421 results about "Mutant strain" patented technology

The invention discloses an Escherichia coli mutant strain which is classified and named as Escherichia coli, the strain number is CR-TK01, and the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.35554. The invention further discloses a preparation method of the Escherichia coli mutant strain. The Escherichia coli CR-TK01 with high yield of cytidine provided by the invention has the characteristics of high yield and stable high-yield character, glucose is used as a carbon source, the Escherichia coli CR-TK01 is used for fermentation production of cytidine under a certain fermentation condition, and the yield of cytidine is as high as 97.23 g / L; the strain is not degraded after passage for more than 20 generations, the performance of high-yield cytidine is maintained in the passage fermentation process, and the yield of cytidine in passage fermentation is improved. The method for producing cytidine through fermentation is simple in process, high in yield and suitable for industrialization.

The invention relates to the technical field of gene engineering, in particular to an L-rhamnose isomerase mutant, a recombinant plasmid, a mutant strain and application. The amino acid sequence of the mutant is as shown in SEQ ID NO.4, and the nucleotide sequence of the coding gene is as shown in SEQ ID NO.3. A specific mutant gene sequence is designed, a recombinant plasmid pET28a (+)-L-Rhi is successfully constructed, the gene sequence is connected between enzyme cutting sites BamH I and Hind III of an escherichia coli expression vector pET-28a (+) to construct a mutant expression vector (the recombinant plasmid pET-28a (+)-L-Rhi), the mutant expression vector is transformed into an escherichia coli BL21 competent cell, a mutant strain is obtained, and the recombinant plasmid pET-28a (+)-L-Rhi is obtained. The obtained mutant strain can overexpress L-rhamnose isomerase, the conversion rate of D-allose is remarkably improved, the thermal stability of the enzyme is remarkably improved through the design of mutation sites, and the half-life period is effectively prolonged.

The invention relates to a Kluyveromyces marxianus strain with high protein yield and application of the Kluyveromyces marxianus strain, which is characterized in that the Kluyveromyces marxianus strain is firstly cultured on a slant, then is transferred into a seed culture medium for seed preparation, and then is inoculated into a fermentation tank, and yeast protein is obtained by adopting index feeding; the bacterial strain is a dominant mutant strain Kluyveromyces marxianus YWX-1, the protein content in a dry thallus reaches 55% or above and is increased by 26% or above compared with that of an original bacterial strain, the bacterial strain can be used for production of single-cell protein, the essential amino acid index (EAAI) value in the protein reaches 1.2, and the bacterial strain is rich in arginine, threonine and lysine and can be applied to production of single-cell protein. These amino acids play a key role in immune regulation, intestinal mucosal barrier function and muscle protein synthesis of young animals. The YWX-1 kluyveromyces marxianus strain has a wide application prospect in the production of neoplasm protein.

The invention provides a phaffia rhodozyma mutant strain for high yield of astaxanthin as well as a screening method and application of the phaffia rhodozyma mutant strain, belongs to the technical field of fermentation microorganism screening, and can solve the problems of low astaxanthin yield, high cost and low growth temperature of wild type phaffia rhodozyma existing in synthesis of astaxanthin from a phaffia rhodozyma strain. The invention provides a phaffia rhodozyma mutant strain capable of producing astaxanthin at high yield, the phaffia rhodozyma mutant strain is a phaffia rhodozyma AA0529 mutant strain, the phaffia rhodozyma AA0529 mutant strain is preserved in China Center for Type Culture Collection in Wuhan, Hubei on September 7, 2023, and the preservation number is CCTCC (China Center for Type Culture Collection) NO: M20231637. According to the method, the yield of the astaxanthin can be increased, and the yield of the astaxanthin is increased to 3.3 mg / g at 26 DEG C.

The invention relates to the technical field of plant genetic engineering, in particular to application of a rice OsERF141 protein and a coding gene thereof in improving low-temperature tolerance of plants. Experiments show that the low-temperature resistance of an OsERF141 function deletion mutant strain is remarkably reduced, and the low-temperature resistance of an overexpressed OsERF141 transgenic strain is remarkably improved. The invention provides a new gene resource for the cold resistance problem of rice, and has important significance for the molecular mechanism research of low-temperature stress and the cultivation of new low-temperature-resistant varieties.

