-4R was inoculated on LB agar and incubated at 28 °C until single colonies formed. A single colony was picked and inoculated into 2 mL of sterile water to prepare a bacterial suspension. The bacterial suspension was then inoculated onto cellulose and protein agar plates using a bamboo stick. After incubation at 28 °C for 5 days, the cellulose agar was stained. The staining method was as follows: 10 mL of 0.1% Congo red was poured into a plate, allowed to stand for half an hour, then poured out. Next, 10 mL of 5% NaCl was added, and the plate was gently shaken for 15 minutes before being discarded to complete the staining. The protein agar plate did not require staining. The presence of a clear zone around the colony was observed, and the diameters of the colony and the clear zone were measured. Results are as follows: Figure 3 As shown, Figure 3 Figures A and B show the clear zones produced in a medium containing cellulose and protein, respectively, indicating that JY-2-4R has the ability to produce cellulase and protease.
[0036] Example 4: The ability of Bacillus rumeli JY-2-4R to produce indoleacetic acid
[0037] A single colony of JY-2-4R was inoculated into LB liquid medium containing L-tryptophan (200 mg / L) and cultured at 28℃ for 48 h. One mL of the bacterial suspension was centrifuged at 10000 rpm for 10 min, and 400 µL of the supernatant was added to an equal volume of Salkowski colorimetric solution. The mixture was then placed in a cool, ventilated place and in the dark for 30 min. The absorbance of the mixture at 530 nm was measured. Indoleacetic acid (IAA) standard solutions of 20 mg / L, 40 mg / L, 60 mg / L, 80 mg / L, and 100 mg / L were prepared, and the mixture was treated in the same manner to plot a standard curve. The IAA content secreted by strain JY-2-4R was calculated. The results showed that the IAA secretion of strain JY-2-4R was 5.12 ± 0.07 mg / L.
[0038] Example 5: Tolerance of Bacillus rumeli JY-2-4R to temperature, pH and NaCl
[0039] Temperature: The tested strains were inoculated onto LB agar plates and heat-shocked at 4 ℃, 28 ℃, 37 ℃, and 65 ℃ for 30 min, respectively, followed by incubation at 28 ℃ for 3 days. Colony growth was observed and recorded. The results showed that JY-2-4R could grow at all the above temperatures, with the best colony growth at 4 ℃, 28 ℃, and 37 ℃, with no significant differences between colonies. At 65 ℃, the colony growth was slightly worse, but the strain still grew well.
[0040] pH: The tested strains were inoculated onto LB agar plates at pH values of 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, and 11.0, and incubated at 28 ℃ for 3 days. Colony growth was observed and recorded. The results showed that JY-2-4R could grow under the above pH conditions ranging from 4.0 to 9.0, with the best growth at pH values of 5.0, 6.0, and 7.0, where there was no significant difference between colonies. The strain grew well at pH 4.0, and could grow at pH values of 8.0 and 9.0, but the growth was slower.
[0041] NaCl concentration: The tested strains were inoculated onto LB plates with NaCl concentrations of 1%, 2%, 3%, 4%, and 5%, respectively, with a 0.5% NaCl concentration as a control. The plates were incubated at 28 °C for 5 days, and colony growth was observed and recorded. The results showed that JY-2-4R could grow under all the above NaCl concentrations, indicating that this bacterium has a very strong ability to resist salt stress.
[0042] Example 6: Antagonistic ability of Bacillus rumeli JY-2-4R against multiple pathogens
[0043] A total of 6 pathogens were tested, including 5 fungal pathogens: *Sclerotium rolfsii* (causing white rot of aconite), *Fusarium oxysporum* (causing root rot of aconite), *Alternaria alternata* (causing black spot disease of kiwifruit), *Botrysphaeria dothidea* and *Diaporthe eres* (causing soft rot of kiwifruit), and 1 bacterial pathogen: *Pectobacterium versatile* (causing soft rot of aconite).
[0044] Preparation of JY-2-4R fermentation broth: JY-2-4R was inoculated onto LB agar medium and cultured at 28 ℃ until single colonies formed. A single colony was picked and inoculated into 1 L LB medium and cultured at 28 ℃ and 120 rpm for 7 days until the bacterial count in the solution exceeded 1 × 10⁻⁶. 9 Fermentation broth was obtained at CFU / mL.
