25 results about "Gram-positive bacterium" patented technology

This disclosure relates to compositions and methods using genetically modified bacteria that express superoxide dismutase (SOD) and catalase enzymes to reduce oxidative stress in the skin, and can be used for various skin conditions. In some embodiments of this disclosure, the genetically modified bacteria are Gram-positive bacteria, for example, of the genus Corynebacterium.

The present invention belongs to the field of microbiology, and particularly relates to membrane vesicles (MVs) isolated from bacteria, and an isolation and preparation system and method for the membrane vesicles, and applications of the membrane vesicles. The bacteria of the present invention comprise Gram-positive bacteria and Gram-negative bacteria. The invention uses ionizing irradiation to irradiate bacteria, and isolates and purifies the produced membrane vesicles. The membrane vesicles prepared can be used as a vaccine, a vaccine adjuvant and / or a pharmaceutical carrier. In addition, the present invention provides a biological composition comprising the membrane vesicles and inactivated bacteria. In addition, the present invention also provides a preparation system, and isolation and purification system for bacterial membrane vesicles and the corresponding method. The membrane vesicles obtained by using the system and method have high yield, high purity and easy to be industrialized.

This invention belongs to the field of antimicrobial peptide technology, and particularly relates to a broad-spectrum antimicrobial peptide with low hemolytic activity and its applications, as well as a broad-spectrum antibacterial drug. The antimicrobial peptide is named AY6, and its amino acid sequence is shown in SEQ ID NO.1. Antimicrobial peptide AY6 exhibits significant antibacterial effects against both Gram-positive and Gram-negative bacteria, with a bactericidal rate far exceeding that of traditional antibiotics, enabling highly effective responses to bacterial infections. AY6 has low hemolytic activity and good biocompatibility, making it suitable for medical anti-infective applications. The antimicrobial peptide provided in this application has a short sequence, is easy to synthesize chemically, can save on large-scale production costs, and has broad application prospects.

The application provides a composite antibacterial peptide preparation, a preparation method and application. The composite antibacterial peptide preparation comprises a first defensin, a second defensin, a first cecropin and a second cecropin. The amino acid sequence of the first defensin is shown in SEQ ID NO:1, the amino acid sequence of the second defensin is shown in SEQ ID NO:2, the amino acid sequence of the first cecropin is shown in SEQ ID NO:3, and the amino acid sequence of the second cecropin is shown in SEQ ID NO:4. Compared with a single antibacterial peptide, the composite antibacterial peptide preparation has good stability, and shows good inhibitory effect on various gram-positive bacteria, gram-negative bacteria and fungi.

The application discloses a complex preparation containing bovine lactoferrin and lyticase and application thereof, and belongs to the technical field of biology. The preparation is composed of bovine lactoferrin and streptococcal lyticase, and both are prepared through a baculovirus-insect cell eukaryotic expression system. Researches show that the complex preparation has a significant synergistic antibacterial effect. The complex preparation not only can effectively inhibit a plurality of gram-positive bacteria, but also can overcome the limitation that single streptococcal lyticase has weak activity on gram-negative bacteria, and significantly enhances the inhibiting effect on escherichia coli and salmonella. Especially, the complex preparation still has clear in-vitro antibacterial activity on multi-drug resistant escherichia coli such as ciprofloxacin and doxycycline, thereby providing a new way for developing a new type of drug for resisting drug-resistant bacteria.

The present application relates to the technical field of microorganism, specifically relates to an engineering bacteria, a construction method, an engineering bacteria medicine delivery system and purposes thereof, and provides an engineering bacteria, which comprises at least one coding gene A capable of coding interferon IFN-gamma; the chassis bacteria of the engineering bacteria is Clostridium butyricum; since Clostridium butyricum is an anaerobic gram-positive bacteria, its spores can resist adverse environment and enter the intestinal cavity through gastric juice, and in view of the hypoxic microenvironment of tumor, the engineering bacteria Clostridium butyricum spores of the present application can target the hypoxic microenvironment of tumor, and further can mildly express IFN-gamma, the expression amount is stable, and it is more safe and reliable.

