336 results about "Psicose" patented technology

Providing a D-psicose-containing sweetener with the modification of the taste of D-psicose, comprising D-psicose, a sugar alcohol and / or a high intensity sweetener, preferably containing D-psicose as the main component, particularly a low-calorie sweetener and / or a sweetener giving refreshing feel in the oral cavity, as well as foods and drinks obtained by using the D-psicose-containing sweetener with the modification of the taste of D-psicose, and other products given with sweetness. The sugar alcohol is one or more sugar alcohols selected from the group consisting of sorbitol, mannitol, lactitol, maltitol, xylitol and erythritol, while the high intensity sweetener is one or more high intensity sweeteners as selected from aspartame, acesulfame K, sodium cyclamate, sodium saccharin, Sucralose (under trade name), stevia sweetener, dulcin, taumatin, neotame and monellin.

Problem: To develop a method for producing a novel sweetener containing glucose, fructose, and psicose, which is produced from glucose liquid sugar using an isomerase and an epimerase; use of the novel sweetener as a food or drink material; and a novel sweetener capable of preventing obesity caused by the intake thereof.Means of Resolution: An isomerase and an epimerase are allowed to act on glucose liquid sugar produced in a glucose liquid sugar production plant to thereby produce D-psicose, thereby providing a novel sweetener (product) that maintains the degree and quality of sweetness of a glucose-fructose mixed solution and never causes obesity, a method for producing the same, and use of the same.

The invention belongs to the technical field of bioengineering, and particularly relates to a genetic engineering strain capable of effectively secreting D-psicose 3-epimerase and a construction method thereof. A D-psicose 3-epimerase gene rdpe from rumen bacterium Ruminococcus sp. 5_1_39B_FAA is obtained firstly, recombinant plasmid pMA5-RDPE construction and bacillus subtilis conversion are conducted, and then constitutive and secretive expression of RDPE in bacillus subtilis is achieved. By comparing three glucose-induced promoters, the optimal inducible promoter P[xylA] is obtained, and the RDPE secretion level is increased remarkably. By knocking out the xylose utilization gene xylAB (xylA and xylB), the xylose metabolism pathway of bacillus subtilis is blocked, the secretion amount of RDPE is further increased, and the optimal induced concentration of the inducer xylose is reduced to 0.5% from 4.0%. Finally, the engineered strain 1A751SD-XR is evaluated in a 7.5 L fermentation tank, and the RDPE secretion level can be as high as 95 U / mL and 2.6 g / L.

The invention provides a preparation method and application of allulose. The preparation method comprises the following step: by adopting glucose as a raw material and adopting molybdate as a catalyst, performing catalytic conversion, separation and purification to obtain allulose with corresponding configuration. The method provided by the invention mainly comprises the following step: by adopting a chemical method, preparing a crystal allulose product by virtue of working procedures such as chemical differential phase isomerism, refined chromatography separation and purification, concentration and crystallization and the like by adopting glucose as the raw material. The preparation method provided by the invention is simple in process, short in time consumption, high in reaction speed and high in efficiency, and the problems that a conventional enzymatic method for preparing D-allulose products is poor in enzyme stability and low in efficiency and the like can be solved.

The present invention relates to a method of successively producing D-psicose from D-fructose or D-glucose by using a psicose-epimerase derived from Agrobacterium tumefaciens which is expressed in a food safety form.

A method of utilizing the physiological activity of a rare saccharide, wherein physiological-activity sensitive cells are treated with the rare saccharide to modify the function of the cells. A composition containing, as an active ingredient, a rare saccharide which is introduced into physiological-activity sensitive cells and has an effect of modifying the function of the cells. The cells are human cells. The composition is a functional food, a drug, or a cosmetic. The rare saccharide is a rare saccharide belonging to aldose and / or ketose. The aldose is D-allose, and the cells are selected from the group consisting of cancer-cell proliferation inhibitory activity sensitive cells and active-oxygen production inhibitory activity sensitive cells. The ketose is D-psicose, and the cells are selected from the group consisting of chemokine secretion inhibitory activity sensitive cells, microglia migration inhibitory activity sensitive cells, and hypoglycemic activity sensitive cells.

