78 results about "Nitrite reductase" patented technology

The invention relates to a reagent (kit) for diagnosing/determining amino acid by using an enzyme colorimetric method and an enzyme link method, and also discloses a method for determining the concentration of the amino acid, a composition and components of the reagent, belonging to the technical field of medicine/food/environmental test determination. The reagent (kit) comprises the main components: a buffer solution, a coenzyme, ferricytochrome C, calcium chloride (calcium salt), an amino acid oxidase, a nitrite reductase, a nitrate reductase and a stabilizing agent. A sample and the reagent are mixed according to a certain volume ratio to generate a series of enzymatic reactions, and reactants are placed under an ultraviolet/visible light analyzer for detecting the degree of absorbance rise at the dominant wavelength of 340 nm, thereby measuring and calculating the concentration of the amino acid.

The invention discloses an assimilation nitrate reductase gene and an assimilation nitrite reductase gene both extracted from bacillus megaterium as well as applications of the assimilation nitrate reductase gene and the assimilation nitrite reductase gene, and relates to the field of the biotechnology. The assimilation nitrate reductase gene is catalytic subunit nasC (Seq ID No.1) which codes assimilation nitrate reductase Nas; the assimilation nitrite reductase gene is large subunit nasD (Seq ID No.2) which codes assimilation nitrite reductase NiR. According to the invention, total RNA is extracted from the bacillus megaterium NCT-2, then cDNA synthesis is conducted to obtain a cDNA template, and function representation is realized through fluorogenic quantitative PCR. The assimilation nitrate reductase gene and the nitrite reductase gene can be further applied to research on removal of overmuch nitrate from soil.

The invention discloses a preparation method of nitrite reductase of lactobacillus casei subsp rhamnosus. The method comprises the following steps: firstly, carrying inductive culture of nitrite reductase on lactobacillus casei subsp rhamnosus 6013; adding an enzyme protective agent to extract coarse nitrite reductase when the wall is broken; after carrying out vacuum-freezing and drying, finally preparing pure nitrite reductase sequentially through anion exchange chromatography and/or sephadex chromatography. The activity of NiR extracted from lactobacillus casei subsp rhamnosus is high and the condition for degrading nitrite reductase by NiR is simple. According to the disclosed condition, the enzyme activity loss of NiR is less, and the obtained NiR is high in purity and can be used for solving problem of nitrite in three fields such as vegetable fermentation, meat products and aquatic water.

The invention discloses a method for degrading nitrites in foods. The method comprises the following steps of adding nitrite reductase in food sauce, performing standing for reaction for 6-12h at the temperature of 27-37 DEG C, then regulating a pH value with an organic acid to 2.0-5.5, and performing standing for reaction for 4-12h at the temperature of 20-37 DEG C, wherein a nitrite reductase gene is from edible bacteria. According to the method provided by the invention, by adopting a method for degrading sodium nitrite by adopting a crude enzyme solution firstly and then adopting the organic acid, and compared with a mode of singly using the organic acid or the nitrite reductase, the method has a good effect; the degradation rate of the sodium nitrite is calculated by determining the concentration of the nitrite in the system with a naphthylethylenediamine hydrochloride method to reach 90 percent or above; and the method can be used for degrading high-nitrite foods with a pH value larger than 5.0, such as pickles.

The invention relates to a processing technique for sausage. The processing technique comprises the processes of selecting materials, treating raw materials, stripping and slicing, pickling, stirring, filling sausage, airing and dewatering and packaging. The pickling process comprises the following steps: adopting a vacuum low-nitrate pickling technique for pickling, placing the treated sausage raw materials into a vacuum pickling machine, and then adding a pickling mixed solution composed of nitrite, lactic acid bacteria and salt into the vacuum pickling machine and soaking the sausage raw materials into the pickling mixed solution. The stirring process comprises the following steps: adopting a vacuum nitrosamine control technique for stirring, namely, adding stirring additive into pickled meat paste, putting into a vacuum stirring machine for stirring, uniformly mixing the meat paste, and then adding 0.3-2wt% of nitrite reductase complex enzyme preparation into the mixed meat paste and uniformly stirring. The invention has the advantages that the processing technique for sausage can reduce the addition of the nitrite and can effectively reduce the nitrite residue in the sausage.

