83 results about "Mutant strain" patented technology

The application relates to a method for extracting ergothioneine and selenoprotein from spirulina, wherein after culturing FACHB-Se1500 strains under the above-mentioned nitrogen deficiency induction condition, a product is obtained, and after purification, selenoprotein containing ergothioneine is obtained; the FACHB-Se1500 strains are cultured in a Zarrouk+Se culture medium for 10 days, and the strain culture conditions are as follows: 25-30 DEG C, pH=9.5, and light intensity is 40 muE.m-2.s-1 ‑2 ·S ‑1 After reaching the plateau, the strains are respectively transferred to a Zarrouk-N, a Zarrouk-Fe and a Zarrouk-Mg culture medium for induction culture for 2 days, and after collecting the algal powder, selenoprotein containing ergothioneine is obtained after purification. The application further screens a spirulina mutant strain with high selenium tolerance, wherein the algal strain tolerating 800 mg / L Na2SeO3 has the best salt tolerance and can tolerate 1000 mM NaCl; and it is found again through the nitrogen deficiency induction that the ergothioneine content can reach 103.65 mu g / g.

This invention discloses a pathogenic gene of barley stripe bacterium. Pg00232 Its application. Barley stripe disease is a fungal disease caused by *Barley Stripe Pathogen*, which seriously affects barley yield and quality. Traditional control methods have limited effectiveness and pose environmental risks; breeding disease-resistant varieties is the best strategy. This invention provides pathogenicity information for *Barley Stripe Pathogen*. Pg00232 Genes, and obtained through RNA interference technology Pg00232 The mutant strain further confirmed that Pg00232 The influence of genes on the growth, development, and pathogenicity of barley stripe causal agent. This discovery provides technical support for subsequent large-scale screening of pathogenic mutants of barley stripe causal agent, promotes the isolation, identification, and pathogenic mechanism research of pathogenic genes, and contributes to the breeding and selection of disease-resistant varieties.

The present application relates to a bivalent new coronavirus vaccine, a preparation method and uses thereof, the bivalent new coronavirus vaccine comprises a fusion protein, the fusion protein comprises a receptor binding domain (RBD) of S protein of a first new coronavirus mutant or a functional fragment thereof, an immunoglobulin Fc and a receptor binding domain (RBD) of S protein of a second new coronavirus mutant or a functional fragment thereof, the first new coronavirus mutant and the second new coronavirus mutant are different mutants. The vaccine can significantly improve the neutralizing antibody titer against the new coronavirus Delta mutant and the Omicron mutant.

The application provides a method for inducing poly-podophylli rhizoma by using clump buds, comprising the following steps: S1, cutting stem segments from a podophylli rhizoma mother plant, soaking and cleaning to obtain explants; S2, disinfecting and cleaning the explants, inoculating into a clump bud induction medium to obtain podophylli rhizoma clump buds; S3, inoculating the clump buds into doubling liquid I, washing with a liquid clump bud induction medium after culture, and then transferring into doubling liquid II; S4, taking out the clump buds, cleaning, inoculating into a clump bud induction medium, and then inoculating into a bud proliferation medium; S5, waiting until 1-2 cm, screening out potential mutant strains through phenotypes, inoculating into the bud proliferation medium for subculture, and obtaining mutant plants; and S6, rooting culture of the mutant plants, and after root systems grow, planting and raising seedlings, and then poly-podophylli rhizoma plants are obtained. In the research, suitable concentration of colchicine is used for induction treatment twice, and through stage concentration switching and intermittent recovery strategies, the poly-ploid induction efficiency and explant survival are effectively considered.

