Offshore mud flat 125-meter deep soil layer source algae-lysing streptomyces strain and application thereof in broad-spectrum bactericidal activity

Abstract

The invention discloses an offshore mud flat 125-meter deep soil source algae-lysing streptomyces strain and application thereof in broad-spectrum bactericidal activity. The invention provides an offshore mud flat 125-meter deep soil layer source algae-lysing streptomyces strain which is named as algae-lysing streptomyces LW20211224-107, and the preservation number of the algae-lysing streptomyces strain is CGMCC (China General Microbiological Culture Collection Center) No.33482. The streptomyces algicidal strain LW20211224-107 provided by the invention can secrete antibacterial substances, has broad-spectrum bactericidal activity on different clinical drug-resistant bacterial strains, can be used for resisting infection of various drug-resistant bacteria, and can be applied to broad-spectrum bactericidal activity as a bacteriostatic agent. The streptomyces algicidal strain LW20211224-107 and the secondary metabolite of the streptomyces algicidal strain LW20211224-107 provided by the invention have an antibacterial spectrum different from that of the existing antibiotics, have a relatively strong antibacterial effect on G < + > bacteria and G <-> bacteria, and have a relatively good development and application prospect in the related antibacterial field.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of microorganisms, and particularly relates to a strain of Streptomyces amritsarensis from a 125-meter-deep soil layer of a coastal beach and application thereof in broad-spectrum bactericidal activity.

[0002] The strain of Streptomyces amritsarensis from a 125-meter-deep soil layer of a coastal beach is named Streptomyces amritsarensis LW20211224-107, which has been preserved in the China General Microbiological Culture Collection Center on January 20, 2025, and the preservation number is CGMCC No. 33482. BACKGROUND

[0003] Pathogenic bacteria can cause diseases in humans and animals, and even cause widespread diseases and deaths, such as plague, tuberculosis, cholera, brucellosis, and the like, which have caused harm and threat to the health and life of humans and animals. Antibiotics have been an important weapon for humans to fight pathogenic bacteria since they were recognized. Since the Second World War, they have been mass-produced and widely used, saving the lives of countless humans and animals. The commonly used aminoglycosides, tetracyclines, glycopeptides and macrolide antibiotics in clinical practice are all derived from actinomycetes. However, in medical and veterinary clinical practice, antibiotics have been misused, and in addition to the variation and directional evolution of pathogenic bacteria, drug-resistant strains have emerged, which are ineffective against the antibiotics used, and even ineffective against multiple antibiotics (multiple and broad-spectrum drug-resistant bacteria), so the amount and types of antibiotics used in clinical practice have increased, further causing this phenomenon to occur and viciously cycle. Therefore, the uselessness of antibiotics and the demonization of antibiotics have become more and more serious. For example, the New Delhi Metallo-β-lactamase (NDM-1) has emerged in recent years. Many clinically used antibiotics have failed to achieve good efficacy, so it is of great importance and practical significance to screen some new and effective antibiotics.

[0004] At present, among nearly 10,000 kinds of bioactive substances discovered from microorganisms, nearly 70% are produced by actinomycetes, and Streptomyces is an important source of new antibiotics. Actinomycetes are widely distributed in the natural environment, and soil with low water content, good ventilation and rich humus is suitable for the growth of a large number of actinomycetes. Since the 1950s, scholars at home and abroad, especially in Japan and the United States, have isolated a large number of actinomycetes from various terrestrial soils, studied their metabolites, and obtained many antibiotics. However, with the involvement of some large companies with abundant funds, the structures of a large number of antibiotics have been resolved, and it has become increasingly difficult to obtain new antibiotics and their source bacteria. In the past 10 years, a large number of research institutions have focused on the ocean, beaches, deep-sea sludge, etc., and the results have shown that marine microorganisms have more diversity and are an important source of many new antibiotics. SUMMARY

[0005] In order to solve the above-mentioned technical problems, the purpose of the present application is to provide a Streptomyces amritsarensis with broad-spectrum bactericidal activity.