The invention discloses a preparation method of preparing nitrite reductase and preparing the preparation of the nitrite reductase, which belongs to the preparing technology field of biologic enzyme and enzyme preparation. Bacillus megatherium which can produce nitrite reductase is activated and prepared into seed, the obtained seed culture fluid is inoculate into a liquid ferment substrate by 1-10 percent of inoculation dosage; the initial pH value is 5.0-7.5, at 25-40 DEG C and 100-240r/min of rotation speed, after 20-36 hours of constant temperature cultivation, bacterial suspension is produced. Re-suspending the bacterial suspension by phosphate buffer can produce thalli. After the thalli is smashed by ultrasonic, the supernatant fluid is frozen and centrifugated, and then the rough enzyme solution is obtained. Nitrite reductases of different consistences and purities can be obtained after the rough enzyme solution is separated and purified. Liquid enzyme preparation can be prepared after enzyme protecting solute is added in the nitrite reductase. The enzyme activity of nitrite reductase preparation produced by using the invention is 4000-8000U/mL. The preparing method is simple, the production period is short, and public food safety can be maintained.

The present invention relates in one aspect to a method for producing a transgenic plant, comprising introducing into an unmodified plant an exogenous gene encoding a nitrite reductase, wherein expression of the nitrite reductase encoded by the exogenous gene reduces nitrite content in the transgenic plant relative to the unmodified plant. Also provided are transgenic plants and plant cells comprising an exogenous gene encoding a nitrite reductase, as well as associated uses, chimaeric genes and plant transformation vectors.

The invention discloses a method for degrading nitrite in salted fish through an enzymic method. The method comprises the following steps: (1) washing fresh fish or frozen fish, salting the fish with salt, taking out the fish, rinsing with clean water, and draining; (2) adding nitrite reductase into the salted fish, wherein the addition amount of the nitrite reductase is 0.8-1.6g per kg of fish, and the enzymatic activity of the nitrite reductase is 3,500-4,500U/g; (3) airing the fish treated with an enzyme solution on a drying rack for 1-2 hours, putting the fish in a low-temperature heat pump dryer or cold-air drying equipment at the temperature of 28-35 DEG C, and airing the fish until the moisture content of the fish body is 35-45 percent. According to the method, the content of the nitrite generated in the process of processing the salted fish can be effectively reduced, the taste and quality of the salted fish products are kept, and the safety of the salted fish products is guaranteed.

The invention discloses a lactobacillus plantarum nitrite reductase gene, a protein coded by the gene and applications of the protein, and belongs to the field of bioengineering. In the present invention, the nitrite reductase gene in lactobacillus plantarum is cloned by a PCR technology and induced to express in escherichia coli, and affinity chromatography purification is utilized to obtain a high-purity recombinant protein. The high-purity protein purified by the method of the invention can effectively degrade nitrite in food, and the structure and properties of the protein can be studied.

The present invention relates in one aspect to a method for producing a transgenic plant, comprising introducing into an unmodified plant an exogenous gene encoding a nitrite reductase, wherein expression of the nitrite reductase encoded by the exogenous gene reduces nitrite content in the transgenic plant relative to the unmodified plant. Also provided are transgenic plants and plant cells comprising an exogenous gene encoding a nitrite reductase, as well as associated uses, chimaeric genes and plant transformation vectors.

The invention discloses a lactobacillus plantarum nitrite reductase gene, protein encoded by the lactobacillus plantarum nitrite reductase gene and a preparation method of the protein. A nucleotide sequence of the lactobacillus plantarum nitrite reductase gene is as shown in SEQ ID NO.1. A gene sequence shown in the SEQ ID NO.1 is cloned to a prokaryotic expression vector pET-32a(+); inducible expression is carried out in recombinant escherichia coli; high-purity recombinant protein is obtained by affinity chromatography purification. By using the high-purity protein purified by the method disclosed by the invention, nitrite can be effectively degraded, an enzymic preparation can be produced, the nitrite in food can be effectively degraded, and the protein can also be applied to preparation of a lactobacillus plantarum nitrite reductase antibody as an antigen, and can be applied to research of structure and property of the antibody.

The invention discloses a production method of lactic acid bacteria nitrite reductase, that is, lactic acid bacteria are activated and cultivated with MRS liquid medium for 2 to 3 generations, and the activated bacteria are obtained by using a seed medium composed of cabbage juice, tomato juice, etc. and fermentation culture The lactic acid bacteria fermented liquid is obtained after medium culture, and the pH value of the lactic acid bacteria fermented liquid is adjusted to 6.3-6.5 with sodium hydroxide, and then 0.4-0.6mg/mL sodium nitrite is added, and the lactic acid bacteria obtained after 32-48 hours of cultivation at 37°C are reduced to nitrite The enzyme fermentation broth is centrifuged to collect the bacteria, and then the bacteria cells are further broken, and the supernatant is collected, and then the nitrite reductase is finally obtained through steps such as precipitation, dialysis, and freeze-drying. The production method of the lactic acid bacteria nitrite reductase of the present invention not only has low production cost, but also has the advantages of simple production process, more convenient operation and the like.

