103 results about "Bacterium coli" patented technology

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 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 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 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 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.

The present invention relates to a method for treatment of polyhydroxyalkanoate (PHA) containing post-consumer product, the method comprising contacting a post-consumer product with a polypeptide that can catalyze degradation of the PHA, the contact taking place at a temperature at least 45° C. In a specific embodiment, the poly peptide is a wild-type PHA depolymerase expressed by a thermophilic microorganism or a modified PHA depolymerase that includes one or more single-site mutations as compared to the wild-type PHA depolymerase. In another specific embodiment, the polypeptide comprising a modified poly hydroxy butyrate (PHB) depolymerase comprising one or more single-site mutations as compared to SEQ ID NO: 1, and the modified PHB depolymerase having an optimum temperature of at least 45° C. The present invention also relates to a host cell transformed to express a polypeptide that catalyzes degradation of a PHA, the polypeptide having an optimum temperature for the degradation reaction of at least 45° C., wherein the host cell is selected from an E. coli cell or a thermophilic microorganism.

The present invention relates to a method for treatment of poly hydroxy alkanoate (PHA) containing post-consumer product, the method comprising contacting a post-consumer product with a polypeptide that can catalyze degradation of the PHA, the contact taking place at a temperature at least 40° C. and in the presence of salt at a concentration of 1 M or greater. In a specific embodiment, the polypeptide is a wild-type PHA depolymerase expressed by a halophilic microorganism or a modified PHA depolymerase that includes one or more single-site mutations as compared to the wild-type PHA depolymerase. In another specific embodiment, the polypeptide comprising a modified poly hydroxy butyrate (PHB) depolymerase comprising one or more single-site mutations as compared to SEQ ID NO: 1, and the modified PHB depolymerase having a solubility of 10 mg / L or greater. The present invention also relates to a host cell transformed to express a polypeptide that catalyzes degradation of a PHA in the presence of salt at a concentration of 1 M or greater, wherein the host cell is selected from an E. coli cell or a halophilic microorganism.

The invention relates to the technical field of biology, and particularly discloses a construction method and application of escherichia coli engineering bacteria for overexpressing uric acid degradation gene clusters. According to the invention, a mixed promoter box is inserted into Escherichia coli, overexpression coding is carried out on genes of regulatory protein YgeV and key genes in a uric acid degradation pathway, and the Escherichia coli engineering bacteria which can overcome inhibition of intestinal glucose on uric acid degradation and enable the Escherichia coli engineering bacteria to overexpress uric acid degradation gene clusters are successfully constructed. The coliform engineering provided by the invention provides a new strategy for prevention and treatment of hyperuricemia and gout.

The invention provides a mutant of a YciE gene coding protein and application of the mutant in preparation of NMN, belongs to the technical field of molecular biology, and particularly provides the mutant of the YciE gene coding protein, the amino acid mutation site is that the 140th methionine of the amino acid sequence SEQ ID NO.3 of the YciE gene coding protein is mutated into isoleucine; the coding gene of the mutant is as shown in SEQ ID NO. 2; a recombinant bacterium containing the coding gene of the mutant; according to the invention, it is found for the first time that methionine at the 140th site in a protein amino acid sequence coded by a YciE gene of escherichia coli is mutated into isoleucine; the synthesis level of NMN can be effectively improved, and generation of by-products is reduced.

Disclosed herein are prokaryotic and eukaryotic microbes, including E. coli and S. cerevisiae, genetically altered to biosynthesize tryptamine and tryptamine derivatives. The microbes of the disclosure may be engineered to contain plasmids and stable gene integrations containing sufficient genetic information for conversion of an anthranilate or an indole to a tryptamine. The fermentative production of substituted tryptamines in a whole-cell biocatalyst may be useful for cost effective production of these compounds for therapeutic use.

The present description relates to a recombinant microorganism having production activity of pentamethylenediamine (PMDA), which comprises an E. coli Nissle-derived decarboxylase enzyme protein, and uses thereof.