[0045] Antagonistic effect of JY-2-4R fermentation broth on pathogenic fungi: *Sclerotium rolfsii* (pathogen of aconite white rot), *Fusarium oxysporum* (pathogen of aconite root rot), *Alternaria alternata* (pathogen of kiwi fruit black spot), *Botrysphaeria dothidea* (pathogen of kiwi fruit soft rot), and *Diaporthe eres* (pathogens of kiwi fruit soft rot) were inoculated into PDA medium and cultured at 25 ℃ until the mycelium fully colonized the medium. Pathogen mycelial discs (3 mm in diameter) were inoculated into the center of fresh PDA medium, and JY-2-4R fermentation broth (5 μL) was inoculated at four points 2 cm away from the mycelial disc in four directions. After 7 days of incubation at 25 ℃, the diameter of the pathogen colonies was measured. Simultaneous inoculation of the pathogens into sterile LB liquid medium served as a control. The inhibition rate (IR) was calculated using the following formula:
[0046] IR (%) = (Dc - Dt) / Dc × 100;
[0047] In the formula, IR is the mycelial growth inhibition rate, Dc is the mycelial diameter of the control group, and Dt is the mycelial diameter of the biocontrol bacteria treatment.
[0048] The results are as follows Figure 4 As shown, the JY-7-2L fermentation broth significantly inhibited the growth of five pathogenic fungi, with an inhibition rate of 75.2% against *S. rolfsii*, 50.1% against *F. oxysporum*, 60.8% against *A. alternata*, 80.2% against *D. eres*, and 51.1% against *B. dothidea*.
[0049] Antagonistic effect of JY-2-4R fermentation broth on pathogenic bacteria: *Pectobacterium versatile*, the pathogen of aconite soft rot, was inoculated onto LB agar medium and cultured at 28 ℃ until single colonies formed. Single colonies were then picked and inoculated into 10 mL of LB medium and cultured at 28 ℃ and 120 rpm for 5 days until the bacterial count in the solution exceeded 1 × 10⁻⁶. 9 A bacterial suspension was obtained at CFU / mL. The bacterial suspension (20 μL) was spread on LB agar medium, dried, and then inoculated with 5 μL of JY-2-4R fermentation broth. After incubation at 25 ℃ for 5 days, the presence of lysis zones was observed. The results showed that obvious lysis zones appeared around the JY-2-4R colonies. Figure 5 This indicates that JY-2-4R inhibits the growth of P. versatile.
[0050] Example 7: Control ability of Bacillus rumeli JY-2-4R against multiple diseases
[0051] The tested pathogens included five fungi: *Sclerotium rolfsii* (causing white mold in aconite), *Fusarium oxysporum* (causing root rot in aconite), *Alternaria alternata* (causing black spot in kiwifruit), *Botrysphaeria dothidea* and *Diaporthe eres* (causing soft rot in kiwifruit), and one bacterium: *Pectobacterium versatil* (causing soft rot in aconite). All pathogens were inoculated onto PDA medium and incubated at 25°C until the mycelium had fully colonized the medium.
[0052] Preparation of JY-2-4R fermentation broth: JY-2-4R was inoculated onto LB agar medium and cultured at 28 ℃ until single colonies formed. A single colony was picked and inoculated into 1 L LB medium and cultured at 28 ℃ and 120 rpm for 7 days until the bacterial count in the solution exceeded 1 × 10⁻⁶. 9 Fermentation broth was obtained at CFU / mL.
[0053] Control efficacy of strain JY-2-4R against kiwifruit black spot and rot: Select healthy and nearly mature kiwifruit and disinfect the surface with 1% (wt / vol) NaOCl for 10 min, then wash with sterile water 5 times, at least 1 min each time. After air drying, make 3 mm × 3 mm × 3 mm holes on the side of each kiwifruit using a punch, and add 1 mL of biocontrol bacteria JY-2-4R fermentation broth (1×10⁻⁶) to each hole. 8 (CFU / mL) was added to sterile liquid LB as a blank control. After standing for 2 h, pathogenic bacterial cakes (3 mm in diameter) were inoculated at the wound site. Ten replicates were set up for each treatment. The inoculated kiwifruit were placed in sterile tissue culture bottles and incubated at 25 ℃. This experiment was repeated three times. After the blank control developed symptoms, the diameter of the lesions was measured, and the biocontrol rate was calculated. The formula for calculating the biocontrol rate (IR) is as follows:
[0054] BE (%) = (Dc - Dt) / Dc × 100;
[0055] In the formula, BE is the lesion biocontrol rate, Dc is the lesion diameter of the control group, and Dt is the lesion diameter of the biocontrol treatment.
[0056] The results showed that the fermentation broth of JY-2-4R could inhibit the occurrence of black spot and soft rot in kiwifruit. Figure 6It achieved a control rate of 50.5% against black spot disease caused by Alternaria alternata, and 60.2% and 40.9% against soft rot disease caused by Botrysphaeria dothidea and Diaporthe eres, respectively.
