Abstract: Disclosed is a hybridoma cell strain that secretes anti-dinitolmide monoclonal antibodies applicable to the field of food safety immunoassay methods. The hybridoma cell strain DAS3H10 that secretes anti-dinitolmide monoclonal antibodies has been deposited in Comprehensive Microbiology Center of China Microbial Culture Collection Management Committee (CGMCC), addressed in No. 1 Hospital No. 3 Institute of Microbiology of the Chinese Academy of Sciences, North Chenxi Road, Beijing Chaoyang District in Beijing. It is classified as a monoclonal cell strain. The deposit date is Nov. 28, 2019, and the deposit number is MCCC No. 19165. The monoclonal antibody secreted by the hybridoma cell strain DAS3H10 has a good affinity and high sensitivity to dinitolmide. Because of IC50 to dinitolmide up to 9.01 ng/mL, the monoclonal antibody could be used to prepare dinitolmide immunoassay kits and colloidal gold test strips, and can further provide a powerful means for detecting dinitolmide in animal-derived foods.

Abstract: A method for preparing a sustained-release antibacterial film includes: (1) mixing a cyclodextrin metal-organic framework (CD-MOF) material with a silver nitrate short-chain alcohol solution to prepare an intermediate material A; (2) mixing the intermediate material A with a caffeic acid short-chain alcohol solution to prepare an intermediate material B; (3) dispersing the intermediate material B in a solvent, adding a polydimethylsiloxane main agent and a PDMS auxiliary agent in sequence, and mixing well by stirring to obtain a casting solution; and (4) coating the casting solution on a film support material, conducting vacuum drying, and peeling off a film from the film support material to obtain the sustained-release antibacterial film. A mixed matrix-based film material in which the CD-MOF and the PDMS are physically blended is prepared based on CD-MOF and PDMS for the first time, and may be used in application researches of food, environment and other fields.

Abstract: The present invention discloses a RamA transcription factor mutant for promoting the production of N-acetylglucosamine and use thereof. The mutant is obtained by mutating lysine at position 90 to asparagine and serine at position 92 to lysine in a parent having an amino acid sequence as shown in SEQ ID NO: 2. The present invention provides a genetically engineered strain that overexpresses the RamA transcription factor mutant and increases the production of N-acetylglucosamine. By overexpressing the transcription factor RamA that is involved in the regulation of carbon metabolism, the extracellular accumulation of N-acetylglucosamine is increased, with a maximum concentration reaching 31.5 g/L, which lays a foundation for further metabolic engineering of Corynebacterium glutamicum to produce glucosamine. The method for constructing recombinant Corynebacterium glutamicum of the invention is simple, and convenient in use, and thus has good application prospects.

Abstract: The invention provides a method for constructing a target prediction model in a multicenter small sample scenario and a prediction method. In combination with the idea of transfer learning, a training set of a new node is predicted by directly using knowledge of a trained node, and a prediction error sample is used to reflect a difference between the new node and the trained node. The difference is used as supplementary knowledge. Model knowledge of the new node is quickly acquired, to avoid training of a new node from scratch each time. Finally, parallel integration of incremental subclassifiers is implemented by using a ridge regression method, so that the deployment time and costs are greatly reduced. The generalization of models is ensured through sharing of historical knowledge and a knowledge discarding mechanism, good classification effect can also be achieved for a node with a small sample size.

Abstract: A hybridoma cell line of secreting cyproheptadine monoclonal antibodies with a preservation number of CGMCC No. 14699 belongs to the field of food safety immunological detection. BALB/c mice are immunized through one time immunization with complete freund's adjuvant, three times of booster immunization with incomplete freund's adjuvant and one time of rush immunization with cyproheptadine complete antigen without adjuvant; the spleen cells from BALB/C mice immunized with high potency and low value of IC50 are fused with murine myeloma cells; and then the hybridoma cell line is obtained through indirect competitive ELISA screening and three sub-clones. The monoclonal antibody secreted by this cell line has good specificity and detection sensitivity to cyproheptadine (value of IC50 is 0.37 ng/ml), being suitable for detection of cyproheptadine in food.

Abstract: The present invention provides a method for promoting N-acetylglucosamine synthesis by using the GlcN6P responsive element. In the present invention, Bacillus subtilis BSGNY-Pveg-glmS-P43-GNA1 is used as a starting strain, in which a CRISPRi system regulated by GlcN6P responsive element is integrated into the genome to dynamically weaken the N-acetylglucosamine synthesis competitive pathway; a GlcN6P responsive promoter is used to regulate the expression of GNA1 on the plasmid to dynamically regulate the N-acetylglucosamine synthesis pathway; and the key gene alsSD involved in the acetoin synthesis pathway is knocked out. During fed-batch fermentation with this strain in a 15 L fermenter, the production of N-acetylglucosamine reaches 131.6 g/L and no by-product acetoin is accumulated, which lays a foundation for the production of GlcNAc by industrial fermentation.

