249 results about "Genetic stability" patented technology

The invention relates to the technical field of stem cell biology, and discloses a stem cell quality evaluation system and method, and the system comprises a data collection module which collects local environment data and image data of stem cells in a preset range; the morphological recognition module is used for obtaining cellular morphological data of all stem cells in a preset range through a cellular morphological recognition model; the graph structure data construction module is used for constructing graph structure data; the score marking module is used for measuring the multiplication capacity, the genetic stability capacity and the surface marker expression capacity of the stem cells after the preset duration, and obtaining the quality score of the stem cells through manual marking; the model training module is used for training a stem cell quality scoring model through an optimization algorithm; according to the method, the cellular morphology data of the stem cells are extracted through the multi-branch network of the cellular morphology recognition model, and the interaction among the stem cells is comprehensively considered through the stem cell quality scoring model, so that the accuracy of stem cell quality evaluation is improved.

The invention provides a uracil production strain and a construction method and application thereof.According to the strain, on an E.coli UR14 genome by means of a CRIPSR / Cas9 gene editing technology, firstly, psuG genes, preTA genes, rutA genes and upp genes are knocked out, so that decomposition of uracil is blocked; then, a uridine phosphorylase gene udp and a pyrimidine-5 '-nucleotide nucleotidase gene ppnN are subjected to overexpression, and synthesis and accumulation of uracil are synergistically enhanced; and finally, overexpression of the ribose phosphate mutase gene pgm further enhances the conversion of a by-product ribose phosphate 1-precursor 5-ribose phosphate 1-pyrophosphate and improves the carbon utilization rate, and the obtained strain has good genetic stability and high fermentation yield, can stably produce uracil, and has wide application prospects.

The invention belongs to the technical field of food microorganisms, and particularly discloses a ganoderma lucidum mutant strain capable of producing polysaccharides and triterpenoids at high yield. The strain is named as Ganoderma lucidum in Latin, the preservation number is CGMCC NO: 41680, the preservation unit is China General Microbiological Culture Collection Center, and the preservation date is December 4, 2024. The strain is named as Ganoderma lucidum, the preservation number is CGMCC NO: 41680, and the preservation number is CGMCC NO: 41680. The polysaccharide content in the ganoderma lucidum spore powder produced by the ganoderma lucidum mutant strain is more than or equal to 8%, and the total triterpenoid content is more than or equal to 12%; a culture medium formula of the ganoderma lucidum mutant strain comprises potato leachate, glucose and monopotassium phosphate, the culture temperature is 25-28 DEG C, and the pH value is 5.5-6.5. The ganoderma lucidum mutant strain is high in genetic stability, the content of active ingredients is remarkably higher than that of parent strains, and the ganoderma lucidum mutant strain is suitable for large-scale fermentation production.

The invention provides a nicotinamide nucleotide transhydrogenase mutant and application thereof, valine at the 169th site of the nicotinamide nucleotide transhydrogenase mutant is designed to be mutated into isoleucine, the isoleucine is used for constructing a lysine production strain, and the new strain does not contain plasmids, does not have growth defects, does not need induction, and has the advantages of good genetic stability, high fermentation yield and the like. The lysine can be efficiently and stably produced from the beginning by taking glucose as a substrate.

The invention provides a valine production strain and a construction method and application thereof, a designed acetohydroxy acid synthase mutant is that the 88th basic group of an ilvB gene is changed from a to c, the 382nd basic group is changed from a to g, the 413th basic group is changed from c to t, the gene sequence of a designed artificial operon comprises a promoter, an ilvB (A138V) gene or ilvB (Q30K, S128G, A138V) gene of coding mutated acetohydroxy acid synthase, and an ilvN (G20D, I21D, I21D, I21D, I21D, I21D, I21D, I21D) gene. I22F) gene, a pyk gene for coding pyruvate kinase, and a terminator; by designing a specific acetohydroxyacid synthase mutant and related biological materials and artificial operon, the strain constructed by directional modification of the strain by using a pK18mobsacB system gene editing technology based on allele exchange has the advantages of good genetic stability, high fermentation yield and the like, and valine can be stably produced.

The invention belongs to the technical field of synthetic biology, and particularly relates to recombinant escherichia coli for efficiently producing O-acetyl-L-homoserine as well as a construction method and application of the recombinant escherichia coli. According to the invention, CRISPR-Cas9 gene editing is combined with metabolic modification, so as to precisely integrate OAH biosynthesis key nodes: introducing and overexpressing a mutant metX gene at a genome pseudogene site to enhance the expression of homoserine acetyltransferase, knocking out byproducts such as poxB and mgsA to synthesize genes, and carrying out high-yield synthesis of OAH. Corynebacterium glutamicum thrA (anti-feedback inhibition), aspB and bacillus subtilis acsA-acuA genes (construction of an acetic acid switch) are introduced, gene expression of gltA, tpiA and the like is optimized to increase supply of precursors such as acetyl CoA and the like, and finally a stable strain without plasmids, antibiotics and inducers is obtained. The production cost is effectively reduced, and the method has the advantage of high genetic stability and shows a good application prospect in OAH industrial production.

