42 results about "Anabaena sp." patented technology

The invention discloses bacillus subtilis for accumulating N-acetylneuraminic acid to recombine and an application thereof, and belongs to the field of genetic engineering. According to the bacillus subtilis, bacillus subtilis 168-delta-nagP delta-nagP delta-gamP delta-gamA delta-nagA delta-nagB delta-1dh delta-pta:: lox72 are taken as expression hosts, through the over-expression of glucosamine acetylase coding geneS GNA 1 which are derived from saccharomyces cerevisiae S288C, N-acetyl-glucosamine epimerase (AGE) which is derived from anabaena sp. CH1 and N-N-acetylneuraminic acid synthase (NeuB) which is derived from escherichia coli K1, genetically engineered bacteria of the bacillus subtilis for accumulating N-acetylneuraminic acid are obtained, the yield of N-acetylneuraminic acid reaches 190mg / L, and bacillus subtilis further lays a foundation for the process that the bacillus subtilis is transformed by metabolic engineering to produce the N-acetylneuraminic acid.

The invention belongs to the technical field of food industry biology and relates to a bacillus subtilis expression vector of efficient secreting expression recombination lipoxygenase and application thereof. The vector utilizes a bacillus subtilis vector pHB201 as a framework, the pHB201 enzyme cutting site is modified first through an enzyme cutting method to obtain a pHB-hc vector, composition type strong promoter P43, composition type strong promoter PamyE, molecular chaperone PrsA of an Sec path and neutral protease signal peptide SnprB are obtained by cloning in bacillus subtilis 168 genome through a polymerase chain reaction (PCR), and a bacillus subtilis secretion type expression vector pHBSR is obtained in construction. Lipoxygenase gene obtained from anabaenagenome DNA in amplification is inserted into autonomously constructed expression vector pHBSR and then electrically converted into a bacillus subtilis host WB800 to achieve secreting expression of the recombination lipoxygenase, and the largest enzyme activity in fermentation liquid can reach 76U / ml.

The invention relates to a blue-green alga-rice complex operation nitrogen-fixing and carbon-fixing method. Anabaena azollae, anabaena sphaerica and anabaena flosaguas are taken as initial materials, and after expanded culture of strains in a sterile chamber and scale production in a small pool of a greenhouse, the strains are processed with the help of a screen to enable the water content to be 40%-60%; then mixing, stirring and crushing are performed at the day according to the weight ratio of 2: 6: (2-3): 4: 3, and a mixture is uniformly sprayed into a watered rice field with the density of 2-5g / m<2>; or wet algae are placed in an oven at the temperature of 35-40 DEG C for 8h or placed under a fluorescent lamp of 30-50W in the sterile chamber for drying for 3-5 days to enable the water content to be 8%-12%, crushing is performed by using a crushing machine, dry alga powder is uniformly blended according to the weight ratio of 1: 8: (1-2): 6: 2 and mixed in 5-10 times of the weight of rice husk, and the dry alga powder is uniformly sprayed into the watered rice field with the density of 0.5g / m<2>. According to the method disclosed by the invention, nitrogen-fixing blue-green algae are cultivated and stocked in the rice field as a fertilizer source, CO2 is absorbed, organic matters are generated, soil is improved, the yield and quality of paddy rice are improved, and the method has the advantages of simple process, easiness in popularization, safety, high efficiency, no pollution and the like.

The invention discloses a composite control method for paddy field weeds. The composite control method comprises the steps that bensulfuron methyl is sprayed synchronously in the process of planting rice, and a chemical method is used for controlling growth of the paddy field weeds; nitrogen fixation anabaena is applied during the period of 30-45 days after the rice is planted, and a biological method is used for further controlling growth of the paddy field weeds. According to the composite control method, the chemical method and the biological method are combined, germination of the weeds is suppressed quickly and effectively, and further germination and growth of the paddy field weeds are controlled under the action of the nitrogen fixation anabaena; as a result, the nitrogen fixation capability and the carbon fixation capability of crops are improved simultaneously, harm of the weeds is greatly reduced, normal growth of the crops is guaranteed, the use amount of paddy field herbicide is reduced, the weeds are prevented from generating resistance, and the composite control method has great significance in maintaining the stability of the ecological system and guaranteeing the quality and yield of the rice.

