10 results about "Dehydratase" patented technology

This invention relates to the fields of microbial genetic engineering and fermentation biomanufacturing technology, specifically disclosing a recombinant Corynebacterium glutamicum with high 5-aminolevulinic acid (ALA) production and its applications. Addressing the problems of existing strains such as crude enzyme activity regulation, inhibited cell growth, the need for external inhibitors, and low yield, this invention uses Corynebacterium glutamicum as a host and removes the gdhA gene without scarring to reduce precursor competitive metabolism. Site-directed mutations of the endogenous hemB gene (S288A, D128E, R231K) are performed to moderately reduce dehydratase activity. A high-expression plasmid pXMJ19-hemA containing the hemA gene from Rhodopsinus capsulatum is constructed and introduced into the modified strain to obtain a recombinant strain with optimized triple metabolism. This strain reduces product degradation without the need for external dehydratase inhibitors, does not affect cell growth, and achieves a yield up to 4.30 times higher than the control after 42 hours of fermentation, with ALA accumulation exceeding 8.9 g / L. The strain exhibits stable characteristics, the process is simple, and it has good industrial application value.

The application discloses a method for fermenting 3-hydroxypropionic acid and acrylic acid. The application provides a recombinant Corynebacterium glutamicum, wherein the ald gene of the aldehyde dehydrogenase of the microorganism is up-regulated, the expression of the glycerolaldehyde-3-phosphate dehydrogenase gapA is down-regulated, the heterologous diol dehydratase gene pduCDEGH is expressed, the heterologous 3-phospho dehydrogenase gdp and glycerol 3-phosphatase gpp are expressed. The recombinant microorganism is fermented in a shake flask or a fermenter with glucose or other organic carbon sources as the substrate to obtain 3-hydroxypropionic acid. The 3-hydroxypropionic acid in the fermentation broth is acidified and heated to further obtain acrylic acid. The recombinant microorganism can efficiently produce 3-hydroxypropionic acid and acrylic acid by using cheap glucose, sucrose, molasses and the like as raw materials, the production process is green, safe and simple, and has a good market application prospect.

This invention discloses an engineered bacterial strain for producing xylitol using glucose as the sole carbon source, its construction method, and its applications, belonging to the field of genetic engineering. Using *Escherichia coli* as the starting strain, this invention optimizes the metabolic pathway by knocking out the 2-keto-3-deoxy-6-phosphate glucuronide gene (eda), knocking out the 6-phosphoglucuronide dehydratase gene (edd), and weakening the glucose phosphoisomerase gene (pgi), thus concentrating the carbon flow in the pentose phosphate pathway. Furthermore, it optimizes the metabolic pathway by knocking out or overexpressing endogenous genes such as the ribulokinase gene (araB). Subsequently, the synthesis of xylitol from glucose was experimentally tested by expressing a recombinant expression plasmid containing 2-arabinol dehydrogenase, 4-arabinol dehydrogenase, and xylitol dehydrogenase. This invention, through optimized metabolic pathways, efficiently converts glucose to xylitol without the need for glycerol addition, and significantly increases the yields of both the precursor arabinol and the product xylitol, demonstrating promising production prospects.

A method for improving the synthetic ability of *Yersinia lipolytica* to synthesize amino acid derivatives. This invention discloses an engineered strain for the biological synthesis of the amino acid derivative β-hydroxy-β-methylbutyric acid (β-methylbutyric acid) and its construction method. Using *Yersinia lipolytica* as the substrate cell, the HMGCL and OCT genes involved in branched-chain amino acid metabolism in its genome are knocked out to obtain a gene knockout strain. Decarboxylase genes, hydratase genes, dehydratase genes, and thioesterase genes are integrated into the genome of the gene knockout strain to obtain an engineered strain capable of de novo synthesis of β-hydroxy-β-methylbutyric acid. Further integration of the CcGCTB-CcGCTA fusion gene expression module enhances the expression level of key enzyme genes, thereby increasing the yield of β-hydroxy-β-methylbutyric acid in the strain. The engineered strain constructed in this invention can synthesize the target product β-hydroxy-β-methylbutyric acid using glucose as a carbon source through fermentation, with a maximum yield of up to 30 g / L.

