39 results about "Oxalate decarboxylase" patented technology

The invention provides a method for cross-linking and fixing oxalate decarboxylase by cross-linked oxalate decarboxylase aggregates (CLEAs), belonging to the technical field of biochemical engineering. The method comprises the following steps: induced expression of recombinant oxalate decarboxylase, separation and purification of oxalate decarboxylase, and preparation of CLEAs. The invention is characterized in that ethanol, acetone or ammonium sulfate are utilized to carry out precipitation separation on oxalate decarboxylase in a crude enzyme liquid; ethanol is utilized to prepare the oxalate decarboxylase aggregates; 0.01-0.15% glutaric dialdehyde is utilized to carry out cross-linking reaction for 0.5-3.5 hours under the conditions of adding 0.1-1.5mg / L BSA (bovine serum albumin), pH value 3-9 and 4 DEG C, thereby preparing the CLEAs; and the enzyme activity recycling rate of the cross-linked immobilized enzyme is up to more than 90%. The invention has the advantages of simple experimental operations and low cost; the obtained CLEAs have obviously higher stability than free oxalate decarboxylase; and thus, the invention can be used for developing enzyme preparations for oxalate calculus disease.

The invention discloses a preparation method of dry powder and fungus powder containing Tricholoma lobayense Heim oxalate decarboxylase and relates to the field of degradation of oxalate in stomachs and intestines of human bodies or animal bodies. The preparation method comprises the following steps of: using Tricholoma lobayense Heim or sibling fungi thereof as raw materials, culturing thalli by adopting a liquid fermentation method, regulating pH (potential of hydrogen) of fermentation solution to 2.0-5.0, inducing to produce oxalate decarboxylase, collection the fermentation solution and the thalli, crushing the thalli, conducting solid-liquid separation to respectively obtain liquid and solid containing the Tricholoma lobayense Heim oxalate decarboxylase, and respectively drying the obtained liquid and solid after separation to obtain the dry powder and the fungus powder containing the Tricholoma lobayense Heim oxalate decarboxylase. The dry powder and the fungus powder containing the Tricholoma lobayense Heim oxalate decarboxylase can be used for oxalic acid removal of food, beverage, feed and the like, can also be used as raw materials to prepare healthcare products or medicines, is suitable for oral taking, can effectively degrade oxalic acid and oxalate and can prevent or cure urine oxalic acid excess symptoms and calcium oxalate calculi.

The invention relates to a method for culturing coriolus versicolor and inducing oxalate decarboxylase by a rice straw carbon source. The method comprises the following steps of: (1) dipping pulverized rice straws by using an acid solution and hydrolyzing under the condition of 100-150 DEG C; (2) preparing a fermentation culture medium and regulating the pH value to be 4.0-5.0; (3) inoculating mycelia into the liquid seed culture medium, transferring both the mycelia and the culture medium into a container containing sterile glass beads when a white mycelium group is formed but does not emerge from the water level, shaking, smashing and inoculating the mycelia into the fermentation culture medium according to an inoculating quantity of 3-15 percent; (4) culturing for 4-6 days, adding oxalic acid and then culturing 0.5-6 days to obtain the mycelia; and freezing the mycelia by liquid nitrogen, then grinding, smashing, extracting mycelium fragments by an acetic acid buffer solution and centrifuging. The method is simple and easy to operate, and has low cost, strong controllability of carbon source preparation of and stable sugar content.

The invention relates to a method for modifying oxalate decarboxylase, particularly a method for modifying oxalate decarboxylase with monomethoxypolyethylene glycol, belonging to the technical field of biochemical engineering. The method comprises the following steps: preparation of recombinant oxalate decarboxylase, activation of monomethoxypolyethylene glycol (mPEG), modification of oxalate decarboxylase and the like. The modified oxalate decarboxylase has higher heat stability, pH adaptability, heat resistance and trypsinase tolerance. The method solves the realistic problem that the oxalate decarboxylase in use can be influenced by digestion of gastric acid and proteinase and can be easily digested to lose activity at present. The method can be used for preparing an enzyme preparation for preventing and treating calculus caused by oxalate crystallization.

The invention discloses a recombinant oxalate decarboxylase expressed by a filamentous fungal host cell, a construction method of the recombinant bacterial strain, a production method and application of the recombinant enzyme, and belongs to the technical field of genetic engineering. The recombinant filamentous fungal host cell comprises one or more copies of an oxalate decarboxylase expression cassette integrated in its genome, the oxalate decarboxylase expression cassette including a promoter, a signal peptide coding sequence, an oxalate decarboxylase coding gene and a terminator. The above-mentioned host cells can be constructed by random integration or site-specific integration. In addition, the present invention also optimizes the medium formulations for different recombinant filamentous fungal host cells. The production of oxalate decarboxylase, through the construction of expression cassettes, vector construction, host cell construction and the adjustment of the final culture positive formula, the final yield and enzyme activity are greatly improved, effectively solving the problem of oxalate decarboxylase in the prior art. Artificial production cannot be industrialized on a large scale.

The invention discloses a method for modifying oxalate decarboxylase by means of ethylenediaminetetraacetic dianhydride. The method comprises the steps of dissolving ethylenediaminetetraacetic dianhydride and oxalate decarboxylase in phosphate buffer, and conducting stirring reaction for 1-24 h; dialyzing the reaction product after reaction ends, and then conducting concentration to obtain ethylenediaminetetraacetic dianhydride modified oxalate decarboxylase. Chemical modification of oxalate decarboxylase is directly conducted with ethylenediaminetetraacetic dianhydride, conditions are mild, operation is easy, and cost is low; the heat stability, heat resistance, pH adaptability and trypsin tolerance of modified oxalate decarboxylase are improved; the adsorption capacity of oxalate decarboxylase on calcium oxalate crystals is improved especially; the problem that oxalate decarboxylase can be affected by gastric acid and pepsin in use to lose activity easily is solved; the practical problem that zymoprotein in enzymic preparations is diluted easily to disappear in practical use is also solved.