85 results about "Host bacterium" patented technology

The invention discloses a bacteriophage host prediction method based on a weighted integrated convolutional neural network. The method comprises the following steps: obtaining a joint feature vector for an input bacteriophage protein sequence and a host receptor protein sequence; taking the bacteriophage-host pair as a positive sample, randomly selecting non-host bacteria for each bacteriophage to generate a negative sample, dividing the negative sample into M subsets, and combining each subset with all the positive samples to form M balance training subsets; for each balance training subset, training an independent one-dimensional convolutional neural network model; independently training a one-dimensional convolutional neural network sub-model for each balance training subset to obtain a plurality of sub-models with different performances; and distributing weights based on the performance indexes of the sub-models on the verification set, performing weighted fusion on the prediction probabilities of the M sub-models, and outputting a final host interaction probability. The method realizes accurate prediction of phage-host interaction on the premise of only needing basic sequence information, and has the advantages of light weight, high efficiency and wide applicability.

The present disclosure provides engineered bacterial cells having one or more genetic modifications that result in increased production of expression products, such as increased production of plasmids with reduced occurrence of plasmid concatemers or multimers. Also disclosed herein are expression systems for product manufacturing in media having reduced antibiotic concentration, as well as methods of making cells for use in the expression systems. The cells and expression systems increase the growth rate and production yields of biomolecules produced within the host bacterial host cells without the use of antibiotics, and can produce the product with little to no endotoxins present.

Provided are a preparation method for a yeast-expressed type I recombinant human collagen with a tri-helical structure and use thereof. The preparation method comprises the steps of performing fermentation using an engineered bacterium and performing purification to obtain the type I recombinant human collagen with a tri-helical structure. A method for constructing the engineered bacterium comprises the step of transforming a host bacterium with plasmids pMChZ-α1(I), pMCrN-α2(I), pPIC9K-P4H(DP)-1, and pMCeH-[α1(I)] 2α2(I) to construct the engineered bacterium. The type I recombinant human collagen with a tri-helical structure prepared using the preparation method comprises hydroxyproline, and hydroxyproline accounts for 30% or more of total proline.

The invention provides an anti-white spot syndrome virus peptide derived from litopenaeus vannamei, and belongs to the technical field of biology. The amino acid sequence of the anti-white spot syndrome virus peptide provided by the invention is as shown in SEQ ID NO.1, and the nucleotide sequence of the coding gene is as shown in SEQ ID NO.2. The invention further provides a recombinant expression vector and host bacteria containing the anti-white spot syndrome virus peptide gene, and application of the recombinant expression vector and host bacteria in anti-white spot syndrome virus drugs, vaccines, feeds and feed additives, and the recombinant expression vector and host bacteria have wide application prospects and economic benefits.

The invention discloses a preparation method and application of a recombinant A-type botulinum toxin, and aims to industrially produce the recombinant A-type botulinum toxin by utilizing the preparation method of the recombinant A-type botulinum toxin provided by the invention. The method comprises the following steps: firstly, constructing genetically engineered bacteria capable of heterologously expressing a botulinum toxin A gene in host bacteria by virtue of a genetic engineering means, then accumulating recombinant botulinum toxin A in a strain by virtue of the genetically engineered bacteria through high-density fermentation, collecting fermented thalli, crushing and purifying to obtain the recombinant botulinum toxin A, and finally, preparing the recombinant botulinum toxin A by virtue of the recombinant botulinum toxin A. And adding an auxiliary poising agent and a protective agent to prepare a liquid agent or a freeze-drying agent to obtain the recombinant A-type botulinum toxin for injection. According to the technical scheme, the complete recombinant botulinum toxin A with the purity as high as 99.9% is obtained, the yield is as high as 7000000 U / L, and the complete recombinant botulinum toxin A has no obvious difference from natural botulinum toxin A in structure and function and can be applied to multiple fields such as medical treatment, medical beauty and military affairs.

The invention provides a method for improving the expression level of a meat toxin light chain. The method comprises the following steps: connecting a dissolution-promoting tag to an N end or a C end of meat toxin light chain protein to form soluble meat toxin light chain recombinant protein; the dissolution-promoting tag is a wild dissolution-promoting tag NT11 or a mutant protein mut7 of the wild dissolution-promoting tag NT11, enzyme digestion removal is not needed, the activity of a meat toxin light chain is hardly influenced and interfered, and the fusion protein can keep 93% of substrate enzyme digestion activity. The method further comprises overexpressing a molecular chaperone htpG in the genome of the host bacterium. According to the invention, a BoNT / A-LC high-efficiency expression system is constructed through multi-strategy optimization, so that the yield of BoNT / A-LC is increased by nearly 20% compared with that of wild type NT11-Lc, the yield reaches 647 mg / L through overexpression of a molecular chaperone htpG, and after combinatorial optimization, the yield is 8.5 times that of only expressed BoNT / A Lc, 1.79 times that of NT11-Lc and 1.43 times that of Mut7-Lc.

