273 results about "Gram-positive bacterium" patented technology

The invention provides an antibacterial peptide and application thereof, and belongs to the technical field of biological medicine. Based on bioinformatics and an AI technology, a novel broad-spectrum antibacterial peptide is expected to be screened from tick (hard tick shoulder) genomes, and the antibacterial peptide has antibacterial activity on bacteria (including clinical drug-resistant strains) and fungi, does not have obvious cytotoxicity and hemolytic activity, and is an important candidate molecule of anti-infective drugs. In the embodiment of the invention, the minimum inhibitory concentration of the antibacterial peptide on gram-positive bacteria, gram-negative bacteria and fungi is verified, and the antibacterial peptide is proved to have obvious antibacterial activity on the gram-positive bacteria, the gram-negative bacteria and the fungi. The invention also verifies that the minimum inhibitory concentration of the antibacterial peptide to clinical drug-resistant bacteria is equivalent to the minimum inhibitory concentration of the antibacterial peptide to standard strains, and verifies that the antibacterial peptide can be used as a broad-spectrum antibacterial peptide and is named as SL-15.

The invention relates to application of ten antibacterial peptides in the antimicrobial field. The ten antibacterial peptides have strong antibacterial activity on multi-drug-resistant bacteria, including but not limited to gram-negative bacteria such as escherichia coli, pseudomonas aeruginosa, acinetobacter baumannii, klebsiella pneumoniae and the like, and gram-positive bacteria such as staphylococcus aureus, enterococcus faecalis and the like. Activity research proves that any one of the ten antibacterial peptides has a remarkable effect of inhibiting, killing or preventing microbial infection. Due to the strong antibacterial property of any antibacterial peptide, the antibacterial peptide has wide application potential in the aspects of preparing antibacterial drugs, preservatives, antibacterial coatings, antibacterial fibers, antibacterial packaging materials and the like. Due to the unique property of the antibacterial peptide in the aspect of antibacterial performance, a new direction is provided for the development of efficient and reliable antibacterial agents and antibacterial technologies and products in multiple fields.

The invention belongs to the technical field of biology, and particularly relates to antibacterial peptide based on large yellow croaker CXCL8 protein and application of the antibacterial peptide. The preparation method comprises the following steps: by taking a large yellow croaker CXCL8 protein as a template, intercepting a linear polypeptide of 13 amino acids, and carrying out carboxyl terminal amidation modification, so as to obtain the antibacterial peptide AVV13N, and the amino acid sequence of the antibacterial peptide AVV13N is Ala-Arg-Trp-Val-Arg-Arg-Val-Leu-Lys-Lys-Met-Val-NH2; the antibacterial peptide AVK13N is obtained by interchanging lysine at the 11th site and valine at the 13th site in an amino acid sequence of the antibacterial peptide AVV13N, and the amino acid sequence of the antibacterial peptide AVK13N is Ala-Arg-Trp-Val-Arg-Arg-Val-Leu-Lys-Lys-Val-Met-Lys-NH2. The molecular weights of the antibacterial peptides AVV13N and AVK13N are both 1669.12 Da, the isoelectric points of the antibacterial peptides AVV13N and AVK13N are both 12.44, and the antibacterial peptides AVV13N and AVK13N are both alkaline polypeptides. The antibacterial peptides AVV13N and AVK13N have broad-spectrum bactericidal activity and can be used for specifically killing gram-positive bacteria and gram-negative bacteria. In addition, the antibacterial peptides AVV13N and AVK13N have relatively weak hemolytic activity, relatively low cytotoxicity and good temperature stability, pH value stability and salt ion stability. The antibacterial peptides AVV13N and AVK13N provided by the invention can replace antibiotics and are applied to prevention and treatment of bacterial diseases.

