25 results about "Host bacterium" patented technology

The application discloses a kind of exogenous bacteriophage inoculation methods for strengthening soil microbial arsenic methylation capacity, comprising the following steps: S1. preparation bacteriophage crude extract;S2. preparation concentrated solution;S3. preparation bacteriophage extract;S4. preparation inoculation soil sample;S5. in the 2, 4, 6th day of culture, bacteriophage extract is added to inoculation soil;S6. after three times inoculation, continue to flood culture 9 days.The application proposes a kind of inoculation method for retaining virulent bacteriophage, not retaining original host bacteria, inoculating after flooding two days, and inoculating three times, so that the proportion of lysogenization of bacteriophage in soil after inoculation is increased by 156%~347%, so that arsenic metabolism genes carried by bacteriophage genome can function, the arsenic methylation capacity of soil microorganism is strengthened, and the arsenic methylation capacity is increased by more than 300%, to efficiently methylate arsenic in soil.

This invention discloses a method for the efficient synthesis of gastrodin using recombinant Corynebacterium glutamicum, belonging to the fields of genetic engineering, fermentation engineering, and synthetic biology. This invention uses Corynebacterium glutamicum as the host bacterium and knocks out… pobA The gene was expressed, and the engineered strain WN01 / pB6 was constructed using the expression plasmid pEC-XK99E to express cladoid-pyruvate lyase, carboxylic acid reductase, and glycosyltransferase, achieving heterologous synthesis of gastrodin. Further overexpression was then performed. aroG Genes, overexpression of protein-coding genes that activate carboxylic acid reductase sfp The engineered strain WN05 / pB6 was able to synthesize 7.37 g / L of gastrodin at the shake flask level, and the gastrodin yield reached 17.77 g / L at 72 h of batch fermentation in a 5-L fermenter, with a yield of 0.247 g / L / h. This provides a brand-new biomanufacturing platform for the industrial production of gastrodin.

This invention discloses an anti-phage system based on ESCRT-III and its applications, relating to the field of biotechnology. This invention utilizes the coding genes for two structural proteins of the Hoda_Snf7_1 and Hoda_Snf7_2 from the Hoda archaea ESCRT-III. Hoda_ snf7_1 and Hoda_snf7_2 This invention is applied to antiphage systems. Compared with existing technologies, the main advantages of the antiphage system of this invention are: (1) it consists of only two genes, making system construction simple and quick; (2) it is composed of structural proteins, making it less prone to losing antiphage activity due to gene mutations; (3) it has a broad-spectrum antiphage effect; and (4) it does not affect the normal growth of host bacteria. This system expands the understanding of antiphage systems and provides new ideas and technical means for preventing and controlling phage contamination in industrial microbial production processes.

This invention relates to the fields of environmental monitoring and biosafety technology, and in particular to a viral aerosol sampling patch for face masks, comprising: a capture layer for intercepting viral aerosol particles in the air; a culture layer disposed inside the capture layer, the culture layer comprising a culture unit supporting the virus to maintain activity and replicate in the presence of a host, a host bacterium sensitive to the virus, and a visual indicator indicating viral replication or host response; and a base layer disposed inside the culture layer; the sampling patch is fixed to the face mask through the base layer, and viral aerosol collection is achieved without external power through the capture layer, and countable detection results are generated after sampling through the culture layer; utilizing the airflow and humidity conditions naturally formed during wearing, effective interception, activity preservation, and visual detection of viral aerosols are achieved without complex equipment and additional operating steps, and the operation is simple and repeatable.

This invention belongs to the field of protein engineering and biomedicine, and particularly relates to a water-soluble membrane protein, a recombinant vector, a recombinant host bacterium, and their modification methods and applications. The method involves the following steps: First, an interface mutant is constructed based on the SQTY code, and its water solubility and ligand binding ability are evaluated. If the requirements are not met, multiple low-impact transmembrane regions are screened, and after mutation modification, the interface mutant is introduced to construct a single-transmembrane combined mutant, whose water solubility and ligand binding ability are evaluated. If the requirements are still not met, the multiple low-impact transmembrane regions are combined in pairs, and the interface mutant is introduced to construct various double-transmembrane combined mutants, whose water solubility and ligand binding ability are evaluated, and the optimal double-transmembrane combined mutant is selected. This method rationally mutates CXCR4 in stages to achieve water solubility, minimizing changes to the protein's structure and other physicochemical properties, thereby maintaining or even enhancing its binding ability to the ligand CXCL12.

