Chaetomium globosum 5141-4, microbial inoculum and application

Abstract

This invention belongs to the field of biocontrol microbial technology, specifically relating to a strain of Chaetomium globosum (… Chaetomium globosum )5141-4 、 Inoculants and their applications. This invention isolates an endophytic fungus from *Lithocarpus* lichens and names it *Chaetoceros globosa*. Chaetomium globosum 5141-4. Verification has shown that the above strains can effectively inhibit the growth of Fusarium oxysporum or anthrax, and also exhibit good inhibitory effects against six pathogens, including Pseudomonas aeruginosa and Enterococcus faecalis. They hold promise for use in the preparation of biocontrol products or further screening of antibacterial compounds.

Description

Technical Field

[0001] This invention belongs to the field of biocontrol microbial technology, specifically relating to a strain of Chaetomium globosum (… Chaetomium globosum 5141-4. Microbial agents and their applications. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Litmus ( Cladonia Lichens mostly grow in extreme environments, commonly found on exposed rocks, decaying wood, and thin layers of soil in high mountains. They secrete lichen acids to erode rock surfaces, creating a primary soil layer that provides conditions for subsequent plant communities to settle. Endophytic fungi are fungi that live within healthy biological tissues and do not cause obvious disease symptoms. Similarly, lichen endophytic fungi live within lichen mycelia and are similar to plant endophytes in terms of classification, diversity, dispersal methods, and evolutionary history.

[0004] Furthermore, endophytic fungi have attracted considerable attention due to the production of bioactive secondary metabolites. These metabolites possess a variety of biological activities, including antibacterial, antiviral, antitumor, and antioxidant effects. With the increasing resistance of microorganisms to antibiotics, the search for new antibacterial substances has become particularly important. Secondary metabolites isolated from lichen endophytic fungi offer a promising avenue for the development of novel drugs. For example, from... Parmotrema rampoddense Endophytic fungi isolated from Fusarium proliferatum Antimicrobial activity was observed against ESKAPE bacterial pathogens (Tan et al., 2020). Compounds with anti-biofilm activity can be obtained from lichen endophytic fungi through bioguided network screening (Toure et al., 2022). The ecological role of endophytic fungi in lichen symbiotic systems is a complex and not yet fully understood area, providing a rich sample library for the screening of active extracts and even small molecule compounds. Summary of the Invention

[0005] This invention used *Lithocarpus* lichens as screening targets and isolated an endophytic fungus from the *Chaetoceros* genus, which was named *Chaetoceros globosa*. Chaetomium globosum5141-4. It has been verified that the above-mentioned strain possesses catalase activity, significantly inhibiting *Fusarium oxysporum* and *Anthrax*, and can be used as a biocontrol agent in agriculture. Furthermore, the present invention also obtained the metabolites of the above-mentioned strain, which have been verified to have inhibitory effects on six common clinical pathogens, including *Pseudomonas aeruginosa* and *Enterococcus faecalis*, exhibiting broad-spectrum antibacterial activity. Based on the above research results, the present invention provides the following technical solution:

[0006] Firstly, provide a strain of Chaetomium globulum ( Chaetomium globosum The strain 5141-4 was deposited on July 25, 2025, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences. Its accession number is CGMCC No. 42140.

[0007] The first aspect refers to Chaetoceros globulus ( Chaetomium globosum )5141-4 possesses the ITS sequence shown in SEQ ID NO:1. The strain is an endophytic fungus of the genus *Lithocarpus*, and based on sequence alignment, phylogenetic analysis, morphological and physiological-biochemical comparison, it was identified as *Chaetomium globosa*. Chaetomium globosum The strain was named *Chaetomium globosum*. Chaetomium globosum )5141-4.

[0008] The Chaetomium globulus ( Chaetomium globosum The optimal culture conditions for 5141-4 are as follows: growth temperature 25-35℃, pH neutral to slightly alkaline (pH 6.0–8.0), and aerobic conditions.

[0009] In a second aspect, the present invention provides a microbial agent comprising the *Chaetomium globosum* described in the first aspect. Chaetomium globosum )5141-4 and / or the metabolites, cultures and / or extracts of the bacteria.

[0010] In the second aspect above, "metabolites" refers to chemical substances produced by the strain during its growth and reproduction, including primary and secondary metabolites; "culture" refers to the collective term for a live fungal population and its growth carriers obtained under certain culture conditions through isolation, inoculation, and cultivation; and "extract" refers to a single or mixed component obtained by separating and concentrating fungal cells and / or their growth carriers using physical and chemical methods. The aforementioned growth carriers include solid and liquid culture media.