The invention relates to the technical field of antibacterial peptide application, in particular to an antibacterial peptide cAMP-1116nc with a broad-spectrum antibacterial effect and application of the antibacterial peptide cAMP-1116nc. The antibacterial peptide cAMP-1116nc is obtained by carrying out N-terminal acetylation modification and C-terminal amidation modification on a polypeptide as shown in SEQ ID NO. 1. The antibacterial peptide cAMP-1116nc is an antibacterial peptide cAMP-1116nc. The antibacterial peptide cAMP-1116nc disclosed by the invention shows remarkable antibacterial activity in a plurality of gram-positive bacteria and gram-negative bacteria. The antibacterial peptide cAMP-1116nc can efficiently kill clinically common gram-negative pathogenic bacteria acinetobacter baumannii under the conditions that the pH is equal to 2, the pH is equal to 7.4 and the pH is equal to 8.4, has relatively low cytotoxicity, has the potential of preparing antibacterial drugs, and is suitable for developing antibacterial products with multiple purposes, including the antibacterial drugs, disinfectants and biological preservatives. The invention provides a novel functional polypeptide for the field of antibacterial peptides, and the novel functional polypeptide has important practical application value.

The invention discloses macromolecular antibacterial artificial leather and a preparation method thereof, and relates to the technical field of artificial leather preparation. The preparation method comprises the following steps: preparing zinc-loaded silicon dioxide with amino grafted on the surface and quaternized polyether polyurethane containing an epoxy group, mixing the zinc-loaded silicon dioxide and the quaternized polyether polyurethane to prepare antibacterial protection slurry, and bonding the zinc-loaded silicon dioxide and the quaternized polyether polyurethane through ring-opening reaction of the amino and the epoxy group during curing to form a cross-linked network, so as to obtain the antibacterial protection layer with antibacterial property, flexibility and wear resistance; zinc ions have an obvious inhibiting effect on bacteria such as gram-positive bacteria and gram-negative bacteria and fungi such as candida albicans, quaternary ammonium salt has an obvious inhibiting effect on influenza viruses, and the zinc ions and the quaternary ammonium salt have a synergistic effect, so that the antibacterial range of the artificial leather is wider, the inhibiting force on germs is stronger, and the antibacterial property of the artificial leather is further improved.

The invention provides an antibacterial peptide derived from zebra fish, the amino acid sequence of the antibacterial peptide is SEQ ID NO: 1, and the sequence of coding nucleotide of the antibacterial peptide is SEQ ID NO: 2. The antibacterial peptide provided by the invention can be used for preparing products for preventing, treating and resisting bacteria. The zebrafish antibacterial peptide mP60-81 disclosed by the invention has a remarkable antibacterial effect on gram-positive bacteria and gram-negative bacteria, is wide in antibacterial spectrum, has great use value, and has better application in the aspect of developing and preparing antibacterial agents. The antibacterial peptide is derived from zebra fish, can be applied to aquaculture as a feed additive, and can also be developed into an antibacterial agent, an antibacterial drug and the like, so that the antibacterial peptide has a wide application prospect.

The present invention discloses a strong, non-toxic, antibacterial and antiviral nano-functional material and a preparation method thereof. The nano-functional material is green, non-toxic and harmless, and its antibacterial and antiviral effect can reach more than 99%. The new nano-material innovatively uses the natural antibacterial agent meta-dichlorostyrene meta-dichloroacetophenone as the main body of the material to exert its antibacterial and antiviral effects. This makes the new nano-material not only have extremely strong antibacterial and antiviral effects, but also as a natural antibacterial agent, when it is used as a textile material, it can be non-toxic and harmless to the human body, green and healthy. It has a better inhibitory effect on both Gram-negative and Gram-positive bacteria than nano-copper oxide and meta-dichlorophenylethanol and meta-dichloroacetophenone. The present invention also provides a preparation method for the nano-functional material, which includes chemical reaction processes such as boron hydrolysis reaction, catalytic oxidation reaction, electrocarboxylation reaction, and esterification reaction.

The invention relates to a Fe3O4 (at) PDA-MnO2 nanometer material and a preparation method and application thereof, and belongs to the technical field of biological medicine, the Fe3O4 (at) PDA-MnO2 nanometer material shows excellent photo-thermal performance and peroxidase (POD) simulation activity, and the catalytic activity is enhanced under NIR irradiation. The Fe3O4 (at) PDA-MnO2 has a sterilization rate up to 99% and good biofilm formation destroying performance on gram-positive bacteria, gram-negative bacteria and gram-variant bacteria, in-vitro and BV mouse model experiments show that the Fe3O4 (at) PDA-MnO2 is combined with NIR irradiation, due to the synergistic antibacterial effect of the Fe3O4 (at) PDA-MnO2, vagina inflammation caused by bacterial infection of BV is remarkably reduced, and the Fe3O4 (at) PDA-MnO2 is superior to that of a positive control drug.

