223 results about "Coli strain" patented technology

A method for isolating succinic acid producing bacteria is provided comprising increasing the biomass of an organism which lacks the ability to catabolize pyruvate, and then subjecting the biomass to glucose-rich medium in an anaerobic environment to enable pyruvate-catabolizing mutants to grow.The invention also provides for a mutant that produces high amounts of succinic acid, which has been derived from a parent which lacked the genes for pyruvate formate lyase and lactate dehydrogenase, and which belongs to the E.coli Group of Bacteria.

A vaccine for protecting birds against infection by avian pathogenic gram negative microbes is disclosed. The vaccine is a recombinant Salmonella strain expressing O-antigen of an avian pathogenic gram negative microbe such as an E. coli strain that is pathogenic in poultry. The recombinant Salmonella strain also does not express Salmonella O-antigen. Methods of using the vaccine to immunize birds are also disclosed.

The invention discloses recombinant escherichia coli using glucose for producing hydroxytyrosol as well as a building method and application. The method comprises the following steps that SEQ ID NO.1 and 2 are used as primers; the escherichia coli BW25113 genome DNA (deoxyribonucleic acid) is used as a template; HpaBC gene PCR (polymerase chain reaction) augmentation is carried out; vectors pTrcHisB are connected; middle plasmids are obtained; the middle plasmids are used as templates; the SEQ ID NO.3 and 2 are used as primers; PCR augmentation is carried out, and plasmids pTrcHisB-ARO10 are connected; expression vectors pTrcHisB-ARO10-HpaBC are obtained; in addition, the vectors and the plasmids pBb3 are simultaneously transferred into escherichia coli strains BMGA to obtain the recombinant escherichia coli. The recombinant escherichia coli contains ARO10 genes from saccharomyces cerevisiae, and HpaBC genes from the escherichia coli endogenesis. The yield of the hydroxytyrosol can be obviously improved.

The invention provides a preparation method of 3'-sialic acid lactose, belonging to the technical field of biological engineering. The preparation method comprises the following steps of: taking colibacillus CCTCC (colibacillus China center for type culture collection) NO: M208088 as a starting strain, adding a fermentation medium into a fermentation tank, fermenting for 2-6h, then adding a fed batch culture medium, and adding lactose in a flowing way at the mid-later period of the fermentation; and centrifuging the fermentation liquid to obtain liquid supernatant 1 and a thallus, diluting the centrifuged thallus by adding water and splitting in a heating way, recentrifuging to obtain liquid supernatant 2, merging the liquid supernatant 1 and the liquid supernatant 2, and absorbing, desorbing and vacuum drying by ion exchange resin to obtain the 3'-sialic acid lactose. A mass of the 3'-sialic acid lactose can be prepared by the CCTCC NO: M208088. The 3'-sialic acid lactose can change the current situation that the sialyloligosaccharide component is less in exogenous adding substances in conventional baby milk, and can provide the guarantee to add more efficient sialic acid trophic factors into the baby milk.

The invention discloses recombinant Escherichia coli producing salidroside, a construction method and applications thereof. The construction method comprises: (1) using Escherichia coli [delta]A as a starting strain, and carrying out gene knockdown or gene silencing to make the galE gene, the galT gene and the ugd gene on the Escherichia coli chromosome be not expressed to obtain an Escherichia coli strain BMGU; and (2) introducing genes such as ARO10, UGT73B6MK, pgm, galU and T7Polymerase to over-express the genes such as ARO10, UGT73B6MK, pgm, galU and T7Polymerase so as to achieve the heterologous synthesis of salidroside, such that the recombinant Escherichia coli producing salidroside is obtained. According to the present invention, the efficient UDP-glucosyltransferase mutant UGT73B6MK is introduced, and the glucose metabolism pathway is optimized, such that the yield of salidroside is significantly improved.

The invention provides a halogenohydrin dehalogenation enzyme originating from Agromyces sp., an encoding gene and a vector, and provides application of the halogenohydrin dehalogenation enzyme, the encoding gene and the vector in the process of preparing epoxy chloropropane and (R)-4- cyano-cn-3- hydroxybutyric acid ethyl ester. The halogenohydrin dehalogenation enzyme amino acid sequence is shown in SEQ ID NO.2, and the encoding gene sequence is shown in SEQ ID NO.1. The halogenohydrin dehalogenation enzyme, the encoding gene, the vector and the application have the advantages that the halogenohydrin dehalogenation enzyme originating from Agromyces sp. CCTCC NO. M 2012299 and the encoding gene of the halogenohydrin dehalogenation enzyme are provided; and the encoding gene of the halogenohydrin dehalogenation enzyme can be connected and constructed with an expression vector to obtain expression recombinant plasmid pET28b-Deh of the encoding gene, then can be transformed to escherichia coli BL21, obtained and transformed to escherichia coli bacterial strain respectively and correspondingly to obtain recombinant escherichia coli, and the recombinant escherichia coli has the halogenohydrin dehalogenation enzyme and can be utilized for carrying out biotransformation and catalysis for an enzyme source.