[0011] In one embodiment of the present invention with better effect, the metabolites of the aforementioned fungi are provided, and the preparation method is as follows: the above-mentioned strain is inoculated into PDB medium for expansion culture for 5-7 days; an equal volume of ethyl acetate is added to the fermentation broth for thorough extraction, the ethyl acetate portion is retained, and the solvent is evaporated to obtain the product.

[0012] In a third aspect, the present invention provides the application of the strains described in the first aspect and the bacterial agents described in the second aspect.

[0013] The applications described in the third aspect above include applications in the production of catalase, as well as applications in broad-spectrum antibacterial activity.

[0014] The aforementioned applications of catalase include the degradation of peroxides or organic pollutants in water and soil, including but not limited to phenol, tetracycline antibiotics, and textile dyes.

[0015] The above-mentioned broad-spectrum antibacterial applications include, but are not limited to, any one of the following:

[0016] 1) Used to prevent and remove harmful microorganisms from the environment, water bodies, and surfaces of objects;

[0017] 2) Used to prepare products that can be used to prevent and eliminate harmful microorganisms in the environment, water bodies, and on the surface of objects;

[0018] 3) Used for the prevention, improvement, or treatment of diseases caused by harmful microorganisms;

[0019] 4) Used to prepare an antimicrobial preparation for the prevention, improvement or treatment of related diseases caused by harmful microorganisms.

[0020] In the above applications 1)-4), the harmful microorganisms include, but are not limited to, one or more of Streptococcus, Staphylococcus, Pseudomonas, Bacillus, and Candida; further, the harmful microorganisms are one or more of Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis, Candida glabrata, and Candida albicans.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] Litmus lichen symbionts possess a unique algal-fungus symbiotic layer structure and thrive in relatively extreme environments. This, based on co-evolution, facilitates the development of unique metabolic pathways in endophytic fungi, leading to the acquisition of highly active metabolites. Current research on Chaetomium fungi is largely lacking, with reports of antibacterial activity being extremely rare. This invention provides a strain of Chaetomium globosum (… Chaetomium globosum)5141-4 can secrete hydrogen peroxide functional enzymes, and its metabolites show inhibitory activity against a variety of different types of plant pathogens and clinical pathogens, which is helpful for the development and screening of biocontrol bacteria and novel broad-spectrum antibiotic compounds in the agricultural field. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0024] Figure 1 This is the maximum likelihood phylogenetic tree constructed based on ITS for the isolation and identification of strains in Example 1.

[0025] Figure 2 This is the neighbor-joining phylogenetic tree constructed based on ITS in the strain isolation and identification in Example 1.

[0026] Figure 3 The *Chaetomium globosum* described in Example 1 ( Chaetomium globosum Morphology of 5141-4; among which, Figure 3 A is a litmus lichen (ZJ240302-4); Figure 3 B in the middle is Chaetomium globosum ( Chaetomium globosum )5141-4 front view of the growth on a PDA tablet; Figure 3 C represents Chaetomium globosum ( Chaetomium globosum )5141-4 Reverse image of growth on a PDA tablet; Figure 3 D in the middle represents Chaetomium globosum ( Chaetomium globosum Photograph of spore 5141-4; Figure 3 E in the middle is Chaetomium globosum ( Chaetomium globosum Photograph of mycelium 5141-4.

[0027] Figure 4 The *Chaetomium globosum* described in Example 1 ( Chaetomium globosum The results of the extracellular catalase activity assay for 5141-4 were obtained; among them, Figure 4 In section A, hydrogen peroxide solution was added to a PDA plate, but no *Chaetomium globosum* was inoculated. Chaetomium globosum The negative control for 5141-4; Figure 4 In section B, hydrogen peroxide solution was added to a PDA plate, and *Chaetomium globosum* was inoculated on it. Chaetomium globosum The experimental group of 5141-4.

[0028] Figure 5 The *Chaetomium globosum* described in Example 2 ( Chaetomium globosum Figure 5141-4 shows the results of a confrontation experiment with plant pathogens; among them, Figure 5 Image A shows a single culture of Fusarium oxysporum (control group).Figure 5 Photo B shows anthrax bacteria cultured alone (control group); Figure 5 C represents Chaetomium globosum ( Chaetomium globosum A comparison of the results of the confrontation between 5141-4 (left) and Fusarium oxysporum (right); Figure 5 D in the middle represents Chaetomium globosum ( Chaetomium globosum A diagram showing the confrontation between 5141-4 (left) and anthrax (right).