The invention belongs to the technical field of biomedicine, and particularly relates to a Chinese mouse ear-derived antibacterial peptide and application thereof. The antibacterial peptide derived from the Chinese mouse ear is MC-CATH1, MC-CATH2 or MC-CATH3, and the antibacterial peptide derived from the Chinese mouse ear is MC-CATH3; the antibacterial peptides MC-CATH1, MC-CATH2 and MC-CATH3 derived from the hepialus sinensis have relatively strong antibacterial activity on gram positive bacteria and gram negative bacteria, have broad-spectrum and efficient antibacterial action, and have the characteristics of low hemolytic activity, small cytotoxicity, salt tolerance and strong antibacterial biofilm activity, so that the antibacterial peptides MC-CATH1, MC-CATH2 and MC-CATH3 can be used for preparing the antibacterial peptides of the hepialus sinensis, and the antibacterial peptides MC-CATH1, MC-CATH2 and MC-CATH3 can be used for preparing the antibacterial peptides of the hepialus sinensis. In addition, the MC-CATH3 can kill bacteria by inducing the bacteria to generate a ferroptosis-like mechanism. The MC-CATH1, the MC-CATH2 and the MC-CATH3 can be applied to the fields of medicines, cosmetics, food preservation and the breeding industry.

The invention relates to application of a plant-derived extracellular vesicle and a compound thereof in preparation of a pharmaceutical composition for treating or preventing diseases caused by high colonization degree of gram-positive bacteria in skin, in particular to application of a purslane extracellular vesicle and a compound of the purslane extracellular vesicle and hydrogel.

The invention discloses an escherichia coli-bacillus subtilis shuttle plasmid and application, and belongs to the field of gene engineering. The shuttle plasmid comprises the following elements: a promoter sequence, a coding sequence of bacillus subtilis signal peptide, a replication initiation sequence of bacillus subtilis, a replication initiation sequence of escherichia coli and an antibiotic resistance gene. According to the plasmid design, a modular structure is adopted, and quick replacement of key elements such as a promoter, a signal peptide and RBS is supported through optimized enzyme cutting site layout; a 6 * His tag introduced at the tail end of a multiple cloning site (MCS) can be adapted to nickel column affinity chromatography, and the purification process of the recombinant protein is simplified. The plasmid has the characteristics of small molecular weight and convenience in operation, can be efficiently cloned and constructed in escherichia coli and then directly converted into bacillus subtilis for protein expression, is particularly suitable for development of a gram-positive bacterium secretory expression system, and provides an efficient tool for large-scale production of industrial enzyme preparations.

A peptidoglycan hydrolase LysPH1 having a broad-spectrum lytic activity, and a mutant and the use thereof, which belong to the technical field of biological formulations. An antibacterial peptide LysPH1-CP, a peptidoglycan hydrolase LysPH1 containing the antibacterial peptide LysPH1-CP and a peptidoglycan hydrolase mutant LysPH1-K containing the peptidoglycan hydrolase LysPH1 all have good thermal stability, and can broadly lyse both Gram-negative bacteria and Gram-positive bacteria. Moreover, the peptidoglycan hydrolase LysPH1 and the peptidoglycan hydrolase mutant LysPH1-K can be solubly expressed in Escherichia coli, and have high enzymatic activity. Therefore, the antibacterial peptide LysPH1-CP, the peptidoglycan hydrolase LysPH1 and the peptidoglycan hydrolase mutant LysPH1-K have good application prospects in the preparation of an anti-infective drug and the research and development of feed additives.

