24 results about "Genetic stability" patented technology

The present application belongs to the field of synthetic biology and functional food technology, and provides a swallowing safety-oriented xanthan gum directional biosynthesis method. In view of the problem that existing xanthan gum is difficult to reduce the risk of swallowing residue and aspiration by relying on viscosity regulation alone, a multi-dimensional evaluation system combining interfacial tribology and extensional rheology is established to determine the side chain modification parameters suitable for swallowing disorder food. By chromosome scarless reconstruction of xanthan gum synthesis gene cluster, the gumF 、 gumG gene is knocked out and the gumL promoter is replaced, an engineering strain without antibiotic resistance gene residue and with genetic stability is constructed, and directional synthesis of xanthan gum with specific side chain structure is realized. The obtained structure customized xanthan gum has a lower mucosal interfacial friction coefficient and a more optimal extensional rheological property, and can synergistically realize interfacial lubrication and bolus cohesion, significantly reducing the wall residue in the pharynx, and keeping the consistency stable in complex food matrix. The present application can provide a safe, stable and industrialized functional xanthan gum raw material for swallowing disorder food.

This invention relates to the field of plant tissue culture and the breeding of superior varieties of traditional Chinese medicinal materials. This invention discloses a method for rapid propagation of Epimedium inflorescences via tissue culture, comprising the following steps: S1, collecting newly sprouted flower inflorescences of Epimedium in early spring, disinfecting them, and setting them aside; S2, cutting the disinfected inflorescences into 1.1-1.2 cm segments, inoculating them into callus induction medium, and culturing them under conditions of 1200-1300 lux light intensity, 12 h / day photoperiod, and 24℃. This invention ensures uniform seedling quality and stable traits through targeted screening of effective components and monitoring of genetic stability. The optimized culture medium ratios at each stage result in a high proliferation coefficient, robust rooting, and a short propagation cycle, enabling efficient year-round propagation. Standardized seedling hardening and transplanting lead to a high survival rate. This method is technically stable and highly applicable, enabling the mass production of high-flavonoid glycoside, genetically stable, high-quality seedlings, fundamentally solving problems such as germplasm degradation, low propagation coefficient, and uneven quality, providing strong support for the breeding and industrialization of superior varieties of Epimedium.

This invention discloses a highly acid-resistant Bacillus belye strain LYBV022-Ac R This invention relates to a method for screening and acclimating bacteria under progressive acid stress, and its application, belonging to the technical field of industrial microbial breeding and probiotic application. The disclosed high-acid-resistant Bacillus belyeis LYBV022-Ac... R By designing a pH gradient decreasing (6.5→3.0) acclimatization strategy and combining it with microplate rapid screening technology, a breakthrough improvement in acid resistance was achieved. After exposure to a simulated gastric acid environment (pH 3.0, containing pepsin) for 4 hours, the survival rate reached 48.52%, a 970-fold increase compared to the original strain (0.05%), while maintaining excellent growth performance and genetic stability. This invention also provides the application of this strain in the preparation of oral probiotic preparations for livestock and poultry, solving the common technical problem of insufficient potency in oral Bacillus preparations due to gastric acid damage.

This invention provides SSR molecular markers for Hibiscus rosa-sinus and their applications, belonging to the field of molecular marker technology. The invention comprises 15 molecular markers, with corresponding primer sequences shown in SEQ ID NO. 1~30. Testing revealed that this series of markers exhibits a 100% polymorphism rate, excellent polymorphism information content, marker index, and resolution, and strong genetic stability. The molecular marker primers of this invention can efficiently distinguish Hibiscus rosa-sinus germplasm materials, clearly revealing the population's genetic structure and phylogenetic relationships. They are suitable for Hibiscus rosa-sinus germplasm resource identification, genetic diversity analysis, molecular fingerprinting construction, and assisted breeding, possessing the characteristics of high specificity, high resolution, and wide applicability.