The invention belongs to the technical field of genetic engineering, and discloses a schizochytrium limacinum genetic engineering strain for enhancing supply of acetyl coenzyme A and efficiently producing astaxanthin, a method and application of the schizochytrium limacinum genetic engineering strain. By heterologous expression of a beta-carotene ketolase CrtO gene and a beta-carotene hydroxylase CrtZ gene from haematococcus pluvialis, synthesis of astaxanthin from beta-carotene in schizochytrium limacinum is promoted, so that the content of astaxanthin in schizochytrium limacinum HX-308 is increased. According to the invention, the endogenous AACT gene and heterologous CrtO, CrtZ, PK and PTA genes of schizochytrium limacinum are integrated into an original strain through homologous recombination, and the obtained strain still keeps genetic stability after multiple subculture, has the capability of efficiently synthesizing astaxanthin, effectively improves the yield of astaxanthin, and lays a foundation for large-scale industrial production.

The invention relates to the technical field of biology, in particular to an SNP (Single Nucleotide Polymorphism) marker combination for identifying tilapia streptococcus agalactiae disease resistance and application thereof. The invention discloses 11 SNP loci significantly related to streptococcus agalactiae resistance in a tilapia UTRN gene, and constructs 18 SNP marker combinations for streptococcus agalactiae resistance phenotype identification, so that the resistance phenotype identification accuracy and hereditary stability can be effectively improved. Besides, according to the SNP typing primer and method based on the # imgabs0 # MALDI-TOF mass spectrum platform, high-throughput and high-precision genetic typing can be achieved, and the SNP typing primer and method have important application value in resistance phenotype identification and assistant selective breeding.

The invention discloses recombinant yarrowia lipolytica with high yield of 3-fucosyllactose as well as a construction method and application of the recombinant yarrowia lipolytica. According to the invention, a reinforced lactose transporter lac12 gene, a reinforced GDP-mannose-4, 6-dehydratase gmd gene, a reinforced GDP-L-fucose synthase gmer gene and a 3-fucosyltransferase SUMO-fut3Bc gene with a reinforced SUMO tag are subjected to integrated expression on a recombinant yarrowia lipolytica chromosome, and a 6-phosphogluconolactonase pgl gene is subjected to overexpression, so that a recombinant yarrowia lipolytica strain is obtained. The constructed recombinant yarrowia lipolytica can maintain the genetic stability of a target gene, the yield and production efficiency of 3-fucosyllactose are remarkably improved, and the requirements of industrial production can be met.

The invention belongs to the technical field of biology and new medicine, and discloses a method for constructing a myxobacteria expression chassis with genetic stability and application of the myxobacteria expression chassis. Through gene deletion and overexpression analysis, it is verified that the spontaneous mutation rate of a strain can be reduced by deletion of a TLS pathway and overexpression of RecA, and a myxobacteria strain 2K7 with genetic stability is further constructed on the basis. The spontaneous mutation rate of the new strain is reduced by 11.5 times, and the transformation capability of growth plasmids of the strain is obviously improved. According to the research, the genetic stability of the myxobacteria is improved for the first time through a repair way after modification and replication, and the research method and the research result are innovative.

The invention relates to the technical field of molecular biology or agriculture, in particular to an SNP (Single Nucleotide Polymorphism) molecular marker related to a southern rust gene RPPK and application. The SNP loci, the primers and the detection method capable of resisting southern rust gene RPPK typing are successfully developed, the southern rust gene RPPK can be accurately subjected to genetic typing, and the SNP molecular marker has the characteristics of high throughput, low average cost, high genetic stability, accurate and reliable genetic typing data, easiness in automatic detection and the like; and the method has an extremely high value in commercial breeding.

The invention provides a valine production strain as well as a construction method and application thereof, the strain is constructed by utilizing a CRIPSR / Cas9 system gene editing technology based on allele exchange, an artificial operon is designed and constructed, the artificial operon is constructed at a ygaY site, a strong promoter Ptrc is used for controlling ilvIH (G14N S17F)-pykF to carry out synchronous multi-copy expression, and the valine production strain can be used for producing valine. On the basis of the strain, an artificial operon is constructed at an ycgH site, a strong promoter Ptrc is used for controlling ilvC-ilvD to carry out synchronous multi-copy expression, meanwhile, feedback inhibition of valine on ilvIH is relieved, and an ilvIH natural promoter is replaced by the strong promoter Ptrc, so that more pyruvic acid flows to valine; the constructed strain does not contain plasmids, has no defects, does not need induction, has the advantages of good genetic stability, high fermentation yield and the like, and can be used for efficiently synthesizing valine from the beginning by taking glucose as a substrate.

The application relates to the technical field of gene chips, in particular to a SNP molecular marker combination of Pinus massoniana and application thereof. The SNP molecular marker combination is composed of 113,709 SNP molecular markers, wherein the physical position of the SNP molecular markers is determined by sequence alignment based on a reference genome Pinus.tabuliformis V1.0 of Pinus tabulaeformis. The application provides a whole genome chip of Pinus massoniana containing 113,709 SNP sites for the first time, and the chip has the advantages of high efficiency, low cost, good genetic stability and the like, and can be widely applied to different application scenarios such as identification of Pinus massoniana germplasm resources, genetic background analysis of breeding materials, gene positioning, whole genome association analysis, whole genome selection breeding and intelligent design breeding.