The invention is applicable to the field of gene engineering, and provides a mycobacterium tuberculosis Ag85B-TB8.4-LS protein nanoparticle, a preparation method and application thereof, the mycobacterium tuberculosis Ag85B-TB8.4-LS protein nanoparticle is formed by sequence fusion of mycobacterium tuberculosis Ag85B protein, TB8.4 protein and LS protein, and the amino acid sequence of the mycobacterium tuberculosis Ag85B-TB8.4-LS protein nanoparticle is shown as SEQ ID NO: 2 in a sequence table. According to the invention, by virtue of a gene recombination technology, key immunogens Ag85B and TB8.4 of mycobacterium tuberculosis are combined with an LS protein fusion vector, and the Ag85B-TB8.4-LS protein nanoparticles with uniform particle size and stable structure are efficiently produced by virtue of an escherichia coli expression system. Animal experiment results show that the Ag85B-TB8.4-LS protein nanoparticle can simultaneously excite strong humoral immunity and cellular immunity response, not only brings a new idea for research and development of tuberculosis vaccines, but also can be popularized and applied to research and development of other infectious disease vaccines due to the modular design, and has important scientific significance and industrialization prospects.

The application discloses a human source pioneer transcription factor SOX15 HMG domain recombinant protein and a preparation method thereof, belongs to the technical field of biology, and specifically comprises the following steps: optimizing the expression SOX15 HMG protein condition of E. coli, purifying the SOX15 HMG protein, and detecting the activity of the SOX15 HMG protein after purification. It is found through the exploration of the optimized expression condition that the soluble protein can be obtained by using 0.1-0.5 mM of the concentration of an inducer IPTG (isopropyl-beta-D-thiogalactoside) and inducing for 3-4 hours at 37 DEG C. The two-step purification strategy of nickel column affinity chromatography combined with molecular sieve chromatography can obtain the recombinant protein with a purity of more than 90% and a molecular weight of about 12 kDa. Electrophoretic mobility shift assay (EMSA) proves that the purified SOX15 HMG recombinant protein has the activity of binding to target DNA.

The invention relates to the field of microbiology, specifically to an antimicrobial composition comprising a first and a second bacteriophage, wherein the composition has lytic activity against E. coli O157. The invention further relates to a use of the antimicrobial composition for controlling bacterial contamination in a food- or feed environment on or in food- or feed processing equipment or food- or feed containers or in a food- or feed product.

The invention discloses a nucleotide sequence of PDRN / PN and a preparation method of PDRN / PN based on genetic engineering and microbial fermentation, and belongs to the technical field of biology. According to the method, the vibrio is adopted as a production chassis strain, and methods of pyrolysis crude extraction, enzyme digestion and magnetic bead selective separation are combined, so that the preparation of the multi-source PDRN / PN is realized, and the application range of the product is expanded. Compared with an escherichia coli system, the method has the advantages that the endotoxin pollution risk can be remarkably reduced, and the product safety is improved; compared with a yeast system, the production efficiency of PDRN / PN can be improved. Meanwhile, the method is simple and convenient to operate, is suitable for laboratory and pilot scale amplification, and has obvious industrial application potential.

The invention discloses a method for synthesizing shikimic acid from shikimic acid dehydrogenase of a plant and microorganisms, which uses a shikimic acid synthesis method based on a shikimic acid dehydrogenase gene of the plant, and is characterized by comprising the following steps: S1, obtaining a shikimic acid dehydrogenase gene sequence from the plant; s2, performing codon optimization on the gene; s3, inserting the optimized shikimic acid dehydrogenase gene into an expression vector; s4, transferring the expression vector into escherichia coli engineering bacteria to express shikimic acid dehydrogenase; and S5, synthesizing shikimic acid through an in-vitro catalytic reaction. The screened enzyme has the advantages of few side reactions, no inhibition by high-concentration products and high activity. A recombinant strain for producing shikimic acid is obtained by utilizing the enzyme through a metabolic engineering means. The strain does not use plasmids, has strong genetic stability, does not need additional aromatic amino acids in a fermentation medium, has low production cost, high yield and yield and few metabolic byproducts, and has important industrial application value.

