168 results about "Transferase Gene" patented technology

The invention discloses an attenuated salmonella typhimurium EN-VNP (Enhanced Natriuretic Peptide) strain as well as a preparation method and application of the attenuated salmonella typhimurium EN-VNP strain. Comprising the following steps: on the basis of a salmonella VNP20009 strain, flagellin genes fliC and fljB, a phosphoethanolamine transferase gene eptA, a 4-amino-4-deoxy-L-arabinose transferase gene arnT and phosphotransferase yeiU are sequentially knocked out or silenced, and a strain is formed after a phosphotransferase gene lpxE is knocked in or overexpressed, so that the attenuated salmonella typhimurium EN-VNP strain is prepared. According to the attenuated salmonella typhimurium EN-VNP with low toxicity and the T cell adjuvant effect and an EN-OMV antigen delivery system prepared from the attenuated salmonella typhimurium EN-VNP, an improved strain does not contain flagellin, an LPS molecular structure is changed, the attenuated salmonella typhimurium EN-VNP has the low toxicity and the T cell adjuvant effect, and normal multiplication culture can be achieved.

The invention belongs to the technical field of plant genetic engineering, and particularly relates to application of a centella asiatica glycosyl transferase gene in catalyzing glycosylation of asiatic acid and madecassic acid. The nucleotide sequence of the gene is shown as SEQ ID No.1, and the protein coded by the gene can catalyze the C-28 site of asiatic acid and madecassic acid to perform glucose group modification so as to generate asiatic acid monoglucoside and madecassic acid monoglucoside, and preferentially catalyzes madecassic acid. By constructing a metabolic regulation network, the genes are widely and accurately screened, and the glycosylation process of catalyzing asiatic acid and madecassic acid is analyzed; an important reference basis is provided for improving the glycosylation efficiency of asiatic acid and madecassic acid and the yield of asiaticoside and madecassoside in the in-vitro synthesis and industrial production process of the centella asiatica triterpenoid saponin, and an important theoretical support is provided for large-scale production of the centella asiatica active saponin.

The invention provides application of acidophilous glycosyltransferase in salidroside production, and belongs to the technical field of biological engineering. The problem of producing salidroside under the acidic condition is solved. Comprising an application of acidophilous glycosyl transferase with an amino acid sequence as shown in SEQ ID NO.1 in salidroside production under an acidic condition and an acidophilous escherichia coli engineering strain for producing salidroside. The escherichia coli engineering strain overexpresses a mutant 3-deoxy-D-arabinoheptulose-7-phosphate (DAHP) synthetase gene aroGfbr, a cyclohexadiene dehydrogenase gene tyrC, a glucose phosphate mutant enzyme gene pgm and a UDP-glucose pyrophosphorylase galU, overexpresses a phenylpyruvate decarboxylase gene ARO10 derived from saccharomyces cerevisiae, and can be used for producing a mutant 3-deoxy-D-arabinoheptulose-7-phosphate mutant enzyme. The kit comprises an ethanol dehydrogenase gene ADH6 and a glycosyl transferase gene LrUGT85AF8. The method is mainly used for producing salidroside under an acidic condition.

The invention relates to the technical field of gene engineering, in particular to a glycosyl transferase mutant and application thereof in synthesis of rebaudioside M. Wild type glycosyl transferase is modified through a directed evolution theory to obtain the glycosyl transferase mutant, so that the efficiency of synthesizing rebaudioside D through reaction of rebaudioside A is effectively improved. Besides, recombinant bacteria capable of simultaneously expressing the glycosyl transferase mutant, a second glycosyl transferase gene and a sucrose synthase gene are constructed, a wet cell obtained by induced culture of the recombinant bacteria or a crude enzyme liquid extracted by crushing the wet cell is used as a catalyst, rebaudioside A is used as a substrate, sucrose is used as an auxiliary substrate, and the rebaudioside M is catalytically synthesized by a one-pot method. According to the present invention, the complete catalysis of 100 g / L of rebaudioside A to produce rebaudioside M only needs 24 h, the conversion rate reaches 97.5%, the yield of rebaudioside M reaches 130 g / L, the raw material conversion rate and the yield of rebaudioside M are effectively improved, and the synthesis time is shortened.

