187 results about "Bacterium coli" patented technology

The invention provides a high-stability recombinant humanized elastin, a genetically engineered bacterium for expressing the protein and application of the high-stability recombinant humanized elastin, and belongs to the technical field of binding tissue peptides. The nucleotide sequence of the recombinant humanized elastin is shown as SEQ ID NO.1; and the amino acid sequence is as shown in SEQ ID NO.4. According to the invention, the nucleotide sequence of the humanized elastin is subjected to codon optimization and transferred into escherichia coli to construct the genetically engineered bacterium for expressing the recombinant humanized elastin, so that the expression quantity of the recombinant humanized elastin can be increased, the stability of the recombinant humanized elastin can be improved, and the recombinant humanized elastin can be used for preparing the recombinant humanized elastin. The migration rate of the recombinant humanized elastin to the HSF cell is improved, and the expression quantity of the h-ELN gene, the h-COL1A1 gene and the h-COL3A1 gene of the HSF cell is improved.

The invention discloses construction and optimization of a gene editing tool based on CRISPR (clustered regularly interspaced short palindromic repeats)-associated transsposases and application of the gene editing tool in escherichia coli, and belongs to the field of synthetic biology and gene engineering. According to the invention, an efficient gene editing system is established in Escherichia coli, and the burden of a MUSCULAR-CAST system on strains is reduced through element optimization; by eliminating the self-targeting effect, large-fragment (> 10k bp) target gene expression cassettes can be efficiently integrated, and the editing degree of the gene editing system is improved. According to the invention, a MUSCULAR-CAST gene editing system is used for constructing the chassis strains for producing 3-fucosyllactose, L-tryptophan, 2 '-fucosyllactose and neotetraose, so that the chassis strains have equivalent or higher expression yield compared with plasmids, and the growth condition is better or the conversion rate is higher.

The invention relates to the technical field of biology, in particular to a recombinant strain for producing nicotinamide mononucleotide and application of the recombinant strain. According to the method, accumulation of the NMN is improved through metabolic flux redirection and gene knockout, a synthesis path of the NMN is successfully established in escherichia coli, and further, the yield of the NMN is effectively improved and reaches 7.0 g / L by optimizing a transport system of NAM-NMN and a PRPP synthesis path. The invention also optimizes the production process of the NMN, realizes the highest yield of the NMN of 28.5 g / L in a fed-batch fermentation system, and obviously improves the yield compared with the traditional batch fermentation.

The invention belongs to the technical field of biosynthesis, and particularly relates to a strain for producing sclareol as well as a construction method and application of the strain. In order to solve the problem of microbial synthesis of sclareol, phosphoketolase in an NOG pathway is mutated and optimized, phosphoketolase NaXpk from nanoarchaea archaeon is subjected to site-directed mutagenesis, a sclareol synthesis pathway is constructed in an escherichia coli host, the influence of NaXpk before and after mutation on the yield of sclareol is compared, and the yield of sclareol is improved. The S472F mutant and the S472Y mutant are determined, the S472F mutant and the S472Y mutant are applied to a sclareol production path, the sclareol yield of the finally obtained production strains can reach 623.3 mg / L and 655.2 mg / L, and the effect is remarkable.

The invention discloses a method and application for enhancing cytidine production, and belongs to the field of genetic engineering and microbial engineering. The present invention knocks out cytidine deaminase gene cdd, uridine kinase gene udk, pyrimidine-specific ribonucleoside hydrolase gene rihB, nucleotide 5'-monophosphate nucleosidase gene ppnN, pyruvate oxidase gene poxB and integrates and expresses 5'-CTP diphosphohydrolase, orotate phosphoribosyltransferase, uridylate kinase mutant gene PyrH (R92G / D93G), as well as phosphoribosyl pyrophosphate synthetase gene prs, glucose-6-phosphate dehydrogenase gene zwf and 6-phosphogluconate dehydrogenase gene gnd, and constructs a recombinant Escherichia coli with enhanced cytidine synthesis ability, and the cytidine yield reaches 61.9g / L in a 30L fermenter without adding antibiotics and inducers, which can be used to realize the industrial production of cytidine and realize green biomanufacturing.

