361results about "Racemaces/epimerases" patented technology

The invention relates to newly discovered nucleic acid molecules and proteins associated with prostate cancer including pre-malignant conditions. Compositions, kits, and methods for detecting, characterizing, preventing, and treating human prostate cancers are provided.

The present invention relates to eukaryotic cells which have the ability to convert L-arabinose into D-xylulose 5-phosphate. The cells have acquired this ability by transformation with nucleotide sequences coding for an arabinose isomerase, a ribulokinase, and a ribulose-5-P-4-epimerase from a bacterium that belongs to a Clavibacter, Arthrobacter or Gramella genus. The cell preferably is a yeast or a filamentous fungus, more preferably a yeast is capable of anaerobic alcoholic fermentation. The may further comprise one or more genetic modifications that increase the flux of the pentose phosphate pathway, reduce unspecific aldose reductase activity, confer to the cell the ability to directly isomerise xylose into xylulose, increase the specific xylulose kinase activity, increase transport of at least one of xylose and arabinose into the host cell, decrease sensitivity to catabolite repression, increase tolerance to ethanol, osmolarity or organic acids; and/or reduce production of by-products. The cell preferably is a cell that has the ability to produce a fermentation product such as ethanol, lactic acid, 3-hydroxy-propionic acid, acrylic acid, acetic acid, succinic acid, citric acid, amino acids, 1,3-propane-diol, ethylene, glycerol, -lactam antibiotics and cephalosporins. The invention further relates to processes for producing these fermentation products wherein a cell of the invention is used to ferment arabinose into the fermentation products.

The invention discloses genetically engineered bacteria capable of increasing the yield of lactoyl-N-trisaccharide II and a production method, and belongs to the field of microbial genetic engineering. According to the invention, the expression of glmM, glmU, glmS and lgtA in a lactoyl-N-trisaccharide II synthetic pathway is regulated and controlled in a combined manner, so the carbon flux of a metabolic pathway is accurately regulated and controlled, and the metabolic pressure is relieved; the expression of wecB, nagB and lacZ in an escherichia coli host, namely the lactoyl-N-trisaccharide IIsynthetic pathway is knocked out, so the yield of the lactoyl-N-trisaccharide II is further increased; in a flask shaking experiment, the capacity of escherichia coli for producing the lactoyl-N-trisaccharide II is increased to 4.82 g/L from 0.53 g/L; in a fermentation tank with a volume of 3 L, the yield of the lactoyl-N-trisaccharide II reaches 46.2 g/L; and thus, thegenetically engineered bacteria have industrial application prospect.

The invention discloses constructed recombinant escherichia coli and a method for biosynthesis of 3'-sialyllactose. The recombinant escherichia coli is named as E.coli-XYY which has a synthesis pathway of the 3'-sialyllactose. Meanwhile, the invention also discloses a constructing method. At the same time, the invention solves the problems of the prior art and provides an efficient gene knockout scheme; an original strain, after undergoing genetic engineering transformation, can produce the 3'-sialyllactose only, without changing other properties of the strain, so that influence on fermentation production is avoided; since mature escherichia coli plasmid is adopted by the strain, bacterium growth and normal metabolism do not affected in a metabolic process. The recombinant escherichia coli constructed by the invention has a good application prospect; therefore, a new thought is provided for the production of the 3'-sialyllactose by virtue of a biological method.

The invention provides a D-psicose-3-epimerase mutant with improved catalytic activity and an application of the mutant and particularly provides mutational D-psicose-3-epimerase. The mutational D-psicose-3-epimerase is obtained by mutation in at least three loci selected from the following groups: the 73rd aspartic acid (D), the 111st tyrosine (Y), the 188th asparaginate (N) and the 250th glycine(G) of wild D-psicose-3-epimerase corresponding to SEQ ID NO:1. The mutational D-psicose-3-epimerase has very high catalytic activity and catalytic efficiency (reaching up to 29.6%).

The invention relates to a preparation method of high-purity D-psicose. The method comprises the following steps: (a) preparing a D-psicose epimerase crude enzyme preparation; (b) immobilizing the crude enzyme preparation prepared in the step (a) and glucose isomerase; (c) preparing a mixed solution containing D-psicose, fructose and glucose; (d) decolorizing, filtering and hybridizing the mixed solution prepared in the step (c) to obtain a D-psicose solution and a mixed solution of the fructose and the glucose; (e) performing chromatographic separation, concentration, crystallization or drying on the D-psicose solution prepared in the step (d) to obtain D-psicose.