[0057] Control efficacy of strain JY-2-4R against Aconitum carmichaelii white mold, root rot, and soft rot: Fresh, healthy Aconitum carmichaelii roots without mechanical damage were selected, cut into slices approximately 5 mm thick, and surface-sterilized. The surface sterilization process was as follows: first, soaking in 75% ethanol for 5 min, then rinsing three times with sterile water; subsequently, soaking in 2% sodium hypochlorite solution (available chlorine content) for 8 min, then rinsing five times with sterile water. The surface-sterilized slices were placed in a petri dish lined with sterile moistened filter paper, and 1 mL of JY-2-4R fermentation broth (1×10⁻⁶) was inoculated in the center of the slice. 8 CFU / mL), after the bacterial culture was allowed to dry naturally, it was inoculated with pathogenic fungal cakes, and a control group was prepared by inoculating an equal volume of sterile LB liquid medium and pathogenic fungus. All culture dishes were sealed with parafilm and incubated at 25 ℃ for 7 days before observing the disease development of aconite sections. The results showed that JY-2-4R significantly inhibited the growth of S. rolfsii and F. oxysporum on aconite sections (CFU / mL). Figure 7 (), Aconite inoculated with JY-2-4R showed no obvious symptoms.
[0058] The control effect of strain JY-2-4R on aconite soft rot: The pathogen of aconite soft rot, *Pectobacterium versatile*, was inoculated onto LB agar medium and cultured at 28 ℃ until single colonies formed. Single colonies were then picked and inoculated into 10 mL of LB medium and cultured at 28 ℃ and 120 rpm for 5 days until the bacterial count in the solution exceeded 1 × 10⁻⁶. 9 Obtain the bacterial suspension at CFU / mL. Inoculate 1 mL of pathogen fermentation broth (1×10⁻⁶ CFU / mL). 8 Inoculate surface-sterilized aconite slices (CFU / mL) onto culture dishes lined with sterile, moistened filter paper and allow to air dry. Inoculate the center of each slice with 1 mL of JY-2-4R fermentation broth (1×10⁻⁶ CFU / mL). 8 (CFU / mL), after the bacterial culture was allowed to dry naturally, it was sealed with parafilm and incubated at 25 ℃ for 7 days. The disease incidence of the aconite sections was then observed. Results are as follows: Figure 7 In the CK treatment, aconite exhibited obvious signs of decay and foul odor, typical symptoms of soft rot. In contrast, aconite treated with JY-2-4R fermentation broth remained intact, with a firm, white interior, and showed no signs of disease. This indicates that JY-2-4R inhibited the occurrence of soft rot in aconite slices.
[0059] In summary, JY-2-4R in this invention belongs to the genus *Rummeliibacillus*, specifically *Rummeliibacillus* sp. JY-2-4R0. This bacterium exhibits strong tolerance to temperature, pH, and NaCl, demonstrating strong stress resistance. It can secrete cellulase, protease, and indoleacetic acid. The fermentation broth of this bacterium shows significant inhibitory effects against *Actinidia chinensis* var. *mongolica*, *Actinidia chinensis* var. *mongolica*, *Actinidia chinensis* var. *mongolica*, and *Actinidia chinensis* var. *mongolica*, and can reduce disease occurrence on both the fruit and *Actinidia chinensis* slices, demonstrating good biocontrol capabilities with broad-spectrum inhibitory function against multiple pathogens. Therefore, JY-2-4R possesses multiple functions including stress resistance, growth promotion, and disease resistance.
[0060] 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 within the protection scope of the present invention.
Claims
1. A type of Rummeliibacillus sp., characterized in that, Named Bacillus rumeli JY-2-4R, it was deposited on February 11, 2026 at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCC No: 67853.
2. The Bacillus rumeli according to claim 1, characterized in that, The 16S rRNA gene sequence of Bacillus rumeli JY-2-4R is shown in SEQ ID No.
1.
3. The use of Bacillus rumeli as described in claim 1 or 2 in the preparation of preparations antagonistic to kiwifruit black spot fungus, kiwifruit soft rot fungus, aconite white rot fungus, aconite soft rot fungus, or aconite root rot fungus.
4. The application according to claim 3, characterized in that, The preparation is a fermentation broth.
5. A fermentation broth, characterized in that, Includes Bacillus rumeli as described in claim 1 or 2.
6. The fermentation broth according to claim 5, characterized in that, The fermentation broth was prepared by the following method: Bacillus rumeli JY-2-4R was inoculated into 1 L LB medium and cultured at 28 ℃ and 120 rpm for one week until the bacterial count in the solution was greater than 1×10⁻⁶. 9 CFU / mL was used to obtain the fermentation broth.