3476results about "Bacteria peptides" patented technology

Disclosed herein are methods, compositions, and kits for determining the presence or absence of a target polypeptide (e.g., a polypeptide involved in nitrogen fixation) in a sample (e.g., a sample of soil from the rhizosphere of a non-leguminous plant).

The invention relates to a recombinant escherichia coli THRS and a method for synthesizing L-threonine by using the recombinant escherichia coli THRS. The invention belongs to the technical field of bioengineering, and provides a recombinant escherichia coli THRS which overexpresses encoding genes of ppc, aspC, aspA, thrAmutBC, asd, rhtC, rhtA, asdtm and thrAmut, knockout an encoding gene of fnr and knockout an encoding gene of iclR, the recombinant escherichia coli THRS takes glucose as a substrate for fermentation, and the yield and conversion rate of L-threonine are obviously improved; the L-threonine strain has the advantages that the L-threonine strain does not contain exogenous plasmids, all modification sites are integrated onto a genome, higher stability is achieved, antibiotics do not need to be added into a fermentation culture medium of the strain, and the produced L-threonine product is free of antibiotic residues and higher in safety.

Methods and systems are provided for generating and utilizing a genetically engineered bacterium comprising a modification in glnD, wherein said modification is selected from the group consisting of: deletion of the entire gene, deletion of substantially the entire gene, deletion of an ACT domain, deletion of more than 50% of an ACT domain, deactivation of an ACT domain, and deactivation of an UTase domain.

The invention discloses construction and application of an engineering bacterium for co-expressing D-mannitol dehydrogenase and D-glucose dehydrogenase, and belongs to the technical field of genetic engineering. The technical problem to be solved by the invention is how to co-express D-mannitol dehydrogenase and D-glucose dehydrogenase through a biosynthetic pathway. In order to solve the technical problem, the invention provides recombinant escherichia coli. The recombinant escherichia coli is characterized by containing a D-mannitol dehydrogenase gene, a D-glucose dehydrogenase gene, a glucokinase gene, an acetyl coenzyme A synthetase gene, a D-lactose transporter gene, a D-glucose PTS permease-free gene and a pyruvate oxidase-free gene. And no regulator gene of galactose operon is contained. The invention establishes a preparation method for co-producing D-mannitol and sodium gluconate, which has guiding significance for the production of D-mannitol and sodium gluconate.

The present disclosure provides guided microbial remodeling (GMR) methods for the rational improvement of plant-associated microbes to perform plant-beneficial functions. The GMR methods described herein allow for non-intergeneric genetic optimization of key regulatory networks within the microbes, which improve plant-beneficial functions over wild-type microbes but don't have the risks associated with transgenic approaches (e.g., unpredictable gene function, public and regulatory concerns, etc.). The present disclosure also provides remodeled microbes and compositions thereof. The utilization of remodeled microbes and compositions thereof will enable farmers to realize more productive and predictable crop yields without the nutrient degradation, leaching, or toxic runoff associated with traditional synthetically derived fertilizers.

Disclosed herein are engineered rhizobia having nif clusters that enable the fixation of nitrogen under free-living conditions, as well as ammonium and oxygen tolerant nitrogen fixation under free-living conditions. Also provided are methods for producing nitrogen for consumption by a cereal crop using these engineered rhizobia.

The present invention relates to the field of bioengineering, and in particular to a modified Bordetella pertussis strain, wherein the mltA gene and the pldA gene are mutated, thereby having an increased bacterial outer membrane vesicle (OMV) yield. The present invention also relates to a method for producing the modified Bordetella pertussis strain and a method for producing OMVs by the modified Bordetella pertussis strain.

The invention discloses an indirect ELISA kit for distinguishing porcine actinobacillus pleuropneumoniae wild virus infection and vaccine immunity and application, and belongs to the technical field of biology. According to the indirect ELISA kit, screened ApxIVA truncated protein serves as a coating antigen, the amino acid sequence of the ApxIVA truncated protein is shown in SEQ ID NO.3, the ApxIVA truncated protein can be subjected to soluble expression in escherichia coli, only one His tag and one S tag are carried, and the structure and the function of the ApxIVA truncated protein are close to those of natural ApxIVA. The pxIVA truncated protein is used as an antigen, an indirect ELISA method and kit for distinguishing APP wild strain infection and gene deletion vaccine immunity are established, the kit has the advantages of high specificity, low background value, low cost and short detection time, and the kit has the advantages of improving animal husbandry APP diagnosis accuracy and improving animal husbandry APP diagnosis accuracy. And the method has important significance in the aspects of optimizing prevention and control measures and guaranteeing animal health and production benefits.