Object: To provide a composition for preventing periodontal diseases (prophylactic agent of periodontal diseases), the composition having an excellent cariostatic property, being safe and stable for prolonged use and having less effects on flavor.Means for Resolution: A non-cariogenic material prepared by blending a rare sugar in the D form as selected from the group consisting of D-psicose, D-sorbose and D-tagatose, a rare sugar in the L form as selected from L-fructose, L-psicose and L-tagatose, or allitol as a rare sugar derivative, singly or in combination. A cariostatic agent comprising D-psicose, D-sorbose, D-tagatose, L-fructose, L-psicose and / or L-tagatose. A cariostatic agent in combination with catechins.

The present invention relates to a D-psicose 3-epimerase mutant of which the thermal stability is improved by substituting an amino acid of a specific sequence number. In addition, the present invention relates to a recombinant vector comprising the gene of the D-psicose 3-epimerase mutant, and a recombinant strain transformed with the recombinant vector. Further, the present invention relates to an immobilized reactor prepared using the enzyme mutant or the recombinant vector, and a method for producing D-psicose using the immobilized reactor.

[OBJECT] To provide an agricultural chemical and the like with the use of an effect of inducing systemic acquired resistance in a plant. To provide a growth inhibitor of not only a plant pathogenic bacterium but also a harmful microorganism.[MEANS FOR RESOLUTION] Utilization of a rare sugar for inducing systemic acquired resistance in a plant or inhibiting the growth of a microorganism. Utilization thereof as an agricultural chemical with the use of the effect of inducing systemic acquired resistance in a plant, a plant disease inhibitor, an inducer of a plant growth regulatory factor (i.e., an inducer of plant hormone-like actions consisting of disease resistance, insect resistance, fruit maturation, breaking of dormancy, regulation of germination, drying resistance, and other than this, resistance to environmental stresses such as low temperature resistance, high temperature resistance, salt resistance and heavy metal resistance and promotion of flowering) and a microorganism growth inhibitor. The rare sugar is an aldose (D-allose, D-altrose or L-galactose) or a ketose (D-psicose or a mixture of D-psicose and D-fructose).

The invention relates to a preparation method for high-purity D-psicose. The preparation method comprises the following steps: (1) subjecting the fermentation broth of Bacillus subtilis to centrifugation and then subjecting obtained thalli to homogenization so as to obtain a mixed solution containing D-psicose 3-epimerase; (2) preparing a fructose solution, adding the mixed solution containing D-psicose 3-epimerase, adjusting a pH value, carrying out a reaction under a heat insulation condition, then adding the fructose solution into the reaction solution in a fed-batch manner, continuing the reaction, and then stopping the reaction so as to prepare a crude D-psicose solution; and (3) subjecting the crude D-psicose solution to decoloring, filtering, ion exchange, chromatographic separation and concentration, and then to crystallization or drying so as to prepare D-psicose. The preparation method provided by the invention uses Bacillus subtilis fermentation broth for direct production and omits the process of enzyme extraction, so production cost is greatly reduced, a reduction of 25% or so compared with traditional production methods, so the competitiveness of prepared D-psicose is greatly improved.

The present invention relates to a method of successively producing D-psicose from D-fructose or D-glucose by using a psicose-epimerase derived from Agrobacterium tumefaciens which is expressed in a food safety form.

The invention discloses a high-catalytic-activity mutant enzyme for D-allulose 3-epimerase and application thereof, belonging to the technical field of gene engineering of enzymes. The single mutant enzyme Y68I is obtained by taking D-sicose 3-epimerase (DPE enzyme for short) derived from clostridiumbolteae ATCC BAA-613 as a parent and replacing 68-bit tyrosine Tyr by isoleucine Ile with a gene mutation technology, is high in catalytic activity, and has an important industrial application value.

