10 results about "Antitoxin" patented technology

The invention provides a production strain of an antibiotic-free plasmid, the production strain is a gene editing strain of a PIR strain and is named as PIR1-WN:: 0636 or PIR1-PR: 0636, the production strain contains a nucleotide sequence for coding toxin protein and the antibiotic-free plasmid, and the antibiotic-free plasmid contains a nucleotide sequence for coding antitoxin protein; and preferably, the replicon DNA element of the nonreactive plasmid is R6K-gamma. The toxin protein gene of the production strain disclosed by the invention can be stably passaged, has lethality after being induced and can be used for plasmid screening; according to the invention, the positive rate of transforming the nonreactive plasmid into the PIR1-WN:: 0636 strain is more than 80%, and stable production of the plasmid with a high superhelix ratio can be realized.

Provided herein are multi-strain population control systems, methods, kits, and compositions. Also provided are methods, systems, kits, and compositions for culturing bacterial cells in multi-strain ecosystems, and temporally arranged multi-strain ecosystems or cultures using a synchronized lysis circuit in combination with multiple toxin / antitoxin systems to cycle continuously over a long period of time.

The application belongs to the field of genetic engineering, and specifically discloses a new sterilization method for realizing precise and efficient sterilization of drug-resistant bacteria by combining CRISPR and a toxin-antitoxin element coupled therewith. The application innovatively uses the guardian RNA element CreTA of CRISPR to improve the stability of the CRISPR-Cas element in the process of sterilizing drug-resistant bacteria, realizes the double sterilization effect of CRISPR and TA, and thus effectively improves the efficiency of the CRISPR sterilization technology in practical application.

The invention discloses a stable and antibiotic-free plasmid expression system and application thereof in preparation of antitumor drugs. The plasmid expression system comprises a replicon, a regulatable promoter, a ribosome binding site RBS and an axe / txe toxin-antitoxin stabilization module, and the plasmid expression system can realize long-term stable expression of exogenous genes under the antibiotic-free condition. The replicon is selected from one or a combination of more of pUC, pMB1, p15A or pSC101; the promoter is selected from one or a combination of more of J23100, J23150 or J23112, and the RBS is selected from one or a combination of more of B0032, B0033 or B0034. According to the invention, an antibiotic-free and lasting plasmid platform is established for salmonella-based therapy, and a framework, synthetic biology and cancer treatment opportunity are provided for reliable gene delivery in vivo.

The utility model discloses a quantitative device for filling antitoxin serum products, which comprises a quantitative liquid guide device and a shell, and the quantitative liquid guide device is arranged in the shell; the quantitative liquid guide device comprises a screw rod, a positioning plate, a sliding column, a positioning frame, an adjusting screw rod, a first adjusting nut, a pressure adjusting spring, a sealing pressing plate, a sealing gasket, a lower sealing ring, a sealing plate and a quantitative liquid guide device body, and the positioning plate is connected between the screw rod and the sliding column; one end of the sliding column sequentially penetrates through the quantitative liquid guide device, the sealing plate and the sealing pressing plate to be connected with the adjusting screw rod, the sealing gasket is connected to the sealing pressing plate and matched with the sealing plate for sealing, the sealing plate is sleeved with the lower sealing ring, and a plurality of transition holes are formed in the sealing plate; the quantifying device for filling the antitoxin serum products is simple in structure, convenient to use and practical, and the amount of antitoxin serum fed every time is controlled by rotating the adjusting nut to move the positioning plate to ascend and descend, so that the use of a metering system is reduced.

This invention relates to an antitoxin protein binding molecule and a kit thereof. The antitoxin protein binding molecule comprises an antibody or an antigen-binding fragment targeting the antitoxin protein. The binding molecule includes a light chain variable region and a heavy chain variable region. The light chain variable region includes a complementarity-determining region (LCDR), which comprises LCDR1 with the sequence SEQ ID NO:1, LCDR2 with the sequence SEQ ID NO:2, and LCDR3 with the sequence SEQ ID NO:3. The heavy chain variable region includes a complementarity-determining region (HCDR), which comprises HCDR1 with the sequence SEQ ID NO:4, HCDR2 with the sequence SEQ ID NO:5, and HCDR3 with the sequence SEQ ID NO:6.