The invention relates to escherichia coli CGMCC NO.3192 for recombined engineering and a variant thereof. The strain is obtained by integrating gene segments subjected to the recombined engineering, i.e. a regulatory gene araC of the Arabinose ara operon from the escherichia coli, a promoter pBAD of the Arabinose ara operon from the escherichia coli, recombined enzyme genes red alpha, red alpha beta and gam from a gamma bacteriophage, a gene recA and gentamicin resistance gene (Gm) from the escherichia coli, into an endA gene area of a gene group of the escherichia coli DH10B, wherein red alpha, red alpha beta, gam and recA are driven by pBAD induced by arabinose. The recombined enzyme can catalyze homologous recombination among DNA short segments to finish the recombined engineering. The length of the DNA segment is about 50 base pairs. The invention has convenient operation of carrying out the recombined engineering by the strain and high recombined efficiency, thereby becoming the universal strain for the recombined engineering.

The invention discloses a construction method of a genetic engineering strain for producing shikimic acid. The method comprises the following steps of: 1, constructing an escherichia coli strain of which the aroA gene is knocked out; 2, constructing a recombinant expression plasmid pAR63 containing key enzyme genes aroGFBR, aroE, aroB, aroD, tktA and ppsA in the metabolic pathway of the shikimic acid, so that the genes are subjected to transcriptional control of a tryptophan promoter Ptrp; and 3, transferring the recombinant expression plasmid pAR63 into the escherichia coli strain of which the aroA gene is knocked out to obtain a production strain for expressing the shikimic acid. In the method, the aim of interrupting the metabolism of the shikimic acid is fulfilled by the knock-out of the single gene aroA, a small number of genes are knocked out, the operating difficulty is low, and the expression of the genes is in the state of starting and stopping automatically and is started automatically in the middle and late period without the induction of inducers, so the possibility of adding toxic substances into a culture medium is reduced, and the shikimic acid has high yield.

An L-amino acid-producing strain of Escherichia coli is bred by modifying an Escherichia coli K12 strain or a derivative thereof so as to become resistant to L-valine and have an ability to produce one or more L-amino acids selected from the group consisting of L-tryptophan, L-phenylalanine, L-lysine, L-tyrosine, L-glutamic acid, L-histidine, L-cysteine, and L-proline.

The invention discloses a recombinant amidase Dt-Ami 2, an encoding gene, a vector, an engineering strain and applications of the recombinant amidase Dt-Ami 2 and the engineering strain. The invention provides a Delftia tsuruhatensis (CCTCC No. M 205115)-derived amidase gene, and a recombinant amidase WB encoded by the gene; and the amidase gene can be connected with an expression vector so as to obtain an intracellular expression recombinant plasmid containing the gene, then the intracellular expression recombinant plasmid is transferred to an escherichia coli strain so as to obtain recombinant escherichia coli, the recombinant escherichia coli contains recombinant amidase, and the recombinant amidase can be used as a catalyst for catalyzing the hydrolysis of a series of amide compounds.

The invention discloses a hepatitis E virus-like particle vaccine preparation method, and belongs to the biological medicine technical field. According to the method, hepatitis E virus truncated capsid protein gene codon optimization is performed, prokaryotic expression system escherichia coli strain B834-pRARE2 is used, by fusion of purification tag MBP expression, different cracking agent screening and combination, bacterial membrane extraction, maltose amylose affinity chromatography, molecular sieve chromatography for removal of MBP and non-virus structural protein, and promotion of virus-like particle assembly, the hepatitis E virus-like particle purity is more than 99.0%, and is free of protein label and bioactive (in the form of non-inclusion body, and soluble). The hepatitis E virus-like particle vaccine produces complete protection to pig, dog and chicken HEV infection, cross protective antigens are between different genotype HEV virus, and the hepatitis E virus-like particle vaccine can be used as an animal vaccine to prevent the diseases and infection caused by pig, dog and poultry HEV.

This invention relates to the metabolic evolution of a microbial organism previously optimized for producing an organic acid in commercially significant quantities under fermentative conditions using a hexose sugar as sole source of carbon in a minimal mineral medium. As a result of this metabolic evolution, the microbial organism acquires the ability to use pentose sugars derived from cellulosic materials for its growth while retaining the original growth kinetics, the rate of organic acid production and the ability to use hexose sugars as a source of carbon. This invention also discloses the genetic change in the microorganism that confers the ability to use both the hexose and pentose sugars simultaneously in the production of commercially significant quantities of organic acids.

The invention relates to a method of producing menaquinone-7, characterized in that cells of an E. coli strain comprising the B. subtilis DSM 1088 hepS gene, the B. subtilis DSM 1088 hepT gene and the putative B. subtilis DSM 1088 heptaprenyl transferase gene are fermented in a fermentation medium, with menaquinone-7 being accumulated in the cells of the fermented E. coli strain.