The invention discloses gene-simplified bacillus subtilis for producing surfactin and application of the gene-simplified bacillus subtilis, and belongs to the technical field of gene engineering. According to the method disclosed by the invention, the variety of non-essential genes is determined by analyzing and identifying the bad performance influencing the fermentation production of the surfactin by the bacillus subtilis. Therefore, on the basis of the bacillus subtilis 168, a phosphopantetheinyl transferase (sfp) gene is firstly integrated, so that the surfactin production capacity of host bacteria is recovered; then, genes (clusters) in five aspects of a biological membrane synthesis pathway, a metabolic by-product pathway, spore generation, a protease system and flagellum generation are simplified. After the strain EX10 is simplified, the fermentation performance is optimized, and the fermentation yield reaches up to 11.2 g / L, which is 2.1 times higher than that of the original strain. Therefore, the genome-simplified strain has a good application prospect as a chassis cell for industrially and efficiently producing surfactin.

The invention discloses an escherichia coli recombinant bacterium for whole-cell catalytic synthesis of rebaudioside M as well as a construction method and application of the escherichia coli recombinant bacterium. The Escherichia coli recombinant bacterium for the whole-cell catalytic synthesis of the rebaudioside M, which is constructed by the invention, contains a glycosyl transferase UGT76G1 coding gene mutant, a glycosyl transferase UGT91C1 coding gene mutant, a sucrose synthase atSuS1 gene and a polyphosphoglucokinase cgPPGK gene; a glucose-1-phosphate uridine transferase galU gene, a nucleoside diphosphate kinase ndk gene and a nucleoside diphosphate kinase ndk gene are over-expressed; meanwhile, an encoding gene araA gene of L-arabinose isomerase and an encoding gene ushA gene of 5 '-nucleotidase / UDG hydrolase are knocked out. According to the recombinant escherichia coli constructed by the invention, Reb D is prevented from being directly used as a synthetic substrate, so that the raw materials are easier to obtain, and the conversion rate of the substrate and the synthetic rate and yield of rebaudioside M are remarkably improved.

The invention belongs to the technical field of gene engineering, and particularly relates to a highland barley flavonoid glycosyl transferase gene and application thereof. A novel glycosyl transferase gene HOVUSG6091200 in highland barley is found, and protein expressed by the gene can efficiently catalyze glycosylation modification of various flavonoid compounds, so that flavonoid compound glucoside is prepared, and the health-care value of the highland barley is improved; the gene is also transferred into tobacco, so that the highland barley flavonoid glycosyl transferase gene is also expressed in a tobacco plant, flavonoid glucoside is further generated, and the value of the tobacco plant is improved; the novel gene, the recombinant vector, the recombinant bacteria and the transgenic plant provided by the invention have good application prospects.

The invention relates to the field of biology, in particular to application of a coix lacryma-jobi diacylglycerol acyltransferase gene (ClDGAT2). The invention discloses an application of a coix lacryma-jobi diacylglycerol acyltransferase gene (ClDGAT2) in improving the yield of oil. The coix lacryma-jobi diacylglycerol acyltransferase gene (ClDGAT2) has the following functions: triglyceride can be generated, a DGAT enzyme function is realized, and the capability of recovering TAG defect type saccharomyces cerevisiae oil production is realized.