[0006] In order to achieve the above-mentioned purpose of the application, the technical solution adopted by the present application is as follows: a Streptomyces amritsarensis from a 125-meter-deep soil layer of a coastal beach, named Streptomyces amritsarensis LW20211224-107, has been preserved in the China General Microbiological Culture Collection Center on January 20, 2025, and the preservation number is CGMCC No. 33482.

[0007] Further, the Streptomyces amritsarensis LW20211224-107 is from a 125-meter-deep soil layer of a coastal beach in Jiangsu.

[0008] Further, the Streptomyces amritsarensis LW20211224-107 is a gram-positive bacterium, and the growth temperature range is 10℃-37℃, and the pH growth range is 6.0-11.0.

[0009] Further, the Streptomyces amritsarensis LW20211224-107 has a genome size of 7.9Mbp and a GC content of 72.43%.

[0010] The second purpose of the present application is to provide an application of a Streptomyces amritsarensis from a 125-meter-deep soil layer of a coastal beach, and the Streptomyces amritsarensis LW20211224-107 with a preservation number of CGMCC No. 33482 is used as a bacteriostatic agent in the application of broad-spectrum bactericidal activity.

[0011] Further, the Streptomyces amritsarensis LW20211224-107 with a preservation number of CGMCC No. 33482 is obtained by fermentation culture to obtain a product with broad-spectrum bactericidal activity.

[0012] Further, the fermentation culture conditions are as follows: pH 7.0-7.5, 28℃-37℃, 150rmp-220rmp shaker culture for 36h-48h; the composition of the fermentation medium includes: 8g / L-12g / L of tryptone, 3g / L-8g / L of yeast extract and 8g / L-12g / L of sodium chloride.

[0013] Further, the broad-spectrum bactericidal effect includes gram-positive bacteria and gram-negative bacteria.

[0014] Further, the gram-positive bacteria and gram-negative bacteria include E. coli, Riemerella anatipestifer, Streptococcus suis, Streptococcus parauberis, Salmonella typhimurium, Serratia, Klebsiella pneumoniae, Edwardsiella, Staphylococcus aureus, MRSA, methicillin-resistant MRSA, Pseudomonas aeruginosa, and Clostridium perfringens from animals.

[0015] Further, the gram-positive bacteria and gram-negative bacteria include Streptococcus pneumoniae, Staphylococcus capitis, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella, Serratia, Klebsiella pneumoniae, Clostridium perfringens, Proteus vulgaris, Proteus mirabilis, Enterobacter cloacae, Micrococcus luteus, Citrobacter koseri, Proteus penneri, Citrobacter freundii, Escherichia coli, Acinetobacter baumannii, Proteus mirabilis, Enteraggregative, Serratia marcescens, and Pseudomonas alcaligenes from humans.

[0016] The beneficial effects of the present application are:

[0017] The strain of Streptomyces amritsarensis from a 125-meter-deep soil layer in a coastal beach and its secondary metabolites provided by the present application have an antibacterial spectrum different from existing antibiotics, and have strong antibacterial effects on G+ bacteria and G- bacteria. In the field of antibacterial research, the present application has good development and application prospects. After successful development, scientific and correct use will be able to cure a large number of patients and animals infected with bacteria, and will protect the health of humans and animals. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Streptomyces amritsarensis LW20211224-107, deposited with the China General Microbiological Culture Collection Center (CGMCC), located at No. 1, Beichen West Road, Yard 3, Chaoyang District, Beijing, China, with a postal code of 100101, on January 20, 2025, and with a deposit number of CGMCC No. 33482.

[0020] Figure 1Figure 1 is the photo of the antibacterial effect of Streptomyces amritsarensis LW20211224-107 provided in Example 1 on E. coli DH5a (PUC19) (A), E. coli DH5a (PUC19-bla NDM-1 ) (B), E. coli DH5a (PUC19-bla NDM-5 ) (C).