The present invention discloses an alginate lyase Alga genetic sequence and a preparation method and application thereof. Alginate lyase Alga is derived from Vibrio alginolyticus 40B. The present invention provides a process for preparing the novel alginate lyase Alga, a genetic engineering method is used, an alginate lyase Alga coding gene is cloned into an E. coli expression vector to obtain a recombinant E. coli strain capable of heterologous expression of the alginate lyase Alga, and the alginate lyase Alga prepared by heterologous expression of the recombinant E. coli strain has the function of degrading sodium alginate to prepare sodium alginate oligosaccharide. The alginate lyase Alga can be widely used in chemical industry, agriculture, food, feed additives, pharmaceuticals and algae genetic engineering and other fields.

The present invention discloses recombinant escherichia coli. The recombinant escherichia coli over-expresses an encoding gene of prostaglandin H synthase and an encoding gene of prostaglandin E synthase. The present invention also discloses an application of the recombinant escherichia coli in production of prostaglandin E2. The present invention also discloses a method for producing the prostaglandin E2. Arachidonic acid is used as a substrate and the recombinant escherichia coli is used to produce the prostaglandin E2. The escherichia coli strain capable of expressing the prostaglandin H synthase and the prostaglandin E2 synthetase is constructed and the expressed enzymes can directly catalyze conversion of the arachidonic acid into the prostaglandin E2.

The invention discloses an Escherichia coli for producing riboflavin and constructing method and use of Escherichia coli. The preparation method comprises the following steps: designing ribosome bind sites RBS1, RBS2, RBS3, RBS4 and RBS5, respectively connecting the ribosome bind sites with genes ribA, ribB, ribD, ribE and ribC into fragments, splicing the fragments in order and enzyme-cutting and linking to a plasmid pTrc99a to obtain plasmid p20C-EC10, transferring into the Escherichia coli to obtain RF01S strain, transforming related gene of glycolytic pathway and ED pathway of the RF01S strain so as to improve the output of the riboflavin, and transforming the consumption pathway of the riboflavin to decrease the metabolism velocity of the riboflavin so as to further improve the riboflavin accumulation, inserting a Ptrc strong promoter into genome of the strain to obtain the Escherichia coli for producing the riboflavin. The constructed Escherichia coli strain has clear genetic background, and the glucose can be used as substrate to produce the riboflavin, and the shake-flask fermenting result is more than 1g/L, and a foundation is provided for improving the riboflavin output and yield.

A bioconversion method of making vanillin including expressing VaoA gene in a mixture, expressing MtSAD1 gene in the mixture, feeding eugenol to the mixture, and converting ferulic acid to vanillin by incubating with a microbial Amycolalopsis sp. strain (Zhp06) and/or a recombinant E.coli strain.

The invention discloses the use of variovoraxboronicumulans CGMCC 4969 in bioconversion of 3-cyanopyridine for forming nicotinamide. The nitrile hydratase gene cluster produced by the strain consists of a DNA sequence represented by SEQ ID No.1 in a sequence table; the DNA consisting of the sequence represented by SEQ ID No.1 is recombined onto a pET28a plasmid and can be induced to express in EscherichiacoliBL21(DE3) strain; and the Escherichia coli cells containing expressed proteins and cell extracting solution can convert 3-cyanopyridine into nicotinamide.

The invention belongs to the technical field of genetic engineering, and relates to a bioconversion method for producing 1,5-pentanediamine. The method can increase the yield of 1,5-pentanediamine bymodifying a metabolic pathway of Escherichia coli. The method specifically comprises the following steps: selecting an Escherichia coli strain, firstly, knocking out a 1,5-pentanediamine degradation pathway; secondly, adding a synthetic precursor,namely lysine, of 1,5-pentanediamine; thirdly, overexpressing a transporter gene and finally directly fermenting the Escherichia coli strain DFC1002 to produce 1,5-pentanediamine. After the metabolic pathway of Escherichia coli is modified, themethod can produce 1,5-pentanediamine with high yield.The method is simple and easy to implement, has high yield of 1,5-pentanediamine, few by-products, and good repeatability, and is suitable for industrialization.

The invention discloses escherichia coli for producing sucrose phosphorylase and belongs to the technical field of microorganisms. A nucleotide sequence shown as SEQ ID NO.1 is used for constructing arecombinant plasmid pET-28a-SPase with pET-28a as a vector, the recombinant plasmid is transformed into escherichia coli BL21(DE3), and recombinant escherichia coli is constructed. Recombinant sucrose phosphorylase is produced by fermentation, the recombinant escherichia coli strain with high yield of sucrose phosphorylase is screened out by adopting an ultraviolet mutagenesis method to mutagenize the constructed recombinant escherichia coli, the enzyme activity of a supernatant on the broken walls in fermentation cells is 819.16 U/mL, the specific enzyme activity is 206.91 U/mg, the stable enzyme production can lay a foundation for further theoretical research and practical application, and practical application is significant.