117 results about "Wild type strain" patented technology

The invention provides a clostridium endophyllum engineering bacterium as well as a construction method and application thereof, and belongs to the technical field of biology, compared with a wild type strain, the clostridium endophyllum engineering bacterium can only produce acetic acid in a low-pH environment under the condition of taking CO2 and H2 as raw materials, and does not generate by-products such as ethanol, lactic acid, 2, 3-butanediol and the like. Besides, the fermentation liquor of the clostridium endophyllum engineering bacteria can be directly used as an acidic substrate to adjust the pH value of downstream yeast fermentation liquor, meanwhile, automatic addition of a carbon source is achieved, zero addition of inorganic salt in the cascade conversion process from CO2 and H2 to grease or yeast protein is achieved, and the economical efficiency and environmental friendliness of the whole process are improved.

The invention discloses an E3 ubiquitin ligase gene ulA, the nucleotide sequence of which is shown as SEQ ID NO: 1. The gene is knocked out from fusarium oxysporum by using a homologous recombination method to obtain a mutant strain ulA; compared with a wild strain, the mutant hulA has the advantages that the spore yield is reduced, the spore germination is delayed, the response capability to various abiotic stresses is reduced, the pathogenicity to panax notoginseng plants is reduced, and the sensitivity to six bactericides is increased, and experimental results show that the gene plays an important role in pathogenicity, drug resistance and the like of fusarium oxysporum. The gene can be used as a target gene for developing an anti-fusarium oxysporum preparation.

The invention discloses a SiERF109 gene for regulating drought resistance, salt tolerance and flavonoid accumulation of millet and application of the SiERF109 gene, and belongs to the technical field of plant breeding. According to the invention, a gene SiERF109 with a nucleotide sequence shown as SEQ ID NO.1 is separated and cloned from millet, and fluorescent quantitative expression analysis shows that SiERF109 participates in drought and salt stress response of millet. After the gene is over-expressed in foxtail millet, in drought and salt stress experiments, compared with a wild type strain, the survival rate and chlorophyll content of a strain over-expressed with the SiERF109 gene are remarkably increased, the flavonoid content is increased by 33.5%-39.5%, and active oxygen accumulation is remarkably reduced; it is shown that the SiERF109 gene and the protein coded by the SiERF109 gene can remarkably improve the drought resistance, the salt resistance and the flavonoid content of the plant.

The invention discloses a bumblebee candida for efficiently producing sophorolipid as well as a construction method and application of the bumblebee candida. According to the invention, metabolic transformation is carried out on a wild type strain of candida bumblebee, a peroxisome membrane transporter gene PXA1 is knocked out, so that a beta-oxidation pathway of fatty acid competing with a sophorolipid synthesis pathway is moderately inhibited, and on the basis, an endogenous potent promoter pENO is utilized to enhance expression of CYP52M1; therefore, the bumblebee candida engineering bacteria for efficiently producing sophorolipid are constructed. Compared with an original strain, the recombinant candida bumblebee has the advantages that efficient conversion of a fermentation substrate and high yield of sophorolipid can be realized, and the sophorolipid yield of shake flask fermentation reaches 88.50 g / L. The strain is fermented in a 5L fermentation tank and fermented for 7 days after rapeseed oil is added, 232.27 g / L of crude sophorolipid is produced, and high productivity is kept.

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.

The invention discloses a genetically engineered probiotic composition for expressing ADH (adenosine dihydrogenase) and ALDH (aldehyde dehydrogenase) and application of the genetically engineered probiotic composition in hangover alleviating and liver protection. The genetically engineered probiotic composition (such as EcN.1917-ADH and EcN.1917-ALDH) is constructed by introducing genes of alcohol dehydrogenase (ADH, NCBI (National Center for Biotechnology Information) Gene ID: 855349) and acetaldehyde dehydrogenase (ALDH, NCBI Gene ID: 855206) of saccharomyces cerevisiae into probiotics (such as escherichia coli). The engineering bacterium shows remarkable ethanol, acetaldehyde and endurance capacity in an in-vitro experiment, and the ethanol degradation rate is remarkably higher than that of a wild type strain; a mouse drunkenness model verifies that drunkenness and death caused by drinking can be reduced through pretreatment, drunkenness tolerance time is remarkably prolonged, and movement coordination disorder caused by alcohol can be improved. The strain can effectively promote alcohol metabolism and relieve alcoholic liver injury, and a new candidate strain is provided for development of a hangover-alleviating and liver-protecting viable bacterial preparation.