[0021] Figure 2 Figure 2 is the photo of the typical colony of Streptomyces amritsarensis LW20211224-107 provided in Example 1 on Gause No. 1 solid medium (A) and on ISP2 solid medium (B).

[0022] Figure 3 Figure 3 is the gel electrophoresis photo of the PCR amplification product of Streptomyces amritsarensis LW20211224-107 provided in Example 1.

[0023] Figure 4 Figure 4 is the phylogenetic tree of Streptomyces amritsarensis LW20211224-107 provided in Example 1 based on the neighbor-joining method.

[0024] Figure 5 Figure 5 is the genome circle chart of Streptomyces amritsarensis LW20211224-107 provided in Example 1.

[0025] Figure 6 Figure 6 is the KEGG pathway result classification chart of Streptomyces amritsarensis LW20211224-107 provided in Example 1. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objectives, features and advantages of the present application more apparent and comprehensible, the specific embodiments of the present application will be described in detail below with reference to the description and examples.

[0027] In the following description, a lot of specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the scope of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0028] Secondly, the "one embodiment" or "embodiment" referred to herein means a specific feature, structure, or characteristic that can be included in at least one implementation of the present application. The "in one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent or alternative to other embodiments.

[0029] In a first aspect of the embodiments of the present application, a strain of Streptomyces amritsarensis with broad-spectrum bactericidal activity is provided.

[0030] Specifically, the present application takes soil from the surface of the coastal mudflat in Jiangsu Province, every 25 meters, up to 150 meters, a total of 7 deep soil samples, using soil suspension dilution plating method to isolate strains, respectively to obtain single colonies. The obtained strains are purified and cultured in LB solid medium. The bacteriostatic activity of the strains on pathogenic bacteria E. coli DH5a (PUC19-bla NDM-1 ), E. coli DH5a (PUC19-bla NDM-5 ), and E. coli DH5a (PUC19) is determined, and the strain with the best bacteriostatic ability is selected, which is the strain marked as No. 107 from the 125-meter deep soil layer. The strain is a gram-positive bacterium. The bacterial DNA of the strain is extracted by boiling method, and according to the 16S rRNA sequencing result, the sequence of No. 107 strain is analyzed by Blast analysis through NCBI online query. According to the 16S rRNA sequence of No. 107 isolated strain and the 16S rRNA sequence of homologous strains published in GenBank, a phylogenetic tree is established by using MEGA5 software and Neighbor-joining method. According to the homology analysis result of 16S rRNA gene sequence, combined with phylogenetic analysis, No. 107 strain is identified as Streptomyces amritsarensis, belonging to Streptomyces, and named as Streptomyces amritsarensis LW20211224-107, and preserved in China General Microbiological Culture Collection Center on January 20, 2025, with the preservation number of CGMCC No. 33482.

[0031] The Streptomyces amritsarensis LW20211224-107 with the preservation number of CGMCC No. 33482 provided by the present application has a genome size of 7.9 Mbp and a G+C content of 72.43%. It has bacteriostatic activity on pathogenic bacteria E. coli DH5a (PUC19-bla NDM-1 ), E. coli DH5a (PUC19-bla NDM-5The bacteriostatic effect of the bacteriostatic agent on E. coli DH5a (PUC19) is excellent, and the bacteriostatic effect on more than 194 strains of G+ and G- bacteria isolated from different kinds of animals in veterinary clinical practice is strong. The bacteriostatic agent also has strong bacteriostatic effect on 64 strains of G+ and G- bacteria isolated from human medical clinical CCU.

[0032] In a second aspect of the embodiments of the present application, the application of Streptomyces amritsarensis LW20211224-107 with the preservation number of CGMCC No. 33482 as a bacteriostatic agent in broad-spectrum bactericidal activity is provided.

[0033] In some possible implementations, Streptomyces amritsarensis LW20211224-107 with the preservation number of CGMCC No. 33482 is obtained by fermentation culture to obtain a product with broad-spectrum bactericidal activity.