The invention provides lactobacillus crispatus, which is preserved in the general microbiological center of the China Committee for Culture Collection of Microorganisms on February 7, 2023, and the preservation number is CGMCC (China General Microbiological Culture Collection Center) No. 26503. The bacillus subtilis can play a relatively strong role in inhibiting pathogenic bacteria such as gardnerella vaginalis, escherichia coli and staphylococcus aureus at the same time, and also has a certain role in inhibiting candida albicans, two-way proteurella and Atortoria vaginalis. Therefore, the lactobacillus crispatus has the potential of maintaining the environment in the vagina to be faintly acid and improving the mucosal immunity and infection resistance of a host, and can be used for preventing and treating vaginal infection and inflammation, and maintaining, improving or recovering the steady state of the environment in the vagina.

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.

The invention discloses a modified bordetella pertussis strain and an application thereof. The modified Bordetella pertussis strain is characterized in that in the Bordetella pertussis strain BAA-589, the BP2992 protein is not expressed, or the inactive BP2992 protein is expressed, the pldA protein is not expressed, or the inactive pldA protein is expressed, and the mla F protein is not expressed, or the inactive mla F protein is expressed. When the Bordetella pertussis strain is treated by combining an ultrasonic method, compared with wild Bordetella pertussis BAA-589, the Bordetella pertussis strain has a remarkable high-foaming phenotype, the OMV secretion amount is remarkably increased, and a good technical foundation is laid for developing a Bordetella pertussis OMV vaccine.

The invention belongs to the field of animal vaccines, and particularly relates to a multi-epitope fusion protein aiming at multi-serotype laisseria parasuis antigen and application. The applicant carries out proteomics analysis on four clinical isolated strains of serotypes 4, 5 and 13 of the parasuis leather serotype 4, 5 and 13 with high toxicity and good immunogenicity, and eight antigen proteins are screened out of the four clinical isolated strains of the serotypes 4, 5 and 13 of the parasuis leather serotype 4, 5 and 13. And further analyzing the screened eight antigen proteins to finally obtain the antigen multi-epitope fusion protein with immunogenicity capable of recognizing three serotypes. When the fusion protein is used as a vaccine, the protection rate of clinically separated piglets infected with a serum type 4 strain HB04, a serum type 5 strain SJZ05 and a serum type 13 strain GD20 reaches 100%.

The invention provides a recombinant halomonas capable of inducing protein self-degradation as well as a construction method and application of the recombinant halomonas. The recombinant halomonas does not express the SspB protein or the expressed SspB protein does not have functions or has reduced functions, and an SsrA tag is inserted into the C end of the to-be-degraded protein in the recombinant halomonas. The recombinant halomonas can degrade target protein in the middle and later stages of growth or the synthesis stage of products, and the method has the advantages of being easy to operate and small in influence on bacterial growth when used for achieving degradation of regulation and control protein.

The invention discloses a Graisseria parasuis three-component subunit vaccine and a preparation method thereof, and belongs to the technical field of biology. The vaccine comprises three kinds of antigen proteins of the Gleisseria parasuis in an immunizing dose and a pharmaceutically acceptable adjuvant, and the amino acid sequences of the three kinds of antigen proteins are respectively shown as SEQ ID NO.1, SEQ ID NO.2 and SEQ ID NO.3. The invention further discloses a preparation method of the vaccine. The three-component subunit vaccine provided by the invention has cross protection force on infection of type-4 and type-5 Graisseria parasuis, has an excellent immune protection effect, and is expected to play a better role in prevention and control of infectious diseases caused by the Graisseria parasuis.

The invention discloses a P450 mutant and application thereof in synthesis of calcifediol, and belongs to the technical field of bioengineering. According to the present invention, the P450 enzyme mutant enzyme is constructed, and the single plasmid three-enzyme co-expression system of the redox partner and the cofactor cycle enzyme is constructed, such that the sufficient electron transport chain is provided for the P450 enzyme, and the calcifediol can be efficiently synthesized under the mild condition by using the vitamin D3 as the substrate; the conversion rate of calcifediol can reach 63.1%, and the conversion rate of the reaction is greatly improved. By adopting the method disclosed by the invention, the catalytic efficiency of the catalyst is improved, and the reaction cost is reduced.

The invention relates to a method for improving luminous intensity of a plant by introducing an exogenous caffeic acid synthesis pathway. A TAL gene and a P450 gene are introduced into a plant body to obtain a remarkable effect of increasing the expression quantity of caffeic acid. Due to the fact that introduction of the TAL gene and the P450 gene promotes deamination of the L-DOPA, the accumulation amount of the L-DOPA is increased, and then the expression amount of caffeic acid in the plant is effectively increased. Based on the pathway, the synthesis of fluorescein in the plant is increased, so that the luminous intensity of the plant is enhanced.