The application discloses a method for constructing a Vietnamese terminalia regenerative system, and comprises the following steps: Vietnamese terminalia stem segment test materials are obtained by grafting seedling saplings with superior branches, semi-lignified stem segments with axillary buds are used as explants, and after disinfection, the explants are inoculated into an induction culture medium to induce axillary buds, then the induced axillary buds are subjected to micro-branch cutting to carry out proliferation and rooting culture, and a large number of Vietnamese terminalia regenerative plants can be obtained. The method has the advantages of high propagation efficiency, high phenotype consistency, good genetic stability and the like, greatly shortens the production cycle of Vietnamese terminalia seedlings, reduces the variation risk of the seedlings, and provides high-quality seedlings for ecological afforestation and landscaping.

This invention discloses a method based on SOD The primers and methods for gene screening of heat-resistant scallop varieties were developed using scallop cDNA and DNA as templates. PCR amplification was performed using upstream and downstream primers (SEQ ID No. 3 and SEQ ID No. 4, SEQ ID No. 5 and SEQ ID No. 6) to obtain samples containing scallop cDNA and DNA. SOD Gene sequence fragments from the exon and promoter regions were used as molecular markers. The genotypes were CT at the c.229 C>T site, CA at the c.284 C>A site, and CA at the c.348 C>A site in the exon region, and CA at the g.1124 A>C site and AT at the g.1359 T>A site in the promoter region. This method screened for high-temperature resistant scallop varieties, demonstrating advantages such as genetic stability, accuracy, and efficiency.

本发明提供了蛋白突变体、包含该蛋白突变体的黄原胶生产菌株及应用。该黄原胶生产菌株包括一株高产黄原胶的黄单胞菌(Xanthomonas campestris)，菌株命名为黄单胞菌HXC001a，保藏于中国微生物菌种保藏管理委员会普通微生物中心，保藏编号为CGMCC No.38053。该菌株的基因组发生突变，导致编码的Q8P6W9蛋白存在T1158P突变。发酵实验表明，该菌株的黄原胶产量可达38.6 g / L，较出发菌株提高36.9%以上，且该高产表型具有良好的遗传稳定性。本发明提供的黄单胞菌可显著提高黄原胶产量，适用于工业化生产黄原胶，具有极高的应用价值。

This invention relates to the field of microbial technology, specifically to a thermoresistant Aeromonas guinea pig bacteriophage, its composition, and its applications. The bacteriophage was deposited on June 14, 2024, at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 45946, and named RKP-AE24003. The composition comprises the aforementioned bacteriophage. The bacteriophage can be used to prepare products that kill or inhibit Aeromonas guinea pig; and products for the prevention and / or treatment of aquatic diseases caused by Aeromonas guinea pig. This bacteriophage RKP-AE24003 exhibits good thermoresistance and strong genetic stability, allowing for stable storage in high-temperature environments, significantly improving the stability of industrial production and its applicability to high-temperature scenarios.

The application discloses application of a broad-spectrum type III esterase derived from Rhodococcus in phthalate ester pollution bioremediation, and overcomes the limitation of low degradation efficiency of a natural strain; through genetic engineering technology, the esterase 5359 gene is cloned into a Rhodococcus-E.coli shuttle vector pNV18 to construct a recombinant Rhodococcus engineering bacterium WT-pNV18-5359 overexpressing the esterase. Experimental results show that the engineering bacterium significantly improves the degradation performance: in single PAEs degradation test, the degradation rates of long-chain PAEs such as DEHP, DnOP and DiNP are respectively increased by 15.71%, 13.99% and 12.82% compared with the wild type; in a mixed PAEs system, the degradation of long-chain PAEs is obviously superior, and the engineering bacterium has good genetic stability and does not affect growth. Through genetic engineering to strengthen the application of known enzymes, efficient and stable PAEs pollution bioremediation is realized.