Abstract: The disclosure discloses a method for producing maltodextrin with a single polymerization degree by multienzyme coupling, and belongs to the technical field of biology. The disclosure provides a method for producing non-reducing maltodextrin with a uniform and low polymerization degree. After a reaction is preformed for 2-6 hours by using the method of the disclosure, the content of 4-O-?-maltohexaosyl ?-D-glucoside in a reaction solution can be as high as 57.2% to 77.3%, accounting for 50% to 90% of the total amount of maltodextrin in the reaction solution. In maltodextrin prepared by using the method of the disclosure, non-reducing maltodextrin with low polymerization degree only includes 4-O-?-maltohexaosyl ?-D-glucoside, and the content of non-reducing maltodextrin with low polymerization degree can be 50% to 90% of the total amount of maltodextrin.

Abstract: The invention relates to an ink based on near-infrared light polymerization. The method and technology of direct writing three-dimensional printing belong to the field of material processing technology area. The method is: direct writing nozzles move in three-dimensional space or stationery, the ink is squeezed out of the direct writing nozzle, receiving the near-infrared light irradiation, after curing, complete the three-dimensional object forming and curing. The solidifying time t does not exceed the ratio of near-infrared light diameter dl and the ink extrusion speed vi, that is, t?dl/vi. Since near-infrared light has a better medium mass penetration, can penetrate the structure during molding to promote both internal and external to a higher degree of curing, so as to achieve cross-scale structure 3D printing, and the method provided by the present invention accurately controls solidifying process of the ink and therefore achieve the DIW array 3D structure real-time curing.

Abstract: The present invention provides a nucleic acid aptamer specifically recognizing ?-lactoglobulin and use thereof. The nucleic acid aptamer has a sequence as shown in SEQ ID NO:1, a sequence having 60% or higher homology to the sequence as shown in SEQ ID NO:1 and specifically recognizing ?-lactoglobulin, or a sequence derived from the sequence as shown in SEQ ID NO:1 and specifically recognizing ?-lactoglobulin. The nucleic acid aptamer specifically binds to the allergen ?-lactoglobulin in cow milk and dairy products, thereby providing a new tool for the high-sensitivity and low-cost detection of the allergen ?-lactoglobulin.

Abstract: The present application belongs to the technical field of research and development of fermented beverages, and a method for preparing Cordyceps militaris ferment by two-stage fermentation and complex enzymatic hydrolysis is provided. The present application involves preparation of a Cordyceps militaris powder and a Cordyceps militaris slurry, preparation of a Cordyceps militaris fermentation substrate, lactic acid bacteria fermentation in combination with complex enzymatic hydrolysis, and yeast fermentation, followed by centrifugation, filtration, formulation, sterilization, and filling to obtain a product. By employing lactic acid bacteria fermentation in combination with complex enzymatic hydrolysis, and secondary fermentation by yeast, the present application can quickly finish a whole fermentation process in 2 to 3 days.

Abstract: The present invention discloses a cyclohexenecarboxylate ester hydrolase, and a mutant, a coding gene, an expression vector, recombinant bacterium and use thereof. The cyclohexenecarboxylate ester hydrolase AcEst1 and its mutant of the present invention have the function of enantioselectively resolving methyl 3-cyclohexene-1-carboxylate with high efficiency to prepare optically active (S)-3-cyclohexene-1-carboxylic acid. When the substrate concentration is as high as 2000 mM (about 280 g/L), the optical purity of the product is higher than 99%, and the substrate/catalyst is as high as 3500 g/g. As compared with other preparation methods, the product prepared by the method of the present invention has high concentration and high optical purity, the catalytic efficiency is high, the reaction conditions are mild. Furthermore, the method is environmentally friendly, simple in operation and easy for industrial scale-up, thus has a good prospect of application in industry.

Abstract: The present invention discloses a visual bionic digestive system for a human gastrointestinal tract model, and belongs to the field of bionic digestive systems.

Abstract: Disclosed is an ultrasonic composite acidic water extraction method for a Cordyceps polysaccharide and cordycepin in Cordyceps militaris, which falls within the technical field of food processing. The method comprises: picking, washing, drying, pulverizing and degreasing Cordyceps militaris fruiting bodies to obtain a Cordyceps militaris dry powder; then immersing same in a prepared diluted hydrochloric acid solution to perform three cycles of ultra-low temperature freezing and microwave defrosting, and at the same time using low-frequency ultrasonic waves to carry out assisted stirring and extraction; then subjecting an extract to evaporation and concentration treatments; and finally, performing freeze-drying on the extract to collect a dry powder of a water extraction product.