The invention discloses application of protein TaTDM and related biological materials thereof, and belongs to the field of plant breeding. The amino acid sequence of the protein TaTDM is as shown in SEQ ID NO: 2 or SEQ ID NO: 4 or SEQ ID NO: 6. The TaTDM gene knockout homozygous mutant strains tatdmm1 and tatdmm2 are obtained by carrying out gene knockout on wild type wheat Fielder, and it is found that at the temperature of 25 DEG C, the total floret number of each spike of the Fielder, the tatdmm1 and the tatdmm2 and the survival rate under the water shortage treatment condition are remarkably higher than those of the wild type wheat Fielder. The protein TaTDM has an important application value in regulation and control of wheat ear type characters and stress tolerance, provides a high-quality germplasm resource, and is of great significance in cultivation of drought-enduring plant varieties and improvement of crop yield.

The invention discloses application of a transcription factor ZmbZIP27 in regulation and control of corn plant height and ear height, and belongs to the technical field of plant genetic engineering and corn molecular breeding. The invention reveals that the bZIP transcription factor family member ZmbZIP27 has an important biological function of regulating and controlling the corn plant height and lodging resistance for the first time. A ZmbZIP27 knockout vector is constructed through a CRISPR / Cas9 gene editing technology, and an obtained homozygous mutant strain shows remarkable plant type improvement characteristics compared with a wild type: the plant height is reduced by 8-12%, and the ear height is reduced by 15-22%. And a new gene target and a breeding strategy are provided for creating a new high-yield lodging-resistant corn variety suitable for mechanical harvesting.

The invention discloses a rape grain weight regulation gene NGAL3 based on whole genome screening and a breeding application thereof, based on the seed size and grain weight phenotypic value of a cabbage type rape germplasm resource, a candidate gene interval is positioned by using GWAS; the method comprises the following steps: selecting large-grain-weight and small-grain-weight extreme phenotypic materials, performing transcriptome sequencing in a critical period of seed development, and screening differential expression genes; and performing cross comparison on the GWAS candidate gene and the differential expression gene to obtain a key gene for jointly regulating and controlling the size and the grain weight of the seed, and performing functional verification on the key gene. The thousand seed weights of the created homozygous three mutant strains L1-sg1-1-4-5 and L2-sg1-4-8-16 are obviously increased by 46% and 29% compared with those of the wild type strains. The invention provides a new target for high-yield rape breeding, and non-transgenic high-grain-weight germplasm can be created through gene editing or beneficial allelic variation of NGAL3 is selected and enriched under the assistance of molecular markers.

Provided are an Aeromonas dhakensis mutant strain with deletion of a surface polysaccharide synthesis gene, a complemented strain, a construction method therefor, and the use thereof. The mutant strain is obtained by deleting one or more of ugd, ugd2, and cap1J from the Aeromonas dhakensis wild strain A. dhakensis C160501.

The invention belongs to the technical field of medicines, and provides a method for screening a mutant strain and a high-virulence Seneca virus A mutant strain. The method for promoting Senecavirus A mutation provided by the invention comprises the following steps: inserting an RNAi target sequence between 3Dpol and a 3'untranslated region of an SVA starting strain; the target sequence of the RNAi contains a complementary sequence of an endogenous sequence of the miRNA. According to the research, mutagenesis is carried out on SVA by constructing a high RNAi pressure system, and a method for screening the mutant strain SVA is carried out by simulating an antiviral RNAi mechanism in a host, so that a natural evolution process of the virus is better met, a large number of stably inherited mutant strains can be obtained, and an efficient research and development means is provided for vaccine research and development aiming at the virus.

The invention belongs to the technical field of gene engineering, and particularly relates to application of an OsNAC4 gene in regulation and control of rice salt tolerance. It is found for the first time that mutation of the OsNAC4 gene can improve the salt tolerance of rice seeds in the seedling stage. Under salt stress, the seedling survival rate of the mutant OsNAC4 strain is obviously higher than that of a wild type. Under normal treatment, the proline content, the hydrogen peroxide content and the malondialdehyde content of the wild type strain and the Osnac4 mutant strain have no significant difference, but after salt stress, the proline content of the Osnac4 mutant strain is significantly higher than that of the wild type strain, and the hydrogen peroxide content and the malondialdehyde content are both lower than those of the wild type strain. Therefore, the OsNAC4 gene can be utilized to cultivate an improved rice material suitable for saline-alkali soil planting through a biotechnology, a new thought is provided for cultivating salt-tolerant rice varieties, and a theoretical basis is also provided for increasing the yield of other crops by utilizing a heterologous gene expression technology.

