Abstract: The present invention provides a polypeptide tag and its application in the synthesis of pharmaceutical chemicals, the recombinant nitrilase was obtained by connecting a polypeptide tag to the N-terminus of the amino acid sequence of the nitrilase; wherein amino acids at both ends of the polypeptide tag are uncharged glycine G, and the rest are a random combination of any one or more of glycine G, histidine H, glutamic acid E, aspartic acid D, lysine K and arginine R; The activity of the recombinant nitrilase in the preparation of 1-cyanocyclohexyl acetic acid is up to 3034.7 U/g dcw, the polypeptide tag significantly improves the soluble expression of nitrilase, and the whole cell catalyst hydrolyzes 1M substrate with the same concentration 30 minutes faster than the mother enzyme.

Abstract: A management and distribution device for insect breeding includes a main body, an upper cover, and a lower cover. The upper cover is clamped to a top portion of the main body, and the lower cover is clamped to a lower end of the main body. Three partition plates for insects to climb are clamped in an inner portion of the main body, and the three partition plates are wave-shaped. A notch is defined at a lower middle portion of each of the three partition plates, a plurality of through holes for insect faeces to pass through are defined on a bottom of the main body, an insertion opening is defined at a lower end of an outer wall of the main body, and a hinge door is rotatably disposed at the lower end of the outer wall of the main body.

Abstract: The present invention provides a nitrilase mutant and application thereof in the synthesis of 1-cyanocyclohexyl acetic acid, the nitrilase mutant is obtained by mutating one or two of the amino acids at position 180 and 205 of the amino acid sequence shown in SEQ ID No. 2. In the present invention, by semi-rational design and protein molecular modification, the specific enzyme activity of the nitrilase double mutant AcN-G180D/A205C was increased by up to 1.6 folds, and the conversion rate>99%. And the reaction time was shortened to a quarter of the original using the recombinant Escherichia coli containing the nitrilase mutant to hydrolyze 1-cyanocyclohexylacetonitrile at high temperature (50° C.). Therefore, the mutants obtained by the present invention have a good application prospect in efficiently catalyzing 1-cyanocyclohexylacetonitrile to synthesize gabapentin intermediate, 1-cyanocyclohexyl acetic acid.

Abstract: The present invention provides a nitrilase mutant protein with increased thermal stability and its application in the synthesis of an anti-epileptic drug intermediate, wherein the mutant is obtained by mutating one or two of the amino acids at position 151, 223 and 205 of the amino acid sequence shown in SEQ ID No. 2. the thermal stability of the nitrilase mutant AcN-T151V/C223A/C250G was increased by up to 1.73 folds. The yield of the final product was up to 95% using the recombinant Escherichia coli containing the nitrilase mutant to hydrolyze 1M 1-cyanocyclohexylacetonitrile to produce 1-cyanocyclohexyl acetic acid at 35° C. And the yield of the final product was up to 97% when hydrolyzing 1.2M 1-cyanocyclohexylacetonitrile at 35° C. The final yield was up to 80% when using the nitrilase mutants obtained by the present invention to synthesize gabapentin.

Abstract: The present invention provides a polypeptide tag and its application in the synthesis of pharmaceutical chemicals, the recombinant nitrilase was obtained by connecting a polypeptide tag to the N-terminus of the amino acid sequence of the nitrilase; wherein amino acids at both ends of the polypeptide tag are uncharged glycine G, and the rest are a random combination of any one or more of glycine G, histidine H, glutamic acid E, aspartic acid D, lysine K and arginine R; The activity of the recombinant nitrilase in the preparation of 1-cyanocyclohexyl acetic acid is up to 3034.7 U/g dcw, the polypeptide tag significantly improves the soluble expression of nitrilase, and the whole cell catalyst hydrolyzes 1M substrate with the same concentration 30 minutes faster than the mother enzyme.

Abstract: A device is provided for fractional condensation of an arsenic-lead vapor mixture and an application method thereof. The device includes a vacuumizing device, a flange, temperature measuring devices, a graded vacuum furnace body, a quartz tube, a push rod, a control cabinet, a heating zone and recycled foil. The length of the quartz tube is 1.2-2 m; the length of the heating zone is 0.15-0.25 m; and the quartz tube is provided with one temperature measuring device every 2-3 cm. The device forms a certain temperature gradient in the quartz tube, so that a material condenses in the corresponding temperature range, thereby achieving the purpose of high-efficiency separation.

Abstract: A non-aqueous liquid concentrate includes starch, an acrylic acid homopolymer salt, vegetable oil, and clay. The non-aqueous liquid concentrate forms an aqueous dispersion when added to water and is capable of clinging to a surface.

Abstract: A non-aqueous liquid concentrate includes starch, an acrylic acid homopolymer salt, vegetable oil, and clay. The non-aqueous liquid concentrate forms an aqueous dispersion when added to water and is capable of clinging to a surface.