The application discloses a method for removing chaperone and application thereof. The method for removing chaperone comprises the following steps: after a sample containing a target recombinant protein is loaded on an affinity chromatography column, a washing liquid containing urea and KCl is used to flush the affinity chromatography column, so as to remove the chaperone combined with the target recombinant protein. The method of the application can effectively remove the chaperone of about 60 kDa from an escherichia coli host bacterium by combined washing of urea and KCl, and has the advantages of simple operation, low cost, good chaperone removal effect for various recombinant proteins with different molecular weights, wide universality, and the like, and can significantly improve the purity and quality of the recombinant protein.

Disclosed herein are methods and compositions for increasing culture stability of a bacterial culture comprising a plurality of a modified bacterium comprising a modified prophage. Also disclosed herein are methods and compositions for decreasing the likelihood of replication of a modified prophage in a bacterial genome as compared to the likelihood of replication of a corresponding prophage lacking the prophage modification in a corresponding bacterial genome. Also disclosed herein are methods and compositions for preventing excision of a prophage in a bacterium. Also disclosed herein are methods and compositions for generating a modified prophage having an impaired ability to lyse a host bacterial cell.

DEPCT6604 / 07 / 2566 This invention involves a DNA structure suitable for expression. Recombinant proteins in bacterial host cells that include the following DNA structure: Coding nucleotide sequence: promoter rhaBAD, RhaR transcription activater, RhaS Transcription activators, antibiotic resistance indicators, actively linked promoters. Along with nucleic acids that encode indicators of antibiotic resistance, the terminators rrnBT1 and rrnBT2. The point for initiating self-replication, pMB1, is a DNA structure that may also be assembled with sequences. The nucleotides that encode the recombinant protein are functionally linked to the promoter. This invention, rhaBAD, involves, in addition to a vector and a bacterial host cell that are combined. Given this DNA structure and the method of producing recombinant proteins... By contacting the host bacterial cells with rhamnose, the expression of these cells is stimulated. Of the aforementioned recombinant proteins;

This invention belongs to the field of bioengineering technology, specifically relating to a gene for efficiently expressing thymosin α1 (Tα1), recombinant lactic acid bacteria, and their applications. This invention provides a Tα1 encoding gene specifically optimized for *Lactococcus lactis* NZ9000, which significantly improves expression efficiency in the host through full-sequence codon adaptation. This gene was cloned into the vector pNZ8148-M, constructing the recombinant expression plasmid NZ9000 / pNZ8148-M. usp45 + T α1 The strain was successfully transformed into the host bacterium NZ9000, yielding recombinant lactic acid bacteria NZ9000 / pNZ8148-M. usp45 + Tα1 This recombinant strain can efficiently secrete the Tα1 fusion protein USP under Nisin induction. 45 +Tα1, the protein is digested in vitro by enterokinase to release active Tα1. The Tα1 produced by the method of this invention has high yield, high purity, high biological activity and excellent safety, providing a new technical platform for the low-cost, large-scale and safe production of Tα1.

This invention relates to an expression vector, engineered bacteria, and method for inducing expression of a serine protease. The expression vector contains a nucleic acid sequence encoding a serine protease, and the amino acid sequence of the serine protease includes the sequence shown in SEQ ID NO.1. This invention transforms the expression vector into a host bacterium and utilizes its unique high-efficiency expression system for protein expression. By optimizing culture and induction conditions, high-efficiency expression of the serine protease was successfully induced. This serine protease exhibits highly efficient hydrolytic ability, with an enzyme activity reaching 925 U / mL.

The application discloses a polypeptide for presenting a heterologous protein to an outer membrane vesicle and application thereof. Specifically disclosed are a polypeptide with an amino acid sequence of SEQ ID No. 1 and application thereof in presenting a heterologous protein to an outer membrane vesicle of a host bacterium. The application successfully expresses the heterologous protein in OMVs of Xanthomonas campestris by connecting the polypeptide with the heterologous protein. Xanthomonas campestris is a plant pathogenic bacterium, has low immunogenicity to human bodies, has a unique advantage for biomedical application of OMVs, and realizes presentation of the heterologous protein in Xanthomonas campestris OMVs for the first time, thereby providing a solution for future plant biotechnology, development and application of a vaccine adjuvant and the like. The polypeptide of the application realizes presentation of the heterologous protein by using only 25 amino acids, and can minimally affect the conformation and activity of the presented protein.

This invention discloses an engineered methanogenic bacterium that produces high levels of squalene, its construction method, and its applications, belonging to the fields of metabolic engineering and synthetic biology. This is achieved by using a strong promoter in the host bacterium (methanogenic bacterium). P mxaF Expression of squalene synthase encoding gene sqs Overexpression of the gene encoding 1-deoxy-xylulose-5-phosphate synthase in the squalene synthesis pathway dxs1 and dxs2 Farnesyl pyrophosphate synthase encoding gene ispA Isopentenyl pyrophosphate isomerase encoding gene My friends Simultaneously overexpressing glucose-6-phosphate dehydrogenase zwf1 and the EMP pathway pfk1 and fba2 An engineered methanogenic bacterium producing squalene was obtained. Using this engineered methanogenic bacterium for squalene fermentation production can significantly increase squalene yield and has excellent prospects for industrial application.