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.

The application discloses a biosynthesis method of blue copper peptide, comprising the following steps: synthesizing a recombinant protein according to an amino acid sequence shown in SEQ ID NO. 1, synthesizing a gene coding the recombinant protein, constructing a recombinant plasmid by using the gene, transferring the recombinant plasmid into a host bacterium, carrying out fermentation culture to induce protein expression, separating the protein, carrying out enzyme cutting and purification, and finally carrying out complexing with copper ions to obtain the blue copper peptide. Compared with the prior art, the biosynthesis method of the blue copper peptide has the advantages of low production cost, green environmental protection and high yield by optimizing the design of the fusion protein, and the yield of the final product can be significantly improved, and the fusion protein has better structure and isoelectric point characteristics.

The invention belongs to the technical field of gene engineering, and in particular relates to a D-psicose-3-epimerase mutant subjected to Spytag / SpyCatcher cyclization modification and an application of the D-psicose-3-epimerase mutant. The preparation method comprises the following steps: carrying out multi-site simultaneous mutation on 109th aspartic acid and 160th serine of wild type D-psicose-3-epimerase to obtain a mutation intermediate, respectively connecting a Spytag tag and a SpyCatcher tag to the N end and the C end of the mutation intermediate, and carrying out cyclization modification, so as to obtain the wild type D-psicose-3-epimerase, wherein the Spytag tag and the SpyCatcher tag are respectively connected to the N end and the C end of the mutation intermediate; when fructose is used as a raw material to produce D-psicose and host bacteria are escherichia coli, the reaction of catalyzing 600 g / L fructose to produce D-psicose is performed for 4 h, and the conversion rate can reach 35.7%; when the host bacteria are bacillus subtilis, the reaction for catalyzing 500 g / L fructose to produce D-psicose is performed for 4 h, and the conversion rate reaches 36.5%; compared with a wild type D-psicose-3-epimerase strain of bacillus subtilis, the conversion rate of the strain is improved by 13.5%.

A phage composition and an use thereof in strengthening soil carbon fixation, said phage composition including three phages, namely, a polyvalent phage φYSZKP that attacks Klebsiella pneumoniae and Pseudomonas aeruginosa; a Bacillus cereus phage φYSZBA1; and a Bacillus cereus phage φYSZBA2. In the present invention, the phage composition is injected into the target soil, and an approach of strengthening soil carbon fixation by means of cooperation with the host bacteria through injection of AMGs from the phage is employed; at the same time, the phage has a function of regulating the soil microbial communities from bottom to top; a network of symbiosis with indigenous bacteria is further optimized, and the soil carbon fixation potential is improved. This technique is an environmental improvement technique that achieves a good carbon fixation effect, has a low price and is environment-friendly.

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.

The invention discloses a recombinant prokaryotic expression vector, an expression strain, soluble human-derived protein and application, the recombinant prokaryotic expression vector comprises a first nucleotide sequence for coding a target human-derived protein and a second nucleotide sequence for coding a cold-adapted molecular chaperone, and a rare codon corresponding to host bacteria is introduced into the first nucleotide sequence to obtain a recombinant prokaryotic expression vector. The translation rate of a key site is actively reduced, a cold-adapted molecular chaperone is introduced into a second nucleic acid sequence, and correct folding and soluble expression of the human-derived protein in a prokaryotic host are promoted in a low-temperature induction manner, so that the high-yield and high-solubility human-derived soluble protein is obtained. The invention provides a feasible way for large-scale preparation of human soluble protein, and has important industrial application value.

The present invention relates to a method for constructing a host bacterium with high expression of human serum albumin, which method comprises: S100, designing an optimized gene encoding human serum albumin; S200, constructing a recombinant expression vector; and S300, transforming the recombinant expression vector into a Pichia pastoris host bacterium. The optimization design of a full-length sequence of a target gene is performed at the molecular level to obtain a target gene with the most suitable expression in Pichia pastoris; at the cellular level, the latest international Pichia pastoris expression system host bacterium CBS7435 is introduced for the gene expression of human serum albumin; and Pichia pastoris transformants harboring high-copy-number exogenous genes are selected by means of using a G418 resistance gene for the construction of an engineering bacterium with high expression of recombinant human serum albumin.

