41results about How to "Good acid and alkali tolerance" patented technology

The invention discloses a preparation method of gamma-polyglutamic acid water absorbing material. Gamma-polyglutamic acid is used as a main raw material, chitosan oligosaccharide-graft-acrylic acid is used as a biodegradable cross-linking agent, and the gamma-polyglutamic acid hydrogel water absorbing material is obtained after preparation in an aqueous solution. The biodegradable cross-linking agent replaces a common chemical cross-linking agent for preparing the hydrogel, the reaction medium is free of toxic organic solvents, gamma-polyglutamic acid which is safe and nontoxic is used as the main raw material, the water-soluble and degradable chitosan oligosaccharide-graft-acrylic acid is used as a cross-linking agent, and the gamma-polyglutamic acid water absorbing material is prepared in the aqueous solution. The raw materials and mediums do not have harmful substances for human body, the safe, nontoxic and biodegradable hydrogel is obtained, and the hydrogel can be applied to disposable hygiene products, drug carriers, medical articles, etc.

The invention relates to a method for detecting etimicin and related substances thereof. The method adopts high performance liquid chromatography; chromatographic conditions are that: polystyrene-divinylbenzene polymer chromatographic column is MKF-RP-ETI (the particle size is between 4 and 10mu m, the column specification is (100-300)*(8.0-4.6)mm (I.D.)); the volume ratio of compositions of a mobile phase is that the volume ratio of an acetate buffer solution (the pH value is between 4 and 7) with a concentration of between 0.10 and 0.50mol/l to acetonitrile is 90-100: 10-0; the flow rate is between 0.8 and 1.2ml/min; a detector is a refractive index detector; and the injection volume is between 10 and 20mu l. The method can finish the on-line detection on the etimicin and the related substances by using the prior HPLC instrument and refractive index detector; and the method is simple, quick and accurate.

The invention relates to a method for detecting acetylcysteine and related substances thereof. The method adopts a high performance liquid chromatography, wherein the chromatographic condition is that styrene-divinylbenzene copolymer type superpolymer chromatographic column, namely MKF-RP-MH is 4 to 10 mu meters and (100-300)*(8.0-4.0) millimeters (I.D.); the volume ratio of phosphate buffer (pH is between 2 and 5) with mobile phase compositions of 0.01-0.05 mol/L to acetonitrile is 80-95:20-5; the flowing speed is between 0.8 and 1.2 mL/min; the detecting wavelength detected by an ultraviolet detector is 210nm; and the sample size is between 10 and 20 mu liters. The method does not use ionpairreagent, overcomes the defects that ODS column detecting method does not have acid resistance or low organic phase resistance when detecting the acetylcysteine.

The invention discloses separation and application of a high-lysis-rate salmonella phage RDP-SA-17118. The host of the salmonella phage RDP-SA-17118 is salmonella S6, and the phage can form a plaque with a diameter of 2mm-4mm on double plates. Through observation by an electron microscope, the phage has a polyhedral stereosymmetric head which wraps nucleic acid and has a diameter of 70nm; the phage has a tail with a length of 120nm and has a tail sheath; a neck is connected with the head and the tail; and the phage belongs to myoviridae of caudovirales. The phage has a high titer of 10<12> pfu/mL and has good tolerance to temperature and pH value, and the titer still keeps 10<12>pfu/mL or above after continuous passage for 29 times. The phage has a good lysis effect on a host after being diluted by 10<6> times, and after the phage is fed, existence of the phage can be detected in heart, liver, lung, kidney, thymus and serum. Through animal experiments, the phage has a good effect in treating chicken salmonella diseases.

The invention discloses a method for preparing recombinant-aspergillus niger glucose oxidase and application of the recombinant-aspergillus niger glucose oxidase. Recombinant trichoderma reesei Tu6 delta tku70::Agod constructed by introducing an Agod gene into trichoderma reesei Tu6 delta tku70 can successfully express the recombinant-aspergillus niger glucose oxidase, the expression quantity is high, and the enzyme activity in fermentation broth can achieve 137 U/mL which is the highest level of the enzyme activity of shake flask fermentation in production of glucose oxidase strains at present. After the recombinant-aspergillus niger glucose oxidase in the fermentation broth is subjected to ni-sepharose purification, the detected enzyme activity can achieve 342 U/mL. The specific activity of the recombinant-aspergillus niger glucose oxidase is 155 U/mg protein. The recombinant-aspergillus niger glucose oxidase prepared by the method has good heat stability and good acid-alkali tolerance, the fermentation process is simple, transferring is not needed, raw materials are cheap and are easily obtained, and the cost is greatly reduced. The recombinant-aspergillus niger glucose oxidase can be widely applied to the fields of food and medicine.

The invention discloses a preparation method for a gamma-polyglutamate water absorption material. According to the method, gamma-polyglutamate adopted as a main raw material and caffeic acid-grafted chitosan oligosaccharide adopted as a biodegradable cross linking agent are used for preparing the gamma-polyglutamate hydrogel water absorption material in a water solution. The biodegradable cross linking agent is adopted to replace a common chemical crosslinking agent to prepare hydrogel, a reaction medium is not a toxic organic solvent any more, the safe and nontoxic gamma-polyglutamate is used as the main material, and the water-soluble degradable acrylic acid chitosan oligosaccharide is adopted as the cross linking agent to prepare the gamma-polyglutamate water absorption material. The real safe, nontoxic and biodegradable hydrogel is obtained as both the raw material and the medium are materials harmless to a human body, and the gamma-polyglutamate water absorption material is high in swelling ratio, excellent in mechanical property and improved in degradation property, and can be widely applied to disposable hygiene products, medicine carriers, medical supplies and the like.