[0034] The present application provides the genome sequence of Streptomyces amritsarensis LW20211224-107 obtained by fermentation, which has different antibiotic bactericidal spectrum from existing antibiotics. Through online website (AntiSMASH (https: / / antismash.secondarymetabolites.org) analysis of the secondary metabolite biosynthesis gene cluster type of Streptomyces amritsarensis LW20211224-107 genome, it is found that there are 9 gene clusters with similarity less than 10%, which may be related to new antibiotics.

[0035] In some possible implementations, the fermentation culture conditions are as follows: pH 7.0-7.5, 28℃-37℃, 150rmp-220rmp shaker culture for 36h-48h; the composition of the fermentation medium includes: 8g / L-12g / L of tryptone, 3g / L-8g / L of yeast extract and 8g / L-12g / L of sodium chloride.

[0036] In some possible implementations, the broad-spectrum bactericidal activity includes gram-positive bacteria and gram-negative bacteria.

[0037] In some possible implementations, the gram-positive bacteria and gram-negative bacteria include E. coli, Riemerella anatipestifer, Streptococcus suis, Streptococcus parauberis, Salmonella typhimurium, Serratia, Klebsiella pneumoniae, Edwardsiella, Staphylococcus aureus, MRSA, methicillin-resistant MRSA, Pseudomonas aeruginosa and Clostridium perfringens.

[0038] In some possible embodiments, the gram-positive and gram-negative bacteria include those derived from human lower respiratory tract Streptococcus pneumoniae, Staphylococcus capitis, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella, Serratia, Klebsiella pneumoniae, Clostridium perfringens, Proteus vulgaris, Proteus mirabilis, Enterobacter cloacae, Micrococcus luteus, Citrobacter freundii, Proteus penneri, Citrobacter freundii, Escherichia coli, Acinetobacter baumannii, Proteus mirabilis, Enteraggregative Escherichia coli, Serratia marcescens, and Pseudomonas alcaligenes, but not effective for most Pseudomonas.

[0039] Obtaining and identification of Streptomyces amritsarensis LW20211224-107

[0040] I. Obtaining of Streptomyces amritsarensis LW20211224-107

[0041] In Jiangsu coastal mudflat, 250 g of soil was taken every 25 meters from the surface, up to 150 meters, and 7 deep soil samples were obtained for standby.

[0042] The soil suspension dilution coating plate method was used to isolate the strains. 10 g of naturally air-dried soil sample was randomly taken from each standby soil sample, ground in a mortar, and treated with 90 mL of sterile water with magnetic beads at 80°C for 1 h. The soil suspension was diluted 10 times by low-speed shaking bed (170 r / min, 28°C) for 1 h. After standing for 1 h, 1 mL of the diluted 10 times soil suspension was added to a test tube containing 9 mL of sterile water, and mixed well to obtain a soil suspension diluted 100 times. Similarly, 1 mL of the diluted 100 times soil suspension was added to a test tube containing 9 mL of sterile water, and mixed well after shaking to obtain a soil suspension diluted 1000 times. 0.2 mL of the diluted 1000 times soil suspension was coated on the isolation plate, and cultured at 28°C for 2 weeks to obtain single colonies. A total of 458 single colonies were obtained from the 7 deep soil samples, and were labeled as 1-458 in order.

[0043] 2. Strain purification and preservation

[0044] Improved Gao's No. 1 medium: soluble starch 20 g / L, KNO3 1 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.5 g / L, NaCl 0.5 g / L, FeSO4·7H2O 0.01 g / L, agar powder 15 g / L.

[0045] The obtained strain was cultured by plug method in modified Gao's No. 1 medium, and the color of mycelium, aerial mycelium and the water content of colony surface were observed by naked eyes, all of which had the characteristics of actinomycete colony, and the strain was actinomycete.