The application discloses a nanoparticle universal new coronavirus vaccine and a preparation method thereof.The nanoparticle universal new coronavirus vaccine disclosed by the application is obtained by mixing a protein shown in SEQ ID No.7 or SEQ ID No.10 in a sequence table with an aluminum adjuvant and a CpG adjuvant.Experiments prove that the nanoparticle universal new coronavirus vaccine of the application can produce antibodies that bind to a new coronavirus in serum after immunizing animals, the vaccine of the application can produce a good cross-protection effect on different new coronavirus mutant strains, and the antigen dose on mice is only 0.05ug.The protein shown in SEQ ID No.7 or SEQ ID No.10 and the vaccine prepared by using the protein have a good application prospect.

The invention relates to a Pseudomonas plecoglossicida pldB gene deletion mutant strain and a preparation method and application thereof, and belongs to the technical field of microorganisms and the field of algae preservation, the pldB gene of the mutant strain is deleted or inactivated, the nucleotide sequence of the pldB gene is shown as SEQ ID NO: 1, and the GenBank accession number of the Pseudomonas plecoglossicida is CP031146.1. The virulence of the mutant strain is obviously reduced compared with that of a wild strain of pseudomonas plecoglossicida; the strain can induce appropriate immune response of a host and up-regulate expression of anti-inflammatory factors, is beneficial to relieving immune pathological injury, has good attenuated live vaccine potential, and provides a brand new vaccine candidate strain for prevention and control of the visceral white-spot disease of the large yellow croaker.

The application provides a porcine epidemic diarrhea virus mutant strain and application thereof. The application obtains a porcine epidemic diarrhea virus mutant strain GX2506 from porcine intestinal tissue, and the strain is purified through passage, and the microorganism preservation number of the strain is CGMCC No. 47089. The isolated strain can stably proliferate on a passage cell, and typical cytopathic effect is generated. The porcine epidemic diarrhea virus mutant isolated strain has excellent immunogenicity; a vaccine prepared by using the isolated strain can induce piglets to generate high-level neutralizing antibodies; meanwhile, an ELISA kit prepared by using the isolated strain can better detect porcine epidemic diarrhea virus antibodies in serum.

This invention relates to a high-yield coenzyme Q method. 10 The establishment and application of *Rhodotorula globulinii* strains. Compared to rational metabolic engineering, the coenzyme Q of this invention... 10 High-yielding Rhodopseudomonas aeruginosa bacteria were used as a template by the global regulatory factor prrA gene. Through directed evolution, different mutant strains were constructed, and combined with high-throughput screening methods, coenzyme Q was achieved. 10 Increased yield. This invention starts from global regulatory factors and leverages complex intracellular regulatory mechanisms to achieve fine-grained global regulation under minute genomic perturbations, providing a new approach for the engineering modification of strains.

The invention belongs to the technical field of preparation of microorganisms and medicines, and particularly relates to a compound FK228D as well as a preparation method and application thereof. The compound provided by the invention is obtained by carrying out culture and liquid fermentation on a Burkholderia thailantensis E264 [delta] tdp:: R-tdp-dep-M4spi which is a mutant strain of Burkholderia thailantensis, and separating the Burkholderia thailantensis from a fermentation liquid of the Burkholderia thailantensis E264 [delta] tdp:: R-tdp-dep-M4spi. In addition, the invention also discloses an application of the FK228 derivative or the pharmaceutically acceptable salt thereof in preparation of antitumor drugs. Experiments prove that the compound 1 produced by the burkholderia mutant strain can obviously inhibit the growth of tumor cells and has no influence on the growth of normal cells. Therefore, the compound provided by the invention is expected to gain the application value in anti-tumor treatment, a new alternative compound is provided for development and application of novel anti-tumor drugs, and the compound has remarkable economic value and social benefit.

The application discloses SiERF4 and SiERF4-like The application of the genes in improving the salt tolerance of millet belongs to the technical field of crop genetic breeding. SiERF4 The genes and SiERF4- like Single knockout or double knockout is performed on the genes to obtain a mutant strain of millet with significantly improved salt tolerance. SiERF4 The mRNA sequence coded by the gene is shown as SEQ ID NO. 1, and the amino acid sequence is shown as SEQ ID NO. 2; SiERF4-like The mRNA sequence coded by the gene is shown as SEQ ID NO. 3, and the amino acid sequence is shown as SEQ ID NO. 4. The application first finds that SiERF4 and SiERF4- like The gene is a negative regulation gene responding to salt stress, and knocking out the gene can significantly improve the salt tolerance of the millet, and has important practical significance for cultivating salt-tolerant millet varieties and developing and utilizing saline land.