The invention relates to application and a method of a biological material for regulating and controlling MYB4 gene overexpression in the aspect of improving the yield of pleurotus edible fungi. The biomaterial exerts an effect of increasing the yield of a Pleurotus edible fungus by overexpressing MYB4 in the fungus. Experimental results show that the expression quantity of the MYB4 gene in the overexpression strain is remarkably higher than that of a wild strain, and the yield of the strain with the overexpression MYB4 gene during fruiting is remarkably improved compared with that of the wild strain.

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 relates to the technical field of agricultural biology, in particular to application of a regulatory gene Mt2312847 in improving the cellulase expression quantity of mycelia thermophila. Through interference or knockout of a regulatory gene Mt2312847 of a wild strain of the mycelia thermophila and knockout of the strain (Mt delta 2312847), the cellulase concentration of fermentation liquor of the interference strain is higher than that of the wild strain, and the CMCase enzyme activity of the Mt delta 2312847 and the CMCase enzyme activity of the Mt delta 2312847 are 2.2 times and 1.6 times that of a control strain.

The invention discloses recombinant xanthomonas campestris with xanthan gum hydrolase displayed on the surface and a construction method and application of the recombinant xanthomonas campestris. The recombinant xanthomonas campestris for surface display of xanthan hydrolase is constructed by introducing a recombinant vector obtained by fusion expression of an ice crystal nuclein (INP) gene and a xanthan hydrolase gene into xanthomonas campestris. The gel yield of recombinant xanthomonas campestris fermentation is twice that of a wild strain and reaches 6.7 g / L. The strain can efficiently hydrolyze xanthan gum with high molecular weight (such as more than 100 wDa), the traditional production process which is relatively complicated is simplified, and a new method is provided for large-scale production of the xanthan gum with low molecular weight.

The invention belongs to the technical field of gene engineering, and discloses a promoter and application thereof in enhancing target gene expression and promoting mannitol metabolism to synthesize bacterial cellulose. The nucleotide sequence of the promoter P00300 is as shown in SEQ ID NO: 2. The promoter is obtained by site-directed mutagenesis of a wild type promoter P06915 of gluconacetobacter xylinum and screening. The promoter provided by the invention can be used for enhancing the expression of a target gene and producing a target compound. For example, the expression level of fk, mdh1 and mdh2 three-gene combination is remarkably improved, the recombinant strain can efficiently synthesize BC by using mannitol, and the yield reaches 6.1 g / L, is about 2.87 times of that of a wild strain, and is 1.27 times of that of a bla promoter in pBla. The result lays a foundation for further understanding mannitol metabolism of gluconacetobacter xylinum and for high-value conversion and utilization of marine carbon resource mannitol and BC synthesis.

The present invention discloses a Schizochytrium strain that efficiently converts food waste to produce single-cell protein and its application, belonging to the field of bioengineering technology. The Schizochytrium spLOX‑2 deposit number is: CGMCC No.41623. The present invention also discloses a method for efficiently converting food waste to produce single-cell protein, fermenting food waste to produce volatile fatty acids; and using it as a carbon source to culture Schizochytrium to obtain single-cell protein. The recombinant strain spLOX‑2 in the present invention has improved utilization of lactic acid, and its biomass and protein yields are increased by 14.19% and 12% respectively compared with the wild-type strain, and the oil content is significantly increased by 107.1%. The present invention provides a new path for a sustainable bioeconomic model, in which waste is converted into valuable biochemicals, laying a solid foundation for expanding the scale of the process and the economic feasibility in industrial applications.

The invention discloses a genetically engineered bacterium and method for producing succinic acid by fermenting corn straw hydrolysate, and the method comprises the following specific steps: 1, preparing the corn straw hydrolysate: treating 1-2% NaOH solution at 110-130 DEG C for 0.5-1.5 h, with the lignin removal rate being greater than or equal to 70% and the cellulose retention rate being greater than or equal to 85%; step 2, aerobic fermentation of the genetically engineered bacteria: a culture medium contains 8-12 g / L of glucose and 3-7 g / L of yeast extract or corn steep liquor, and the genetically engineered bacteria are cultured at 35-39 DEG C and 180-220 rpm until OD600 is 2.5-3.5; and 3, anaerobic fermentation of the bacterial strain: taking the corn straw hydrolysate obtained in the step 1 as a carbon source, and adding a buffering agent into the genetically engineered bacteria for anaerobic fermentation. According to the recombinant escherichia coli E.coli SUCC-01, succinic acid is produced by knocking out an acetic acid synthesis gene pta / ackA and overexpressing an sdhA / mdh gene and combining with corn straw hydrolysate through fermentation, the yield of the succinic acid can reach 80 g / L, the total sugar utilization rate is larger than or equal to 90%, the by-product acetic acid is smaller than or equal to 12 g / L, and the yield is increased by 60% compared with that of a wild type strain.