Disclosed herein are engineered rhizobia having nif clusters that enable the fixation of nitrogen under free-living conditions, as well as ammonium and oxygen tolerant nitrogen fixation under free-living conditions. Also provided are methods for producing nitrogen for consumption by a cereal crop using these engineered rhizobia.

The invention discloses a method for displaying foreign protein by utilizing salmonella and application of the method, and belongs to the technical field of biological medicine. According to the invention, the SpyCatcher and an outer membrane protein Lpp-OmpA gene are fused and are expressed in salmonella, a recombinant strain is constructed, and the SpyCatcher is displayed on the surface of bacteria; the foreign protein gene and the SpyTag gene are fused and subjected to prokaryotic expression purification, and recombinant foreign protein is obtained; after the recombinant foreign protein and the recombinant salmonella are incubated, the foreign protein can be anchored on the surface of the salmonella through a SpyCatcher-SpyTag covalent bond. When the foreign protein is an antigen protein, the foreign protein is displayed on the surface of the attenuated bacterial vector, and a live vector vaccine can be prepared. The invention provides a novel universal antigen display method, overcomes the limitation of the traditional antigen display method on the protein size and conformation, and has a good application prospect in live vector vaccine construction.

The invention discloses an adjuvant and application thereof in vaccine preparation. The amino acid sequence of the adjuvant is shown as SEQ ID NO: 5, 7, 9, 11, 13, 15, 17, 19, 23, 27, 31, 35 or 39. The immune protection effect of the nanoparticle vaccine can be improved by activating TLR2, and good vaccine adjuvant activity is shown in a common immunogen SD or new coronavirus RBD immunogen model. Furthermore, an assembly construction method of the self-adjuvant-nanoparticle vaccine is optimized, and the prepared self-adjuvant-nanoparticle vaccine has a remarkable effect of inducing the generation of an antibody in an animal body. The novel adjuvant provided by the invention can be widely applied to vaccine research and development, and meanwhile, the assembled nanoparticle self-adjuvant vaccine can also become a novel vaccine.

The invention relates to a recombinant pichia pastoris strain capable of producing astaxanthin at high yield as well as a construction method and application of the recombinant pichia pastoris strain. The recombinant pichia pastoris strain is obtained by expressing ATP (adenosine triphosphate) citrate lyase (ACL) and acetyl-CoA synthase (ACS) or phosphoketolase (PK) and phosphotransacetylase (PTA), choline kinase (CK), inositol polyphosphate kinase (IPK) and vitreoscilla hemoglobin (VHB) in host bacteria. Wherein the host bacterium is a pichia pastoris gene modified strain PP-LC2. The astaxanthin production performance of the recombinant strain is verified on the basis of comparison of precursor supply pathways, IUP pathway construction and improvement of the oxygen supply capacity of the engineering strain, and the astaxanthin production capacity of the pichia pastoris is further improved. The construction method of the recombinant pichia pastoris is simple, the synthesis of astaxanthin can be better promoted, the engineering strain can efficiently synthesize the astaxanthin by utilizing methanol through amplification fermentation of a 5L fermentation tank, and industrial production is facilitated.

The invention belongs to the technical field of gene engineering, and particularly relates to a mutant of polymyxin efflux transporter and application of the mutant. The mutant is a PmxD transporter mutant, the amino acid sequence of the PmxD transporter mutant is shown as SEQ ID NO: 1, and compared with wild type PmxD, the polymyxin transport capacity of the PmxD transporter mutant (T38W) is improved by 450.46%; and the total discharge amount of polymyxin is increased by 85.72%. Meanwhile, the mutant can significantly improve the growth ability of the strain on a plate containing 250 [mu] g / mL of polymyxin B, namely significantly improve the autoresistance of paenibacillus polymyxa to polymyxin.

The invention relates to a carbon and nitrogen dual-recovery method and device for collecting grease and phycocyanin in an algae-bacterium symbiotic sewage treatment system, and the method comprises the following steps: 1, carrying out mud-water separation on phycomycete suspension taken out from the sewage treatment system to obtain phycomycete biomass precipitate; 2, extracting grease in the precipitate in the first step by adopting a chloroform-methanol solution, and collecting the grease to recover carbon; and step 3, adding a hydrochloric acid solution into the biomass extracted in the step 2, heating and stirring, and collecting phycocyanin in supernate to recover nitrogen. According to the method disclosed by the invention, the mode of firstly collecting the grease to extract the carbon and then collecting the phycocyanin to extract the nitrogen is adopted, so that grease loss caused in the process of collecting the phycocyanin is avoided, the collection rate of the grease is improved, and dual recovery of the carbon and the nitrogen can be realized.