The application belongs to the field of genetic engineering and medical engineering, and discloses virK Application of gene in regulation of Klebsiella pneumoniae virulence. The application finds that the expression level of the gene is significantly increased in polymyxin-resistant mutant strains through transcriptome analysis, virK Further research shows that the expression of the gene is regulated by the PhoP / PhoQ two-component regulatory system. The application constructs virK Gene deletion mutant strains and complementary strains, and compares the virulence difference of the strains in an animal infection model, finds that virK The virulence of the deletion strain is significantly reduced, and the complementary strain can restore the virulence phenotype, indicating that virK The gene plays an important role in the regulation of Klebsiella pneumoniae virulence. The application first finds that PhoP can regulate virK Gene expression, and affects the virulence phenotype of Klebsiella pneumoniae through the regulation pathway, thereby revealing a new virulence regulation mechanism, and providing a theoretical basis for subsequent targeted intervention.

An Aspergillus niger mutant strain designated MTCC 25759 derived from parent strain Aspergillus niger ATCC 9142 through chemical mutagenesis using ethyl methane sulfonate at 1 mg / mL for 30 to 60 minutes demonstrates enhanced production capabilities for both citric acid and gluconic acid. The mutant strain exhibits genetic modifications at 47 specific sequence positions that contribute to improved metabolic pathways, enhanced substrate utilization efficiency, and increased tolerance to acidic fermentation conditions. The mutant strain achieves gluconic acid production of 198.836 g / L representing a 66% improvement over the parent strain's 119.776 g / L yield, and citric acid production reaching 0.415 g / L with consistent late-phase productivity. The enhanced production capabilities provide economic advantages through improved substrate conversion rates, reduced raw material costs, and increased production capacity within existing fermentation infrastructure while maintaining the Generally Regarded As Safe (GRAS) status for commercial applications.

This invention relates to the fields of microbial genetic engineering and brewing technology, and provides a PDC1 gene mutant strain resistant to 2-phenylethanol and its application in the brewing of wheat-aroma baijiu. The mutant strain is *Saccharomyces cerevisiae* PDC1_473 (HM 03), with the preservation number CCTCC M20252996. The PDC1 gene of this strain has a base mutation from T to C at position 473. When this mutant strain is applied to the solid-state fermentation of wheat-aroma baijiu, it becomes the absolutely dominant fungal community, significantly altering the microbial community structure of the fermentation system, inhibiting the growth of various conditionally pathogenic and spoilage bacteria, strengthening the fermentation environment centered on *Lactobacillus*, and significantly enhancing the rose, citrus, grassy, ​​fatty, and caramel aromas of the baijiu. It imparts a pleasant, rich ester aroma and complex aroma to the baijiu, increasing its fullness, and has broad application potential in the brewing of wheat-aroma baijiu.

This invention provides a composition, preparation method, and application for preventing Helicobacter pylori infection. The composition comprises a mixture of outer membrane vesicles and a solution of *Ackermania pseudomallei* bacteria; the outer membrane vesicle mixture is composed of outer membrane vesicles of *Salmonella* mutant strain QS0074 and outer membrane vesicles of *Escherichia coli* Nissle 1917 at a weight ratio of 2:1; the weight-to-volume ratio of the outer membrane vesicle mixture to the *Ackermania pseudomallei* bacterial solution is 1 mg:1 mL. The composition obtained by this invention significantly outperformed the control group in challenge tests, demonstrating a highly effective preventive effect against Helicobacter pylori infection. Furthermore, the components of the composition of this invention exhibit significant synergistic effects in inducing secretory IgA levels in mice and inducing resistance to Helicobacter pylori infection, showing promising application prospects.