Compositions and methods for treating or reducing the severity or likelihood of occurrence of a parasitic worm or helminth infection in a subject are described. The methods include administering to the subject a therapeutically effective amount of a recombinant bacterium expressing a crystal protein such as a Bacillus thuringiensis crystal protein (Cry). The crystal proteins may be full length, truncated, variant, or sub-variant Cry proteins. Examples of crystal proteins include Cry5B, Cry21, Cry14A, Cry6A, and Cry13A. The recombinant bacterium may be, for example, a Bacillus subtilis or other Gram-positive bacterium, for instance, a lactic acid fermenting bacterium such as Lactococcus or Lactobacillus. Related compositions and recombinant microorganisms are also described.

The application discloses a bacteriocin expressed by bacillus subtilis WB800N and application thereof. The original sequence of the bacteriocin is a bacteriocin PA from bacillus polymyxa, the nucleotide sequence of the bacteriocin PA is shown as SEQ ID NO:1, and the amino acid sequence is shown as SEQ ID NO:2. The bacteriocin PA coding gene is modified by a tag and optimized by a codon to obtain a bacteriocin PFH, the nucleotide sequence of the bacteriocin PFH is shown as SEQ ID NO:3, and the amino acid sequence is shown as SEQ ID NO:4. The bacteriocin PFH expressed by the bacillus subtilis WB800N has a good bacteriostatic effect on gram-positive bacteria such as streptococcus suis, enterococcus faecium, staphylococcus aureus and bacillus subtilis, and has a wide application prospect in the development of a new type of replacement product for infection treatment and a feed antibacterial peptide.

This invention discloses a polypeptide derived from human lactoferrin and its applications. This invention relates to the field of biotechnology, providing the application of the polypeptide or related biomaterials in the preparation of products with anti-inflammatory and soothing functions; the amino acid sequence of the polypeptide is shown in SEQ ID NO:1. The lactoferrin peptide of this invention can reduce the expression of the inflammatory factor IL-6 in cells, exhibiting anti-inflammatory and soothing effects. Simultaneously, this lactoferrin peptide has an inhibitory effect on the growth of Gram-negative and Gram-positive bacteria, represented by *Escherichia coli* and *Staphylococcus aureus*. This lactoferrin peptide shows promising application prospects in the preparation of drugs and cosmetics for the prevention and / or treatment of bacterial infectious diseases.

The application provides a kind of base hornet MP-B peptide site-directed mutation derivative antibacterial peptide and its preparation method and application, belong to biotechnology field, the sequence of antibacterial peptide is as shown in SEQ ID No.1.The application uses base hornet MP-B peptide as template, respectively, the serine of 5, 8 is replaced by threonine, the amino acid sequence formed as shown in SEQ ID No.1, and the C-terminal is acylated with-NH2, is synthesized by solid phase chemistry, and after reversed-phase high performance liquid chromatography purification and mass spectrometry identification, the preparation of the antibacterial peptide is completed, the application of the antibacterial peptide in preparing antibacterial drug for treating gram-negative bacteria and / or gram-positive bacteria and / or fungal infectious diseases is disclosed.The antibacterial peptide of the application has the characteristics of high activity, low toxicity and high stability, and has the application potential of becoming a high-efficiency antibiotic substitute.

This invention discloses a highly efficient and safe antimicrobial peptide variant and its applications. Based on the natural antimicrobial peptide Upperin 3.6 sequence (as shown in SEQ NO:1), it involves replacing the disordered N-terminal region with the basic amino acid arginine; repeating two amyloid C-terminal sequences and adding three arginine residues to each end; and inserting a four-amino acid sequence DPDG (which has the greatest tendency to form a β-turn structure) between the two repeated amyloid C-terminal sequences and adding three arginine residues to each end. The antimicrobial peptide of this invention enhances the activity and safety of antimicrobial peptides, exhibiting good antimicrobial properties against both Gram-negative and Gram-positive bacteria. This antimicrobial peptide has broad application prospects as a novel antimicrobial agent.