[0046] The single colony was selected on a 15d culture dish at 28℃, the strain was inoculated on modified Gao's No. 1 medium plate, and the strain was purified by plate streaking method, and the single colony of the purified strain was inoculated on the slant of modified Gao's No. 1 medium as the preliminary preservation of the strain. The purified strain was cultured in Gao's No. 1 liquid medium at 28℃ in a shaker at 170r / min for 3-5d. The glycerol with a mass percentage of 50% was prepared, and the glycerol and the bacterial liquid were mixed at a volume ratio of 1:1, and then preserved in a-80℃ refrigerator.

[0047] 3. Determination of the antibacterial activity of actinomycete on pathogenic bacteria

[0048] LB solid medium: yeast extract powder 5.0g / L, tryptone 10.0g / L, sodium chloride 10.0g / L, agar powder 15g / L.

[0049] LB liquid medium: yeast extract powder 5.0g / L, tryptone 10.0g / L, sodium chloride 10.0g / L.

[0050] The purified actinomycete in step 2 was vertically streaked on the LB solid medium, and then cultured in a 28℃ incubator for 3-4d.

[0051] 3.2) Preparation of pathogenic bacteria suspension:

[0052] The pathogenic bacteria E. coli DH5α (PUC19-bla NDM-1 ), E. coli DH5α (PUC19-bla NDM-5 ) and E. coli DH5α (PUC19) were inoculated in LB liquid medium, and cultured in a 28℃ shaker at 200r / min for 1d, and then anaerobically cultured in liquid thioethanolate medium to obtain the pathogenic bacteria suspension.

[0053] 3.3) Determination of antibacterial activity:

[0054] The pathogenic bacteria suspension was dipped, and then vertically streaked at 90° on the LB solid medium of the actinomycete cultured for 3-4d in 3.1), and then the plate was placed in a 37℃ incubator for 24h to observe the results.

[0055] 4. Screening

[0056] The pathogenic bacteria E. coli DH5α (PUC19-bla NDM-1)、E.coli DH5α(PUC19-bla NDM-5 ) and E.coli DH5α (PUC19), and found that the actinomycete No. 107, which was labeled as 107 and originated from the 125-meter-deep soil layer, had the best antibacterial ability.

[0057] Actinomycetes No. 107 were further subjected to an inhibition zone test. The method is as follows: streak a circle on LB solid medium and incubate in a 28°C incubator for 3-4 days. Once the actinomycetes have grown into a circular ring, apply a suspension of the pathogen to the entire medium with a cotton swab and incubate in a 37°C incubator for 24 hours before observing the results.

[0058] Figure 1 It is the activity of Actinomycetes No. 107 against E.coli DH5α(PUC19)(A), E.coli DH5α(PUC19-bla NDM-1 )(B), E. coli DH5α(PUC19-bla NDM-5 ) (C) Antibacterial effect photos. Its antibacterial effect on E.coli DH5α (PUC19) (A), E.coli DH5α (PUC19-bla NDM-1 )(B) and E. coli DH5α(PUC19-bla NDM-5 The diameter of the inhibition zone of )(C) is 42 mm.

[0059] 2. Identification of Streptomyces amritsarensis LW20211224-107 1. Actinomycete morphological identification:

[0060] Modified Gao's medium No. 1: soluble starch 20 g / L, KNO3 1 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.5 g / L, NaCl 0.5 g / L, FeSO4·7H2O 0.01 g / L, agar powder 15 g / L.

[0061] ISP2 medium: yeast extract powder 4.0 g / L, malt extract powder 10.0 g / L, glucose 4.0 g / L, agar powder 20 g / L.

[0062] 107 Actinomycetes, and observed the colony morphology and hyphae morphology, as shown in Table 1 and Figure 2 It can be found that the colonies on Gao's No. 1 solid culture medium are oval, without wrinkles, with a dry surface, and white aerial mycelium; the colonies on ISP2 solid culture medium are round, with wrinkles, a dry surface, white aerial mycelium, and radiation around the colonies.