The invention discloses an escherichia coli engineering strain with high benzyl acetate yield and application thereof. The escherichia coli strain efficiently expresses a brand new biosynthetic pathway related gene of benzyl acetate; comprising a phenylalanine lyase gene, a cinnamic acid coenzyme A ligase gene, a 3-hydroxyacyl coenzyme A dehydrogenase gene, a 3-oxoacyl coenzyme A ketohydrolase gene, an enoyl coenzyme A hydratase gene, a carboxylic acid reductase gene, a phosphoric acid pantetheinyl transferase gene and an acyltransferase gene. The obtained escherichia coli engineering strain can utilize a sustainable and cheap raw material glucose as a carbon source to realize efficient synthesis of benzyl acetate. The yield of benzyl acetate synthesized by the escherichia coli benzyl acetate engineering bacteria is the highest yield of benzyl acetate synthesized by a microbial fermentation method reported at home and abroad from beginning. The benzyl acetate produced by the engineering strain has the advantages of reliable quality, economic product, green production and the like, and has important economic value and social benefit.

The invention discloses a Zymomonas mobilis recombinant strain for producing D-pantothenic acid as well as a preparation method and application of the Zymomonas mobilis recombinant strain. A hydroxymethyl transferase gene panB, a ketopantoic acid reductase gene panE and a pantothenic acid synthase gene panC are integrated in a genome of the recombinant strain; an expression plasmid containing an acetolactate synthase gene Bsals, a keto acid reductoisomerase gene ilvC and a dihydroxy acid dehydratase gene ilvD is also transferred into the recombinant strain; wherein the nucleotide sequences of the gene Bsals, the gene ilvC, the gene ilvD, the gene panB, the gene panE and the gene panC are shown as SEQ ID NO. 1 to SEQ ID NO. 6 in sequence. The zymomonas mobilis ZM4 is systematically modified through a genetic engineering means, and an optimal enzyme combination adaptive to the zymomonas mobilis is defined by screening hydroxymethyltransferase, pantothenic acid synthase and ketopantoic acid reductase from different sources, so that a core foundation is laid for efficient operation of a D-pantothenic acid synthesis route, and the method has a wide application prospect. The technical bottlenecks of single metabolic pathway and low synthesis efficiency of the traditional strain are broken through.

The invention discloses glycosyltransferase in safflower and a related biological material and application thereof. The invention firstly discloses any one of the following proteins: A1) a protein consisting of an amino acid sequence as shown in a sequence 2; a2) a fusion protein obtained by connecting the N end or / and C end of the protein as shown in the sequence 2 with a protein tag. The invention further discloses the protein related biological material and application thereof. The HSYA biosynthesis key glycosyl transferase gene UGT708U5 is obtained from safflower for the first time, it is proved that the protein UGT708U5 coded by the gene can catalyze phloretin to form HSYA precursor compounds, namely phloretin-mono-C-glucoside and phloretin-di-C-glucoside, and the gene plays an important role in biosynthesis and heterologous production of HSYA; the method has important theoretical and practical significance for regulating and producing the quinonechalcone C-glycoside compounds of plants and cultivating high-quality safflower carthamus.

The invention discloses a corynebacterium glutamicum engineering strain produced by L-glutamine as well as a construction method and application of the corynebacterium glutamicum engineering strain. The corynebacterium glutamicum engineering strain is prepared by integrating a glutamine synthase encoding gene glnA which is sourced from saccharomyces cerevisiae and has a tyrosine residue mutation at the 99th site on the surface and an sRNA-MicC-EcHfq regulation module of a targeted adenylyltransferase gene glnE into a vector plasmid; the method comprises the following steps: constructing a recombinant plasmid for removing adenosine acylation of glutamine synthase; and transferring the recombinant plasmid into corynebacterium glutamicum of which the odhA gene expression is controlled by a growth stage specific promoter Pcg2705, so as to obtain a corynebacterium glutamicum engineering strain for producing L-glutamine. According to the invention, through multi-gene synergistic modification and space-time metabolic flux optimization, the problem of'growth-synthesis' tradeoff in the prior art is solved, the fermentation efficiency is improved, the fermentation process is simple, and the application prospect is good.