The invention discloses a method for improving the solubility and thermal stability of sweet protein, and belongs to the technical field of biosynthesis, the method comprises the following steps: constructing a gene tandem recombinant plasmid containing a monellin x-3C-sfGFP-3C-monellin y expression cassette, x is greater than or equal to 1, y is greater than or equal to 1, 5 is greater than or equal to x + y is greater than or equal to 3, a 3C protease recognition sequence is also inserted between adjacent copies of monellin, and each monellin is connected with a purification tag; the gene tandem recombinant plasmid is transformed into escherichia coli and inducible expression is carried out, thalli are split and purified to obtain fusion protein, 3C protease is used for enzyme digestion, and the target protein is obtained after re-purification. The total protein yield and the solubility proportion are remarkably improved by adopting a series construction mode of plasmids, meanwhile, the stability of monellin is effectively improved, the purification step is simpler and more convenient, and the method is suitable for industrial production.

The invention belongs to the technical field of synthetic biology genome editing, and relates to a chassis strain for gene cluster in-vivo traceless editing, a construction method and a gene cluster traceless editing method.The chassis strain is based on escherichia coli BL21 (DE3) and integrates a CRISPR-Cas9 system and a homologous recombination system (lambda Red) of a lambda bacteriophage source; and then knocking in an inducible sgRNA expression cassette (sgT) of a targeted editing vector to construct the vector. The strain has an efficient editing capability aiming at exogenous DNA, traceless editing of a target biosynthetic gene cluster is realized, and editing plasmids can be quickly eliminated, so that iterative editing is facilitated. The method is simple, convenient and rapid to operate and high in practicability, and provides powerful technical support for metabolic engineering and synthetic biology breeding transformation of streptomyces industrial strains, activation of synthetic gene clusters of recessive natural products and excavation of novel natural products.

The invention belongs to the technical field of bacteriophages, and discloses a salmonella bacteriophage with cross-species lysis capability, a bacteriophage composition and application of the salmonella bacteriophage, the salmonella bacteriophage is named as salmonella bacteriophage PC553, the preservation number of the salmonella bacteriophage PC553 is CGMCC No.46166, and the preservation The strain is preserved in China General Microbiological Culture Collection Center (CGMCC) on August 16, 2024, and the preservation address is No.3, Yard 1, Beichen West Road, Chaoyang District, Beijing. The bacteriophage is wide in splitting spectrum and high in titer, shows cross-species strong splitting energy to escherichia coli, can be prepared into drugs, environment disinfectants, feeds, water additives and the like for preventing and treating pigeon salmonellosis and / or colibacillosis for application, effectively prevents and treats spreading of salmonellosis and avoids the problem of secondary infection of escherichia coli, and has a good application prospect in preventing and treating pigeon salmonellosis and / or colibacillosis. The feed additive has the effects of effectively reducing the death and culling rate of pigeons, reducing the positive rate of salmonellosis antibodies, improving the production performance index of pigeons and the like.

The invention discloses Escherichia coli with high fructose chondroitin yield and a production method of the Escherichia coli, and belongs to the technical field of microorganisms. On the basis of Escherichia coli K4, a coding gene of a key enzyme in a fructose chondroitin synthesis route is mutated, and a strain for improving the fructose chondroitin synthesis capability is constructed. The yield of fructose chondroitin in a 5 L fermentation tank reaches 10 g / L, the yield of fructose chondroitin in a 100 L fermentation tank reaches 15-20 g / L, the obtained final product is uniform in structure and stable in quality, the production cost is effectively reduced, the environmental pollution risk is reduced, and the strain is suitable for large-scale industrial production and application.

The invention provides a recombinant microorganism with high yield of leucine as well as a construction method and application of the recombinant microorganism, two key exogenous enzymes, namely acetohydroxy acid synthase which is not subjected to feedback inhibition of leucine and an NADH-dependent acetohydroxy acid isoreductase mutant, are introduced to relieve the feedback inhibition effect of the leucine and improve the H balance of coenzyme NAD (P); therefore, the yield of the escherichia coli leucine is improved.