The application relates to a high-throughput screening method of a glycosaminoglycan backbone synthase. The method comprises the following steps: (1) constructing a glycosaminoglycan backbone synthase library; (2) constructing a recombinant vector; (3) constructing a recombinant bacterium for screening the glycosaminoglycan backbone synthase; (4) culturing the recombinant bacterium; (5) after the bacterial liquid of the recombinant bacterium is analyzed or sorted through flow, the fluorescence is measured, and the target glycosaminoglycan backbone synthase is screened. In the application, the Bacillus subtilis BS168ASS is used as a host bacterium, the uridine diphosphate-glucose-6-dehydrogenase gene and the glycosaminoglycan backbone synthase gene are overexpressed, and the recombinant bacterium for screening the glycosaminoglycan backbone synthase is constructed. Then, the fluorescence of the strain is measured, the glycosaminoglycan backbone synthase strain is accurately screened in a high-throughput mode, the screening efficiency is improved, and a new starting point is provided for the discovery of new glycosaminoglycan backbone synthases in microorganism groups of new sources, especially in the microorganism groups that cannot be cultured in a metagenome library.

This invention provides a bovine FSH recombinant protein, a recombinant expression vector, and a method for preparing the same. The bovine FSH recombinant protein has the amino acid sequence shown in SEQ ID NO.1, SEQ ID NO.2, SEQ ID NO.3, or SEQ ID NO.4. A method for preparing the bovine FSH recombinant protein involves expressing the coding gene shown in SEQ ID NO.5, SEQ ID NO.6, SEQ ID NO.7, or SEQ ID NO.8 in a host bacterium or host cell to obtain a low-glycemic FSH recombinant protein. This invention, through genetic engineering, obtains a bovine FSH recombinant protein by first constructing a vector and then artificially regulating post-translational N-glycosylation modification by introducing the Asn-X-Thr mutation of the N-glycosylation motif, achieving stable and efficient expression of low-glycemic FSH with significantly enhanced biological activity.

The application belongs to the technical field of genetically engineered bacteria, and specifically discloses a high-yield thiostrepton engineered bacterium based on double reporter genes, a construction method and application thereof. The construction method comprises the following steps: introducing a recombinant expression vector containing a promoter sequence of tsrI-tsrH and a reporter gene XylE into a host bacterium to obtain a donor bacterium; co-culturing the donor bacterium with Streptomyces laurentii to obtain a conjugant; culturing the conjugant in a culture medium containing kanamycin for screening, and then verifying XylE enzyme activity coloration, and finally screening a positive recombinant strain with yellow color. Through a double reporter gene combined screening strategy, the hit rate of screening of high-yield strains is increased from 28.0% of traditional single resistance screening to 92.0%, the fermentation titer of the screened recombinant strain reaches 333.43 U / mL, and the average yield is 3.3 times that of the single resistance screening group. The recombinant strain also has excellent genetic stability and is suitable for industrial production.

The application belongs to the technical field of genetic engineering, and particularly relates to a recombinant humanized type XVII collagen COL1115 and a preparation method thereof. The amino acid sequence of the recombinant humanized type XVII collagen COL1115 comprises the amino acid sequence shown in SEQ ID NO:1. SEQ ID NO:5 is cloned into a vector to obtain a recombinant vector; the recombinant vector is transformed into a host bacterium to obtain a recombinant engineering bacterium; and after fermentation culture and induction expression of the recombinant engineering bacterium, the recombinant humanized type XVII collagen COL1115 is obtained. The recombinant humanized type XVII collagen COL1115 prepared by the application has excellent expression performance in a Pichia pastoris expression system, can realize high-efficiency secretory expression, and is confirmed to have significant cell proliferation activity and cell adhesion activity through activity detection, thereby laying a foundation for application of the collagen in the biomedical field.

This invention belongs to the field of synthetic biology and discloses tetracycline compounds modified with a polysaccharide group at the C8 position, their biosynthetic methods, and applications. The tetracycline compounds with a polysaccharide group modification at the C8 position provided by this invention have a novel structure; the trisaccharide and hexasaccharide groups present at the C8 position are not found in known tetracycline natural products or tetracycline skeleton antibiotics. The biosynthetic method involves using a polysaccharide group derived from *Streptomyces rubrum*. ech Gene clusters, in which mis This invention expresses the gene cluster in the *Streptomyces micranthum* host, fully utilizing the different biosynthetic enzymes contained in two similar but different tetracycline natural product biosynthetic gene clusters to synthesize novel compounds that neither host bacterium can synthesize. These compounds exhibit significant inhibitory activity against *Staphylococcus aureus*, *Enterococcus faecalis*, and *Enterococcus faecium*. This invention provides new candidate compounds for the innovative development of tetracycline-based antibacterial drugs and is of great significance to the development of microbial drug resources.