This invention discloses a porcine lactobacillus mucosa HEB-FEC-LM-001 and its applications, belonging to the field of feed additive technology. The porcine lactobacillus mucosa HEB-FEC-LM-001 provided by this invention is a Gram-positive bacterium with a milky-white, raised colony appearance, clear edges, and a smooth surface. It was deposited at the China Center for Type Culture Collection on October 21, 2025, with accession number CCTCC NO:M 20252272. A synbiotic is prepared by combining porcine lactobacillus mucosa HEB-FEC-LM-001 with raffinose. When fed as a feed additive to weaned piglets, it can significantly improve the piglets' intestinal health, apparent nutrient digestibility, and immune function, significantly reduce the diarrhea rate, and improve the growth performance of weaned piglets. Therefore, it has broad application prospects as a feed additive for weaned piglets.

This invention relates to the field of detection and provides a bioaerosol sampling solution. The bioaerosol sampling solution comprises the following components in the following proportions: a chelating agent, a buffer, a surfactant, a protein denaturant, a humectant, and a solubilizer. The sampling solution with specific components of this invention can directly achieve a lysis effect, thereby integrating the nucleic acid extraction step into the collection step, reducing existing sampling operations, reducing system losses, and achieving highly efficient collection results. Simultaneously, the sampling solution with specific components of this invention has excellent bactericidal effects on Gram-negative and Gram-positive bacterial solutions of different concentrations, effectively preventing microbial toxicity and personnel infection during the sampling process. Furthermore, when using the sampling solution of this invention for sampling, there is no need for repeated removal / replacement, further ensuring the potential biosafety of operators.

The application discloses a kind of chitosan / nano clay antibacterial non-woven fabrics and its preparation method and application.The method is: under the state of stirring, chitosan or its derivative is stirred and dissolved, and a certain amount of nano clay is added to obtain a mixed solution;Then the mixed solution is loaded on non-woven fabric (such as soaking, spraying, smearing), and the chitosan / nano clay antibacterial non-woven fabric is obtained after drying.The cloth has excellent antibacterial properties, including gram-positive bacteria, negative bacteria and fungi, and good softness and air permeability, and can be used for medical or disposable sanitary products such as masks, protective clothing, paper diapers.Compared with the prior art, the preparation method is simple and easy to operate, and has good application prospect.

The application discloses a pearl capsule antibacterial peptide and application thereof, and belongs to the technical field of biological medicine. The amino acid sequence of the pearl capsule antibacterial peptide is KRLF. The theoretical molecular weight is 562.76 Da, the isoelectric point is 11.54, the net charge is +2 at pH=7.0, and the antibacterial experiment result shows that the polypeptide has broad-spectrum and high-efficiency antibacterial activity and has obvious inhibiting effect on the proliferation of gram-positive bacteria and gram-negative bacteria. The safety evaluation experiment result shows that the antibacterial peptide is beneficial to the proliferation of keratinocytes and fibroblasts and is safe and non-toxic.

This invention discloses a recombinant lysozyme derived from the myxomycete *Leptospora*, a species of myxomycete, and its preparation method and applications, relating to the field of biotechnology. The amino acid sequence of this recombinant lysozyme is shown in SEQ ID NO.1. This invention screened and obtained a novel lysozyme from *Leptospora*. Unlike traditional lysozymes that prefer Gram-positive bacteria, this lysozyme exhibits highly efficient antibacterial activity against Gram-negative bacteria such as *Escherichia coli* and *Pseudomonas aeruginosa*, and is equally effective against multidrug-resistant and carbapenem-resistant strains. This lysozyme maintains high enzyme activity at 20-60℃ and exhibits excellent stability at pH 7.0-9.0. 2+ It can significantly activate enzyme activity and has good industrial compatibility. Overall, this enzyme overcomes the bottlenecks of traditional lysozymes, such as narrow antibacterial spectrum and weak efficacy against Gram-negative bacteria, and has broad application prospects in fields such as pharmaceutical antibacterial, food preservation, and animal disease prevention.