[0029] Figure 6 The *Chaetomium globosum* described in Example 3 ( Chaetomium globosum Results of the antibacterial activity of the metabolites of 5141-4 against clinical pathogens; Figure 6 A in the middle is Chaetomium globosum ( Chaetomium globosum The inhibitory effect of metabolites of 5141-4 on Candida albicans CMCC98001; Figure 6 B in the middle is Chaetomium globosum ( Chaetomium globosum The inhibitory effect of the metabolites of 5141-4 on Enterococcus faecalis ZDZA0109; Figure 6 C represents Chaetomium globosum ( Chaetomium globosum The inhibitory effect of metabolites of 5141-4 on Candida glabrata ATCC15126; Figure 6 D in the middle represents Chaetomium globosum ( Chaetomium globosum The inhibitory effect of the metabolites of 5141-4 on Staphylococcus aureus CMCC26003; Figure 6 E in the middle is Chaetomium globosum ( Chaetomium globosum The inhibitory effect of metabolites of 5141-4 on Bacillus subtilis CMCC63501; Figure 6 F is *Chaetomium globosum* ( Chaetomium globosum The inhibitory effect of metabolites of 5141-4 on Pseudomonas aeruginosa CMCC10104.

[0030] Figure 7 As described in Example 4 Chaetomiumglobosum The biocontrol effect of the metabolite of 5141-4 on cucumber wilt disease; Figure 7 In Figure A, the cucumber leaves of the control group are in their state in the field. Figure 7 Image B shows the state of cucumber leaves in the experimental group in the field. Figure 7 The image in middle C shows a comparison of cucumber leaves between the control group and the experimental group. Detailed Implementation

[0031] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] In the context of this specification, the word "comprising" is considered to mean "especially including". It should not be interpreted as "consisting of only".

[0034] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0035] The culture materials involved in the following examples are as follows:

[0036] PDA medium: Take 200g of potatoes (cut into small pieces) and put them in 1L of distilled water. Heat the potatoes to a boil for 20-30 minutes. Filter out the potato pieces with gauze and bring the liquid to a final volume of 1000mL with distilled water. Pour the liquid back into the pot and heat it. After boiling, add 20g of glucose and 20g of agar powder, stir to dissolve, dispense into containers, and autoclave at 115℃ for 15 minutes.

[0037] PDB medium: Take 200g of potatoes (cut into small pieces) and put them in 1L of distilled water. Heat the potatoes to a boil for 20-30 minutes. Filter out the potato pieces with gauze and make up the volume to 1000mL with distilled water. Pour the liquid back into the pot and heat it. After boiling, add 20g of glucose, stir to dissolve, dispense into containers, and autoclave at 115℃ for 15 minutes.

[0038] LB solid medium: Take 10g peptone, 5g yeast extract, 10g NaCl and 20g agar powder in 1L distilled water, heat to boiling until completely dissolved, dispense into containers, autoclave at 115℃ for 15 minutes, and set aside.

[0039] LB liquid medium: Take 10g peptone, 5g yeast extract and 10g NaCl in 1L distilled water, heat to boiling until completely dissolved, dispense into containers, autoclave at 115℃ for 15 minutes, and set aside.

[0040] MH medium: Take 38g of MH agar powder and dissolve it in 1L of distilled water. Heat to boiling until completely dissolved, dispense into containers, and autoclave at 115℃ for 15 minutes.

[0041] The clinically pathogenic bacteria appearing in the following examples have the following product information: Pseudomonas aeruginosa ( Pseudomonas aeruginosa CMCC 10104, Enterococcus faecalis (Enterococcus faecalis ZDZA0109, Staphylococcus aureus ( Staphylococcus aureus CMCC26003, Bacillus subtilis ( Bacillus subtilis 136. Candida glabrata ( Candida albicans ATCC 15126 and Candida albicans ( Candida albicans CMCC 98001.

[0042] The plant pathogens mentioned in the following examples have the following product information:

[0043] Bacillus anthracis ( Bacillus anthracis The platform number for purchasing anthrax bacteria is bio-25761, hereinafter referred to as "anthrax bacteria".

[0044] Fusarium oxysporum ( Fusarium oxysporum Purchase platform number bio-74063.