The application discloses a glycerol dehydrogenase mutant and application thereof, and the glycerol dehydrogenase is derived from Klebsiella pneumoniae and is encoded by gene dhaD. The application improves the molecular structure of the glycerol dehydrogenase by rational design and a site-directed mutagenesis technology to obtain a mutant enzyme F245Q / GDH, and the mutant enzyme is back-supplemented into Klebsiella pneumoniae which is deficient in glycerol dehydrogenase. Compared with a wild-type strain, the yield of a main product 1,3-propanediol of the back-supplemented mutant enzyme F245Q / GDH strain is improved, and the yield of a by-product 2,3-butanediol is significantly reduced.

The invention discloses an amylosucrase mutant and application thereof in synthesis of alpha-arbutin, the mutant is obtained by mutation of an amino acid sequence of amylosucrase derived from coprophilobacterium mediterranei, and the amino acid sequence of the mutant is shown as SEQ ID NO.4. The invention further discloses a preparation method of the amylosucrase mutant. Compared with a wild strain, the catalytic activity, the temperature stability and the substrate tolerance of the amylosucrase mutant disclosed by the invention are remarkably improved; the recombinant bacteria constructed by using the recombinant bacteria can be used as a whole-cell catalyst to efficiently catalyze a substrate to synthesize alpha-arbutin in a reaction system containing hydroquinone. Therefore, the amylosucrase mutant disclosed by the invention has a good application prospect.

The invention provides a pseudomonas aeruginosa engineering bacterium which is based on a PAO1 wild type strain, and two of the following genes, namely cyaA and cyaB, are knocked out from a genome at the same time. According to the pseudomonas aeruginosa engineering bacterium, the cyaA gene and the cyaB gene are knocked out at the same time, and the yield of rhamnolipid is remarkably increased on the premise that existing PAO1 fermentation process parameters and processes are not changed. The yield cannot be increased when the cyaA or the cyaB is singly knocked out, and the synergistic effect of double-gene knockout is proved.

The present invention discloses an L-arginine-glycine amidinotransferase and use thereof in the production of guanidinoacetic acid. In the present invention, through combined multi-site amino acid mutation, a technical effect of significantly improved enzyme activity of the mutant AkAGATT225Q / A258P / L278K than that of the wild-type strain is achieved, providing an application value for large-scale production of guanidinoacetic acid in industry. When the L-arginine-glycine amidinotransferase mutant constructed in the present invention is used in the production of guanidinoacetic acid, by optimizing the conversion conditions, the yield of guanidinoacetic acid is up to 21.4 g / L and the conversion rate is 90.4%, after 24 hrs of reaction in a 1 L reaction system. Compared with the production of guanidinoacetic acid with the raw enzyme, the yield is increased by 49.6%.

Genetically transformed fungal strains for preparing a leather-like bioproduct and methods for obtaining said bioproduct, wherein the transformed strain has an increased carbohydrate hydrolytic activity as compared to the parent wild type strain and overexpressing genes such as swi6B, glsnf 1, gcn4, and / or nmnat.

The invention discloses a genetically engineered bacterium for producing heparinogen and a construction method and application thereof, the genetically engineered bacterium takes Escherichia coli Nissle 1917 as a chassis bacterium, and the construction method comprises the following steps: (1) knocking out endonuclease I coding gene endA in a chassis bacterium genome; (2) knocking out a 6-phosphofructokinase I coding gene pfkA in a chassis bacterium genome; (3) carrying out overexpression on a 6-phosphoglucosamine synthetase encoding gene glmS and / or a UDP-glucose-6-dehydrogenase encoding gene kfiD from a chassis bacterium genome; (4) removing the feedback inhibition of the 6-phosphate glucosamine on the GlmS so as to promote the synthesis of UDP-N-acetylglucosamine; and (5) knocking out the 6-phosphate glucosamine deaminase coding gene nagB in the chassis bacterium genome. The engineering strain obtained by the invention can more efficiently synthesize the proheparin, the shake flask titer reaches 397.9 mg / L, which is increased by about 3 times compared with a wild strain, and the engineering strain has certain industrial application value.