The invention provides a recombinant, acetogenic bacterium that consumes a substrate comprising CH₄ and converts at least a portion of the CH₄ to a product. In particular, the bacterium of may comprise one or more of exogenous methane monooxygenase (MMO), exogenous nitrite reductase (NIR), and exogenous nitric oxide dismutase (NOD). The invention further provides a method for producing a product comprising providing a substrate comprising CH₄ to a culture comprising a recombinant, acetogenic bacterium, whereby the bacterium converts at least a portion of the CH₄ to a product.

The invention relates to the technical field of plant genetic engineering and provides a transcription factor ZmNLP4 derived from corn and application thereof. A nucleotide sequence of the transcription factor is shown as SEQ ID NO.1, and a coded amino acid sequence of the transcription factor is shown as SEQ ID NO.2. Compared with a receptor Arabidopsis, the Arabidopsis in which the transcriptionfactor is transferred has the advantages that the total biomass is obviously increased, the content of in-vivo amino acids and total nitrogen is increased, the main root length and quantity of lateral roots are obviously increased, the yield per plant is obviously increased, and the expressions of nitrate transporters, nitrate reductase genes and nitrite reductase genes are obviously increased.

The invention discloses a transcription factor derived from corn and new use of a coding gene thereof. The new use provided by the invention is a method using a coding nucleic acid molecule of ZmNLP1;1 to cultivate a transgenic plant. The method is a method for cultivating the transgenic plant with at least one characters of the following 1)-4): 1) aboveground biomass is higher than that of a receptor plant; 2) after induction of a nitrate, the nitrate transport protein gene expression is higher than that of the receptor plant; 3) after induction of the nitrate, nitrate reductase gene expression is higher than that of the receptor plant; and 4) after induction of the nitrate, nitrite reductase gene expression is higher than that of the receptor plant; and the method comprises a step for introducing a ZmNLP1;1 gene into the receptor plant; and the ZmNLP1;1 gene codes a protein shown in SEQ ID No.2. Experiments show that, in the condition of using nitric nitrogen (NO<3->) as a sole nitrogen source, the aboveground biomass and the total biomass of arabidopsis transgenic with the ZmNLP1;1 gene are increased significantly compared with that of receptor arabidopsis.

The invention discloses recombinant nitrite reductase and a construction method of the recombinant nitrite reductase. An NiR (nitrite reductase) gene in bacillus cereus LJ01 is amplified by adopting the PCR technology, the amplified gene is cloned to a carrier, an expression host strain is transformed, recombinant bacteria induced by IPTG is added, shaking culture is carried out at 16-37 DEG C, fermentation liquor is centrifugalized, bacterial sludge is taken, resuspending is carried out, high-pressure grinding is carried out, and crude enzyme liquid is extracted, wherein the bacillus cereus LJ01 is assigned with the accession number of CGMCC NO.9360. According to the technical scheme, the NiR gene is cloned, the cloned gene is expressed in a large amount in a host cell, meanwhile, the recombinant protein is provided with a specific label through plasmids, so that the purification process is simplified, and the extraction amount of NiR is improved.

The invention relates to engineering bacteria based on nitrite reductase and an implementation method of the engineering bacteria in the technical field of genetic engineering. The method comprises the following steps: by taking streptomyces griseorubens genome DNA as a template, performing PCR amplification with a primer containing enzyme cutting sites to sequentially obtain nucleotide sequences for encoding nitrite reductase large-subunits and nitrite reductase small subunits; sequentially connecting the gene sequences obtained by amplification to a coexpression vector pETDuet-1, and finally obtaining a recombinant coexpression vector pETDuet-NC-ND; and transforming the nitrite reductase expression vector into an Escherichia coli expression strain. Aiming at the defects that the application range and effect are severely limited because most of the nitrite reductases are intracellular enzymes in a living body and the expression quantity is low in the prior art, the engineering bacteria can realize great in-vitro expression synthesis of the nitrite reductase by using genetic engineering means and has high significance for rapidly repairing secondary salinization soil and realizing precision agriculture.