Abstract: The disclosure discloses a mutant of nitrile hydratase derived from Caldalkalibacillus thermarum, and belongs to the technical field of enzyme engineering. The nitrile hydratase mutant Cal. t Nhase-A20V provided by the disclosure has a half-life of about 10 min at 70° C., which does not change much compared with the thermal stability of the wild enzyme. The specific enzyme activity of the mutant Cal. t Nhase-A20V is 128% of that of the wild enzyme. At the same time, the mutant also has better tolerance to a substrate and a product, and the final yield of nicotinamide produced by whole-cell catalysis reaches 598 g/L. Therefore, the nitrile hydratase mutant Cal. t Nhase-A20V provided by the disclosure has good enzymatic properties and is beneficial to future industrial production.

Abstract: The present disclosure discloses a Bacillus subtilis efficiently-induced expression system based on an artificial series promoter, and belongs to the technical field of gene engineering. According to the present disclosure, an efficient artificial series constitutive promoter is used, and by compositely designing the promoter and elements (a repressor and a binding site thereof) relevant to an operon, the activity of the constitutive promoter is regulated and controlled by an inducer to finally construct the B. subtilis efficiently-induced expression system induced by the inducer. The result indicates that compared with a P43 strongly constitutive promoter, the activity of the artificial series promoter in the system is about 15 times higher. The activity of the promoter can be accurately controlled by adding different concentrations of inducers.

Abstract: The present disclosure relates to a method to improve the encapsulation efficiency and physicochemical stability of ginsenosides Rg3 and CK nano-emulsion, belonging to the field of functional emulsions. The method to improve the encapsulation efficiency and physicochemical stability of ginsenosides Rg3 and CK nano-emulsion, includes the following steps: (1) WPI, Tween 80 and water were mixed evenly according to the amount ratio of 0.5 g:0.5-0.7 g:50 mL to obtain the aqueous phase; (2) Mixing a saponin extract containing the minor ginsenosides Rg3 and CK with edible oil evenly to obtain the oil phase; (3) Mixing the aqueous phase with the oil phase, carrying out shearing dispersion to obtain coarse emulsion, and then allowing the coarse emulsion to be subjected to microfluidization homogenization to obtain an oil-in-water nano-emulsion containing the minor ginsenosides Rg3 and CK.

Abstract: The disclosure discloses a Saccharopolyspora composition and its application in foods, and belongs to the technical field of food fermentation. The disclosure screens Saccharopolyspora hirsuta J2 and Saccharopolyspora jiangxiensis J3 that have an effect of reducing biogenic amine content from wheat koji, and the two strains are prepared into a Saccharopolyspora mixed preparation for use in a preparation process of a fermented alcoholic beverage, fermented food or fermented condiment, so that amino acid content and nutritional value of a fermented product can be improved while the biogenic amine content is reduced, thereby achieving effects of enhancing quality of the fermented food and improving safety of the fermented food, and therefore, the Saccharopolyspora composition has a broad application prospect.

Abstract: The present invention provides a chain plate flexible finger including a chain plate framework, a pneumatic elastic bellows artificial muscle, and a plastic annular frame. The axial expansion of the elastic bellows artificial muscle is restricted by the chain plate framework to overcome the elastic force of a tension spring to bend, to generate conformal contact between one or more chain plates and an object to be gripped and generate a contact force for a gripping state. With the control of a high-speed on-off valve, the air pressure in an inner cavity of the elastic bellows artificial muscle is accurately controlled to vertically or horizontally grip a cylindrical object, a cuboid object, a spherical object or an ellipsoid object. The flexible finger has adequate flexible adaptability and a simple structure, and is reliable to use, and adapts to differently shaped objects to be gripped and vertically and transversely placed objects.

Abstract: The present invention belonging to the technical field of biopharmaceutical discloses bifunctional molecules which are used to recruit antibodies and target tumor cells. The bifunctional molecules in the present invention comprise at least one recruitment moiety capable of binding to the existing antibodies in the body and a targeting moiety capable of selectively binding to the tumor cell. The compounds according to the invention selectively bind to the surface of the cancer cells, and recruit the existing antibodies through the recruitment moiety, and mediate the humoral and cellular immune responses to the cancer cell in the patient. According to this physiological function of the compounds according to the invention, cancer cells can be immunoregulated, which provides a new strategy for tumor immunotherapy.

Abstract: The invention discloses a recombinant Corynebacterium glutamicum for efficient synthesis of highly pure hyaluronic acid and oligosaccharides thereof, belonging to the technical field of bioengineering. The recombinant Corynebacterium glutamicum constructed in the present invention can produce hyaluronic acid with a yield up to 40 g/L, and a crude product purity of 95%. Addition of exogenous hyaluronic acid hydrolase and optimization of the fermentation conditions results in hyaluronic acid oligosaccharides with specific molecular weight, and can further improve the yield of hyaluronic acid to 72 g/L. The invention lays a solid foundation for the efficient synthesis of highly pure hyaluronic acid by microorganisms, and the constructed recombinant Corynebacterium glutamicum is suitable for industrial production and application.