Abstract: This invention discloses a natural polyphenols-based, multi-stage porous hydrogel sustained release drug delivery system, which relates to the field of drug delivery. It consists of the hydrogel matrix and the supramolecular filler, which is a complex of natural bio-based polymers and metal ions. The natural bio-based polymer can be natural polyphenols, dopamine or its derivatives, polysaccharide biomass, or protein biomass. The hydrogel matrix can be chitosan, carboxymethyl chitosan, sodium alginate, carboxymethyl cellulose, hyaluronic acid, collagen, gelatin, or agarose. The metal ion can be one of the cations of Al, Fe, Zn, Mn, Ni, Co, or V. By this invention, the supramolecular filler based on natural bio-based polymer can form in situ in the hydrogel, to regulate the pores of the hydrogel and interact with different drugs, thus adjusting the drug release rate.

Abstract: An encapsulated probiotic, an encapsulating layer and a method of encapsulating probiotics are disclosed. The encapsulated probiotic includes an encapsulating layer and probiotics, and the encapsulating layer includes a nano-film having two layers for encapsulating probiotics. A first layer is formed through biological macromolecules and metal ions on surfaces of the probiotics by covalent cross-linking or metal chelating action in situ, and a second layer is formed by interactions between a bio-enzyme and the biological macromolecules. The nano-film formed in situ on cell walls of probiotics is used for encapsulation and protection of probiotics.

Abstract: The invention discloses a hydrophilic anti-fog nano paint for endoscope, which includes the following according to the number of weight parts: plant polyphenols of 1-10 parts, metal ions of 0.1-2 parts, biomass molecules of 0.1-0.5 parts, additives of 10-20 parts and solvents of 250 parts; the paint is coated on the surface of the substrate, and the desired coating can be obtained after drying; the plant polyphenol and metal ions in the invention combine to form the plant polyphenol-metal nano complex, form hydrophilic nano-film with biomass molecules on the surface of the laparoscope, and cooperatively enhance the surface interface hydrophilicity of the lens; the formula of the invention has good biocompatibility, will not cause clinical side effects when it comes into contact with tissues, and can meet the needs of clinical use.

Abstract: The disclosure discloses an L-aspartate ?-decarboxylase mutant and application thereof, and belongs to the technical field of enzyme engineering. In the disclosure, lysine at position 221 of L-aspartate ?-decarboxylase is mutated to arginine, glycine at position 369 is mutated to alanine, and the obtained new mutant enzymes have better temperature tolerance and are beneficial to industrial production. The K221R and G369A recombinant strains are subjected to high-density fermentation, and with sodium L-aspartate as a substrate, a whole cell catalytic reaction is carried out to prepare ?-alanine. Compared with a chemical production method, the method has the advantages that the production process is safe and clean, and has no environmental pollution. Compared with a pure enzyme catalysis method, the method has the advantages that the operation is simple and convenient. The yield of the final product ?-alanine reaches 91% and 90% respectively, and the concentration reaches 162.15 g/L and 160.42 g/L respectively.

Abstract: Described herein are functionalizing nanocomplexes comprising one or more polyphenol molecules; and one or more biomolecules. Further described herein are functionalized cells comprising one or more of the nanocomplexes. In some embodiments, the biomolecules can be therapeutic agents and the functionalized cells can be administered to patients to provide improved delivery (e.g., dosing and specificity) of the therapeutic agent.

Abstract: The disclosure discloses a nitrile hydratase mutant, a genetically engineered bacterium containing the mutant and applications thereof, and belongs to the technical field of enzyme engineering. In the disclosure, glycine at position 47 of a nitrile hydratase mutant ?L6T/A19V/F126Y-?M46K/E108R/S212Y (disclosed in the patent of disclosure CN102216455A) is mutated to asparagine. The obtained new mutant enzyme has better temperature tolerance and tolerance to a product, and is conducive to future industrial production. The recombinant strain containing the nitrile hydratase mutant is fermented at high density, and 3-cyanopyridine is used as a substrate to carry out a whole-cell catalytic reaction to prepare nicotinamide. Compared with a chemical production method, the method has a safe and clean production process and no environmental pollution. Compared with an enzymatic method, the substrate price is cheap and the catalytic efficiency is high.

Abstract: A biomass-based encapsulating material for protection of probiotic activity and an encapsulating method are disclosed. The biomass-based encapsulating material includes a nano-film having two layers for encapsulating probiotics. A first layer is formed through natural biological macromolecules and metal ions on surfaces of the probiotics by covalent cross-linking or metal chelating action in situ, and a second layer is formed by interactions between a bio-enzyme and the natural biological macromolecules. The nano-film formed in situ on cell walls of probiotics is used for encapsulation and protection of probiotics. The nano-film is made of natural biomass, has low cost and has no toxic side effects. The relative activity of encapsulated probiotics is close to or higher than 90%, whether they are cultivated in environments under high concentration of antibiotics or active-free radicals. The relative activity of unprotected probiotics is below 30%, or even completely unable to survive.