The invention relates to the technical field of microorganisms, and provides a rhizobium mutant and application thereof, the rhizobium mutant is HH103 delta nuo, and is a mutant obtained by taking sinorhizobium fredii (sinorhizobium fredii) HH103 as a starting strain and performing gene knockout on a nuo control unit in an NADH oxidoreductase subunit I of the sinorhizobium fredii HH103. When the HH103 delta nuo is inoculated in the soybean seedling stage, the plant shows that the leaves are darker green, the plant biomass is up-regulated, the nitrogenase activity of a single plant is obviously higher than that of a wild type strain, and the plant height is integrally increased, so that the HH103 delta nuo improves the symbiotic effect of the rhizobium and the soybean.

The invention relates to the technical field of biology, and provides a method for constructing a bacterial mutant library and application thereof, and the method comprises the following steps: (1) based on a mutation site of a target protein, carrying out splitting treatment on coding nucleic acid of the target protein, and constructing a saturated mutation site fragment for coding the target protein; (2) constructing a first vector which contains an expression signal marker and an SUMO-FutC enzyme fragment and does not contain an IIS type restriction enzyme digestion site; (3) connecting the saturated mutation site fragment with a first vector to obtain a saturated mutation vector library; and (4) transferring the vectors in the saturated mutation vector library into bacteria to obtain the bacterial mutant library. The bacterial mutant library can be combined with a microfluidic technology to screen key functional sites and corresponding strains of a target protein, for example, a target strain with high yield of 2 '-fucosyllactose can be efficiently obtained, the yield of the target strain is 4.7-7.6 times that of a wild strain, meanwhile, the time, instrument and reagent cost is saved, and the operation requirement is low.

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 invention discloses an application of a regulatory gene FgCTF1 beta 1 for synthesizing deoxynivalenol from fusarium graminearum. The regulatory gene FgCTF1 beta 1 is used for synthesizing deoxynivalenol from fusarium graminearum. According to the invention, a gene engineering strain delta FgCTF1 beta 1 is obtained by knocking out an FgCTF1 beta 1 gene in a fusarium graminearum genome. Compared with a wild strain PH-1, the genetic engineering strain delta FgCTF1 beta 1 has no significant change in the aspects of mycelial growth, conidium generation, pathogenicity to wheat coleoptiles and the like, but the biosynthesis amount of deoxynivalenol is significantly reduced. The invention also provides application of the FgCTF1 beta 1 gene as an inhibition target or a knockout target in inhibition of synthesis of DON from fusarium graminearum, and provides a new strategy and technical approach for prevention and control of pollution of deoxynivalenol in agricultural products.

The invention discloses an acetate-resistant domesticated algal strain HpAc50 and an application thereof. The algal strain is preserved in the China Center for Type Culture Collection on January 12, 2026, and the preservation number is CCTCC M 202690. The haematococcus pluvialis strain is obtained by carrying out acetate-resistant domestication on haematococcus pluvialis and can be cultured under the condition that the acetic acid concentration is 0-10g / L, and the yield of astaxanthin is effectively increased. The invention specifically provides three application conditions: illumination of 0-5000lux and a full-nutrient culture medium; illumination is performed at 0-5000 lux, a nitrogen-phosphorus-deficient culture medium is adopted, and an exogenous stimulant is added According to the present invention, with the application of the strain, the cell density, the biomass and the astaxanthin accumulation can be significantly improved under the conditions of illumination of 5000-15000 lux and nitrogen and phosphorus deficiency culture medium, such that the strain has strong acetate tolerance and strong production performance compared with the wild type strain, and is suitable for the large-scale astaxanthin production.

The present invention discloses a recombinant Pantoea alpina strain and its use in the fermentation production of exopolysaccharides. The recombinant Pantoea alpina strain has the gene mdoG encoding a transcription factor knocked out; wherein the amino acid sequence of the transcription factor is shown in SEQ ID NO.2. The present invention constructs a recombinant strain with high exopolysaccharide production using CRISPR technology. The gene encoding the transcription factor can be used to direct the improvement of the exopolysaccharide-producing strain, making its exopolysaccharide production significantly higher than that of the wild-type strain, laying the foundation for further metabolic engineering of Pantoea alpina strain to produce polysaccharides. The recombinant strain construction method provided by the present invention is simple and easy to use. The exopolysaccharide produced by the recombinant Pantoea alpina strain constructed by the present invention has a static viscosity of 10.32 to 24.11 Pa·s at room temperature for a 10 g / L exopolysaccharide aqueous solution prepared using the exopolysaccharide, showing good application prospects.