The invention relates to a preparation method of L-arginine-based carbon dots and an application of the L-arginine-based carbon dots in lemon yellow detection, which comprises the following steps: dissolving L-arginine and o-phenylenediamine in water, methanol, ethanol, n-propanol, acetone or N, N-dimethylformamide according to a molar ratio of 1: 20-1: 1 at normal temperature; transferring into a polytetrafluoroethylene high-temperature reaction kettle, and reacting at 170-210 DEG C for 2-12 hours; after the product is naturally cooled, centrifuging at a high speed, dialyzing for 24-72 hours by using a 500-5000Da dialysis bag, drying to obtain crude carbon dots, separating and purifying by using column chromatography, carrying out gradient elution by using an eluent, collecting a blue fluorescence part, and recovering the solvent under reduced pressure to obtain relatively pure carbon dots; continuously carrying out secondary gradient elution on the relatively pure carbon dots by using an eluent by adopting the column chromatography, and carrying out thin-layer chromatography detection to obtain fluorescent and ultraviolet dual-mode detection carbon dots; the fluorescence quenching mechanism of the prepared L-Arg-CDs and lemon yellow belongs to an inner filter effect, the optimal linear detection concentration range is 0-55 [mu] M, the detection limit LOD is 42.3 nM and is far lower than the detection limit 187.14 [mu] M provided by the national standard GB/T5009.35-2003, and the L-Arg-CDs and lemon yellow can be used as a rapid detection method of lemon yellow.

The invention belongs to the technical field of microorganisms, and particularly relates to an environment-tolerant aeromonas hydrophila bacteriophage ZPAH34 and application, and the preservation number of the aeromonas hydrophila bacteriophage ZPAH34 is CCTCC (China Center For Type Culture Collection) NO: M 2022141. The aeromonas hydrophila bacteriophage provided by the invention is separated from the natural environment, has the characteristics of high specificity, strong splitting ability, better temperature and pH tolerance and the like, and can have stronger inhibition and removal effects on a biofilm formed by aeromonas hydrophila. As a bacterial control means, the bacteriophage can reduce the viable count of aeromonas hydrophila in lettuce and fish slices. Meanwhile, the phage provided by the invention can effectively prevent and treat infection caused by aeromonas hydrophila on zebra fish, and has a wide application prospect in aquaculture. The research provides a scientific basis for bacteriophage application research, and also provides a theoretical reference for biological prevention and control strategy development of aeromonas hydrophila.

The invention discloses a preparation method and an application of a layered Steiner network structure fiber membrane. The layered Steiner network structure fiber membrane is prepared from the following polymers: polyvinyl alcohol, chitosan, polyvinylpyrrolidone, polyacrylic acid, polypropylene cellulose, polycarbonate and polyimide, the following pore-foaming agent: dichloromethane, polyvinyl alcohol, dimethyl sulfoxide, ammonium bicarbonate, sodium bicarbonate, acetone or tetrahydrofuran, the following cross-linking agents: glutaraldehyde, methylene bisacrylamide, triethanolamine, polyethyleneimine or diethylenetriamine, the following catalysts: hydrochloric acid, sulfuric acid or phosphoric acid and a solvent being deionized water. When the layered Steiner network structure fiber membrane prepared by adopting the preparation method is applied to colorimetric explosive detection, the sensitivity of colorimetric detection can be improved in two aspects of reaction time and response degree, and the layered Steiner network structure fiber membrane has the advantages of being sensitive in reaction, instant in result display, simple in operation and use method and the like. Moreover,various non-standard explosives and standard explosive raw materials are detected and identified according to different explosive detection reagents loaded in the fiber membrane, so that the layered Steiner network structure fiber membrane has universality.

The invention discloses a method for preparing recombinant-penicillium amagasakiense glucose oxidase and application of the recombinant-penicillium amagasakiense glucose oxidase. Recombinant trichoderma reesei Tu6 delta tku70::Pgod constructed by introducing a Pgod gene into trichoderma reesei Tu6 delta tku70 can successfully express the recombinant-penicillium amagasakiense glucose oxidase, the expression quantity is high, and the enzyme activity in fermentation broth can achieve 28 U/mL. The recombinant-penicillium amagasakiense glucose oxidase in the fermentation broth is subjected to ni-sepharose purification, the enzyme activity in a protein solution obtained by ultrafiltration concentration can achieve 330 U/mL, and the specific activity of the recombinant-penicillium amagasakiense glucose oxidase is 407 U/mg protein. The recombinant-penicillium amagasakiense glucose oxidase prepared by the method has good heat stability and good acid-alkali tolerance, the fermentation process is simple, transferring is not needed, raw materials are cheap and are easily obtained, and the cost is greatly reduced. The recombinant-penicillium amagasakiense glucose oxidase can be widely applied to the fields of food and medicine.

The invention provides a salmonella phage composition and application thereof, and belongs to the technical field of biology. The salmonella bacteriophage composition provided by the invention comprises at least one of a bacteriophage GSP162, a bacteriophage GSP193, a bacteriophage GSP001 and a bacteriophage GSP032. The salmonella bacteriophage composition provided by the invention plays a role in four receptors of salmonella lipopolysaccharide (LPS) O antigen, LPS core polysaccharide, outer membrane protein BtuB and outer membrane protein TolC respectively. The four bacteriophages screened by the invention have good temperature tolerance and acid-base tolerance, can be used for cracking salmonella of various different serotypes, and are wide in cracking spectrum; an in-vitro bacterial lysis experiment shows that compared with the use of a single phage, the phage cocktail can effectively delay the appearance of an anti-phage strain, and the synergistic effect is obvious. A mouse intestinal sterilization test shows that the bacteriophage composition disclosed by the invention can be used for effectively reducing the salmonella carrying amount in cecum.