This invention discloses a method for preparing 1,2-pentanediol, comprising using 2-pentanone as a substrate, adding 2-keto reductase, linalool dehydratase, formate dehydrogenase, lysozyme, coenzyme NAD+, and water to react and obtain n-pentene. The obtained n-pentene is then thoroughly mixed with ethanol. This mixture is then fed into a reaction system containing olefin monooxygenase, epoxide hydrolase, formate dehydrogenase, lysozyme, coenzyme NAD+, MgSO4, and water using a fed-batch method. After the n-pentene and ethanol mixture has been completely added, the reaction continues for a period of time, followed by extraction to obtain 1,2-pentanediol. This preparation method uses 2-pentanone as a raw material, catalyzing the synthesis of 2-pentanol via 2-keto reductase. 2-pentanol is then catalyzed by a dehydrating enzyme to generate n-pentene, which is then catalyzed by an olefin monooxygenase to generate 1,2-epoxypentane. Finally, epoxide hydrolase ring-opens the 1,2-pentanediol. This process requires only four enzymatic catalytic reactions for efficient synthesis.

A method for preparing fucose and intermediates thereof and applications thereof. In the method for synthesizing GDP-fucose, GDP-fucose is generated by catalytic reaction of sucrose synthase, CDP-threose 2-epimerase, GDP-mannose dehydratase and isomerase with guanosine diphosphate and sucrose as substrates. In the method for synthesizing fucosyllactose, fucosyllactose is obtained by catalytic action of Hp13FucT2 enzyme with GDP-fucose and pNP-lactose as initial substrates. In the method for preparing L-fucose by enzyme, L-fucose is generated by catalytic reaction of fucosidase with fucosyllactose as substrate. The E. coli expression system has the characteristics of high expression efficiency, large expression amount, low cost and easy operation, and the expressed fucosidase has the advantages of high purity and high yield.

Recombinant proteobacteria, including γ-proteobacteria, comprising a heterologous acyl-ACP desaturase and a heterologous acyl-ACP thioesterase, wherein the native dual 3-hydroxy acyl-ACP dehydratase / isomerase is deleted are provided herein. The recombinant proteobacteria produce non-native monounsaturated free fatty acids or derivatives thereof. Methods of producing non-native monounsaturated free fatty acids or derivatives thereof are also provided, in addition to cell cultures and fatty acid compositions produced by the recombinant proteobacteria. The recombinant proteobacteria may be used to produce insect pheromones or precursors thereof, and fragrances or precursors thereof.

The application belongs to the field of genetic engineering and enzyme engineering, and discloses a 3-dehydroshikimate dehydratase mutant T308L derived from corynebacterium glutamicum and application of the mutant in synthesis of protocatechuic acid. T308L The yield of the mutant for synthesizing protocatechuic acid is 10.79% higher than that of the wild type. The 3-dehydroshikimate dehydratase mutant obtained in the application can significantly improve the ability of the engineering strain in fermenting and synthesizing protocatechuic acid, and has a good industrial application prospect.

The application discloses a recombinant ammonium acetate-producing bacterium and a method for preparing ammonium acetate, and belongs to the technical field of bioengineering.The application aims to provide a method for producing ammonium acetate.The application provides a recombinant ammonium acetate-producing bacterium, which is obtained by knocking out the genes poxB of pyruvate oxidase, pflB of pyruvate formate-lyase and the key subunit aceE of pyruvate dehydrogenase of Escherichia coli as a starting bacterium, and overexpressing the genes Agx1 / BhcA of glyoxylate aminotransferase, Dhaa / BhcC of hydroxyaspartate aldolase, BhcB of beta-hydroxyaspartate dehydratase and BhcD of iminosuccinate reductase.The application combines the carbon sequestration path with the fermentation process optimization, realizes direct and efficient synthesis from glucose to ammonium acetate, significantly simplifies the process flow, and improves the carbon atom utilization efficiency and product yield.