[0063] Table 1. Culture morphology of LW20211224-107 on Gause I solid medium and ISP2 solid medium

[0064] Medium Colony characteristics State of water content Color of aerial hyphae Gause's No. 1 solid medium Elliptical, flat — White ISP 2 solid medium Circular, raised in the middle of the colony — White

[0065] 2. Physiological and biochemical characteristics of Actinomyces No. 107

[0066] Actinomyces No. 107 is a gram-positive bacterium with well-developed aerial hyphae and surface wrinkles. Its growth temperature range is 10-37°C, with an optimal growth temperature of 28°C. Its pH growth range is 6.0-11.0, with an optimal pH of 7.2.

[0067] 3. Extraction of DNA of Actinomyces No. 107 and PCR amplification, determination, comparison, and analysis of 16S rRNA gene

[0068] 3.1) Extraction of total DNA of Actinomyces No. 107:

[0069] In the super-clean bench, add single colony into 100 μL ddH2O and mix well by blowing. Boil at 100°C for 10 min and reserve.

[0070] 3.2) PCR amplification of 16s rRNA gene of Actinomyces No. 107:

[0071] Take 3 μL as template for 16S rRNA PCR amplification. Refer to the product manual of TIANGEN 2×Taq PCR Mastermix II for identification.

[0072] Upstream primer 27-F: 5'-AGAGTTTGATCCTGGCTCAG-3'

[0073] Downstream primer 1492-R: 5'-TACGGTTACCTTGTTACGACTT-3'

[0074] Synthesized in Suzhou Jinyuzhi Biological Technology Co., Ltd. The pre-amplified fragment size is about 1500 bp.

[0075] PCR reaction system 20 μL: 0.5 μL of upstream and downstream primers, 10 μL of 2×Taq PCR Mastermix II, 3 μL of template, and 6 μL of ddH2O.

[0076] PCR reaction conditions: 94°C pre-denaturation for 3 min; 94°C denaturation for 30 s, 58°C annealing for 30 s, 72°C extension for 1.5 min, for a total of 30 cycles; 72°C extension for 5 min.

[0077] 3.3) PCR amplification results of 16S rRNA gene:

[0078] The 16S rRNA gene sequence fragment of the actinomycete No. 107 was obtained by PCR amplification. The amplification product was detected by agarose gel electrophoresis, and observed and photographed by gel imaging instrument. The results are shown in Figure 3 . As shown in Figure 3 It can be seen that there are uniform and bright bands at the corresponding positions of 1500 bp.

[0079] The PCR product was sent to Nanjing Qikexi Biological Technology Co., Ltd. for sequencing. The 16S rRNA gene sequence is shown in SEQ ID No. 1. According to the 16S rRNA sequencing results, the sequence of the actinomycete No. 107 was analyzed by Blast (searching the database in GenBank using 16S rRNA sequence) by online query of NCBI. The sequence with the highest sequence similarity was found (Table 2). The phylogenetic tree was established by using MEGA5 software and Neighbor-joining method according to the 16S rRNA sequence of the isolated strain No. 107 and the 16S rRNA sequence of the homologous strain published in GenBank. The results are shown in Figure 4 .

[0080] According to the 16S rRNA gene sequence homology analysis results, combined with the phylogenetic analysis, the actinomycete No. 107 was identified as Streptomyces amritsarensis, belonging to the genus Streptomyces, and was named Streptomyces amritsarensis LW20211224-107.

[0081] Table 2. Comparison results of 16S rRNA gene sequence of strain LW20211224-107

[0082]

[0083] 4. Extraction and sequencing of genomic DNA of Streptomyces amritsarensis LW20211224-107

[0084] The single colony was inoculated into sterilized LB liquid medium, and cultured at 28°C and 180 r / min for 5-7 days. The bacterial cells were collected and sent to the sequencing company. The assembled genome was completed, and the gene prediction, functional element analysis and genome function annotation were carried out. The secondary metabolic gene clusters were analyzed on the online website of antiSMASH (https: / / antismash.secondarymetabolites.org). The corresponding products of the gene clusters were predicted by searching the homologous sequences of genes or proteins, and the prediction was carried out according to the composition of the biosynthetic genes in the gene clusters and the catalytic function of the enzymes encoded by the genes.