This invention relates to the field of microbial technology, specifically to a highly efficient lysing Vibrio alginolyticus phage derived from abalone, its composition, and its applications. The phage, named RKP-VA24471, has been deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 46426. The phage has a titer of not less than 1 × 10⁻⁶. ^10 With a PFU / mL concentration and an optimal MOI of 0.01, this phage exhibits advantages such as a short latency period, high outbreak rate, good genetic stability, and a wide adaptability to temperature and pH. Lysis spectrum experiments show that this phage has broad-spectrum lytic activity against various Vibrio species, including *Vibrio alginolyticus* and *Vibrio parahaemolyticus*, with an overall lysis rate of 80.6%. Animal experiments have demonstrated that this phage significantly improves the survival rate of abalone infected with *Vibrio alginolyticus*, outperforming antibiotics and fish-derived phages. The phage and its composition provided by this invention can be used for the prevention and treatment of vibriosis in aquatic animals such as abalone, offering a highly efficient and environmentally friendly biological control solution as an alternative to antibiotics.

The present application relates to a kind of recombinant bacillus subtilis of PRRSV ER protein on spore surface display, construction method and application.The recombinant bacillus subtilis is by genetic engineering method, with integrated plasmid pDG364 as foundation, constructs a recombinant vector with spore coat protein CotB as anchor protein, surface display PRRSV ER protein, is obtained by chemical transformation method with the recombinant vector is transformed into wild type bacillus subtilis 168, it has genetic stability, and will not be lost in the process of passage.The antigen protein is directly displayed on the spore surface of the bacterium, without crushing, can be directly mixed with material or through drinking water immunization animal, avoid the cumbersome process of large-scale injection.Benefiting from the good stress resistance of spore, the bacterium is easy to preserve and transport, significantly reduce cost.The bacterium can induce specific immune response, which provides a new way for the prevention and treatment of PRRSV, suitable for the development of commercial vaccine.

The application discloses a probiotic EcN△lpp-A5 strain and a construction method and application thereof, the probiotic EcN△lpp-A5 strain takes the probiotic Escherichia coli Nissle 1917 as a chassis, knocks out the outer membrane lipoprotein gene lpp, introduces a fusion protein formed by annexin V (Annexin V) and an Lpp signal peptide sequence and an OmpA anchoring domain sequence, and expresses the annexin V fusion protein on the surface of bacterial cells. The probiotic EcN△lpp-A5 constructed in the application has the characteristics of genetic stability and no exogenous resistance; the strain retains the original probiotic characteristics of EcN, realizes intestinal target colonization and long-time retention, and has the performance of continuously expressing and secreting exogenous recombinant proteins. The strain has strong intestinal targeting and high colonization ability, is safe, is suitable for oral administration, has a mature preparation process, and is convenient for large-scale production.

The application provides a method for efficiently and stably transforming algae strains of Porphyra yezoensis by Agrobacterium mediation, and belongs to the technical field of plant transgenesis. The application uses a mixed suspension of leaf thallus fragments, single spores and leaf thallus seedlings of Porphyra yezoensis as a transformation receptor, and establishes an efficient and stable genetic transformation technology through steps such as optimization of an infection solution and gradient screening culture. The application effectively solves the technical problems of low genetic transformation efficiency, poor repeatability and difficulty in screening of transformants of the existing Porphyra yezoensis, and the transformation efficiency can reach 30% to 40%, and the genetic stability of positive plants is close to 100%, thereby providing a reliable technical platform for gene function verification, trait improvement and molecular breeding of Porphyra yezoensis, and having important scientific research value and application prospect.

This invention provides a uracil-producing strain, its construction method, and its application. The strain utilizes CRIPSR / Cas9 gene editing technology to produce... E. coli On the UR14 genome, firstly by knocking out psuG Gene, black Gene, rutA Genes and upp Genes were introduced to block the breakdown of uracil; then, the uridine phosphorylase gene was overexpressed. udp and pyrimidine-5'-nucleotide nuclease gene ppnN This synergistically enhances the synthesis and accumulation of uracil; finally, overexpression of the phosphoribosyltransferase gene... pgm, Further enhancing the conversion of the byproduct 1-phosphate ribose into the precursor 5-phosphate ribose-1-pyrophosphate improves carbon utilization. The resulting strain exhibits good genetic stability and high fermentation yield, enabling stable production of uracil and demonstrating broad application prospects.