Abstract: Disclosed is a double enzyme tandem preparation method of L-2-aminobutyric acid, and belongs to the field of bioengineering. In the disclosure, recombinant Escherichia coli expressing L-glutamate mutase and recombinant Escherichia coli expressing L-aspartate-?-decarboxylase are separately cultured to obtain L-glutamate mutase and L-aspartate-?-decarboxylase. The two enzymes are added to a reaction system at a certain mass ratio, and L-glutamate is used as a substrate to carry out an enzyme reaction to prepare the L-2-aminobutyric acid. When the dosage of the L-aspartate-?-decarboxylase is 2 mg/mL, and the reaction time is 24 h, 8.5 mmol/L L-2-aminobutyric acid is produced by conversion, with a molar conversion rate of 85.00%. Compared with a chemical production method, the method disclosed by the disclosure has a safe production process and no environmental pollution. Compared with a multi-enzyme synthesis system with threonine as a substrate, the substrate is cheaper and the process is simpler.

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: Modular biohybrid systems, some of which suitable for photochemical biosynthesis, are described. These systems are characterized by functionalized photocatalytic nanoparticles that are independently prepared, then assembled and attached to the modified surface of a cell, thereby enabling the cell to absorb light energy and convert it into chemical energy, for example in the form of a redox cofactor. The generated chemical energy then serves as fuel for production pathways of metabolites useful for the manufacturing of fuels, nutraceuticals, pharmaceuticals and cosmetics.

Abstract: The disclosure discloses an L-aspartate ?-decarboxylase mutant and application thereof, and belongs to the technical field of enzyme engineering. In the disclosure, lysine at position 221 of L-aspartate ?-decarboxylase is mutated to arginine, glycine at position 369 is mutated to alanine, and the obtained new mutant enzymes have better temperature tolerance and are beneficial to industrial production. The K221R and G369A recombinant strains are subjected to high-density fermentation, and with sodium L-aspartate as a substrate, a whole cell catalytic reaction is carried out to prepare ?-alanine. Compared with a chemical production method, the method has the advantages that the production process is safe and clean, and has no environmental pollution. Compared with a pure enzyme catalysis method, the method has the advantages that the operation is simple and convenient. The yield of the final product ?-alanine reaches 91% and 90% respectively, and the concentration reaches 162.15 g/L and 160.42 g/L respectively.

Abstract: The disclosure discloses a nitrile hydratase mutant, a genetically engineered bacterium containing the mutant and applications thereof, and belongs to the technical field of enzyme engineering. In the disclosure, glycine at position 47 of a nitrile hydratase mutant ?L6T/A19V/F126Y-?M46K/E108R/S212Y (disclosed in the patent of disclosure CN102216455A) is mutated to asparagine. The obtained new mutant enzyme has better temperature tolerance and tolerance to a product, and is conducive to future industrial production. The recombinant strain containing the nitrile hydratase mutant is fermented at high density, and 3-cyanopyridine is used as a substrate to carry out a whole-cell catalytic reaction to prepare nicotinamide. Compared with a chemical production method, the method has a safe and clean production process and no environmental pollution. Compared with an enzymatic method, the substrate price is cheap and the catalytic efficiency is high.

Abstract: The present disclosure discloses a method for constructing an efficient Bacillus subtilis promoter, and belongs to the technical field of gene engineering. According to the present disclosure, natural promoters identified by different sigma subunits are connected in series to obtain some double-series and triple-series promoters, the lengths of intervening sequences between core areas of the promoters are optimized on the basis of series connection of the promoters to further improve the activity of the promoters, finally, different RBS designs are performed on the promoters, and it is verified that this strategy can not only improve the compatibility between the promoters and other gene expression regulating and controlling elements, but also controllably regulate the expression of exogenous genes.

Abstract: The invention relates to the technical field of bioengineering, and discloses a method for synthesizing L-aspartic acid with maleic acid by whole-cell biocatalysis. In the invention, a recombinant strain co-expressing maleate cis-trans isomerase and L-aspartate lyase is constructed, and engineered and optimized to produce L-aspartic acid from maleic acid with a high conversion rate by whole-cell catalyzing. Relatively inexpensive maleic acid is utilized by the recombinant strain to produce L-aspartic acid, where maleic acid is reacted completely in 40-120 min, there is almost no buildup of the intermediate fumaric acid, and the conversion rate is up to 98% or more.

Abstract: The invention relates to the technical field of bioengineering, and discloses a method for synthesizing L-aspartic acid with maleic acid by whole-cell biocatalysis. In the invention, a recombinant strain co-expressing maleate cis-trans isomerase and L-aspartate lyase is constructed, and engineered and optimized to produce L-aspartic acid from maleic acid with a high conversion rate by whole-cell catalyzing. Relatively inexpensive maleic acid is utilized by the recombinant strain to produce L-aspartic acid, where maleic acid is reacted completely in 40-120 min, there is almost no buildup of the intermediate fumaric acid, and the conversion rate is up to 98% or more.