Methods of producing bioconjugates of O-antigen polysaccharides covalently linked to a carrier protein using recombinant host cells are provided. The recombinant host cells used in the methods described herein encode a particular oligosaccharyl transferase enzyme depending on the O-antigen polysaccharide bioconjugate to be produced. The oligosaccharyl transferase enzymes can be PglB oligosaccharyl transferase or variants thereof. Also provided are compositions containing the bioconjugates, and methods of using the bioconjugates and compositions described herein to vaccinate a subject against extra-intestinal pathogenic E. coli. (ExPEC).

The invention provides a complex microbial inoculant for producing beta-glucuronidase and application of the complex microbial inoculant in calculus bovis production, and relates to the technical field of microorganisms. The culture method of the complex microbial inoculant provided by the invention comprises the following steps: culturing lactobacillus ATCC 53103 in an initial culture medium to a logarithmic phase, sterilizing to obtain a complex culture medium, mixing the complex culture medium with nutritional ingredients, inoculating escherichia coli ATCC 25922 and riemerella CCUG 14215, and co-culturing to obtain the complex microbial inoculant. The complex microbial inoculant provided by the invention can generate a large amount of high-activity beta-glucuronidase, so that the efficiency of in-vitro production of calculus bovis can be effectively improved.

The present invention discloses an antimicrobial peptide and its application, wherein the antimicrobial peptide comprises one or more of an antimicrobial peptide PFK having an amino acid sequence as shown in SEQ ID NO: 1, an antimicrobial peptide PVK having an amino acid sequence as shown in SEQ ID NO: 2, and an antimicrobial peptide PIK having an amino acid sequence as shown in SEQ ID NO: 3. The antimicrobial peptides PFK, PVK and PIK of the present invention have antimicrobial effects on Porphyromonas gingivalis, Streptococcus mutans, Acinetobacter baumannii, Escherichia coli and Staphylococcus aureus, and the antimicrobial peptides PFK, PVK and PIK have low hemolytic activity and low cytotoxicity, and can be used to prepare biological antimicrobial preparations, anti-infective drugs or oral products.

The invention discloses lactobacillus arrhizatae and application thereof, and relates to the technical field of microorganisms. The lactobacillus arrhizatae is preserved in the Guangdong Microbial Culture Collection Center on December 10, 2024, the preservation number is GDMCC 65603, and the preservation address is the 5th floor, No. 59 building, No. 100 Courtyard, Xianlie Middle Road, Guangzhou. According to the invention, a strain of Lactobacillus argenteus is screened from healthy free-ranging adult local partridge chickens from Guangxi Zhuang Autonomous Region Tibetan City, the strain is named as LB19, and verification proves that the Lactobacillus argenteus has a good inhibition effect on food-borne pathogenic bacteria including salmonella and escherichia coli, and can be used for preparing food-borne pathogenic bacteria. Good application potential is realized in the aspect of preventing and treating food-borne pathogenic bacteria.

The invention relates to the field of fiber technology, and in particular to a method for preparing an antibacterial and anti-mite intelligent constant temperature fiber, comprising the steps of preparing a soybean protein solution, preparing a temperature regulating solution, preparing a mixed spinning solution, pre-spinning injection, spinning and post-processing. The antibacterial and anti-mite intelligent constant temperature fiber prepared by the invention has better softness and hand feel than the same type of added functional fibers in the industry due to the addition of soybean protein isolate, and has obvious advantages. The melting enthalpy is 44.5-55.6 J / g, the crystallization enthalpy is 42.4-53.1 J / g, and the fiber has better constant temperature performance. The fiber has an antibacterial rate of more than 98% against Staphylococcus aureus, more than 94% against Escherichia coli, and more than 95% against Candida albicans, and has a very strong anti-mite effect, with a detection rate of 0 dust mites and an avoidance rate of ≥99%.