The application belongs to the technical field of genetically engineered bacteria, and specifically discloses a high-yield thiostrepton engineered bacterium based on double reporter genes, a construction method and application thereof. The construction method comprises the following steps: introducing a recombinant expression vector containing a promoter sequence of tsrI-tsrH and a reporter gene XylE into a host bacterium to obtain a donor bacterium; co-culturing the donor bacterium with Streptomyces laurentii to obtain a conjugant; culturing the conjugant in a culture medium containing kanamycin for screening, and then verifying XylE enzyme activity coloration, and finally screening a positive recombinant strain with yellow color. Through a double reporter gene combined screening strategy, the hit rate of screening of high-yield strains is increased from 28.0% of traditional single resistance screening to 92.0%, the fermentation titer of the screened recombinant strain reaches 333.43 U / mL, and the average yield is 3.3 times that of the single resistance screening group. The recombinant strain also has excellent genetic stability and is suitable for industrial production.

The application discloses a SNP molecular marker associated with a pig intramuscular fat content character, the SNP molecular marker is located at 55,097,258 bp of a No. 4 chromosome in a 11.1 version reference sequence of a pig genome, and there are three genotypes of GG, AG and AA, wherein the intramuscular fat content of the AA genotype is higher than that of the AG genotype, and the intramuscular fat content of the AG genotype is higher than that of the GG genotype. The application also discloses application of the SNP molecular marker in pig intramuscular fat content character molecular marker assisted selection. The application further discloses a KASP primer group for detecting the SNP molecular marker and application of the KASP primer group in pig intramuscular fat content character molecular marker assisted selection. The KASP primer group can be used for accurately, efficiently and low-costly early screening of a genotype of a newborn live piglet, and a piglet with high intramuscular fat content and genetic stability can be selected, so that the process of pig genetic improvement can be accelerated.

This invention discloses a linearized mutant plasmid of Tembusu virus SLII, a recombinant virus, and its applications, belonging to the field of molecular biology. Using the pACNR CQW1-Intron infectious clone as a backbone, the SLII stem-loop structure within the 3′UTR Domain-I region was linearized to construct the SLII linearized mutant infectious clone pACNR-CQW1-SLIILiner, which was then rescued to obtain the recombinant virus CQW1-SLIILiner. This recombinant virus exhibits limited replication capacity at the in vitro cellular level and displays a significantly attenuated phenotype in animal models. It can also induce specific neutralizing antibodies and cellular immune responses, providing significant protection against virulent strains. Therefore, the recombinant virus of this invention possesses advantages such as clear molecular genetic markers, high safety, good immunogenicity, and strong genetic stability, and can be applied to the preparation of live attenuated vaccines or related biological products for the prevention of TMUV infection.

This invention discloses a type of Leymus chinensis 1H t This paper discusses S-chromosome-specific KASP molecular markers and their applications, relating to the fields of biotechnology and crop genetics and breeding. The KASP molecular marker is KASP-1H. t The primers for this marker include an upstream primer for the *Elymus styrax* allele, an upstream primer for the wheat allele, and a shared downstream primer, with nucleotide sequences shown in SEQ ID No. 1, SEQ ID No. 2, and SEQ ID No. 3, respectively. This marker possesses advantages such as good genetic stability, high specificity, high resolution, and high detection efficiency. It enables high-throughput, automated genotyping without gel electrophoresis, and can accurately detect and track *Elymus styrax* 1H in the complex genetic background of wheat. t The S chromosome. This marker can be widely used in the identification of wheat-Leymus chinensis distant hybrids, chromosome engineering breeding, and molecular marker-assisted selection breeding, providing important technical support for the efficient transfer and utilization of superior genes in Leymus chinensis.