This invention belongs to the field of biomedical technology, specifically relating to a recombinant human plasminogen mutant, its preparation method, and its application. A recombinant human plasminogen mutant, the amino acid sequence of which is shown in SEQ ID NO.3. The recombinant human plasminogen mutant of this invention, compared to wild-type mPLG, can be directly expressed solublely in the supernatant of *E. coli* fermentation broth. Soluble expression allows for direct chromatography of the fermentation broth to obtain the target protein, which has significant advantages over inclusion body renaturation treatment in terms of process simplification, activity loss, time cost, and production cost. Furthermore, the activity of the mutant protein was tested using the fibrin plate method and kit method. The results showed that the titer of the target protein was approximately 8 UI / mg, which is similar to the titer of mPLG obtained by renaturation before mutation and PLG obtained from human blood. In summary, compared to the wild type, the mutant strain exhibits significantly improved solubility while maintaining high protein activity.

The application provides a bacteriostatic and deodorizing composite preparation for pets and application thereof, which comprises 30-40% of enzyme preparation, 20-30% of plant extract, 20-30% of probiotic powder, and 0-10% of inorganic salt and filling aid. The application can efficiently remove ammonia and effectively reduce the ammonia gas yield in excrement; can efficiently inhibit E. coli, Salmonella, MRSA, C. perfringens and the like; can reduce fecal odor and effectively reduce fecal odor substances in pet excrement, such as indole, cadaverine, spermidine, putrescine and skatole and the like; is safe and harmless, avoids the negative influence of chemical synthetic substances on pet health, prevents clumping, and maximally reduces the influence on cat litter clumping, thereby guaranteeing the use effect.

The present application relates to the technical field of biological medicine, and discloses a double-targeting adhesion-immune activation fusion peptide, an anti-E.coli O157:H7 monoclonal antibody GS2-D3, curcumin nanoparticles and a probiotic composition composed of the same. The fusion peptide solves the structural conflict by inserting an alpha-helix stable domain composed of four EAAAK repeat units and a GPGP flexible buffer domain, introduces a targeting domain YIGSR and a MUC2 binding domain PTPSFTT to improve the targeting efficiency, and is subjected to site mutation to enhance the anti-enzymatic property. The monoclonal antibody GS2-D3 can specifically recognize E.coli O157:H7. The curcumin nanoparticles improve the stability and bioavailability of curcumin. The probiotic composition contains the above components, has the effects of efficient colonization, bacteriostasis, anti-inflammation and regulation of intestinal flora, can effectively treat intestinal inflammation, has low cost and high safety, and has good clinical transformation potential.

This invention belongs to the field of biosynthesis technology, specifically relating to a strain for producing perillaldehyde, its construction method, and its application. Addressing the microbial synthesis problem of perillaldehyde, this invention mutates and optimizes the phosphotransketase in the NOG pathway, using a strain derived from nanoarchaemonas (…). Nanoarchaeota archaeon Site-directed mutagenesis was performed on the phosphoketolase NaXpk, and a perillaldehyde synthesis pathway was constructed in E. coli. The effects of NaXpk mutation on perillaldehyde yield were compared to identify the S472F and S472Y mutants. These mutants were then applied to the perillaldehyde production pathway, and the resulting production strains achieved perillaldehyde yields of 623.3 mg / L and 655.2 mg / L, respectively, demonstrating significant effectiveness.

The present application provides a method for producing amino acid and nucleoside by microbial reinforced fermentation, which is achieved by analyzing lysine fermentation process, screening excellent fermentation strains, and adding the preferred E. coli (or adding the preferred C. glutamicum) in a timely and quantitative manner in the fermentation process based on C. glutamicum (or in the fermentation process based on E. coli), so as to obviously improve the yield and conversion rate of lysine. The present application can effectively solve the problems of unstable product quality and difficult effective control of production process in traditional lysine fermentation, and has important significance for improving fermentation efficiency and conversion rate.