The application discloses a single-cell green alga chlorophyll synthesis-defective mutant strain and application thereof. The mutant strain includes Parachlorella kessleri SCUT-ACB 4 and SCUT-ACB 4-65, and the preservation numbers are CCTCC NO: M 2022518 and CCTCC NO: M 2022519, which are preserved in the China Center for Type Culture Collection of Wuhan University in Wuhan, China on April 28, 2022. Compared with wild-type algae strains, the mutant strain in the application fundamentally cuts off non-light-dependent chlorophyll synthesis, and the content of chlorophyll a is reduced by more than 98%, and the content of chlorophyll b is reduced by 100%, and the algal body is golden yellow, and the mutant strain can be used for producing protein, and provides high-yield and high-quality fermentation algae for replacing protein in precise fermentation production.

The application discloses a kind of high thermal stability glutamine transaminase mutant and its method of expression in streptomyces, belong to enzyme engineering field.The high thermal stability glutamine transaminase mutant provided by the application can efficiently catalyze casein crosslinking at high temperature, realizes the heterologous efficient expression of glutamine transaminase.Rational mutation is carried out to key amino acid site of glutamine transaminase, and the mutant strain with significantly improved thermal stability is obtained.Among them, the optimal mutant strain FRAPD-TGm2A3 has a half-life of up to 537.91 min at 60 DEG C.The mutant can still efficiently catalyze the crosslinking reaction of casein at high temperature of 85 DEG C.The present application not only lays a solid research foundation for the modification of thermal stability of glutamine transaminase, but also provides a generalizable strategy framework for the rational modification of other thermostable enzymes, and has important industrial application value and academic reference significance.

This invention belongs to the field of plant genetic engineering technology, specifically relating to the transcription factor BnC05.PLATZ04 gene regulating resistance to Sclerotinia sclerotinia in rapeseed and its application. A transcription factor BnC05.PLATZ04 gene that can be induced to express by Sclerotinia sclerotinia was screened, and its nucleotide sequence is shown in SEQ ID NO:1; the protein sequence encoded by this gene is shown in SEQ ID NO:2. Using Agrobacterium-mediated transformation, a CRISPR / Cas9 knockout mutant line of transcription factor BnC05.PLATZ04 was obtained. Identification with Sclerotinia sclerotinia through inoculation of the transgenic material revealed that the BnC05.PLATZ04 knockout line showed increased resistance to Sclerotinia sclerotinia, indicating that transcription factor BnC05.PLATZ04 is a negative regulator of rapeseed resistance to Sclerotinia sclerotinia, playing a negative regulatory role in this resistance. Deficient expression of this gene significantly improves the resistance of rapeseed to Sclerotinia sclerotinia.

The invention discloses a method for enhancing the synthesis capacity of a yeast double-metabolic-pathway pigment product and application, and belongs to the field of synthetic biology and metabolic engineering. The method comprises the following steps: constructing a saccharomyces cerevisiae engineering strain capable of simultaneously synthesizing violacein and lycopene; constructing a mutant library of the global transcription factor SPT15; transforming the mutant library into the engineering strain, and screening the mutant strain with increased yield based on bacterial colony color visualization. According to the invention, a single global transcription factor SPT15 is modified, so that the cell metabolism is regulated and controlled on the whole, the synergistic interaction of a diheterologous synthesis pathway is realized, and the tedious multi-gene rational modification is avoided. The method is easy and convenient to operate and short in period, and a new strategy is provided for efficient construction of yeast cell factories for high-yield pigment and other double-way products.