This invention relates to an improved engineered Saccharomyces cerevisiae strain, its construction method, and its application in the preparation of PDRN, belonging to the field of microbial technology. The improved engineered Saccharomyces cerevisiae strain uses diploid Saccharomyces cerevisiae INVSC1 as the starting strain, knocking out the RNH1 and RNH201 genes, while simultaneously overexpressing the ORC1 and Cdc6 genes; wherein the nucleotide sequences of the RNH1, RNH201, ORC1, and Cdc6 genes are shown in SEQ ID NO. 1-4. This invention uses diploid Saccharomyces cerevisiae as the starting strain and constructs an improved engineered Saccharomyces cerevisiae strain through a targeted gene editing strategy of overexpressing the ORC1 and Cdc6 genes and knocking out the RNH1 and H2 genes. This strain retains the advantages of diploid yeast, such as genetic stability, high biomass, and short fermentation cycle, while also achieving increased intracellular DNA content, providing sufficient raw materials for high PDRN production, and maintaining a cell viability rate of over 80%, ensuring the stability of the fermentation process.

This invention belongs to the fields of biomedicine, marine microbiology, and microbial fermentation, and discloses a high-EPA-producing Schizochytrium fungus and its applications. The Schizochytrium fungus KDW-306 provided by this invention has the accession number CGMCC No. 42323. This Schizochytrium fungus KDW-306 exhibits high biomass, high oil yield, high EPA titer, and high DHA titer, excellent EPA and DHA synthesis capabilities, and excellent production stability and genetic stability through generations, thus well meeting the needs of large-scale industrial production of EPA and DHA.

This invention provides an acetolactate synthase mutant, a valine-producing strain, its construction method, and its application. The acetolactate synthase mutant is obtained by mutating acetolactate synthase, specifically by mutating isoleucine at position 325 to threonine, serine at position 330 to arginine, and asparagine at position 477 to aspartic acid. The valine-producing strain constructed from the acetolactate synthase mutant is plasmid-free, has no growth defects, requires no induction, and possesses advantages such as good genetic stability and high fermentation yield. It is an excellent strain for stable valine production. This strain efficiently synthesizes valine de novo using glucose as a substrate, significantly increasing valine yield.

The application provides an engineering strain for constructing high-yield anti-insect immunity cyclic peptide GXP-A based on metabolic engineering and synthetic biology strategies, and the yield of GXP-A is significantly improved from 0.92 mg / L of the wild type to 587.5 mg / L, which is more than 600 times, and has the industrial production potential. The genetic stability of the application is high: through genome simplification and chassis optimization, the genetic background of the strain is clear, and is suitable for long-term fermentation production. The strategy of the application can be popularized: the integrated strategies such as promoter engineering, precursor engineering and efflux engineering can provide reference for the high-yield construction of other microbial natural products, and solve the problems of low yield, high production cost and difficult industrial application of GXP-A in the prior art. Through systematic metabolic engineering modification, the synthesis capacity of GXP-A is significantly improved, and key raw materials are provided for the development of efficient and environmentally friendly biological insecticide synergist.

This invention relates to an infectious clone of CA16 virus carrying the luciferase gene Nluc, its construction, and its applications. The P1 region of the CA16 genome from strain OP293089 was constructed into pcDNA, and the P2 and P3 regions were constructed into the pUC57 vector. The P1 and P2+P3 regions were recombined with the pSVA vector to construct an infectious CA16 clone. The Nluc luciferase reporter gene was then introduced to construct the pSVA-CA16-Nluc infectious clone. After rescuing the CA16-Nluc virus, its activity was experimentally verified to be similar to that of the parent virus. After continuous passage in Vero cells, the genetic stability of CA16-Nluc in in vitro cell culture was experimentally verified. Furthermore, this infectious clone can be used for high-throughput drug screening and has wide applications in basic research on viral replication and pathogenesis mechanisms, high-throughput drug screening, and neutralizing antibody screening.