This invention belongs to the field of biotechnology, specifically relating to a perforin derived from *Staphylococcus warwickiana* temperate bacteriophage and its applications. The perforin has the nucleotide sequence shown in SEQ ID NO:1. This perforin is a key gene for phage lysis and growth, playing a crucial role in the lysis of host bacteria. Therefore, this study aims to verify whether the perforin, whose coding site is located on the genome of *Staphylococcus warwickiana* temperate bacteriophage, as a cell lysis gene, can serve as a potential antibacterial substance, providing a theoretical basis for the prevention and control of Gram-negative pathogens.

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 invention relates to a methanophilic genetically engineered bacterium for producing gamma-polyglutamic acid (gamma-PGA) as well as a construction method and application of the methanophilic genetically engineered bacterium, EQU2420670 gene is knocked out on a host bacterium genome, and meanwhile, an exogenous gamma-PGA synthetase encoding gene cluster pgsBCAE under the control of an inducible arabinose promoter (Pbad) is introduced at the site. The construction method comprises the following steps: obtaining a multi-cistron structure DNA fragment pgsBCAE for coding gamma-PGA synthetase through artificial gene synthesis in combination with a codon optimization strategy, and constructing the expression module Pbad-pgsBCAE under the control of a Pbad promoter. A suicide vector pK18mobsacB carrying a SacB sucrose reverse selection system is used for constructing a gene replacement vector, upstream and downstream homologous arms of an EQU2420670 gene on a genome of methanophilic bacteria M. buryatase 5GB1 are designed on two sides, an EQU2420670 site is replaced by a Pbad-pgsBCAE expression module, the methanophilic genetically engineered bacterium PGA is obtained, and the methanophilic genetically engineered bacterium PGA is applied to production of gamma-PGA and has important economic and social significance; the gamma-PGA produced by the engineering methanophilic bacteria by using methane as a carbon source and an energy source can be used as a cosmetic additive; the invention provides a novel low-carbon biosynthesis approach for commercial production and application of gamma-PGA, and has a good industrial application prospect.

The invention provides I-type alpha-mannosidase, an expression vector, and a transgenic cell line and host bacteria containing the expression vector. According to the invention, the function of the SlMNSI1 gene related to tomato protein N-glycosylation is cloned and verified for the first time, heterologous active expression of the SlMNSI1 gene is realized, and the recombinant protein can utilize a high mannose type N-sugar chain (H8N2F0X0) as a substrate to efficiently catalyze and shear mannose residues connected with alpha-1, 2-at the tail end of the recombinant protein so as to generate a Man5GlcNAc2 (H5N2F0X0) product. The invention also provides the SlMNSI1 gene and an encoding protein thereof, an expression vector containing the SlMNSI1 nucleotide sequence, and application of a transgenic cell line and host bacteria containing the expression vector in N-carbohydrate chain modification and glycosylation engineering. The invention further provides application of the expression vector and a transgenic cell line or host bacteria containing the vector in glycoprotein structure optimization, drug research and development and metabolic engineering.

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.

The application provides a flavonol synthase, a coding gene, an expression vector, a host bacterium and application, and belongs to the technical field of bioengineering. The application provides a flavonol synthase, and the amino acid sequence of the flavonol synthase is shown as SEQ ID NO. 1. The application can realize utilization of the Rhododendron simsii flavonol synthase and realize regulation and improvement of biosynthesis of plant flavonol and anthocyanin.

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;

One aspect of the invention provides a method of generating bacteriophages adapted to infect a target bacterial strain. The method comprises: providing host bacteria that are susceptible to phage as input to a host chemostat containing phage; providing target bacteria that are related to the host bacteria, but not susceptible to phage as input to a target chemostat containing phage; filtering outflows from the host chemostat and the target chemostat to isolate phage from the populations of the host bacteria, the target bacteria, and macromolecules; combining the outflows; and introducing the combined outflow into each of the host chemostat and the target chemostat.

The invention relates to a phage cocktail and application thereof, and belongs to the technical field of biology. The phage cocktail disclosed by the invention can be used for carrying out fluorescence labeling imaging and efficient killing on bacteria and infectious bacteria in a biofilm of the bacteria. A luminous photosensitizer, glucose oxidase and horse radish peroxidase are coupled to the surface of the phage to obtain three phage conjugates with different functions, and the three phage conjugates jointly form the phage cocktail. The three bacteriophage conjugates are simultaneously colonized in host bacteria by utilizing the targeting ability of the bacteriophages, and show efficient targeting, and the killing efficiency on the host bacteria can reach 100%. The phage cocktail can specifically recognize and fluorescently label bacteria in a biofilm, can efficiently destroy the structure of the biofilm and thoroughly eradicates the biofilm and antibiotic-sensitive and drug-resistant host bacteria in the biofilm.