Most of the conventional final treatment plants for sewage and polluted water exist at a position in contact with the ocean and discharge the sewage and polluted water into the sea after treatment, and the principle of the treatment is bacterial decomposition, which is a method using biodegradation by freshwater microorganisms. Although the contents of Escherichia coli and chemical substances are prescribed as numerical values by law, they are far from perfect including human errors. In recent years, the global environment has been emphasized, and marine pollution is an essential problem imposed on mankind.SOLUTION: To construct a technique for improving a final treatment plant of sewage or waste water in consideration of the environment, to verify the conventional biological decomposition theory of only bacteria, and to enable safe marine discharge by a technique requiring complete treatment in a land facility. To provide a technique and a means capable of greatly improving a complete decomposition treatment in which the natural environment of land and sea is built up by a land facility, by utilizing the ecology of organisms living in a fresh water area and a sea water area, providing a fresh water tank group and a sea water tank group, allowing a bacteria group and small organisms to coexist, utilizing the respective biological characteristics, and aiming at the advancement and completion of the present biodegradation.SELECTED DRAWING: Figure 1

The invention is applicable to the field of gene engineering, and provides a mycobacterium tuberculosis PPE18-LS protein nanoparticle, a preparation method and application thereof, the mycobacterium tuberculosis PPE18-LS protein nanoparticle is formed by sequence fusion of mycobacterium tuberculosis PPE18 protein and LS protein, and the amino acid sequence of the mycobacterium tuberculosis PPE18-LS protein nanoparticle is shown as SEQ ID NO: 2 in a sequence table. According to the invention, the key protective antigen PPE18 of mycobacterium tuberculosis and the LS protein with self-assembly characteristic are subjected to fusion expression, and the PPE18-LS protein nanoparticles with uniform structure are successfully prepared through an Escherichia coli expression system. In-vivo experiment results show that the PPE18-LS protein nanoparticles can effectively activate response pathways of humoral immunity and cellular immunity of a host, show obvious protective efficacy in a mouse model, provide an important technical path for developing a new generation of tuberculosis preventive vaccines, and have wide clinical application prospects and industrialization values.

This invention belongs to the field of biosensing and fiber optic detection technology, and discloses a photoelectric-coupled fiber optic real-time in-situ detection system for monitoring the adsorption process of *E. coli* (DH5α). Addressing the core pain points of existing *E. coli* detection technologies, such as reliance on complex sample pretreatment (taking over 24 hours) and the inadequacy of false positives and sensitivity with single-fiber SPR or electrochemical detection, which fail to capture the dynamic process of bacterial adsorption, this invention uses a fiber optic SPR probe with a dual recognition layer consisting of a surface-modified dopamine polymer membrane, an LPS-specific nucleic acid aptamer, and a *E. coli* shape-imprinted cavity as the working electrode. It simultaneously acquires SPR resonance wavelength shift and electrochemical current signals, achieving cross-validation of multi-dimensional detection results. The system can be in-situ implanted into complex detection systems such as water samples and food homogenates without labeling. It exhibits strong anti-interference capabilities and high detection specificity, and can track the entire dynamic process of *E. coli* adsorption-desorption in real time. It can be widely applied in scenarios such as rapid on-site screening of foodborne pathogens, research on bacterial interfacial adsorption mechanisms, and monitoring of microbial pollution in aquatic environments.

This invention relates to the field of genetic engineering technology, and particularly to TEV protease mutants, their preparation methods, and applications. This invention modifies the TEV enzyme molecule, with mutation points differing from those reported in previous studies. This enhances the activity of the TEV protease at the molecular level. Furthermore, this invention utilizes CRISPR / Cas9 gene editing techniques to modify the host bacterial chassis, obtaining engineered strains that express TEV at high yields. Further, the provided high-density fermentation control method can rapidly promote TEV enzyme expression, resulting in high E. coli cell yield, with an OD600 value reaching approximately 150, a cell wet weight of 80–130 g / L, and high expression levels of the target protein, accounting for 40%–64% of the total bacterial protein. Simultaneously, the method provided by this invention is simple and easy to implement, using readily available raw materials, achieving good application results while reducing production costs, resulting in significant economic benefits.