The invention provides anabaena sp. PD-3 capable of efficiently degrading polychlorinated biphenyl (PCB), and application thereof to microbiological degradation of polychlorinated biphenyl. The anabaena sp. PD-3 is collected in the China Center For Type Culture Collection, with an address of Wuhan universality, Wuhan, China, a postal code of 430072, a collection date of September 8, 2013, and a collection number of CCTCC No.M2013398. The invention provides anabaena PD-3 capable of efficiently degrading polychlorinated biphenyl. The anabaena is capable of effectively degrading PCB28, 29, 30 and 31; after the exposure for a week, the degradation efficiency of the anabaena to PCB28 exceeds 60 percent, the dechlorinating percents of the anabaena to PCB44 and PCB61 are respectively 63.6 percent and 57.3 percent, and are superior to those (49.3 percent and 48.3 percent) of anabaena PD-1 (with a collection number of CCTCC No: M2011446). Thus, the anabaena PD-3 can be widely applied to the degradation of polychlorinated biphenyl in the environment, and has an important application prospect.

The invention discloses a mutant of phenylalanine deaminase with an anabaena source and belongs to protein engineering. The phenylalanine deaminase E75L obtained in the invention has trypsin degradation resistance and low pH resistance which are greatly improved compared with those of wild-type enzymes. The phenylalanine deaminase E75L provided by the invention achieves the effect of promoting application of the phenylalanine deaminase in oral medication of phenylketonuria (PKU) to a certain degree.

The invention discloses a method for producing N-acetylneuraminic acid through recombinant bacillus subtilis whole-cell transformation, and belongs to the field of genetic engineering. Bacillus subtilis serves as an expression host, and recombinant bacillus subtilis genetically engineered bacteria accumulating N-acetylneuraminic acid is obtained through N-acetamide glucose isomerase (AGE) with free plasmid pP43NMK excessively coming from Anabaena sp.CH1 and N-nacetylneuraminic acid aldolase (NanA) coming from Escherichia coli K12; N-acetylglucosamine and sodium pyruvate serve as a substrate for whole-cell transformation, the yield of N-acetylneuraminic acid reaches 21.89 g / L, and a foundation is laid for industrialized production of N-acetylneuraminic acid by using food-safety-level bacillus subtilis.

The invention utilizes the property that nonspecific endonuclease from Anabaena sp. is provided with natural inhibitor protein to change the original expression way of the nonspecific endonuclease, i.e. to change secretory expression into endoenzyme high efficient expression. The invention adopts a strong promoter to largely express in cells in a way of inclusion bodies with no activity; wherein, the moment when the endonuclease is expressed, the natural inhibitor protein is expressed together so as to eliminate the strong toxicity that farthing activated nuclease imposes on the cells; protein engineering technology is used for replacing a non-activated central amino acid, thus reducing the possibility of forming multimer in renaturation, improving efficiency, and furthermore, raising the output in terms of improving the expression efficiency and the renaturation efficiency.

The invention relates to an anabaena PCC7120 fat oxygenase gene which belongs to the biologic technical field of the food industry. The gene is derived from anabaena sp. PCC7120 and is multiplied andobtained from genome DNA by PCR, colibacillus is converted after an expression vector is inserted and is induced to express, and the expressed recombinant enzyme catalyzes the oxidation of unsaturatedfatty acid to generate a fatty acid hydrogen overoxidation derivative with conjugated double bonds. The hydroperoxide is used as an unstable primary enzyme promoting product and can further generatea series of oxidation secondary reactions. In the improvement of the quality of flour, the hydroperoxide has an important application value in the following two aspects: (1) oxidizing cysteine with reducibility, forming a disulfide bond, applying to the improvement of the quality of the flour, enhancing the strength of gluten and replacing potassium bromate with a carcinogenic action; and (2) oxidizing pigments, applying to the bleaching of the flour and replacing benzoyl peroxide.

The invention discloses a method for increasing content of zeaxanthin in anabaena. The method is characterized by comprising the following specific steps: cloning critical rate-limiting enzyme gene beta-carotene hydroxylase gene for synthesis of zeaxanthin from dunaliella salina teodoresce, constructing the gene into a shuttle expression vector pRL25C, and transferred into anabaena by a triparetal conjugation method, genetically modified anabaena is obtained by resistance screening, and after 16000Lx high-light treatment, the method has the advantage that the content of zeaxanthin in genetically modified anabaena is increased greatly compared with wild type anabaena, and can be increased by 3.8 times to the greatest extent.