The invention relates to a bacillus megaterium co-expression vector for nitrite reductase and a construction method thereof, belonging to the technical field of genetic engineering. According to the co-expression vector, all genome sequences of bacillus megaterium are determined and serve as a template, gene sequences containing restriction enzyme cutting sites, namely a large subunit (Bm-Nas D) and a small subunit (Bm-Nas E) of nitrite reductase, are amplified according to designed PCR (Polymerase Chain Reaction) primers and are sequentially connected to the co-expression vector pETDuet-1, and positive clones of Escherichia coli DH5alpha containing target gene fragments are selected by a colony PCR technology. The co-expression vector has the advantages that the defect in the prior art that the use effect is seriously restricted due to the fact that the expression level of the gene sequence of the small subunit of nitrite reductase in natural bacillus megaterium is very low is overcome, and the genetic expression level is increased greatly.

The invention relates to a method for preparing nitrite reductase from flammulina velutipes and belongs to the technical field of a food enzyme biotechnology. The method comprises washing, draining and freeze-drying fresh flammulina velutipes, crushing the flammulina velutipes at a low temperature, screening the flammulina velutipes powder through a sieve of 60-100 meshes, carrying out extraction through an ultrasonic-assisted wall-dissolution enzyme method, carrying out salting-out, carrying out dialysis desalination, carrying out concentration to obtain a crude enzyme solution, carrying out separation purification through a DEAE-SepharoseFast Flow and dextrane gel G-150 chromatographic column, collecting a protein with enzyme activity, and carrying out dialysis, PEG20000 embedding and concentration, and freeze-drying to obtain nitrite reductase. The method provides a new idea for preparation of nitrite reductase, can be used in the field of fermented foods such as pickles, bacon and pickle development and reduces the content of nitrite in the product.

The present invention relates to the use of mutant glycoproteins from pathogenic bacteria lacking one or more phosphorylcholine and/or glycosylation post-translational modifications as immunogens. These post-translational modifications act as masking structures that elicit an immune response which does not confer protection on an infected individual. The removal or modification of these masking structures alters the protein such that it elicits a stronger immune response to the protein and/or the bacterial pathogen. Particular examples are pilin proteins and nitrite reductase glycoproteins of Neisseria bacteria.

The invention discloses a Bacillus cereus NiR (nitrite reductase), a gene and an application. The NiR gene in Bacillus cereus LJ01 is cloned and induced for expression in Escherichia coli with the PCR (polymerase chain reaction) technology, cells of blank-plasmid-containing BL21 subjected to IPTG (isopropyl beta-D-thiogalactopyranoside) induction, recombinant-plasmid-containing BL21 subjected to induction without IPTG and recombinant-plasmid-containing BL21 subjected to IPTG induction are subjected to ultrasonic crushing for extraction of crude enzymes, SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) is performed on the crude enzymes for detection of recombinant protein expression, high-purity recombinant protein is obtained through affinity chromatography purification, and the problem about separation of NiR with higher purity and content from the Bacillus cereus is solved. A large amount of NiR recombinant protein can be used for degrading nitrite in food, non-acid environments and aquatic water.

The invention discloses a specific fragment for nitrate-assimilation bacillus megatherium and an application thereof. The fragments are specifically shown as Seq ID No. 1-No.3. The bacillus megatherium comprises assimilated nitrate reductase and nitrite reductase genes, is capable of improving secondary salinity soil by utilizing a biological enzyme method, and has the characteristics of being rapid in efficiency and environment-friendly. By performing whole genome sequencing on the nitrate-assimilation bacillus megatherium and performing GenBank database whole-genome sequence parallel comparison, the specific sequence fragments are finally obtained. By virtue of the specific fragments disclosed by the invention, the bacillus megatherium can be rapidly and accurately detected from the environment, and related engineering bacteria are prepared according to the specific fragments.

The present invention relates generally to the field of molecular biology and concerns a method for enhancing various economically important yield-related traits in plants. More specifically, the present invention concerns a method for enhancing yield-related traits in plants by modulating expression in a plant of a nucleic acid encoding a NITR (Nitrite Reductase) polypeptide or an ASNS (Asparagine Synthase) polypeptide. The present invention also concerns plants having modulated expression of a nucleic acid encoding a NITR polypeptide or an ASNS polypeptide, which plants have enhanced yield-related traits relative to control plants. The invention also provides constructs comprising NITR-encoding nucleic acids or ASNS-encoding nucleic acids, useful in performing the methods of the invention.

The present invention discloses functional nitrite reductase as a potential drug target for anti-tubercular drug development. The present invention also relates to the development of an easy method for identification of nitrite in clinical samples as well as its correlation with the severity of the disease. Presence of active as well as dormant/latent stages of Mycobacterium tuberculosis (MTB) could be identified from nitrite in clinical samples like sputum of potential TB patients.