[0085] The extracted genome of Streptomyces amritsarensis LW20211224-107 was sent to Wuhan Benya Biotechnology Co., Ltd. for sequence determination. The genome size of Streptomyces amritsarensis LW20211224-107 is about 7.9 Mbp, and the G+C content is 72.43%. The genome circle map of Streptomyces amritsarensis LW20211224-107 is as shown in Figure 5 .

[0086] 5. Annotation of Streptomyces amritsarensis LW20211224-107

[0087] The protein coding regions (CDS) of the genome were functionally annotated in the KEGG database, as shown in Figure 6 there are 3713 CDS pathways related to metabolism, including 121 CDS related to nucleotide sugar metabolism, 147 CDS related to lipid metabolism, 198 CDS related to energy metabolism, 389 CDS related to amino acid metabolism, and 113 CDS related to the biosynthesis of other secondary metabolites; there are 251 CDS related to genetic information processes, including transcription, translation, replication and repair; there are 380 CDS related to environmental information processes, including signal transduction and membrane transport; there are 182 CDS related to cellular processes.

[0088] The type of secondary metabolite biosynthesis gene cluster of Streptomyces amritsarensis LW20211224-107 genome was analyzed by AntiSMASH (https: / / antismash.secondarymetabolites.org) online website, and the results showed that the gene clusters with similarity less than 10% (Table 3) were potential gene clusters of new antibiotics.

[0089] Table 3 Type of secondary metabolite biosynthesis gene cluster in Streptomyces amritsarensis LW20211224-107 genome (<10%)

[0090]

[0091]

[0092] Example 2 Determination of the antibacterial spectrum of Streptomyces amritsarensis LW20211224-107

[0093] 1. Method as follows:

[0094] 1.1) Streptomyces amritsarensis LW20211224-107 spore culture:

[0095] Inoculate the center of LB medium plate with a sterile loop dipped in LW20211224-107 spores, and use after 2-3 days of culture.

[0096] 1.2) Preparation of pathogenic bacteria suspension:

[0097] Inoculate the pathogenic bacteria into LB medium, and use Clostridium perfringens assay solid medium to activate anaerobically at 37°C for 24h, and then use liquid sulphite medium to obtain pathogenic bacteria suspension.

[0098] 1.3) Assay

[0099] Dip the pathogenic bacteria suspension and plate beside the Streptomyces amritsarensis LW20211224-107 colony after fermentation culture in 1.1).

[0100] 2. Drug resistance spectrum of veterinary clinical isolates

[0101] Streptomyces amritsarensis LW20211224-107 has good antibacterial effect on 194 strains of Gram-negative (G-) and Gram-positive (G+) bacteria isolated from different types of animals in veterinary clinics (Table 4). As can be seen from the comparison between the diameters of the inhibition zones, except for Pseudomonas aeruginosa, LW20211224-107 has strong antibacterial effect on Gram-negative and Gram-positive bacteria, especially on various Escherichia coli isolates.

[0102] Table 4 Results of antibacterial spectrum of LW20211224-107 against veterinary clinical isolates of Gram-negative and positive bacteria

[0103]

[0104]

[0105] Ec-1~Ec-115: clinical isolates of E. coli; Pae: Pseudomonas aeruginosa; Sty: Salmonella typhimurium; Se: Serratia marcescens; Kp: Klebsiella pneumoniae; Ed: Edwardsiella; Cp-1~Cp-96: clinical isolates of Clostridium perfringens; Sts: Streptococcus suis; Stp: Streptococcus parauberis; values are diameters of inhibition zones (mm)

[0106] 2. Drug resistance spectrum of strains isolated from upper respiratory tract samples of medical clinical CCU patients

[0107] Streptomyces amritsarensis LW20211224-107 has good antibacterial effect on 64 strains of medical clinical isolates of gram-negative and gram-positive bacteria (Table 5). As can be seen from the comparison between the diameters of inhibition zones, except for Pseudomonas aeruginosa, LW20211224-107 has strong antibacterial effect on gram-negative and gram-positive bacteria.