This invention relates to the field of antimicrobial peptide technology, and particularly to the antimicrobial peptide Ple-AB, its preparation method, and its applications. Using the fungal defensin Plectasin as a template, this invention designs and modifies the antimicrobial peptide Ple-AB. Compared with Plectasin, this antimicrobial peptide exhibits significantly higher antimicrobial activity and better bactericidal effects against Gram-positive bacteria; it also shows higher stability, particularly excellent resistance to trypsin; and its fermentation expression level is significantly improved. Furthermore, this antimicrobial peptide has very low hemolytic activity and cytotoxicity, making it suitable for development in antimicrobial drugs, additives, cosmetics, health products, and other fields, with broad application value and market prospects.

The application discloses application of bicyclic phloroglucinols in preparation of antibacterial drugs, and relates to the technical field of medicines.Bicyclic phloroglucinols (BPs) synthesized based on the skeleton of natural phloroglucinols have universal inhibitory activity on gram-positive bacteria, and the BPs can effectively reduce the effective concentration of common antibiotics (vancomycin, norfloxacin, meropenem, erythromycin and rifampicin) on bacteria, enhance the antibacterial effect of the antibiotics, and expand the antibacterial spectrum of the antibiotics. S. aureus The BPs involved in the application have the advantages of brand-new structure, high antibacterial activity, synergistic effect when combined with antibiotics, and the like, have great potential to be prepared into antibacterial drugs, and have high commercial potential.

The application belongs to the technical field of fine chemical industry, and discloses a target gram-positive bacteria near-infrared fluorescent probe based on bacterial wall peptidoglycan synthesis and a preparation method and application thereof. The application provides a target gram-positive bacteria near-infrared fluorescent probe based on bacterial wall peptidoglycan synthesis. The target gram-positive bacteria near-infrared fluorescent probe takes quinoline nitrile as a parent unit to realize assembly lighting for the bacterial wall limited environment; D-lysine structural units are taken as bacterial wall peptidoglycan binding groups; groups such as thiophene are introduced to prolong the fluorescent emission of the dye; a double-charged group such as a sulfonic acid group betaine is introduced to improve the dispersity of the probe, so as to reduce the background fluorescent interference of the probe, improve the labeling efficiency, and realize efficient no-wash imaging; based on the above molecular rational design, the probe has many advantages such as long fluorescent emission wavelength (near-infrared fluorescent emission), good selectivity, high bacterial labeling efficiency and the like.

The present invention relates to a bacterium, in which the expression and / or the activity of surface proteases is / are inhibited, to its preparation process and to the uses of this bacterium.

The application of FGF8 protein in the preparation of antibacterial agents is provided. Escherichia coli BL21 (DE3) is used to express grass carp FGF8a and murine FGF8b. After purification through Ni2+-TED agarose gel column, recombinant proteins of grass carp FGF8a and murine FGF8b are obtained. Both proteins exhibit significant bactericidal effects against Gram-negative bacteria and Gram-positive bacteria, and can be used to prepare broad-spectrum antibacterial agents or antibacterial drugs, demonstrating high application value.

The application discloses an aromatic polyketone compound and a preparation method and application thereof, and belongs to the field of biological medicines. Two aromatic polyketone compounds are produced by streptococcus, and the structural formula is shown as formula (I). The antibacterial activity test is carried out on the compounds 1 and 2, the compounds 1 and 2 have broad-spectrum antibacterial activity on four kinds of gram-positive bacteria, and therefore the aromatic polyketone compounds can provide alternative compounds for developing new antibacterial drugs.

The present application belongs to the technical field of molecular biology, and relates to a truncated fish peptidoglycan recognition protein and application thereof. The amino acid sequence of the truncated fish peptidoglycan recognition protein is shown in Table SEQ ID NO. 1. The truncated fish peptidoglycan recognition protein provided by the present application has higher expression efficiency and higher yield in a prokaryotic expression system compared with a natural peptidoglycan recognition protein. The truncated fish peptidoglycan recognition protein has stronger binding capacity with peptidoglycan (PGN) and lipopolysaccharide (LPS), which are main components of cell walls of gram-positive bacteria and gram-negative bacteria. The bacteriostatic and agglutination capacity of the truncated fish peptidoglycan recognition protein on gram-positive bacteria and gram-negative bacteria is significantly improved. These characteristics show that the truncated fish peptidoglycan recognition protein has development potential as an aquatic immunopotentiator, and provides important support for subsequent application research.