The endogenous pnp gene encoding polynucleotide phosphorylase in the Zymomonas genome was identified as a target for modification to provide improved xylose utilizing cells for ethanol production. The cells are in addition genetically modified to have increased expression of ribose-5-phosphate isomerase (RPI) activity, as compared to cells without this genetic modification, and are not limited in xylose isomerase activity in the absence of the pnp modification.

The invention discloses a D-psicose 3-epimerase mutant with improved catalytic efficiency and belongs to the technical field of enzyme engineering. The Dorea sp. DPEase mutant enzyme A38E/G105A keepsthe optimal catalytic conditions. Under the optimal catalytic conditions, the relative enzyme activity of the enzyme for catalytic conversion of D-fructose as a substrate into D-psicose is improved by38.6%. The discovery has an important research value for the industrial production of D-psicose.

The invention discloses a D-psicose 3-epimerase production strain and an immobilization method thereof, and belongs to the technical field of bioengineering. According to the invention, recombinant bacillus subtilis pHY300PLK-DPEase for producing D-psicose 3-epimerase is constructed, and the recombinant bacterium (the recombinant bacillus subtilis) serves as the production strain; an enzyme activity recovery rate of immobilized cells reaches 64%, the optimum temperature of the immobilized cells is improved by 5 DEG C in comparison with that of whole cells and the optimum pH value of the immobilized cells is free from obvious change; and after continuous conversion with 300g/L of fructose as a substrate for seven times, a conversion rate can be still kept at 28% and residual enzyme activitycan be still kept at 81%. The immobilization method is simple and easy to implement and immobilized particles are excellent in performance; therefore, a quite high industrial application value is achieved.

The invention discloses a construction method of an engineering strain for generating allulose and an application thereof. The construction method comprises the following steps: increasing content ofintracellular fructose 6-phosphoric acid by reducing enzymatic activity of fructose 6-phosphokinase and glucose 6-phosphate dehydrogenase in corynebacterium glutamicum and enhancing enzymatic activityof glucokinase and glucose 6-phophate isomerase by regulating glucose intracellular metabolism; constructing a synthetic route of allulose composed of 6-aloxone phosphate 3-epimerase and 6-aloxone phosphate phosphorylase; constructing a metabolic pathway of fructose composed of fructose transmittase and fructokinase; constructing a metabolic pathway of glycerinum composed of glycerol transmittase, glycerol dehydrogenase and dihydroxyacetone kinase, thereby acquiring a corynebacterium glutamicum recombinant strain. The strain is capable of metabolizing glycerinum, glucose, fructose or saccharose for synthesizing allulose. Compared with the present reported method for compounding allulose through bioconversion of fructose, the construction method provided by the invention has the advantagesof high conversion rate, low production cost, and the like, and is suitable for large-scale production of allulose.

The invention belongs to the technical field of genetic engineering and in particular relates to novel D-allulose 3-epimerase, DNA (Deoxyribonucleic Acid) for encoding the novel D-allulose 3-epimerase, an expression vector and a transformant containing the DNA and application of the enzyme to production of D-allulose. The D-allulose 3-epimerase is derived from thermoacidophile mesoaciditoga lauensis of a deep-sea spring and has relatively high conversion rate and thermal stability when being used for converting D-fructose into the D-allulose.

The present invention provides a novel psicose epimerase derived from Flavonifractor plautii and capable of converting fructose to psicose. The novel psicose epimerase according to the present invention possesses an activity producing psicose by epimerizing the carbon-3 position of fructose, and has maximal activity for the conversion of fructose to psicose at a relatively high temperature and a pH less than or equal to neutral, has excellent thermal stability, and can mass-produce psicose from fructose in a high yield for a short amount of time. Therefore, the psicose epimerase according to the present invention is advantageous in the industrial production of psicose, and it is expected that the psicose produced thereby can be usefully utilized in the functional sugar industry and also as materials for health food, medicine, cosmetics, and the like using the psicose.