A novel use of D-psicose (for suppressing the abnormal intra-day increase of blood glucose level) is provided. A composition containing D-psicose as the active component and for use in suppressing the abnormal intra-day increase of plasma glucose concentration. The composition is a composition in blend with D-psicose and / or a derivative thereof. The composition is in a form selected from sweeteners, seasonings, food additives, food materials, food and drink products, health food and drink products, pharmaceutical products, and feeds and blended with D-psicose, and / or a derivative thereof as the active component, for use in preventing and therapeutically treating diseases requiring the saving of insufficient insulin, the amelioration of insulin sensitivity and the amelioration of hyperglycemia, and / or diseases of which the symptoms can be ameliorated via the suppression of the abnormal intra-day increase of plasma glucose concentration or of which the onset can be prevented via the suppression thereof, such as diabetes mellitus, occult diabetic states, obesity, hyperglycemia, and / or arteriosclerosis. A method for using D-psicose in suppressing the abnormal intra-day increase of plasma glucose concentration, comprising giving D-psicose at given times to suppress the abnormal increase of plasma glucose concentration throughout the day.

A D-allulose syrup including, besides D-allulose, a D-allulose dimer mass content, expressed in terms of dry mass, greater than 1.5%. Also, a method for producing the syrup and the use thereof for producing food or pharmaceutical products.

The invention discloses a method for efficiently preparing D-psicose 3-epimerase and a use of the D-psicose 3-epimerase and provides a method for efficiently preparing an enzyme catalyst for catalyzing the same reaction through isozyme combined expression. The method utilizes corynebacterium glutamicum as a host cell to construct a recombinant strain expressed by plasmid dissociation and chromosomal integration, measures D-fructose catalytic efficiency, improves enzyme catalytic efficiency by 2-4 times than that of single expression of D-psicose 3-epimerase through combined expression and hasa conversion ratio of 29% when 70% of fructose is a substrate. The method improves D-psicose production efficiency and is suitable for industrial production of D-psicose. The invention also disclosesa novel use of the D-psicose 3-epimerase in psicose synthesis. The enzyme is derived from Paenibacillus senegalensis, has catalytic activity of about 25 U / mg and can be used to convert D-fructose intoD-psicose.

The invention provides a 68th and 109th double mutant enzyme of D-psicose 3-epimerase and an application thereof, and belongs to the technical field of enzyme genetic engineering. The invention discloses the mutant enzyme Y68I / G109P which is obtained by using the D-psicose 3-epimerase (called DPE enzyme for short) derived from clostridium bolteae ATCCBAA-613 as a parent and utilizing a gene mutation technology for respectively replacing 68th tyrosine Tyr and 109th glycine Gly with isoleucine Ile and praline Pro. The heat stability and catalytic activity of the mutant enzyme Y68I / G109P are improved, therefore, the mutant enzyme Y68I / G109P has important industrial application value.

The invention discloses application of L-rhamnulose-1-phosphate aldolase in catalytic synthesis of rare sugars. In order to avoid the direct use of DHAP (dihydroxyacetone phosphate) and greatly decrease the synthesis cost of rare sugars, a 'single kettle with four enzymes' strategy is adopted, the L-rhamnulose-1-phosphate aldolase derived from Thermotoga maritima MSB8 is used for synthesizing a series of rare sugars such as D-allulose, D- sorbose, L-fructose and L-tagatose. Experiments show that the aldolase has good thermal stability and can be used for highly selectively synthesizing D-allulose having important application value while D-glyceraldehyde is used as a receptor.