The application provides a recombinant bacillus subtilis producing phage lytic enzyme LysJPP58 and a construction method and application thereof. The recombinant bacillus subtilis integrates the lytic enzyme LysJPP58 into the genome of a host bacterium bacillus subtilis, wherein the lytic enzyme LysJPP58 is derived from a staphylococcus aureus phage, and an amino acid sequence of the lytic enzyme LysJPP58 is shown as SEQ ID NO. 1. The recombinant bacillus subtilis can effectively secrete the LysJPP58 protein with lytic activity, and can significantly lyse staphylococcus aureus. The recombinant bacillus subtilis has the characteristics of safety, sustainability and industrial fermentation production, and provides a new technical approach for the development of animal health, food safety and medical antibacterial preparations.

This invention relates to the field of biomedical genetic engineering, specifically to a *Lactococcus lactis* expression vector suitable for in vitro induction and its application. The expression vector utilizes the promoter and secretory signal peptide of the *Bifidobacterium* exoxylanase (ECX) gene to control the expression and secretion of exogenous genes. It can induce the expression and secretion of exogenous target genes in the intestinal lumen or in vitro using *Lactococcus lactis* as the host bacterium and xylooligosaccharides or xylans as inducers. By inserting the exogenous target gene into the *Lactococcus lactis* exogenous gene inducible expression vector of this invention, the host bacterium is electroporated to obtain genetically engineered bacteria, which can then be used to produce biopharmaceuticals or food products.

The application belongs to the technical field of genetic engineering and enzyme engineering, and discloses a nitrile hydratase mutant and application thereof, wherein the mutant is obtained by single mutation or multiple mutations of positions 22, 42, 63, 73, 105, 131, 145 and 163 of the amino acid sequence shown in SEQ ID NO. 1. The nitrile hydratase mutant of the application can be expressed in a high-density fermentation host bacterium in a heterologous manner, can improve the substrate catalytic concentration to 1000 g / L, is applied to catalytic synthesis of 4-acetyl-2-methylbenzamide, is green, environmentally friendly, non-polluting, has high catalytic efficiency and high product conversion rate.

The application discloses a sweet orange low-temperature response gene in the technical field of plant genetic engineering CsFBK and application thereof, and aims to solve the problem that new genes of citrus low-temperature stress response need to be further mined in the prior art, and provide a basic problem for plant low-temperature stress response research work. The application comprises a plant low-temperature response gene CsFBK , a protein coded by the gene, an expression vector containing the plant low-temperature response gene CsFBK CsFBK CsFBK CsFBK CsFB or a fragment thereof, a transgenic cell line or a host bacterium, and a method for preparing a low-temperature sensitive plant material; and the low-temperature sensitive material provided by the application is suitable for scientific research work of plant low-temperature stress response regulation.

The application discloses a method for improving expression of exogenous glycoprotein by yeast, comprising the following steps: without changing endogenous genes of a yeast host cell and without introducing exogenous sugar chain processing enzymes, an exogenous N-acetylglucosamine transferase I (GnT1) gene from different species is integrated into a genome of a Pichia pastoris host bacterium for expressing glycoprotein, and a Pichia pastoris engineering bacterium for expressing the exogenous GnT1 is constructed, so that the expression amount of the exogenous glycoprotein in the Pichia pastoris engineering bacterium is significantly improved, the proportion of high mannose type N-glycan is reduced, and the proportion of complex type N-glycan is increased. The method is suitable for biosynthesis of polysaccharide glycosylation protein, high isoelectric point protein and complex folding protein, and has good popularization and application prospect in the fields of biological pharmacy, functional protein, nutritional and healthy raw material and industrial biological manufacturing.

This invention discloses a novel bacteriophage for targeting Klebsiella pneumoniae and its preparation method, relating to the fields of microbiology and medical technology; comprising the following steps: S1: providing an environmental sample containing a lytic bacteriophage; S2: processing and filtering the environmental sample to obtain an initial filtrate containing the bacteriophage; S3: co-culturing the initial filtrate with the host bacterium Klebsiella pneumoniae CRKP-2503074069 to obtain a culture mixture; S4: filtering the culture mixture to obtain a bacteriophage lysate. The bacteriophage of this invention contains a glycoside hydrolase family 28 domain, a capsular polysaccharide depolymerase; this enables it not only to lyse bacteria but also to enzymatically lyse the thick capsule of Klebsiella pneumoniae, explaining the formation of its characteristic target-like plaques and endowing it with the additional ability to disrupt biofilm structures.