[0108] Table 5 Results of antibacterial spectrum of LW20211224-107 against medical clinical isolates of gram-negative and gram-positive bacteria

[0109]

[0110]

[0111]

[0112] Those skilled in the art will readily understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict. The above is merely a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is merely a preferred embodiment of the present application, and it should be noted that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications shall be regarded as the protection scope of the present application.

Claims

1. A strain of Streptomyces algae-dissolving bacteria, originating from a 125-meter-deep soil layer on a coastal mudflat, characterized by: It was named Streptomyces amritsarensis LW20211224-107 and was deposited in the General Microbiology Center of China Culture Collection Administration on January 20, 2025, with the deposit number CGMCC No. 33482.

2. The algae-dissolving Streptomyces strain from the 125-meter-deep soil layer of the near-shore mudflat according to claim 1, characterized in that: The algae-lytic Streptomyces amritsarensis LW20211224-107 is derived from a 125-meter-deep soil layer on the coastal mudflats of Jiangsu Province.

3. The algae-dissolving Streptomyces strain from the 125-meter-deep soil layer of the near-shore mudflat according to claim 1, characterized in that: The Streptomyces amritsarensis LW20211224-107 is a Gram-positive bacterium with a growth temperature range of 10° C.-37° C. and a pH growth range of 6.0-11.

0.

4. The algae-lytic Streptomyces strain derived from the 125-meter-deep soil layer of a coastal mudflat according to any one of claims 1 to 3, characterized in that: The Streptomyces amritsarensis LW20211224-107 has a genome size of 7.9 Mbp and a GC content of 72.43%.

5. The application of a strain of Streptomyces algae-dissolving bacteria from a 125-meter-deep soil layer on a coastal beach, characterized in that: The use of Streptomyces amritsarensis LW20211224-107 with a deposit number of CGMCC No. 33482 as an antibacterial agent in broad-spectrum fungicidal activity according to any one of claims 1 to 4.

6. The use according to claim 5, characterized in that The product with broad-spectrum bactericidal activity was obtained by fermentation culture of Streptomyces amritsarensis LW20211224-107 with a preservation number of CGMCC No. 33482.

7. The use according to claim 6, characterized in that The fermentation culture conditions are: pH 7.0-7.5, 28° C.-37° C., 150 rpm-220 rpm shaking culture for 36 h-48 h; the fermentation medium comprises: 8 g / L-12 g / L tryptone, 3 g / L-8 g / L yeast extract and 8 g / L-12 g / L sodium chloride.

8. The use according to any one of claims 5 to 7, characterized in that: The broad-spectrum bactericidal activity includes Gram-positive bacteria and Gram-negative bacteria.

9. The use according to claim 8, characterized in that The Gram-positive bacteria and Gram-negative bacteria include Escherichia coli, Riemerella anatipestifer, Streptococcus suis, Streptococcus paralactis, Salmonella typhimurium, Serratia marcescens, Klebsiella pneumoniae, Edwardsiella, Staphylococcus aureus, MRSA, methicillin-resistant MRSA, Pseudomonas aeruginosa and Clostridium perfringens derived from animals.

10. The use according to claim 8, characterized in that The Gram-positive and Gram-negative bacteria include Streptococcus pneumoniae, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella, Serratia marcescens, Klebsiella pneumoniae, Clostridium perfringens, Proteus vulgaris, Proteus mirabilis, Enterobacter cloacae, Micrococcus luteus, Citrobacter kluyveri, Proteus pennywise, Citrobacter freundii, Escherichia coli, Acinetobacter baumannii, Proteus mirabilis, Enterobacter agglomerans, Serratia marcescens and Pseudomonas alcaligenes from the human lower respiratory tract.

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