The invention belongs to the technical field of microbial engineering, and discloses a method for producing eicosapentaenoic acid (EPA) with high yield by schizochytrium limacinum based on random mutation and low-temperature screening and application, and the method comprises the following steps: driving overexpression of a G418 resistance gene through a P2520 promoter, constructing a random insertion mutant library, and screening to obtain a schizochytrium limacinum mutant strain with a randomly mutated genome; coating in a culture medium containing G418 resistance for culturing, and screening out strains which are resistant to low temperature and good in growth state at 15 DEG C; and inoculating into a fermentation culture medium, adding MgSO4 with the final mass concentration of 0.1% at the initial stage of fermentation, supplementing MnCl2 with the final mass concentration of 0.05% when fermentation is performed for 72 hours, and culturing to obtain a mutant strain. According to the invention, the G418 resistance gene carried by the plasmid is randomly inserted into the schizochytrium limacinum genome, and low-temperature induced screening is combined, so that the target limitation of traditional homologous recombination is broken through, and a stable strain with multiple mutation superposition can be obtained through enrichment.

The invention provides Saccharomyces cerevisiae for producing squalene as well as a screening method and application of the Saccharomyces cerevisiae. The method comprises the following steps: culturing a Saccharomyces cerevisiae engineering strain ySC782 for synthesizing squalene to obtain a to-be-mutagenized bacterial solution, carrying out ARTP mutagenesis on the to-be-mutagenized bacterial solution, adding the to-be-mutagenized bacterial solution into a YPD liquid culture medium, culturing to obtain a resuscitation bacterial solution, adding the resuscitation bacterial solution into a sucrose solution with gradient concentration distribution, screening, and repeating the ARTP mutagenesis-sucrose solution screening step to obtain the squalene mutant strain. And finally, the saccharomyces cerevisiae strain ySC782-M5 is obtained through screening, and the saccharomyces cerevisiae strain ySC782-M5 is obtained through screening. The yield of squalene produced by the saccharomyces cerevisiae ySC782-M5 reaches 49.83 g / L, so that a solution is provided for breaking through the yield bottleneck of squalene synthesized by yeast.

The invention discloses a ganoderma lucidum mutant strain as well as an open liquid fermentation method and application thereof. The Ganoderma lucidum mutant strain provided by the invention is Ganoderma lucidum MKX25023, and the registration number of the Ganoderma lucidum mutant strain in the China General Microbiological Culture Collection Center is CGMCC (China General Microbiological Culture Collection Center) No. 42078. The strain has no difference between biomass in an open culture environment and that in a sterilized culture environment, the stable yield of intracellular products (such as chitin) can be ensured, and when the strain is used as a chassis cell, the utilization value of the strain can be further expanded, and the industrialization practicability and economic value are remarkably improved.

The invention belongs to the field of microbial breeding and fermentation engineering, and particularly relates to a saccharomyces cerevisiae mutagenesis strain with high yield of S-adenosyl-L-methionine as well as a mutagenesis method and application of the saccharomyces cerevisiae mutagenesis strain. Saccharomyces cerevisiae is induced to generate genetic diversity through multiple rounds of ultraviolet mutagenesis, and high-throughput screening is performed in combination with strain color phenotypic difference; and the mutant strain HY2402-Z18 with high yield of S-adenosine-L-methionine and genetic stability is obtained. The SAM yield of the mutagenic strain is increased by 40.1% compared with that of an original strain, the SAM yield reaches 13.44 g / L when the mutagenic strain is fermented for 60 h in a 5 L fermentation tank system, the unit yield reaches 0.156 g / L / OD, and the methionine conversion rate is 75%. After thalli are collected through centrifugation of fermentation liquor, an S-adenosine-L-methionine product with the purity of 98%-100% can be obtained through purification of ion exchange resin, no by-products are accumulated, the yield, the substrate conversion rate and the production efficiency of the S-adenosine-L-methionine can be remarkably improved when the mutagenesis strain is used for fermentation production, and the production cost is reduced. The production cost is effectively reduced, the product purity and quality are improved, and the method is suitable for industrial large-scale production of SAM.