[0045] Example 1

[0046] In this embodiment, a *Chaetomium globosum* ( Chaetomium globosum )5141-4, this strain was isolated from lichens of the genus Litmus. The identification and physicochemical characteristics of this strain are as follows:

[0047] 1. Isolation and Identification of Strains

[0048] Tissue blocks (4×4 mm) from different parts of the lichen were cut and surface-sterilized (immersed in 75% ethanol for 5 min, immersed in 30% sodium hypochlorite for 1 min, and rinsed three times with sterile water). These blocks were then inoculated into PDA medium, 4-5 blocks per dish, and incubated at 25°C for 5-7 days until colonies formed at the edges of the tissue blocks. Subsequently, mycelial blocks (4×4 mm) from the outer periphery of the colonies were transferred to fresh PDA medium and incubated at 25°C for 5-7 days to complete purification. Single colonies were inoculated into the medium and incubated at 37°C with shaking at 180 rpm for 24 h. Genomic DNA was extracted from the strain using a plant genomic DNA extraction kit. The genomic DNA of the strain was amplified using universal ITS primers and sequenced. The ITS sequence is shown in SEQ ID NO:1. Sequences were assembled using Geneious v.9.0.2, and aligned using BLAST software. Sequences with a similarity ≥98% were selected, and then aligned using MAFFT v.7. After pruning, Phylogeny.fr was used to ensure that the phylogenetic trees were constructed from evolutionarily homologous sites. Maximum-likelihood (ML) and neighbor-joining (NJ) phylogenetic trees were constructed using MEGA X, with 1000 bootstrap replication tests performed on each node.Achaetomium strumarium As an outgroup, a bootstrap value (BS) greater than or equal to 70% was considered significantly supported. The ML and NJ phylogenetic trees indicate that this bacterium is related to Chaetomium globosa. Chaetomium globosum They clustered together, with all strains having a support score of 99, so the strain was named *Chaetomium globosum*. Chaetomium globosum )5141-4.

[0049] The strain described above was isolated, and its morphological characteristics are as follows: The hyphae grow along the substrate, initially white, gradually turning light brown as they mature. Aerial hyphae thicken into a dense, villous texture, while the edges remain white and flocculent. Granular olive-brown to grayish-brown ascothecia are present in the center and near-center, appearing yellowish-brown to dark brown on the dorsal side. The appendages are straight or curved, light bluish-brown in color, slightly rough on the surface, usually unbranched, and septate is rare. The ascospores are lemon-shaped. Its physiological and biochemical characteristics are as follows: It can utilize sugars such as glucose; it has the ability to degrade with hydrogen peroxide; its growth temperature is 25-35℃, growth ceases at 4℃, but spores can survive; its pH is neutral to weakly alkaline (pH 6.0–8.0); it can produce alkaloids with antibacterial and cytotoxic activities, such as chamomile.

[0050] 2. Enzyme production characteristics of the strain

[0051] Globulus spp. ( Chaetomium globosum )5141-4 was inoculated into a culture medium containing hydrogen peroxide. Extracellular catalase was detected based on the gas bubbles produced by the decomposition of hydrogen peroxide. Figure 4 As shown in Figure B, dense small air bubbles are visible in the culture medium, proving that *Chaetomium globosa* (…) Chaetomium globosum )5141-4 has the ability to synthesize extracellular catalase.

[0052] Example 2

[0053] This embodiment provides the *Chaetomium globosum* described in Example 1 (… Chaetomium globosum Application of 5141-4 in inhibiting plant pathogens.

[0054] Globulus spp. ( Chaetomium globosum )5141-4 was subjected to a two-point confrontation experiment with Fusarium oxysporum and anthracnose fungus, respectively. The distance between the edge of the fungal species and the edge of the plant pathogen was 2 cm, and the points were marked.

[0055] (1) Use a ruler to measure 2cm below the petri dish and mark it. Take a round mycelium with a diameter of 5.3mm and inoculate it at the marked location. Place it in an incubator and incubate upright for 24 hours, then invert it for incubation.

[0056] (2) Take another plate and inoculate it separately with plant pathogens as a control.

[0057] (3) The antibacterial rate was calculated and the effect of the confrontation was evaluated with an observation period of 4 days. The formula for calculating the antibacterial rate is as follows: The diameter of the pathogenic bacteria in the control group Rc (mm) and the diameter of the pathogenic bacteria in the experimental group Rp (mm) were measured by the cross-multiplication method. The antibacterial rate was calculated according to the following formula: Antibacterial rate (%) = [(Rc-Rp)] / [Rc-5.3]×100.