The invention discloses a flavin monooxygenase FMO mutant and application thereof in indigo production, and belongs to the technical field of microbial engineering. Through rational design, directional mutation or random mutation, a mutant with catalytic efficiency several times higher than that of wild-type flavin monooxygenase is obtained, then the mutant is integrated into escherichia coli to obtain a recombinant strain capable of expressing the mutant, and the obtained recombinant strain not only can realize cyclic regeneration of cofactors, but also can be used for preparing the flavin monooxygenase. An expensive cofactor NADPH does not need to be additionally added, so that the effects of saving materials and reducing the production cost are achieved; the fermentation period can be shortened, and the yield of indigo blue is increased and reaches the g-level level. Therefore, the flavin monooxygenase mutant and the constructed recombinant bacteria have good application prospects in the field of indigo production, and large-scale industrial production of indigo is promoted.

The invention discloses a genetically engineered bacterium for biosynthesis of gastrodin as well as a construction method and application of the genetically engineered bacterium. According to the genetically engineered bacterium, through overexpression of sucrose permease CscB derived from escherichia coli W, sucrose phosphorylase Basp of bifidobacterium adolescentis, uridine triphosphoryl-glucose-1-phosphate uridine acyl transferase UgpA of bifidobacterium bifidum and UDP-glycosyl transferase RsUGT of hedyotis diffusa, an exogenous path for synthesizing UDP-glucose from sucrose is constructed in a cell, and the UDP-glucose is synthesized into UDP-glucose. And the glycosylation capability of the gastrodin precursor on hydroxybenzyl alcohol is enhanced. The invention also provides a construction method of the genetically engineered bacterium and a method for synthesizing gastrodin through whole-cell catalysis by using the strain and taking p-hydroxybenzyl alcohol and cane sugar as substrates. The genetically engineered bacterium is high in gastrodin synthesis efficiency, the molar conversion rate can reach 97.8%, the highest yield reaches 3.61 g / L, and a new green manufacturing scheme is provided for solving the problems that a traditional gastrodin production method is low in efficiency, high in cost, large in pollution and the like.

The invention provides a method for producing beta-glucuronidase from escherichia coli and application of the beta-glucuronidase, and relates to the technical field of microorganisms. The method provided by the invention comprises the following steps: inoculating Escherichia coli ATCC 25922 on a composite culture medium for pre-culture, and culturing in an electric field environment of 1-10N / C for 12-24h to obtain a mixture containing beta-glucuronidase; wherein the composite culture medium comprises 10-100 [mu] mol / L of ferric citrate, and the concentration of the ferric citrate is increased in stages in the pre-culture process. According to the method, the escherichia coli ATCC 25922 is cultured in the iron-containing culture medium and the low-intensity electric field environment, so that the synthesis of the beta-glucuronidase by the escherichia coli ATCC 25922 can be effectively improved, and the enzyme activity and the enzyme yield of the beta-glucuronidase are improved.

The subject relates to an isolated antibody that specifically binds to O25b antigen of multi drug resistant (MDR) E. coli strains, its medical and diagnostic use, method of producing the antibody, including an isolated nucleotide sequence, plasmids and host cells as used in the production of the antibody; and further an isolated epitope recognized the specific antibody.

The present invention belongs to the field of biotechnology, and relates to a protein RNA complex that can be used for directional binding and delivery to plant leaves. The protein consists of three parts: a functional domain that can be directional bound to plant leaves, a functional domain containing surface activity, and a functional domain that binds to RNA. By co-expressing with target RNA, the protein can form a protein RNA complex with the target RNA in vivo. Droplets containing the protein RNA complex have good wettability on the surface of leaves, and the protein can fix RNA on the surface of leaves to increase the overall effect of RNA. The protein and RNA are co-expressed in Escherichia coli to form a complex, and its production is easy to scale and low cost, and has important practical promotion value.

The invention provides a quality control kit of a nucleic acid detection system as well as a quality control method and application of the quality control kit. The quality control kit comprises the coliphage MS2 and a first sequence group. The first sequence group comprises a forward primer of a sequence as shown in SEQ IQ NO: 1, a reverse primer of a sequence as shown in SEQ IQ NO: 2 and a probe of a sequence as shown in SEQ IQ NO: 3. The quality control method comprises the following steps: mixing a specimen with bacteriophage MS2, and carrying out nucleic acid extraction to obtain an eluent; and mixing an eluent with the feline blood plasma bacterial plastid, the first sequence group and the second sequence group, and carrying out multiple real-time polymerase chain reaction. The quality control kit of the nucleic acid detection system is used for evaluating the recovery rate of nucleic acid and the whole-process quality control of the nucleic acid detection system.