The invention provides an application of an anabaena and / or spirulina extract as a biostimulant in agricultural production, and belongs to the technical field of agricultural production. The anabaenaand / or spirulina extract is prepared by the following steps: carrying out wall breaking treatment on collected anabaena and / or spirulina at the temperature of 4-45 DEG C, carrying out water extraction, and carrying out spray drying on the obtained soluble algae cell extract and cell debris particles with the particle size of not more than 400 nm to obtain the anabaena and / or spirulina extract. According to the invention, the complete extraction of active components can be achieved by combining a conventional wall breaking method and a normal temperature water extraction method, so that the damage on the algae active components is avoided, the production cost is reduced, the completely water-soluble extract is obtained, the basis is provided for the subsequent preparation of the water-soluble fertilizer, and the characteristics of rapid effect and accurate fertility are provided. The application of the anabaena and / or spirulina extract as a biostimulant in agricultural production is beneficial to promoting crop growth and increasing crop yield.

The invention relates to a method for preparing a human basic fibroblast growth factor by using bacillus subtilis and endonuclease. Specifically, the invention provides a nucleic acid construct which comprises an insert, the insert comprises, from the 5' end to the 3' end, a polynucleotide sequence encoding an oligopeptide affinity tag, a trans-spliced intein derived from Anabaena sp., and an exogenous polypeptide, wherein the oligopeptide affinity tag is used as the N-terminal exon peptide of the trans-spliced intein, and the exogenous polypeptide is used as the C-terminal exon peptide of the trans-spliced intein. The invention also provides an expression vector and a host cell containing the construct, and a method for producing and purifying the foreign protein. According to the expression system and method, the expression efficiency of the foreign protein with biological activity can be remarkably improved, the generation of inclusion bodies is reduced, the purification step is simplified, the purification cost is greatly reduced, and the expression system and method are particularly suitable for large-scale culture.

The invention discloses a method for counting fishy algae cells based on a microscope image. The method comprises the following steps: (1) image preprocessing: enhancing the contrast ratio of the image; (2) image binaryzation: finding out a fishy algae area in the image; (3) calculating the minimum bounding rectangle of the fishy algae: calculating the outer contours of the binary image, and finding the minimum bounding rectangle of the contours; (4) detecting a binary image of the fishy algae: generating the binary image of the fishy algae for cell statistics according to the minimum bounding rectangle of the fishy algae; and (5) calculating the number of the fishy algae cells: counting the number of the fishy algae cells through the binary image calculated in the step (4). According to the method, the problem that the sizes of the anabaena cells are inconsistent under the same resolution ratio can be solved, the statistical accuracy is improved, and the applicability of cell number statistics is also enhanced.

The invention provides a method for extracting streptomyces alga dissolution active substances, and belongs to the field of eutrophic water body bioremediation. An isometric absolute ethyl alcohol isused for repeatedly extracting streptomyces fermentation liquor filtrate, after centrifugalization is completed, a rotary evaporator is used for concentrating an organic phase to be dry, crude substances are obtained, then methyl alcohol is used for dissolving the crude substances, and silica gel column chromatography separation is carried out; the components with efficient alga dissolution activity are subjected to high-performance liquid chromatographic separation, and the alga dissolution active substances are obtained. Adopted streptomyces comes from an eutrophic water body, the alga dissolution active substances secreted by the streptomyces are secondary metabolites, high safety is achieved, and no secondary pollution is caused to the water body. The alga dissolution active substancescan be used for treatment of the eutrophic water body caused by typical harmful algae such as microcystis, anabaena, aphanizomenon and oscillatoria. The extraction method is simple in process, high in operability, low in production cost, good in alga dissolution effect and suitable for large-scale production.