[0058] The results of the confrontation experiment between the above strains and plant pathogens are as follows: Figure 5 As shown, among them, *Chaetomium globosum* ( Chaetomium globosum The inhibition rate of 5141-4 against Fusarium oxysporum was 49.54%. Figure 5 (C), the inhibition rate against Bacillus anthracis was 34.04% ( Figure 5 (D).

[0059] Example 3

[0060] In this embodiment, a *Chaetomium globosum* strain from Example 1 is provided. Chaetomium globosum Metabolites of 5141-4, and the application of said metabolites in inhibiting pathogens.

[0061] 1. Crude extraction of metabolites

[0062] (1) Endophytic fungal expansion culture: The target strain was inoculated into PDB liquid medium and expanded cultured in a constant temperature shaking incubator (150 r / min) at 25±0.5℃ for 5-7 days.

[0063] (2) Metabolite extraction: Add an equal volume of ethyl acetate to the fermentation broth, mix thoroughly immediately, and allow to stand for 24 hours for extraction. Transfer the supernatant to a new conical flask. Concentrate the extract in a rotary evaporator (40 °C, 0.08 MPa) to obtain a crude extract, which is then dissolved in methanol to prepare a 100 mg / mL solution. Store at 4 °C in the dark for later use.

[0064] 2. Antibacterial performance verification

[0065] (1) Fermentation culture of pathogens

[0066] The six clinical pathogens were inoculated onto six LB agar plates using the three-zone streak method. After incubation at 37 °C for 24 h, single colonies grew. Single colonies were picked and inoculated onto LB liquid medium and cultured in a constant temperature incubator with shaking (37 °C, 150 r / min) until the logarithmic growth phase (OD600 value of 0.6-0.8).

[0067] (2) Coating and punching

[0068] 100 μL of fermentation suspensions of six clinically pathogenic bacteria were evenly spread onto the surfaces of six corresponding MH agar plates. Five equidistant wells were prepared on each MH agar plate. One well contained 100 μL of sterile methanol as a negative control, one well contained 100 μL of 0.1 g / ml ampicillin solution as a positive control, and the remaining three wells contained 100 μL of crude extract solutions (in methanol) of three lichen endophytic fungi, respectively.

[0069] 3. Evaluation of antibacterial effect

[0070] After adding the samples, the agar plates were transferred to a 35°C incubator and incubated upright for 24 hours. The diameter of the inhibition zone was measured using the cross-hatching method, with three biological replicates for each treatment. Based on the Quinto and Santos protocol, the Zone of Inhibition (ZOI) was classified into the following categories: inactive (ZOI < 10 mm), partially active (ZOI 10-12 mm), active (ZOI 13-19 mm), and highly active (ZOI > 19 mm).

[0071] The antibacterial activity results of the crude extracts of the above strains are shown in Table 1 and... Figure 6 As shown:

[0072] Table 1. Screening results of antibacterial activity of crude extracts from strains

[0073]

[0074] Note: + (ZOI less than 10mm); ++ (ZOI between 10-12mm); +++ (ZOI between 13-19mm); ++++ (ZOI greater than 19mm)

[0075] According to Table 1 and Figure 6 The methanol group served as a negative control and showed no antibacterial activity; the ampicillin group served as a positive control and showed high antibacterial activity. *Chaetomium globosa* ( Chaetomium globosum The metabolites of 5141-4 showed significant inhibitory effects on all six clinically pathogenic bacteria (ZOI>19 mm), demonstrating broad-spectrum antibacterial properties.

[0076] Example 4

[0077] In this embodiment, based on the *Chaetoceros globosum* described in Example 1 ( Chaetomium globosum The application of catalase produced by 5141-4 involves applying the above-mentioned strain and its metabolites to the degradation treatment of H2O2 or organic pollutants in industrial wastewater. The application methods of the strain or its secretions include applying the above-mentioned strain, or applying the metabolites described in Example 3 to the industrial wastewater to be treated, or fixing the strain and metabolites on a carrier and placing them in the water to be treated.

[0078] The aforementioned strains or their metabolites can also be used to decompose organic pollutants in soil or water, such as phenol, tetracycline antibiotics, and dyes.

[0079] Example 5

[0080] The strain described in Example 2 can significantly inhibit Fusarium oxysporum and anthracnose, and can be used as a biocontrol agent in agriculture, especially suitable for crops such as bananas, tomatoes, cotton, cucumbers, citrus, grapes, and strawberries. The specific usage method is as follows:

[0081] The bacterial strain described in Example 1 or the metabolite described in Example 3 can be mixed with organic fertilizer and applied to the planting hole or soil surface; or the above bacterial solution can be diluted and used for root irrigation, with the bacterial solution diluted to 10. 6 -10 8 CFU / mL, drench the roots once a week after transplanting, for 2-3 consecutive weeks.