The invention provides an antibacterial agent based on co-assembly of an anionic surfactant and polyarginine, and particularly relates to a safe and efficient antibacterial agent. The antibacterial agent provided by the invention is an aggregate formed by co-assembly of polyarginine (Arg) n and an anionic surfactant, and the preparation method is simple. The antibacterial agent is high in safety and has no toxicity to mammalian cells; the compound has remarkable antibacterial activity on escherichia coli and staphylococcus aureus. According to the invention, the assembly structure of the antibacterial agent can be regulated and controlled by adjusting the number (such as 4, 8, 12 or 16) of arginine in the polyarginine and the charge ratio between the polyarginine and the anionic surfactant; and when the layered structure is formed, the antibacterial agent has the strongest antibacterial activity. Meanwhile, in a mouse in-vivo experiment, the antibacterial agent also shows efficient antibacterial activity and can promote wound healing.

The invention discloses a preparation method and application of a hexavalent multi-epitope fusion protein of avian pathogenic Escherichia coli. The invention preferably selects antigenic epitopes of the curli fimbriae subunit CsgA, lipoprotein SlyB, maltose porin LamB, outer membrane protein PhoE, proteolytic enzyme activator NlpD and lipoprotein Pal main structural subunit of avian pathogenic Escherichia coli, and preferably connects with the heat-labile enterotoxin LTb fusion protein in series to construct an antigenic multi-epitope fusion protein of six proteins of avian pathogenic Escherichia coli. The antigenic multi-epitope fusion protein has a wide serotype coverage, is non-allergenic, has strong immunogenicity, and produces strong specific humoral immunity and cellular immune response after immunizing animals.

The invention relates to the technical field of aquatic animal immune regulation and control, in particular to rHoLL-like stepped lectin-like recombinant protein as well as a preparation method and application thereof. The recombinant protein has pathogen-related molecular pattern recognition and combination capabilities, can promote aggregation of pathogens in a body fluid environment, and activates an aquatic animal complement system, so that the non-specific immune defense capability is enhanced. The preparation method comprises the following steps: amplifying a HoLL-like mature peptide coding sequence, constructing a recombinant expression vector, and converting the recombinant expression vector into an escherichia coli expression host for induced expression to obtain rHoLL-like lectin-like recombinant protein existing in an inclusion body form; and carrying out affinity chromatography purification on the inclusion body protein, and carrying out renaturation treatment in a manner of gradient reduction of denaturant concentration to obtain the rHoLL-like stepped lectin-like recombinant protein. The rHoLL-like stepped lectin-like recombinant protein has good biological safety, and can be applied to aquaculture as an aquatic animal immunopotentiator or a related biological product.

The application discloses a Mycoplasma bovum adhesion protein FtsZ and application thereof. The nucleic acid sequence of the Mycoplasma bovum adhesion protein FtsZ is shown as SEQ ID NO. 1. The application also discloses a recombinant plasmid pET-30a-ftsZ and an E. coli containing the recombinant plasmid pET-30a-ftsZ. ftsZ The recombinant protein rFtsZ has the advantages of being capable of specifically combining with EBL cell membrane protein, being capable of combining with extracellular matrix components (fibronectin, fibronectin, laminin and type IV collagen), having the direct adhesion host cell effect, having good antigenicity, being capable of producing high-level antibodies, being capable of providing good immune protection effect, and providing a new target and thought for elucidating the pathogenic mechanism of the Mycoplasma bovum and developing a new vaccine and medicine.