Provided herein are isolated polynucleotides encoding a polypeptide comprising an antigen protein fused to a signal sequence and a transmembrane domain, and optionally fused to a ferritin. Also provided herein are isolated polynucleotides encoding alphaviral non-structural proteins nsp1, nsp2, nsp3, and nsp4 and polypeptides comprising an antigen protein fused to a signal sequence and a transmembrane domain, and optionally fused to a ferritin. The antigen may be influenza. Polynucleotides, such as RNAs, can be used as vaccines against influenza infection.

Provided herein are fusion polypeptides comprising an amino acid sequence of a bacteriocin, the amino acid sequence of the bacteriocin being a cleavage intein both on both the N-terminus and on both the C-terminus that cyclizes the bacteriocin. Also provided are nucleic acids and genetic vectors encoding the fusion polypeptides, as well as microbial cells genetically engineered with the nucleic acids or genetic vectors. Also provided are methods of making the cyclic bacteriocin, methods of screening using a library of nucleic acids or genetic vectors encoding the fusion polypeptides, and methods of controlling growth of organisms using the cyclic bacteriocin made by the methods provided herein.

A fusion protein comprising a DNA binding domain operably-linked to a dimerization domain, wherein the DNA binding domain specifically binds to a response element.

The invention belongs to the field of gene engineering and biological treatment, and provides a hypoxia specific gene expression cassette, gram-negative bacteria containing the expression cassette and application of the gram-negative bacteria in preparation of tumor drugs. According to the invention, the forward hypoxia promoter and the reverse hyperxia promoter are reasonably designed, and appropriate survival essential genes are matched, so that the hypoxia specific gene expression cassette which is more efficient and safer is obtained. Gram-negative bacteria modified by the hypoxia specific gene expression cassette designed by the invention are low in overall mutation rate, and in a mouse in-vivo tumor model, more bacteria are distributed in tumors and the clearing speed in normal organs is higher.

A method for enhancing hydrogen uptake by cells of an acetogenic bacterium in a culture is provided. The method comprises incubating the cells in a liquid medium supplemented with an external gas mixture, wherein the external gas mixture comprises H2 and CO2; overexpressing an uptake hydrogenase and an associated electron transfer protein in the cells; increasing uptake of the H2 by the cells; and enhancing uptake of the CO2 by the cells. The culture may be a coculture with additional cells of a non-acetogenic bacterium, which produces natively H2 from catabolism of an organic molecule.

The invention discloses an application of pore protein PorA in improving ammonia nitrogen utilization capacity of methane-oxidizing bacteria. The amino acid sequence of the pore protein PorA is as shown in SEQ ID NO. 1. The nucleotide sequence of the coding gene porA of the pore protein PorA is as shown in SEQ ID NO. 2. The invention also relates to an application of the pore protein PorA in the aspect of improving the utilization capability of Methyluvimicrobium burylate ammonium nitrogen, and particularly relates to an application of the pore protein PorA in the aspect of improving the utilization capability of Methyluvimicrobium burylate ammonium nitrogen. The porous protein is inactivated, so that the methane-oxidizing bacterium Methyluvimicrobiuretic can grow by utilizing ammonium nitrogen, the cost of fermenting and culturing the bacterium is reduced, and the porous protein has important significance on industrial application of the bacterium.

According to the invention, a structural domain reaction substrate sequence consisting of Exon1 (E1), P1 and Exon2 (E2) sequences of ribozyme is mutated, and E1, P1 and E2 sequences are mutated under the condition of maintaining the structural stability, so that the Azoarcus group I intron ribozyme still has enzyme activity and can maintain the capability of forming circular RNA (Ribose Nucleic Acid). The invention discloses a flexible vector construction method for preparing circular RNA (Ribonucleic Acid) without limitation of a substrate sequence, which comprises the following steps: determining a target to-be-cyclized site sequence NNUNNNN, and segmenting the target to-be-cyclized site sequence NNUNNNN into E1: NNU and E2: NNNN; with E1 and E2 sequences as references, designing IGS sequences to respectively form complementary pairing with E1 and E2; and 5'and 3 'homologous arms, IRES, CDS and other elements are respectively added. The method provided by the invention can be used for preparing the circular RNA for any target sequence, has no residual sequence, and has relatively high cyclization efficiency. The FlexCirc cyclization system designed on the basis of Azoarcus group I intron ribozyme can form the circular RNA, the cyclization substrate sequence has the characteristic of flexible design, and the cyclization efficiency can realize a relatively high cyclization proportion.

The present application relates to a novel zearalenone-degrading enzyme and a use thereof.