[0082] In this embodiment, the biocontrol effect of the strain in Example 1 was verified: when cucumber seedlings reached the two-leaf-one-heart stage, 10 mL of Fusarium oxysporum spore suspension (1×10⁻⁶) was inoculated using the root irrigation method. 6 The seedlings were divided into a control group and an experimental group after inoculation (number of seedlings per mL). 24 hours after inoculation, the experimental group was irrigated with 10 mL of the fermentation broth described in Example 3, while the control group was irrigated with the same amount of deionized water. After being transplanted into the field for 30 days of cultivation, the growth status of the two groups was compared. The cucumbers in the control group showed obvious infection symptoms, such as... Figure 7 As shown, over 70% of the cucumber leaves in the control group developed yellowish-brown spots, while the cucumber leaves in the experimental group showed almost no yellowing and the plants did not wilt significantly, proving that the fermentation liquid has a biocontrol effect.

[0083] Example 6

[0084] The metabolites of the strain described in Example 3 can be used to develop antibacterial drugs, and active small molecules can be screened by methods such as chromatography-mass spectrometry separation.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A type of Chaetomium ( Chaetomium globosum The strain 5141-4 was deposited on July 25, 2025, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, with accession number CGMCC No. 42140. The strain has the ITS sequence shown in SEQ ID NO:

1.

2. The Chaetomium globosum as described in claim 1 ( Chaetomium globosum )5141-4, characterized in that, The Chaetomiumglobosum The morphological characteristics of 5141-4 are as follows: The mycelium grows on the substrate, initially white, gradually turning light brown as it matures. The aerial mycelium thickens into a dense, fluffy texture, while the edges remain white and flocculent. Granular olive-brown to grayish-brown asthenospheres appear in the center and near the center, and are yellowish-brown to dark brown when viewed from the dorsal side. The appendages are straight or curved, light bluish-brown in color, and slightly rough on the surface. They are usually unbranched and septate is rare. The ascospores are lemon-shaped.

3. The Chaetomium globosum as described in claim 1 ( Chaetomium globosum )5141-4, characterized in that, The Chaetomium globulus ( Chaetomium globosum The physiological and biochemical characteristics of 5141-4 are as follows: it can utilize glucose; it has the ability to degrade hydrogen peroxide; its growth temperature is 25-35℃, growth stops at 4℃, but the spores can survive; the suitable pH for survival is neutral to weakly alkaline; its metabolites have antibacterial effects. The Chaetomium globulus ( Chaetomium globosum The cultivation conditions for 5141-4 are as follows: growth temperature 25-35℃, pH neutral to slightly alkaline, and aerobic conditions.

4. A microbial agent, characterized in that, The microbial agent includes *Chaetomium globulus* as described in any one of claims 1-3. Chaetomium globosum )5141-4 and / or the metabolites, cultures and / or extracts of the bacteria.

5. The microbial agent as described in claim 4, characterized in that, The metabolites refer to the chemical substances produced by the strain during its growth and reproduction, including primary metabolites and secondary metabolites; The culture refers to the collective term for the active fungal population and its growth carrier obtained through isolation, inoculation and cultivation under certain culture conditions; The extract refers to a single or mixed component obtained by separating and concentrating bacterial cells and / or their growth carriers through physical and chemical methods; the growth carriers include solid culture media and liquid culture media.

6. The microbial agent as described in claim 5, characterized in that, The metabolite was prepared as follows: the strain was inoculated into PDB medium and cultured for 5-7 days; an equal volume of ethyl acetate was added to the fermentation broth for extraction, the ethyl acetate fraction was retained, and the solvent was removed by evaporation.

7. The Chaetomium globosum as described in any one of claims 1-3 ( Chaetomium globosum 5141-4. The application of the microbial agent according to any one of claims 4-6, characterized in that, The application is a broad-spectrum antibacterial application, selected from any of the following: 1) Used to prevent and remove harmful microorganisms from the environment, water bodies, and surfaces of objects; 2) Prepare products for preventing and eliminating harmful microorganisms in the environment, water bodies, and on the surface of objects; 3) Used to prepare an antimicrobial agent for the prevention, improvement or treatment of related diseases caused by harmful microorganisms; In applications 1)-3), the harmful microorganism is Candida glabrata.

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