The invention relates to the field of gene editing, in particular to a gene editing system based on Escherichia coli endogenous EcoTnpB protein and application of the gene editing system, and the gene editing system comprises a) EcoTnpB protein expressed by Escherichia coli endogenous or a nucleotide sequence for coding the EcoTnpB protein; and b) an omega RNA molecule or a nucleotide sequence encoding the omega RNA molecule, the sequence of the omega RNA molecule comprises an RNA scaffold sequence and a guide sequence complementarily paired with a target sequence, and the omega RNA molecule can form a complex with the EcoTnpB protein and guide the EcoTnpB protein to recognize the target sequence. Escherichia coli endogenous protein is combined with customized omega RNA and a corresponding editing template for genome editing, efficient knockout, insertion and continuous editing of target genes can be achieved in Escherichia coli, and the method has wide application value in different Escherichia coli hosts.

The invention discloses an antibiotic resistance prediction method based on a metric element learning architecture. According to the framework, an adaptive mechanism is adopted, and the characteristics of different antibiotics and the distribution characteristics of genome data are precisely matched with an adaptive machine learning model by deeply analyzing the characteristics of the different antibiotics and the distribution characteristics of the genome data. Escherichia coli whole genome sequencing data is adopted, and prediction research is carried out aiming at whether antibiotics have drug resistance or not, so that an optimal prediction model under different drug types and data distribution conditions is evaluated. In addition, molecular structure characteristics and data distribution modes of antibiotics are deeply excavated, and a metrics-based meta learning model matching mechanism is constructed. According to the method, through a metrics-based meta learning framework, the problem of model selection in antibiotic resistance prediction in a complex scene can be effectively solved; meanwhile, in a new drug resistance prediction task, a zero sample learning ability is realized, model adaptation can be completed without extra training data, and the computing resource consumption cost in a model training process is effectively reduced.

The application discloses a method for constructing a tag sequence-containing vector library by short oligonucleotides and application thereof. The method needs two oligonucleotides, i.e. a customized tag primer and a universal primer which can be used for all library constructions. The middle of the tag primer is a tag sequence, and both sides are annealing sequences. The universal primer has sequences complementary to the annealing sequences of the tag primer on both sides, and a modified base which can be recognized as a base damage by a host microorganism in the middle. The tag primer library is annealed with an equal amount of the universal primer to obtain primer dimers. The primer dimers have base-paired DNA double strands on both sides, and are cohesive ends. The middle of the primer dimers is an unpaired omega loop structure, and the double strands of the omega loop contain the tag information carried by the tag primer and the modified base carried by the universal primer respectively. The primer dimers are connected with linearized vectors, and then are transformed into E. coli, so that the region of the modified base of the omega loop is replaced by the tag sequence through the base excision repair mechanism of the endogenous cells.

The application belongs to the field of enzyme engineering and biotechnology, and discloses a 4-hydroxybenzoic acid hydroxylase mutant and application thereof in synthesis of gallic acid or a salt thereof. The 4-hydroxybenzoic acid hydroxylase mutant is obtained through directional evolution modification and high-throughput screening, and has an increased protocatechuate hydroxylase activity by more than 4 times. The 4-hydroxybenzoic acid hydroxylase mutant is expressed by using E. coli, and the obtained recombinant E. coli can efficiently catalyze the conversion of protocatechuate into gallic acid. The 4-hydroxybenzoic acid hydroxylase mutant is expressed in the recombinant E. coli for producing protocatechuate, and the obtained recombinant E. coli can de novo synthesize gallic acid from glucose as a substrate, and the yield reaches 58.65 g / L, and the residual amount of protocatechuate is only 0.33 g / L. The application solves the problem of a large amount of residual protocatechuate in the fermentation process of the existing strains, and can provide an efficient enzyme element for the creation of gallic acid industrial strains.

The invention provides a plasmid and application thereof. The plasmid comprises a recognition site of a first endonuclease, a target gene and a recognition site of a second endonuclease from a 5 '-3' direction. According to the invention, the plasmid is amplified by using a rolling circle amplification method, the rolling circle amplification product is cleaved by using the first endonuclease and the second endonuclease, the enzyme cleaved product is digested by using exonuclease, and the product is further purified by using oligonucleotide. The obtained product can be used for in vitro transcription or directly applied to eukaryotic expression. According to the scheme provided by the invention, a simple, high-yield, economic, rapid and amplifiable preparation process of the full chemical synthesis DNA template for escherichia coli fermentation is established.