The invention discloses preparation and application of a hand mycin derivative with gram-positive bacterium activity resistance, and belongs to the technical field of medicine preparation. According to the present invention, the ctd gene cluster is subjected to heterologous expression in the strain Streptomyces lividans TK64, such that the obtained hand mycin derivatives Carpatamide N and Carpatamide O show excellent biological activity on the gram-positive bacteria; the MIC (minimal inhibitory concentration) values of the Carpamide N and the Carpamide O on streptococcus faecium and enterococcus faecium are 4 mu g / mL and 1 mu g / mL respectively; the MIC (minimal inhibitory concentration) values for staphylococcus aureus and bacillus subtilis are respectively 0.25 mu g / mL and 0.125 mu g / mL, the MIC values for MRSA (Methicillin-Resistant Staphylococcus Aureus) are respectively 1 mu g / mL and 0.5 mu g / mL, and the Gram-positive bacterium resisting activity of the compound is equivalent to or better than that of vancomycin.

The invention discloses a membrane-rupturing antibacterial peptide and application thereof. On the basis of an artificial intelligence screening method, a membrane-rupturing antibacterial peptide KLAKLLKLLLWAQNELDQKK is identified from a proteome of toads, the membrane-rupturing antibacterial peptide has three positive charges, and 50% of amino acid is hydrophobic amino acid. Through experimental tests, the antibacterial peptide can inhibit the growth of 10 different strains including gram negative strains and gram positive strains; meanwhile, the semi-maximum hemolysis concentration and the semi-maximum cytotoxicity concentration of the antibacterial peptide are both greater than 128 mu g / mL, and the antibacterial peptide has good biological safety. The antibacterial peptide plays an antibacterial role by destroying cell membranes, has the characteristic that the drug resistance of bacteria is not easily caused, and is an ideal development object of antibacterial drugs and antibacterial products such as disinfectants, detergents and feed additives.

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 invention belongs to the technical field of biological medicines, and particularly relates to a cyclic ester peptide compound, a producing strain thereof, a preparation method and application of the cyclic ester peptide compound in preparation of antibacterial medicines. The invention provides a cyclic ester peptide compound as shown in a formula I, a stereoisomer, a tautomer and an isotope derivative of the cyclic ester peptide compound, or a pharmaceutically acceptable salt of the cyclic ester peptide compound, a producing strain Streptomyces alboflavus sp.NX-12 of the cyclic ester peptide compound, and fermentation, separation and purification methods of the cyclic ester peptide compound and the stereoisomer, the tautomer and the isotope derivative of the cyclic ester peptide compound. The cyclic ester peptide compound has strong inhibitory activity on a variety of gram-positive bacteria, can be used for preparing antibacterial drugs, shows application potential in treatment of infection and other related diseases, and compared with the existing similar gram-positive bacterium-resistant glycopeptide antibiotic vancomycin, the cyclic ester peptide compound has the advantages that the cyclic ester peptide compound can be used for preparing the antibacterial drugs; the cyclic ester peptide compound disclosed by the invention has an equivalent antibacterial effect. The preparation method of the cyclic ester peptide compound is simple in process, short in time consumption, capable of greatly reducing the medicine cost and suitable for large-scale production. # imgabs0 #

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.

The application discloses an antibacterial peptide RV15 and application thereof, and belongs to the technical field of biology. The amino acid sequence of the antibacterial peptide RV15 is shown as SEQ ID NO. 1. The antibacterial peptide RV15 provided by the application has broad-spectrum antibacterial activity, has a significant bacteriostatic effect on gram-positive bacteria and gram-negative bacteria, and has a long bactericidal duration. The hemolytic activity is very low, and the biological safety is good. The antibacterial peptide RV15 can be used for treating bacterial infection, and can also be applied to other scenes requiring bactericidal action or bacterial growth inhibition. The antibacterial peptide RV15 provided by the application has a short sequence, a small molecular weight and low chemical synthesis difficulty, and can save the production cost on a large scale.