This invention discloses a *Hymenopellis raphanipes* mutant strain EBD13 and its applications. The invention measured and observed the growth rates and vigor of the mutant strain, the original strain, and commercially available strains in the mother culture, original culture, and cultivated culture, respectively, and statistically analyzed the fruiting results. Finally, a fast-growing *Hymenopellis raphanipes* mutant strain EBD13 was selected, which can produce fruit without soil covering. This strain can significantly reduce production costs for enterprises and solves the problems of requiring large amounts of manpower and soil for *Hymenopellis raphanipes* cultivation, resulting in significant economic benefits.

The present disclosure provides a mutant strain of Aspergillus niger designated MTCC 25761 on deposit with the Microbial Type Culture Collection and Gene Bank, Institute of Microbial Technology, Chandigarh, derived from parent strain Aspergillus niger ATCC 9142 through UV mutagenesis at 254 nm wavelength for 19 minutes with constant stirring The mutant strain demonstrates enhanced production capabilities for both citric acid and gluconic acid compared to the parent strain. The mutant strain exhibits enhanced metabolic performance through improved enzyme expression, substrate utilization efficiency, and regulatory control mechanisms. Gluconic acid production is 1.37-fold higher (164.045 g / L) and citric acid production is 1.29-fold higher (0.506 g / L) than the parent strain.

The present application relates to a human monoclonal neutralizing antibody targeting metapneumovirus F protein and application thereof, which comprises a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region comprises: a complementarity determining region HCDR1 having an amino acid sequence as shown in SEQ ID NO:1, a complementarity determining region HCDR2 as shown in SEQ ID NO:2, and a complementarity determining region HCDR3 as shown in SEQ ID NO:3; and / or the light chain variable region comprises: a complementarity determining region LCDR1 having an amino acid sequence as shown in SEQ ID NO:4, a complementarity determining region LCDR2 as shown in AAS, and a complementarity determining region LCDR3 as shown in SEQ ID NO:5. The metapneumovirus monoclonal neutralizing antibody MV61 of the present application can specifically bind to metapneumovirus F antigen, has high affinity (about 0.18nM), high neutralization activity to different mutant strains of metapneumovirus, and excellent broad spectrum.

This invention discloses a method for enhancing salt tolerance in rice by knocking out the OsAKIP30 gene, belonging to the field of plant genetic engineering technology. This invention utilizes CRISPR / Cas9 technology to target and mutate this gene. Specific steps include: selecting target sequences T1 and / or T2 in the CDS region of the OsAKIP30 gene; constructing a recombinant vector pYLCRISPR / Cas9Pubi-B-OsAKIP30 containing the corresponding sgRNA and Cas9 expression cassette; transforming rice varieties using Agrobacterium-mediated transformation; identifying mutant plants through genomic PCR and sequencing; and identifying the salt tolerance phenotype of the mutants (e.g., seedling survival rate after salt treatment, ion leakage rate, and chlorophyll content), screening for lines with superior salt tolerance compared to the wild type. This invention provides an effective technical approach for salt-tolerant rice breeding.

The application discloses a mutant strain of Grifola frondosa for improving yields of mycelium, protein and triterpenes and application thereof, and belongs to the technical field of microorganisms. The mutant strain of Grifola frondosa has a preservation number of CGMCC No. 42006. The mutant strain is obtained by using diethyl sulfate mutagenesis technology to treat protoplasts of Grifola frondosa, screening excellent strains of Grifola frondosa, continuously culturing the strains obtained through preliminary screening, and finally obtaining the mutant strain of Grifola frondosa with obviously improved yields of mycelium dry weight, intracellular protein and triterpenes. The mutant strain has good genetic stability and is suitable for being used as a strain for industrialized production of mycelium, triterpenes and protein of Grifola frondosa, thereby providing technical support for promoting development of the Grifola frondosa industry.

The present application belongs to the technical field of biological pharmacy, and particularly relates to a polypeptide composition of a novel coronavirus, a vaccine prepared therefrom and application thereof. The polypeptide composition of the novel coronavirus comprises four polypeptides of GY, VV, VS and DL. Experiments show that the polypeptide or the composition thereof can effectively induce T cell immune response and specific humoral immunity against SARS-CoV-2 and its mutant strains, stimulate the body to produce antigen-specific antibodies, provide a basis for constructing SARS-CoV2 preventive and / or therapeutic antibodies with high affinity, high quality and strong specificity, and have high application value for prevention and treatment of the novel coronavirus.