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 present invention relates to a D-psicose 3-epimerase variant with improved thermostability by substituting an amino acid at a specific position of an amino acid sequence of a wild type D-psicose 3-epimerase. Further, the present invention provides a recombinant expression vector including a gene of the D-psicose 3-epimerase variant, and a recombinant strain transformed with the recombinant expression vector. Furthermore, the present invention provides an immobilized reactor prepared using the D-psicose 3-epimerase variant or the recombinant strain, and a method of continuously producing D-psicose using the immobilized reactor.

To develop a method for producing a novel sweetener containing glucose, fructose, and psicose, which is produced from glucose liquid sugar using an isomerase and an epimerase; use of the novel sweetener as a food or drink material; and a novel sweetener capable of preventing obesity caused by the intake thereof. An isomerase and an epimerase are allowed to act on glucose liquid sugar produced in a glucose liquid sugar production plant to thereby produce D-psicose, thereby providing a novel sweetener (product) that maintains the degree and quality of sweetness of a glucose-fructose mixed solution and never causes obesity, a method for producing the same, and use of the same.

The present invention relates to a preparation method of psicose crystals. The preparation method comprises the following steps: carrying out chromatographic separation of psicose liquid after an enzymatic conversion is finished and purifying the psicose to a purity of 98.5% or more; concentrating the purified psicose to a solid content by mass of 75-85% and conducting rapid cooling to 35-45 DEG C; adding seed crystals, keeping temperature at 35-45 DEG C and a vacuum degree of -0.03 to -0.09 MPa, and performing constant-temperature evaporative crystallization; and performing centrifugal separation to obtain crystals with a particle size larger than 60 meshes, and conducting washing and drying to obtain the psicose crystals. The technical means of controllable evaporation, constant-temperature crystallization, etc. are used to solve a problem that fine crystals are generated under a condition of high supersaturation degree, greatly improve particle diameter of the crystals, enable one-time crystallization yield to reach 60-70%, greatly simplify preparation processes and also improve crystallization yield.

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 provides thermal stability improved mutant enzyme of D-psicose 3-epimerase and application thereof, and belongs to the technical field of enzyme genetic engineering. The mutant enzyme is characterized in that D-psicose 3-epimerase (DPE enzyme for short) sourced from clostridium ((i) Clostridium bolteae ( / i)) ATCC BAA-613 is used as a parent, and glycine Gly at the position 109 is replaced by proline Pro through the gene mutagenesis technique so as to obtain single mutant enzyme G109P; the stability of the mutant enzyme is improved; high industrial application value is brought.

The invention belongs to the technical field of co-expression of dienzyme, and in particular relates to co-expression of site-specific mutational glucose isomerase and D-allulose-3-epimerase. For overcoming the shortcomings of the prior art, the invention provides a method for performing site-specific mutagenesis to the 146th amino acid of the glucose isomerase and performing co-expression with the glucose isomerase and the D-allulose-3-epimerase. Specifically, the method comprises the following steps: respectively performing PCR (Polymerase Chain Reaction) amplification, purification and cloning to the nucleotide sequence of the glucose isomerase after site-specific mutagenesis and the nucleotide sequence of the D-allulose-3-epimerase; respectively digesting the cloned bienzyme nucleotide sequence with a pCDFDuet-1 carrier; purifying and connecting the digestion product to build a recombinant expression vector; inducing expression to obtain recombinant bacteria; collecting the recombinant bacteria and treating the recombinant bacteria by ultrasonication to obtain a crude enzyme liquid containing bienzyme.

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 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.

A D-psicose 3-epimerization enzyme of the present invention is an enzyme with excellent activity for producing psicose by epimerizing a third carbon location of fructose. By applying the enzyme based on the wide pH range useful for industries and stability at high temperatures, the psicose with high economic feasibility can be mass-produced. The enzyme can be applied for producing functional saccharide, and for health food materials, medicines, and cosmetics using the same.

The present invention relates to a sweetener composition for alleviating diabetes, containing psicose and a slowly digestible or digestion-resistant polysaccharide as active ingredients, wherein diabetes alleviating effects and the quality of sweetness are enhanced.