The present application belongs to the technical field of genetic engineering, and particularly relates to a methyltransferase gene CmCMT2 and CmDRM2 application in regulating chrysanthemum flowering. The present application constructs an RNAi silencing expression vector by isolating CmCMT2 and CmDRM2 genes in a chrysanthemum variety "Jinma", and obtains CmCMT2 -RNAi and CmDRM2 -RNAi transgenic "Jinma" plants by using a genetic transformation method, then performs phenotype observation and statistics on the transgenic plants, and explores CmCMT2 and CmDRM2 the mechanism of the genes affecting early flowering of chrysanthemum by using an RNA-seq method. The CmCMT2 and CmDRM2 genes are cloned from the chrysanthemum variety "Jinma", and spatiotemporal expression analysis shows that CmCMT2 and CmDRM2 the genes are highly expressed during the process of "Jinma" from bud development to color change; and CmCMT2 and CmDRM2 the expression level in leaves gradually decreases during the growth and development of "Jinma". The research results show that CmCMT2 and CmDRM2 the content of GA1 is changed by negatively regulating the expression of CmG20ox2a and CmG20ox2b , so that the flowering period of chrysanthemum is advanced by 15 and 8 days, respectively.

The invention belongs to the technical field of gene engineering, and particularly relates to application of methyltransferase genes CmCMT2 and CmDRM2 in regulation and control of flowering of chrysanthemum. According to the invention, CmCMT2 and CmDRM2 genes in a chrysanthemum variety 'Shenma' are separated, an RNAi silent expression vector is constructed, CmCMT2-RNAi and CmDRM2-RNAi transgenic 'Shenma' plants are obtained by using a genetic transformation method, then phenotype observation and statistics are carried out on the transgenic plants, key genes influencing chrysanthemum flowering are excavated by using an RNA-seq method, and a mechanism of the CmCMT2 and CmDRM2 genes influencing chrysanthemum early flowering is explored. The CmCMT2 gene and the CmDRM2 gene are cloned from a chrysanthemum variety 'Shenma', and spatio-temporal expression analysis shows that the CmCMT2 gene and the CmDRM2 gene are highly expressed in the process from bud development to coloring of the 'Shenma'; moreover, in the growth and development process of the'miraculous horse ', the expression levels of the CmCMT2 and the CmDRM2 in leaves are gradually reduced. Research results show that the CmCMT2 and the CmDRM2 change the content of the GA1 by negatively regulating the expression of the CmG20ox2a and the CmG20ox2b, so that the florescence of the chrysanthemum is respectively advanced by 15 days and 8 days.

The invention discloses an ergothioneine-producing recombinant engineering bacterium as well as a construction method and application thereof, and belongs to the technical field of gene recombination fermentation. The method comprises the following steps: by taking escherichia coli as a starting bacterium, carrying out recombinant expression on a histidine trimethyl inner salt cysteine sulfoxide synthetase egt1 gene, an L-histidine methyltransferase egtD gene, a histidine trimethyl inner salt cysteine sulfoxide lyase egt2 gene, a methionine adenosine transferase metK gene, an adenylate kinase adK gene and an adenine phosphoribose transferase apt gene; on this basis, supply of precursor substances including histidine, cysteine and methionine is further improved through metabolic transformation, the yield of the finally obtained recombinant engineering bacterium for producing ergothioneine reaches 2.54 g / L after 48 h of shake-flask culture, the yield of a 5L fermentation tank reaches 18 g / L after further enlarged culture, the yield of ergothioneine is guaranteed while energy consumption and cost are reduced, and the method is suitable for industrial production. The method is suitable for practical popularization.

The invention discloses a salmonella typhimurium EN-VNP strain based on flagellin and LPS attenuation as well as a preparation method and application of the salmonella typhimurium EN-VNP strain, and particularly relates to the technical field of biology. The bacterial strain is formed by sequentially knocking out or silencing flagellin genes fliC and fljB, a phosphoethanolamine transferase gene eptA, a 4-amino-4-deoxy-L-arabinose transferase gene arnT and phosphotransferase yeiU on the basis of a salmonella VNP 20009 bacterial strain, and knocking in or overexpressing a phosphotransferase gene lpxE. The salmonella typhimurium EN-VNP strain disclosed by the invention has relatively high safety, the attenuated strain does not contain flagellin, and a lipid A molecule of LPS only retains one phosphate group, so that the safety of the strain is improved, and the strain is more suitable for serving as a vaccine and a drug delivery carrier.