This invention belongs to the fields of locust biotechnology and gene editing technology, specifically relating to a method for preparing locusts. Crz Methods using gene mutants and their application in locust control. This invention discovers that inhibiting gene mutants in locusts... Crz Gene expression can be used to control locusts. Crz The gene sequence is shown in SEQ ID NO:3. This invention successfully established a homozygous Crz mutant strain of the migratory locust using gene editing technology. It was found that the albino migratory locusts obtained after Crz deletion were more easily preyed upon by natural enemies than the wild-type locusts, exhibited significantly lower levels of the aggregation pheromone 4VA, and showed weaker adaptability to low temperatures compared to the wild type. This provides a new strategy for the biological control of migratory locusts and can also serve as a reference for the biological control of other pests.

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.

The present invention relates to a Corynebacterium glutamicum mutant strain having increased L-citrulline productivity, and a method of producing L-citrulline using the same. The Corynebacterium glutamicum mutant strain is capable of producing L-citrulline in high yield and high concentration while inhibiting the production of by-products, because the activity of the protein that is expressed by the NCgl2657 gene therein has been weakened or inactivated.

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 invention provides a culter turunx2b gene knockout method and application of the culter turunx2b gene knockout method in creation of intermuscular thorn-free mutants, and belongs to the technical field of gene editing. The invention provides an efficient gene knockout method which comprises the following steps: selecting two targets on a second exon of a culter turunx2b gene as target sites, designing and synthesizing two gRNAs, mixing the gRNAs with Cas9mRNA, introducing the mixture into a fertilized egg of culter turunx2b in an I cell stage in a microinjection manner, hatching, and screening mutated F0-generation culter turunx2b individuals. By utilizing the method disclosed by the invention, the F0-generation knockout efficiency is up to 87.5% under the condition of ensuring that the fertilized eggs are hatched to survive. The method disclosed by the invention is simple and easy to implement and simple to operate, the culter alburnus gene mutation strain can be rapidly obtained by utilizing the gene mutation method, and the method has important scientific significance for developing economic fish gene function research, revealing genetic development law and creating new germplasm.

The purpose of the present invention is to provide an antibody against a coronavirus (SARS-CoV-2) mutant strain, in particular, an omicron substrain. Moreover, another purpose of the present invention is to provide a pharmaceutical composition against coronavirus infections, the pharmaceutical composition using said antibody. The present invention provides: an antibody that binds to a spike protein of coronavirus and has the ability to neutralize coronavirus including an omicron substrain, or an antigen-binding fragment thereof; and a pharmaceutical composition for preventing or treating coronavirus infections, the pharmaceutical composition comprising said antibody or antigen-binding fragment thereof.

The application discloses a protein separated from Pinus tabulaeformis Carr. Pinus tabuliformis ​ and an encoding gene PtAMT2.8 of the protein, which can significantly enhance nitrogen absorption and transportation of plants. 31019b The PtAMT2.8 gene is introduced into a yeast mutant strain with a deficiency in ammonium nitrogen absorption function, so that the growth phenotype of the yeast mutant is recovered, and the PtAMT2.8 gene is introduced into Pinus tabulaeformis and Arabidopsis thaliana, so that the nitrogen absorption and transportation capacity of the transgenic plants can be significantly enhanced. The application has important significance for accelerating genetic improvement of plants and cultivating new varieties with high yield, high quality and multi-resistance.

The invention discloses a protein which is separated from pinus tabuliformis and is capable of remarkably enhancing nitrogen absorption and transport of a plant, and a coding gene PtAMT2.8 of the protein. The PtAMT2.8 gene is introduced into a yeast ammonium nitrogen absorption function deficient mutant strain 31019b, so that the growth phenotype of a yeast mutant can be recovered, and the nitrogen absorption and transport capability of a transgenic plant can also be remarkably enhanced by introducing the PtAMT2.8 gene into pinus tabulaeformis and a model plant arabidopsis thaliana. The invention has important significance in accelerating plant genetic improvement and cultivating high-yield, high-quality and multi-resistant new varieties.