The invention provides enterococcus faecalis bacteriophage vBEfaS-1017 and application thereof, the enterococcus faecalis bacteriophage vBEfaS-1017 is preserved in China General Microbiological Culture Collection Center (CGMCC), the preservation number is CGMCC NO.46182, and the preservation time is September 6, 2024. The bacteriophage vBEfaS-1017 is high in specificity, short in incubation period and ultrahigh in stability, and has activity under the conditions of extreme pH, high temperature and ultraviolet radiation; by evaluating the in-vitro bactericidal efficacy of the bacteriophage vBEfaS-1017, it is determined that the bacteriophage vBEfaS-1017 can effectively remove a biological membrane formed by host bacteria Ef 10-17, the removal rate is as high as 90%, and the bacteriophage vBEfaS-1017 is expected to become a scavenger for solving the biological membrane. Further experiments prove that the bacteriophage vBEfaS-1017 has in-vivo and in-vitro safety. Through combined use of the bacteriophage and different antibiotics, it is found that combined use of the bacteriophage vBEfaS-1017 and the antibiotic levofloxacin can effectively treat bacteremia of mice, the treatment time after infection can be prolonged by using the bacteriophage in advance, and the bacteriophage has a good application prospect in the aspect of preventing and treating enterococcus faecalis.

The invention relates to application of an ACADM gene in increasing the yield of spinosad in saccharopolyspora spinosa, and belongs to the field of biological fermentation. The method mainly comprises the step of overexpressing the ACADM gene in the saccharopolyspora spinosa. Specifically, the ACADM gene is introduced into the saccharopolyspora spinosa, and the ACADM gene is efficiently expressed in the host bacterium, so that the biosynthetic pathway of the spinosad can be effectively promoted, and the final yield of the spinosad is remarkably increased. Experiments show that the method is feasible to operate and remarkable in effect, and an effective genetic modification strategy is provided for industrial production of spinosad.

Disclosed are host bacterial strains, methods of making such host bacterial strains and methods of using such host bacterial strains to improve plasmid production. In some embodiments, an engineered bacterial host cell is provided that has a knockout of SbcC, SbcD, or both, and a knockout of one or all of recA, endA, and pgi. In some embodiments, methods for replicating a vector in an engineered E. coli host cell of the present disclosure are provided.

This invention discloses a laccase derived from *Coprinus gracilis*, its recombinant expression strain, and a highly efficient expression method, belonging to the fields of microbiology and bioengineering technology. Using *Aspergillus niger* MA70.15 as the experimental strain, this invention employs a random integration strategy to achieve pC3-P... citA -SP GlaA - lcc9‑ T trpC ‑pyrG The expression vector was integrated into the upstream region of the promoter of the host bacterium citrate synthase in the form of nine consecutive copies. To investigate the effects of microparticles and osmotic regulators in the fermentation medium on laccase production by recombinant Aspergillus niger, this invention added different types and concentrations of microparticles and osmotic regulators, resulting in a laccase activity of 1566.7 U / L in shake-flask fermentation of recombinant strain AnRcgL1 and 1961 U / L in a 1 L fermenter, successfully achieving efficient recombinant expression of laccase Lcc9 in Aspergillus niger.

The invention relates to a plasmid-free gene editing system based on T7RNA polymerase and application of the plasmid-free gene editing system, and belongs to the technical field of gene editing. The plasmid-free gene editing system constructed by the invention comprises a T7 RNA polymerase, a Cas12a nuclease, a selection marker gene and a short double-stranded DNA expression cassette, wherein the short double-stranded DNA expression cassette sequentially comprises a T7 promoter, a first forward repetitive sequence, a spacer sequence and a second forward repetitive sequence. According to the plasmid-free gene editing system, T7RNA polymerase is expressed in host bacteria, short double-stranded DNA is transcribed to generate guide RNA, Cas12a nuclease is driven to achieve rapid and efficient gene editing, the problems that in the prior art, linear fragment transformation is complex and tedious, and part of strains lack genetic plasmids are solved, iterative editing and multi-site editing are supported at the same time, and the plasmid-free gene editing system is suitable for large-scale popularization and application. And a brand-new convenient tool is provided for gene editing of non-model fungi.