The invention discloses a plant nutrient composition as well as a preparation method and application thereof. The composition comprises a plurality of microalgae, and comprises the following algae ina living body state in terms of the individual number of microalgae cells: 10-40 parts of chlorella, 10-40 parts of anabaena, 10-40 parts of Scytonema Agardh., 10-40 parts of Spirogyra, 10-40 parts ofeuglenophyta and 10-40 parts of Phoridium foveolarum. The composition includes multiple microalgae, during use, the microalgae in a living body state is directly applied to plants or land; microalgaeare high in environmental adaptability and rapid in proliferation, molecular nitrogen in the atmosphere can be fixed into combined nitrogen to be supplied to plant root systems for use, substances needed by plant growth can be effectively supplemented, the plant quality can be improved, soil or water fertility solidification can be improved, the soil quality can be effectively improved, and the saline-alkali soil treatment effect is outstanding.

The invention discloses bacillus subtilis for accumulating N-acetylneuraminic acid to recombine and an application thereof, and belongs to the field of genetic engineering. According to the bacillus subtilis, bacillus subtilis 168-delta-nagP delta-nagP delta-gamP delta-gamA delta-nagA delta-nagB delta-1dh delta-pta:: lox72 are taken as expression hosts, through the over-expression of glucosamine acetylase coding geneS GNA 1 which are derived from saccharomyces cerevisiae S288C, N-acetyl-glucosamine epimerase (AGE) which is derived from anabaena sp. CH1 and N-N-acetylneuraminic acid synthase (NeuB) which is derived from escherichia coli K1, genetically engineered bacteria of the bacillus subtilis for accumulating N-acetylneuraminic acid are obtained, the yield of N-acetylneuraminic acid reaches 190mg / L, and bacillus subtilis further lays a foundation for the process that the bacillus subtilis is transformed by metabolic engineering to produce the N-acetylneuraminic acid.

The invention provides a straw biological decomposition method by adoption of an anabaena decomposition accelerator. The method comprises the step of adding the anabaena decomposition accelerator, the anabaena decomposition accelerator is composed of, by mass, 37-49 parts of anabaena, 5-8 parts of complex microbial inoculants, 32-38 parts of cortex ailanthi and 25-29 parts of cushaw flower pollen. According to the straw which is subjected to the decomposition treatment by means of the straw decomposition method, the total carbon content is 27.3-31.2%, the total nitrogen content is 1.86-1.92%, when the decomposition is finished, C / N is 14.2-16.8, T is 0.41-0.48, the total phosphorus content is 0.149-0.164%, and the germination index of seeds can reach 109.5-113.4%; the invention further provides the application of the method in the improvement of saline-alkali soil, by means of the application, the soil salinity and soil pH can be reduced remarkably, the soil porosity can be increased, the soil bulk density can be reduced, the soil water infiltration rate can be enhanced, and the soil fertility can be enhanced.

The invention discloses a special oily bat repellent for airports and a preparation method of the special oily bat repellent. The special oily bat repellent consists of the following raw materials inpercentage by mass: 2-10% of cinnamaldehyde, 10-15% of camphor oil, 5-10% of anabaena, 2-10% of lavender essential oil, 2-10% of jasmine flower essential oil, 2-10% of mint essential oil, 2-6% of methyl phosphonoformate, 0.1-0.5% of a preservative, 2-3% of an antifreeze agent, 0.1-0.5% of an antioxidant and 30-34% of a slow release carrier. On the premise of not damaging bats, the special oily batrepellent for airports is prepared according to a certain proportion and is put into a spraying device. A smoky bat repellent is sprayed out, can have a lasting effect on nervous systems and respiratory systems of bats, and repel the bats through comprehensive effects on taste, smell and the like, so that the bats do not return in a memory period, and therefore lifting and landing safety of airplanes in the airport is effectively protected.

The invention discloses a target object and redox dual-response aptamer sensor, a preparation method and application thereof and a quantitative detection method of anabaena toxins. DNA S1 is connected to an AgNPs@Ru-MOF material through an Ag-S bond; a solution of the material, a DNA S3 solution and a solution obtained after mixed incubation of DNA S2 and ferrocenecarboxylic acid are sequentially modified to the surface of a pretreated GCE electrode to prepare the aptamer sensor, when a target object anabaena toxin exists, a second structure of DNA S3 can be triggered, so that DNA S1 and DNA S2 form a special structure capable of being recognized by silver ions, and then along with addition of H2O2, H2O2 can etch silver nanoparticles to generate silver ions, the silver ions cut DNA S2 by recognizing cutting sites to release an inhibitor ferrocene, electrochemical luminescence of ruthenium on the surface of the electrode is induced, and quantitative detection of anabaena toxins is achieved.