The invention is applicable to the technical field of molecular biology, and provides a mutant gene, a mutant, a transformant and a genetic transformation plant of tobacco deoxycarboxy-putrescine lysine synthase and application of the mutant gene, the mutant, the transformant and the genetic transformation plant of the tobacco deoxycarboxy-putrescine lysine synthase of the tobacco deoxycarboxy-putrescine lysine synthase of the tobacco deoxycarboxy-putrescine lysine synthase. The nucleotide sequence of the mutant gene is shown as SEQ ID NO.2 in a sequence table. After the gene is mutated, a mutant strain shows the phenotype of white veins, and various nutrients are greatly changed. According to the mutant gene of the tobacco deoxycarboxamide lysine synthase provided by the invention, by detecting the mutant and comparing the potassium content in tobacco leaves, the result shows that the mutant gene of the tobacco deoxycarboxamide lysine synthase can improve the potassium content in the tobacco leaves. Therefore, a better choice is provided for genetic improvement of new plant varieties, and the gene has important application value.

The invention discloses a genetic engineering strain of high-yield secondary metabolite Fumagillin as well as a construction method and application of the genetic engineering strain, and the genetic engineering strain is obtained by taking aspergillus fumigatus as a chassis bacterium through hosA gene knockout or hosA catalytic active site mutation. According to the method, a hosA gene knockout strain (delta hosA) and catalytic active site mutation strains (HosAD133A, HosAH175A and HosAD210A) are constructed by means of molecular biology, and the mutant strains are subjected to liquid or solid fermentation under the culture condition of 37 DEG C, so that the yield of Fumagillin can be remarkably increased. According to the method disclosed by the invention, the inhibition on a Fumagillin biosynthetic pathway is relieved and the metabolic flux is enhanced by utilizing the activity change of histone deacetylase caused by hosA defects, and an efficient and directional production method for high-yield Fumagillin is provided, so that the method has an important industrial application value.

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 invention provides an application of CC-115 in preparation of an anti-new coronavirus drug. The chemical name of the CC-115 is 1-ethyl-7-[2-methyl-6-(1H-1, 2, 4-triazole-3-yl) pyridine-3-yl]-3, 5-dihydropyrazino [2, 3-b] pyrazine-2 (1H)-ketone, and the structural formula of the CC-115 is shown in the description. An in-vitro Vero cell infection model finds that the CC-115 can inhibit the replication of a new coronavirus (SARS-CoV-2) original strain and an Omicro variant (EG.5.1), and the IC50 (half maximal inhibitory concentration) of the CC-115 aiming at the SARS-CoV-2 original strain is 0.004 [mu] M and 0.005 [mu] M. The CC-115 has the advantages that the CC-115 can inhibit the replication of the SARS-CoV-2 original strain and the Omicro variant (EG.5.1); the CC-115 can be used for research and development of anti-new coronavirus infection drugs, and has a good development prospect.

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 invention provides application of an OsZIP13 gene. The OsZIP13 gene is used for regulating and controlling saline-alkali stress tolerance of rice plants. The OsZIP13 gene in the rice plant is over-expressed and is used for enhancing the saline-alkali stress tolerance of the rice plant; or / and the OsZIP13 gene in the rice plant is subjected to gene editing and is used for reducing the saline-alkali stress tolerance of the rice plant; the nucleotide sequence of the coding region of the OsZIP13 gene is as shown in SEQ ID No: 1; the amino acid sequence of the coding region of the OsZIP13 gene is as shown in SEQ ID No: 2. The gene is excessively expressed in rice, the tolerance of rice to saline-alkali stress in the germination stage and the seedling stage can be enhanced, a mutant strain is more sensitive to saline-alkali stress compared with wild rice, and the discovery of the gene provides an important gene resource and a theoretical basis for cultivation of saline-alkali tolerant plants; wide application prospects are realized.

The invention belongs to the technical field of microorganisms, a streptococcus zooepidemicus mutant strain CGMCC (China General Microbiological Culture Collection Center) No.26991 is screened out, the streptococcus zooepidemicus mutant strain is obtained through screening by adopting a phage secondary infection method, resistance experiments and genetic stability experiments prove that the screened strain is an anti-phage strain, the resistance can be stably inherited, and the strain can be used as a high-yield streptococcus zooepidemicus mutant strain. The strain not only has good resistance to bacteriophages, but also has excellent high-yield hyaluronic acid characteristics, and can be used as an industrial fermentation strain of hyaluronic acid.