The present invention belongs to the technical field of aspergillosis treatment, and specifically discloses the use of carbonyl cyanide-4-trifluoromethoxyphenylhydrazone in the prevention and treatment of Aspergillus fumigatus infection, that is, using it as the sole active ingredient in the preparation of a drug for preventing or treating diseases caused by Aspergillus fumigatus infection, or for the preparation of an antibacterial and / or bactericidal product for Aspergillus fumigatus. The present invention first discovered that carbonyl cyanide-4-trifluoromethoxyphenylhydrazone has a significant inhibitory effect on both wild-type and drug-resistant strains of the human pathogenic fungus Aspergillus fumigatus, and can inhibit its colony growth, hyphal growth, and conidia formation, thereby providing a new therapeutic drug for Aspergillus fumigatus infection. At the same time, it solves the problem of antibiotic resistance that plagues the clinical treatment of Aspergillus fumigatus infection, and can circumvent the disadvantage that antibiotics are prone to drug resistance.

The invention discloses an amylosucrase mutant and application thereof in synthesis of alpha-arbutin, and belongs to the technical field of genetic engineering. An amylosucrase mutant is obtained through an error-prone PCR technology, the mutant is obtained by mutation on an amylosucrase amino acid sequence derived from coprophilobacterium mediterranei, and the amino acid sequence of the amylosucrase mutant is shown as SEQ ID NO.4. The invention further discloses a preparation method of the amylosucrase mutant. Compared with a wild strain, the amylosucrase mutant disclosed by the invention has higher catalytic activity, temperature stability and substrate tolerance; when the catalyst is added into a hydroquinone-containing reaction system, alpha-arbutin can be efficiently catalyzed and synthesized. Therefore, the amylosucrase mutant disclosed by the invention is suitable for industrial production and has a good application prospect.

The invention discloses a sugar-inducible promoter and application thereof in prevention and treatment of monochamus alternatus, and relates to the technical field of genetic engineering and biological prevention and treatment. Based on the technical background of transgenic symbiotic bacteria in prevention and treatment of monochamus alternatus, the scheme has the advantages that the transgenic symbiotic bacteria and wild strains have a competitive relationship in ecological niche; under high-level expression driven by a constitutive promoter, the transgenic symbiotic bacteria may be too greedy in resource utilization, so that the transgenic symbiotic bacteria conflict with wild strains and even are eliminated by the wild strains; according to the scheme, expression of Cry3Aa-T protein is regulated and controlled by using the sugar-induced promoter so as to reduce the cost of fitness of exogenous genes carried by serratia marcescens, and a hidden and effective method is provided for preventing and controlling propagation of vector insect monochamus alternatus.

The invention provides an L-homoserine genetically engineered bacterium without amino acid defects as well as a construction method and application of the L-homoserine genetically engineered bacterium. Compared with a wild type strain, the modified L-homoserine genetically engineered bacterium provided by the invention can better utilize glycerol and other carbon source substances to produce L-homoserine, is a strain without amino acid defect and plasmid, and simplifies a fermentation process while having good production performance. The transformed strain has better performance in the aspect of fermentation production of L-homoserine by taking glycerol as a carbon source, 4.68 g / L can be accumulated at a shake flask level, 60.56 g / L can be accumulated at a 5L tank fermentation level, the conversion rate is 0.49 g / g glycerol, and the space time yield is 1.01 g / L / h. Therefore, the L-homoserine genetically engineered bacterium provided by the invention has an important industrial application value.

This invention discloses a method for designing optimal strains for product synthesis using an enzyme-constrained model combined with an evolutionary algorithm, comprising the following steps: Step S1, solving the enzyme-constrained model with the objective function of maximizing the specific growth rate of the strain to obtain the simulated metabolic flux of the wild-type strain; Step S2, performing dimensionality reduction analysis and labeling on genes directly related to enzyme synthesis within the model by solving a series of flux balance analysis problems with fixed biomass synthesis rates; Step S3, predicting the yield of single-target editing; Step S4, using a genetic algorithm to search for combined targets after dimensionality reduction, adjusting relevant parameters to obtain the optimal gene editing combination strategy; Step S5, repeating the experiment to verify the stability of the algorithm. This invention utilizes genetic algorithms and enzyme-constrained models to discover non-intuitive gene editing combination strategies, providing a new method for constructing efficient microbial cell factories for synthetic chemicals, and demonstrating the potential of applying heuristic algorithms to strain optimization design.