The invention provides a resistance-free selection marker plasmid, a preparation method, recombinant bacteria and application, and belongs to the technical field of gene engineering. The plasmid comprises an EM7 promoter, a ccdA41 antitoxin gene and an R6K gamma replication origin, the length of the plasmid molecule is less than 600bp, and the plasmid molecule does not contain antibiotic resistance genes. The plasmid is small in molecular weight and free of antibiotic resistance genes, effectively avoids safety risks caused by use of antibiotics, strictly depends on designated host replication of chromosome integration ccdB, meets biological safety requirements and is suitable for safe production of biological products such as vaccines and recombinant proteins. According to the invention, the recombinant bacterium is used for producing the plasmid without the resistance selection marker simply, conveniently and quickly, the success rate is high, and the recombinant bacterium utilizes the GT115-ccdb strain and the plasmid containing the ccdA41 antitoxin gene to realize stable maintenance and expression of the plasmid in a host through a toxin-antitoxin composite regulation mechanism.

The invention discloses a recombinant genetically engineered bacterium for stably producing beta-alanine without antibiotics and inducers and application of the recombinant genetically engineered bacterium, the recombinant genetically engineered bacterium takes Escherichia coli probiotics E15 as a starting strain, and one or more of the following gene editions are carried out: (1) weakening an icd gene; (2) introducing a toxin-antitoxin system hok / sok; (3) knocking out the lacI gene; and (4) overexpression of a temperature-sensitive regulation and control system: the temperature-sensitive regulation and control system is obtained by replacing a lacI gene promoter with a PR promoter and introducing a CI857 repressor protein coding gene expressed by a PL promoter. Finally, the strain constructed by the invention can realize stable and efficient production of beta-alanine in the fermentation process without adding antibiotics and inducers.

The invention relates to a protein interaction screening system based on a bacterial two-hybrid technology, which comprises a bait protein and prey protein co-expression plasmid pCDFduet1-lambda cI-RNAP, the sequence of which is as shown in SEQ ID No. 1; a reporter plasmid is pACYC184-cIamp; the sequence of the lac promoter-GFP is as shown in SEQ ID No. 2, and the lac promoter-GFP is as shown in SEQ ID No. 2; the positive control plasmid is a pCDFduet1-lambda cI-LG2-RNAP-Gal11p plasmid, and the sequence of the positive control plasmid is as shown in SEQ ID No. 3; the invention further relates to a high-throughput protein interaction screening method of mycobacterium tuberculosis toxin-antitoxin and application of the protein interaction screening system. The protein interaction screening system can realize high-throughput, high-sensitivity and semi-quantitative many-to-many protein interaction analysis by utilizing a flow cytometry sorting technology and three-generation sequencing analysis, effectively solves the problem of false negative caused by non-uniform conversion efficiency of a traditional double-plasmid system, remarkably improves the practicability of high-throughput screening, and has a good application prospect. The large-scale screening bottleneck is broken through, and wide application prospects are achieved.

Provided is an antibiotic resistance gene-free plasmid-containing production strain. The production strain is a gene-edited strain of the PIR strain, designated as PIR1-WN::0636 or PIR1-PR::0636. The production strain contains a nucleotide sequence encoding a toxin protein and an antibiotic resistance gene-free plasmid, wherein the antibiotic resistance-free plasmid contains a nucleotide sequence encoding an antitoxin protein; preferably, the replicon DNA element for the antibiotic resistance gene-free plasmid is R6K-γ. The toxin protein gene of the provided production strain can be stably maintained during strain passage, and has lethality upon induction, which can be used for plasmid screening. When the provided antibiotic resistance gene-free plasmid is transformed into the PIR1-WN::0636 strain, the positive rate reaches 80% or higher. Moreover, the antibiotic resistance gene-free plasmid can enable the stable production of plasmids with a high supercoiled proportion.