This invention provides a Dunaliella salina mutant strain DS-HC01, which exhibits both rapid growth and high carotenoid accumulation capabilities, with the preservation number CCTCC NO: M 2026726. The mutant strain was obtained through high-energy proton beam mutagenesis at 300 MeV and a dose of 100 Gy, followed by three-stage screening. Under 25°C culture conditions, DS-HC01 overcomes the trade-off between growth and product accumulation, achieving a cell density more than 1.2 times that of the wild type on day 10, and a total carotenoid content more than 1.25 times higher. It also exhibits higher SOD activity and lower MDA content, demonstrating extremely strong antioxidant regulation capabilities and synergistic advantages in growth and pigment accumulation, making it suitable for efficient fermentation production of carotenoids.

The present disclosure is in the field of dairy technology. It relates to a method for producing a Streptococcus thermophilus strain exhibiting a low excretion of carbohydrates comprising the steps: (a) providing a mother strain which is able to ferment lactose and glucose; (b) selecting a mutant strain derived from the mother strain which mutant strain has a change in: (i) one or more of the genes encoding a protein involved in the metabolism of galactose wherein said strain is able to ferment galactose; and (ii) the lacS gene encoding a lactose permease which change results in at least one mutation in the amino acid sequence of lactose permease selected from a position corresponding to position 148, 377 and 476 in SEQ ID NO:2; and wherein the mutant strain has a Lac(+) Glu(+) Gal(+) phenotype and has a reduced secretion of carbohydrates as compared to the mother strain. It furthermore relates to Streptococcus thermophilus strains exhibiting a low excretion of carbohydrates, Composition comprising said strains, methods for manufacturing a fermented product, fermented products, and use of said strains.

This invention belongs to the fields of microbiology and molecular biology, specifically relating to a homologous recombinase combination in myxobacteria and its application in gene editing. Specifically, this invention provides four pairs of homologous recombinase systems capable of efficiently mediating in vivo recombination in myxobacteria. Each pair includes a protein YqaJ with exonuclease function and a protein RecT with single-strand annealing function. This invention provides a method for myxobacterial gene editing: under the action of homologous recombinase pairs, mutant strains are obtained through positive screening using resistance tags. The resistance tags are then successfully removed through the combined action of the Cre / loxP system and the reverse screening gene galK. This method achieves a gene editing efficiency of up to 100%, has a short cycle time, requires no purification, and can be used for iterative deletion of multiple genes to achieve genome simplification in myxobacteria, or for inserting functional promoters and other elements to activate silent gene clusters. This method is of great significance for the bioexploration and functional genomics research of myxobacteria.

This invention provides a method for mutagenesis of *Aspergillus cristatus* and its application, belonging to the field of microbial technology. The mutagenesis method provided by this invention includes the following steps: first, pretreating *Aspergillus cristatus* suspension by mixing it with a compound enzyme solution; then culturing the pretreated *Aspergillus cristatus* in a culture medium supplemented with a mutagen; the compound enzyme solution consists of a cell-lysing enzyme solution and a β-glucanase solution; the mutagen includes ethyl methanesulfonate and / or diethyl sulfate. This invention can improve the efficiency of the mutagen entering the bacterial cells, thereby enhancing the mutagenesis effect; the mutant strains obtained by mutagenesis, compared to the original strain, exhibit more vigorous colony growth on plates, larger average diameter, denser hyphae, and / or better morphological stability. Furthermore, it can achieve ideal mutagenic selection pressure at lower mutagen concentrations and shorter treatment times, reducing sublethal damage, which is beneficial for the recovery and screening of mutant strains and improving the efficiency of mutagenesis experiments.