The application belongs to the technical field of biology and relates to a Clostridium butyricum engineering strain for improving butyric acid synthesis through a coenzyme A transferase pathway as well as a construction method and application of the Clostridium butyricum engineering strain. Clostridium tyrobutyricum The application expresses a butyryl coenzyme A:acetic acid-coenzyme A transferase gene from Clostridium tyrobutyricum Ctcat1 A coenzyme A transferase (CoAT) pathway is constructed, the pathway synthesizes butyric acid by taking acetic acid as a substrate, therefore, the content of acetic acid in a fermentation product is greatly reduced, and the butyric acid yield is significantly improved.

The invention discloses application of a methyltransferase gene EFS in regulation and control of plant salt stress resistance, and belongs to the technical field of plant molecular biology. The methyltransferase gene EFS is separated from arabidopsis thaliana, the full-length CDS of the methyltransferase gene EFS is 5418bp, the methyltransferase gene EFS has three conservative protein function structural domains which are respectively an SET structural domain, an AWS structural domain and a ZnfCW structural domain, and the protein coded by the methyltransferase gene EFS contains 1805 amino acids. After the methyltransferase gene EFS is knocked out, 100mM NaCl and 125mM NaCl are used for treating a mutant, so that the sensitivity of the mutant to the salt stress is increased, which indicates that the mutant plays an important role in the response of the plant to the salt stress, and therefore, the gene can be applied to the salt stress resistance of the plant.

The present invention relates to the field of biotechnology, and discloses a dsRNA for efficiently controlling Phyllotreta striolata and its application. A dsRNA for efficiently controlling Phyllotreta striolata, the dsRNA is transcribed from an arylalkylamine N-acyltransferase gene, and the dsRNA has an RNA sequence as shown in SEQ ID NO.1. The arylalkylamine N-acyltransferase gene sequence is as shown in SEQ ID NO.2. By using the dsRNA for efficiently controlling Phyllotreta striolata and its application as described above, the provided target gene, the arylalkylamine N-acyltransferase gene, has specificity and is highly expressed in the digestive tissues of adult Phyllotreta striolata, which can reduce the difficulty of the dsRNA reaching the target tissue, improve the interference effect of the dsRNA on Phyllotreta striolata, and further improve the control effect of the dsRNA on Phyllotreta striolata.

The invention provides glycosyl transferase and application thereof in preparation of salidroside, and relates to the technical field of enzyme engineering. The glycosyl transferase FpUGT provided by the invention is derived from fraxinus pennsylvanica, the existence of the glycosyl transferase gene capable of directly catalytically synthesizing the salidroside in the plant is not reported in literatures, and a new biological way is provided for finding the glycosyl transferase for efficiently synthesizing the salidroside. And a new biological material is provided for preparing the salidroside.

This invention provides a chalcone isopentenyltransferase gene. GiPT16 This invention relates to the GiPT16 protein, amplification primer set, and applications, belonging to the field of biogenetics technology. It is based on *Glycyrrhiza inflata* (GiPT16 protein, amplification primer set, and applications). Glycyrrhiza inflata Using whole-genome sequencing data and a reverse genetics strategy, the key aromatic isopentenyltransferase GiPT16, involved in the isopentenylation modification of chalcone active ingredients, was successfully identified and functionally characterized. This enzyme was confirmed to specifically catalyze the biosynthesis of psoralen and glycyrrhizin C using DMAPP as a donor. It is the first chalcone isopentenyltransferase characterized in *Glycyrrhiza inflata*, filling a gap in the study of key enzymes in the chalcone isopentenylation metabolic pathway of this species and providing important evidence for further elucidating the molecular mechanisms of quality formation in *Glycyrrhiza inflata* medicinal materials.