The present invention relates to the field of microorganisms, and particularly to a Bacillus amyloliquefaciens BZWQ833, a microbial agent and its application. A Bacillus amyloliquefaciens was screened from the rhizosphere soil of a potato common scab field with continuous cropping for many years, named Bacillus amyloliquefaciens BZWQ833 and subjected to biological preservation. This bacterium is a Gram-positive bacterium that can produce spores and can produce protease, cellulase and pectinase. The present invention first discovers that Bacillus amyloliquefaciens BZWQ833 can inhibit the growth and incidence of Streptomyces scabies, Rhizoctonia solani, Fusarium oxysporum and Fusarium solani, and the antibacterial effect is stable. Moreover, through greenhouse pot experiments and field control experiments, it is verified that Bacillus amyloliquefaciens BZWQ833 has a significant control effect on various plant soil-borne diseases (common scab, powdery scab and fruit rot), providing a new biological control resource for the biological control of plant soil-borne diseases.

The application discloses a kind of implant and its preparation method and application, the implant includes material body, metal oxide layer and mixed crystal layer, the mixed crystal layer is located the surface of the metal oxide layer;The metal oxide layer includes metal oxide nanorod array;The metal oxide is selected from zinc oxide, silver oxide or its combination;The mixed crystal layer includes CaP crystal and metal oxide crystal.The implant of the application is sterilized by the bacteriostatic metal ion generated by physical puncture and degradation of metal oxide nanorod, has good antibacterial effect to gram-positive bacteria and gram-negative bacteria, prevents infection;It can also relieve post-implantation inflammatory response, reduce immune response under post-implantation infection, shorten wound healing time.In addition, due to the coating effect of mixed crystal layer on metal oxide layer, the bacteriostatic metal ion is slowly released, the release time is long, and long-lasting antibacterial effect can be achieved, and post-implantation inflammatory response can be reduced.

The invention belongs to the technical field of biological high-throughput data analysis, and particularly relates to a method, a system, equipment and a medium for predicting inhibition specificity of an antibacterial peptide to gram-positive bacteria and gram-negative bacteria, the method comprises the following steps: acquiring an antibacterial peptide sequence with known activity, and respectively sorting antibacterial peptide data sets with gram-positive bacteria activity and gram-negative bacteria activity; on the basis of the obtained antibacterial peptide sequence, three feature models are constructed, the three feature models are trained and predicted through multiple machine learning algorithms, and the optimal model is screened through cross validation. According to the method, by introducing a multi-source feature construction and multi-model integration evaluation mechanism, the limitation that a traditional method depends on a single feature or a single algorithm is broken through, and accurate prediction of the activity difference of the antibacterial peptides between gram-positive bacteria and gram-negative bacteria can be achieved. Besides, the method not only can be used for classifying and predicting the activity of known antibacterial peptides, but also can be used for excavating potential novel antibacterial peptides which are not recognized in the past and have specific activity, and has a wide application prospect.

The present invention relates to a pyrazine macrolide compound and the use thereof. Specifically disclosed is a compound as represented by formula I or a pharmaceutically acceptable salt thereof. The compound of the present invention exhibits activity against bacteria, mycoplasmas, or chlamydias, and is useful for preventing and / or treating diseases caused by bacteria, mycoplasmas, or chlamydias. Further, the compound of the present application can achieve an antibacterial activity comparable to or better than that of azithromycin or solithromycin at a lower dosage. Furthermore, the compound of the present application achieves a superior antibacterial effect on Gram-positive bacteria. Still furthermore, the compound of the present application exhibits a better inhibitory activity against mycoplasmas and a lower hepatotoxicity.

The invention relates to an antimicrobial peptide consisting of the amino acid sequence: RX1WILX2WLRTWX3X4 wherein X1, X2, X3 and X4 are independently selected from K and R, and wherein each amino acid is independently in the L or D configuration, or a salt or solvate thereof. The use of said antimicrobial peptide in the treatment of an infection caused by Gram negative bacteria, Gram positive bacteria, fungi, and / or yeasts, as well as the use of said peptide as an antimicrobial agent for the prevention of contamination of an article or a living tissue by and / or for the decontamination of an article or a living tissue from Gram negative bacteria, Gram positive bacteria, fungi, and / or yeasts are further aspects of the invention.