The present invention discloses a genetically engineered bacterium for the whole-cell catalyzed synthesis of glucoside ferulate and its application, belonging to the technical field of bioengineering. In the present invention, by overexpressing the expression of two key enzymes involved in the synthesis of uridine diphosphate glucose (UDP-glucose) in the host cell, namely phosphoglucomutase and uridine diphosphate glucose pyrophosphorylase genes, the intracellular accumulation level of UDP-glucose is further increased; by transferring the UDP-glucosyltransferase gene into the host cell and achieving its high-efficiency expression, a genetically engineered bacterium capable of biocatalytic synthesis of glucoside ferulate is obtained. By adopting the technical scheme of the present invention, the problem of intracellular UDP-glucose supply can be solved, and glucoside ferulate is prepared by whole-cell catalysis using ferulic acid as a substrate. Finally, the yield of glucoside ferulate reaches 220.47 mg / L, and the molar conversion rate is 60.1%.

The present invention belongs to the field of plant genetic engineering technology, and in particular to the application of a Centella asiatica glycosyltransferase gene in catalyzing the glycosylation of asiatic acid and madecassic acid. The nucleotide sequence of the gene is as shown in SEQ ID No.1, and the protein encoded by it can catalyze the C-28 position of asiatic acid and madecassic acid to carry out glucose group modification to produce asiatic acid monoglucoside and madecassic acid monoglucoside, and prefers catalysis madecassic acid. The present invention, by building a metabolic regulatory network, widely and accurately screens the above-mentioned gene, resolves the glycosylation process of catalyzing asiatic acid and madecassic acid, for the in vitro synthesis of Centella asiatica triterpenoid saponins and industrial production process to improve asiatic acid and madecassic acid glycosylation efficiency and asiaticoside and madecassin yield provide important reference basis, and provide important theoretical support for large-scale production of Centella asiatica active saponins.

The invention belongs to the technical field of biology, and relates to a clostridium butyricum engineering strain for improving butyric acid synthesis through a coenzyme A transferase pathway, and a construction method and application thereof. According to the method disclosed by the invention, a coenzyme A transferase (CoAT) pathway is constructed by expressing butyryl coenzyme A: acetic acid-coenzyme A transferase gene Ctcat1 from clostridium tyrobutyricum, and the pathway is used for synthesizing butyric acid by taking acetic acid as a substrate, so that the content of acetic acid in a fermentation product is greatly reduced, and the yield of butyric acid is remarkably increased.

The application provides a kind of aromatic isopentenyl transferase mutant, which is based on the aromatic isopentenyl transferase gene MenA derived from Bacillus subtilis ( Bacillus subtilis ) and six aromatic isopentenyl transferase mutants MenA-1 to MenA-6 are obtained by site-directed mutagenesis PCR technology, and the recombinant bacteria Bacillus subtilis expressing the above mutants are constructed, respectively. The yield of heptamethylnaphthoquinone fermented by the recombinant bacteria is 64.49 mg / L, 69.30 mg / L, 83.86 mg / L, 105.84 mg / L, 119.23 mg / L and 125.45 mg / L, respectively, which is 133%, 143%, 173%, 219%, 246% and 259% of the yield of heptamethylnaphthoquinone fermented by the Bacillus subtilis expressing the wild-type aromatic isopentenyl transferase MenA.

The invention relates to a gastrodia elata glycosyl transferase GaUGT131 gene and application thereof in preparation of gastrodin, and belongs to the technical field of biology. The nucleotide sequence of the gastrodia elata glycosyl transferase GaUGT131 gene is as shown in SEQ ID NO. 1, and the total length of the sequence is 1524 bp; the amino acid sequence of the encoded protein is shown as SEQ ID NO.2, and 508 amino acid residues are encoded. The gastrodia elata glycosyl transferase GaUGT131 gene can be used as a biosynthesis regulation gene of gastrodin, is applied to preparation of gastrodin, and is remarkable in application prospect and easy to popularize and apply.