The invention discloses a pearl sac antibacterial peptide and application thereof, and belongs to the technical field of biological medicine. The amino acid sequence of the gene is KRLF. According to the present invention, the theoretical molecular weight is 562.76 Da, the isoelectric point is 11.54, and the net charge is + 2 when the pH value is 7.0, and the antibacterial experiment result shows that the polypeptide has broad-spectrum and efficient antibacterial activity, and has significant inhibition effect on the proliferation of Gram-positive bacteria and Gram-negative bacteria. Safety evaluation experiment results show that the antibacterial peptide is beneficial to proliferation of keratinocytes and fibroblasts and is safe and non-toxic.

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 invention discloses a lactobacillus paracasei bacteriocin for inhibiting multi-drug-resistant pseudomonas aeruginosa and a preparation method of the lactobacillus paracasei bacteriocin, and belongs to the field of fermentation engineering. According to the invention, a multi-drug-resistant pseudomonas aeruginosa inhibition zone and lactic acid bacteria growth and acid production are taken as indexes, the casei paracasei KD10 capable of remarkably inhibiting multi-drug-resistant pseudomonas aeruginosa is screened and separated, fermentation conditions are optimized, bacteriocin is obtained by separation and purification from supernate of fermentation liquor, and the amino acid sequence of the bacteriocin is identified. Bacteriostatic experiments show that the lactobacillus paracasei KD10 bacteriocin has broad-spectrum bacteriostasis, and has a certain bacteriostatic effect on various clinically common gram-positive bacteria and gram-negative bacteria. In addition, bacteriocin has good stability to temperature, pH, non-digestive enzymes, storage temperature and ultraviolet rays, and is sensitive to digestive enzymes. The invention provides theoretical and technical references for the development of bacteriocin required for treating and preventing multi-drug-resistant pseudomonas aeruginosa infection.

The application provides a fluorescent compound, a preparation method and application of the fluorescent compound, and the compound is shown in formula (I). The compound can be used as a fluorescent probe for Gram-positive bacteria targeted imaging, and can directly kill bacteria, so that dual effects of fluorescent identification and bacterial killing on Gram-positive bacteria are realized.

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 invention discloses a preparation method of a tobacco stem extract and application of the tobacco stem extract as a microbial corrosion inhibitor, and belongs to the field of metal microbial corrosion and protection.The preparation method comprises the steps that collected tobacco stems are cleaned, aired and ground into powder to obtain tobacco stem powder, the tobacco stem powder is dispersed in an ethanol water solution to be soaked, then the solution is filtered, and filtrate is concentrated; and drying to obtain the tobacco stem extract. Antibacterial and corrosion characterization experiments prove that when the concentration of the tobacco stem extract reaches 200mg / L, a broad-spectrum antibacterial effect on gram-negative bacteria and gram-positive bacteria can be achieved, initial adhesion of microorganisms on the metal surface is effectively inhibited, a formed mature biofilm is eliminated, and an obvious inhibition effect on microbial corrosion is achieved. The raw materials of the tobacco stem extract are cheap and easy to obtain, the preparation method is simple, the process is green and environment-friendly, the antibacterial and corrosion inhibition effects are remarkable, and efficient prevention and control of metal material microbial corrosion in the environment can be achieved.

The invention provides bacillus licheniformis for high-yield protein glutaminase as well as a construction method and application of the bacillus licheniformis, a target strain is obtained by knocking out an alkaline protease gene aprE and extracellular protease genes bpr, epr, vpr or wpr and heterologously expressing the protein glutaminase gene, an EPE strain is optimal in expression, PG enzyme activity reaches 0.358 U / mL and is improved by 3.55 times compared with that of a wild type, and the bacillus licheniformis has the advantages that the bacillus licheniformis is high in yield and high in protein glutaminase yield. In addition, the growth condition of each mutant strain is not obviously abnormal, and the growth speed is obviously increased. It is fully proved that the expression level of the heterologous protein PG can be remarkably improved by targeted knockout of the extracellular protease gene of the bacillus licheniformis, and a theoretical basis is laid for construction of an efficient protein expression host. The invention not only provides a new scheme for high-efficiency expression of PG, but also provides important reference for expression optimization of heterologous proteins of other gram-positive bacteria, and shows a wide industrial application prospect.