This invention belongs to the field of biotechnology and discloses a recombinant strain of Saccharomyces cerevisiae that enhances the efficient synthesis of vitamin K2 and its application. By heterologously integrating the hepS / T and naphthoquinone cyclotransferase genes (menA) of Bacillus subtilis, four genetically engineered strains were constructed based on the designed MK-7 biosynthetic pathway: YK-1, YK-2, YK-3, and YK-4. YK-1 is an expression strain containing the target genes MenF, MenD, and MenH; YK-2 is an expression strain integrating the target genes MenC, MenE, and MenB on the basis of YK-1; YK-3 is an expression strain integrating the target genes hepS and hepT on the basis of YK-2; and YK-4 is an expression strain integrating the target genes yuxO, MenA, and MenG on the basis of YK-3. YK-4 is the final engineered strain that produces high levels of vitamin K2. The optimal fermentation time was determined by measuring OD600 and yield curves. YK-4 reached its maximum cell concentration in 18 hours, which can effectively shorten the fermentation cycle.

The invention discloses a genetically engineered bacterium for synthesizing N-acetyl blue as well as a construction method and application of the genetically engineered bacterium. The genetically engineered bacterium is prepared by knocking out a lactic dehydrogenase gene ldh and inserting a phosphoketolase gene xfpK on a knockout site, knocking out a pyruvate oxidase gene poxB and inserting a phosphate transacetylase gene pta on a knockout site of a microorganism for producing N-acetyl blue, and knocking out an aconitase inhibition factor gene acnR, inserting a glutamate dehydrogenase gene gdhA on a knockout site, knocking out a glutamine synthetase adenylation transferase gene glnE, and inserting an alpha-ketoglutarate dehydrogenase inhibition factor gene odhI on a knockout site to obtain the strain. According to the method, the supply of the precursor acetyl coenzyme A is enhanced by introducing a non-oxidative glycolysis pathway, the pH dynamic regulation system balances the metabolic flux, and the double breakthrough of the yield and the carbon recovery rate of the N-acetyl blue is realized by combining a two-stage fermentation process.

This invention belongs to the fields of fermentation and genetic engineering technology, and provides a high-yield hexanoic acid-producing engineered *Escherichia coli* strain, its construction method, and its applications. This engineered strain is *Escherichia coli*... E. coli w3110 was the starting strain, overexpressing the acetyl-CoA transferase gene. act and β-ketothiolase gene bktB Overexpression of trans-enoyl-CoA reductase gene ter 3-Hydroxybutyryl-CoA dehydrogenase gene hbd, and 3-hydroxybutyryl coenzyme A dehydratase gene crt Or, simultaneously not expressing the pyruvate formate lyase gene. pflB or lactate dehydrogenase gene ldhA This engineered bacteria can convert glucose into hexanoic acid, a high-value product, with a yield of 4.968 g / L after 18 hours of fermentation. It adopts aerobic fermentation, resulting in rapid cell growth, a short fermentation cycle, and a high acid production rate. The fermentation process is simple, easy to control, and has low production costs, which is conducive to its promotion and application in industrial production.

The invention discloses genetically engineered corynebacterium glutamicum and an application of the genetically engineered corynebacterium glutamicum in preparation of ectoine, and the genetically engineered corynebacterium glutamicum contains an L-diaminobutyric acid transaminase gene ectB, an L-diaminobutyric acid acetyltransferase gene ectA and an ectoine synthetase gene ectC, the invention relates to an aspartic acid transferase gene aspB, an aspartic acid kinase gene lysC and an aspartic acid semialdehyde dehydrogenase gene asd, wherein the nucleotide sequences of the gene aspB, the gene lysC and the gene asd are respectively as shown in SEQ ID NO.4, SEQ ID NO.5 and SEQ ID NO.6. The invention further discloses a preparation method of the aspartic acid transferase gene aspB, the aspartic acid kinase gene lysC and the aspartic acid semialdehyde dehydrogenase gene asd. After the recombinant corynebacterium glutamicum constructed by the invention is fermented for 60 hours, the yield of ectoine can reach 50g / L. The genetically engineered corynebacterium glutamicum disclosed by the invention has important practical significance on industrial production and large-scale application of ectoine.