The invention discloses a method for degrading antibiotics by activating persulfate by using a Fe-N self-doped algae-based carbon catalyst, the Fe-N self-doped algae-based carbon catalyst is used as a catalyst for activating persulfate to degrade the antibiotics, and the Fe-N self-doped algae-based carbon catalyst is prepared by using anabaena as a raw material, soluble carbonate as a pore-forming agent, and the Fe-N self-doped algae-based carbon catalyst is prepared by using the Fe-N self-doped algae-based carbon catalyst as a catalyst for activating persulfate. And calcining under the condition that the temperature is greater than 600 DEG C to obtain the catalyst. According to the method disclosed by the invention, the Fe-N self-doped algae-based carbon catalyst with the advantages of large specific surface area, multiple reaction active sites, high catalytic activity and the like is taken as a catalyst, and the Fe-N self-doped algae-based carbon catalyst can effectively activate persulfate and convert the persulfate into active groups with strong oxidation effect on antibiotics, so that the active groups can be utilized to realize effective degradation of the antibiotics; the method has the advantages of being simple in process, convenient to operate, low in cost, good in degradation effect and the like, has a good degradation effect on various antibiotics, and is high in use value and good in application prospect.

The invention provides lightweight thermal insulation gypsum mortar. The lightweight thermal insulation gypsum mortar is prepared from gypsum powder, glass beads, cement, ash calcium powder, mica, silicon dioxide, a water repellent, oyster powder, floating beads, anabaena, polypropylene fibers, a lubricant, a stabilizer, an air entraining agent and a water reducing agent. By adding the glass beads, the thermal insulation performance of the gypsum mortar is improved; through chemical reaction and physical action of the silicon dioxide and the water repellent, the strength and the water resistance of the gypsum mortar are improved; by adopting the oyster powder and the herba houttuyniae, the growth and reproduction of microorganisms can be directly inhibited, so that a bacteriostatic effect is formed, the light gypsum mortar can be prevented from mildewing, and the wall cannot be discolored due to mildewing for a long time.

The invention discloses a thermostable citrate synthase gene, engineering bacteria containing the gene and expression method thereof, in accordance with that present invention, the gene of the heat-resistant citrate synthase of the invention takes the genome of Anabaena sp. PCC7120 as a template and is obtained by using PCR amplification technique, the recombinant plasmid containing citrate synthase gene was transformed into Escherichia coli, after kanamycin resistance screening and sequencing, the citrate synthase produced by the genetic engineering bacteria has the characteristics of heat resistance and high enzyme activity, which provides a basis for its better application in the industrial production of citric acid. The characteristics of heat resistance and high enzyme activity enableit to better save production costs.

The invention relates to preparation of human basic fibroblast growth factor by utilizing Bacillus subtilis and endonuclease. Specifically, the invention provides a nucleic acid construct, which comprises an insert, the insert contains an affinity tag encoding a short peptide, a trans-splicing intein derived from Anabaena sp., and a polynucleotide sequence of an exogenous polypeptide, from the 5'end to the 3' end, wherein the short peptide affinity tag is used as an N-terminal extein of the trans-splicing intein, and the exogenous polypeptide is used as a C-terminal extein of the trans splicing intein. The invention also provides an expression vector and a host cell which contain the construct, and a method for generating and purifying exogenous proteins. According to the expression system and method of the present invention, the expression efficiency of exogenous proteins with biological activities can be significantly improved, the generation of inclusion bodies can be reduced, thepurification steps are simplified, the purification cost is greatly reduced, and the expression system and method is particularly suitable for large-scale culture.

The invention discloses a skin wound healing preparation, and the effective components of the skin wound healing preparation comprise an epidermal growth factor and / or a fibroblast growth factor, the epidermal growth factor and / or the fibroblast growth factor are / is obtained by culturing transformed host cells; the transformed host cell comprises an expression vector, the expression vector comprises a nucleic acid construct, and the nucleic acid construct comprises an insert, the insert comprises, from the 5'end to the 3'end, a polynucleotide sequence encoding an oligopeptide affinity tag, a trans-spliced intein derived from Anabaena sp., and an exogenous polypeptide, wherein the oligopeptide affinity tag is used as the N-terminal exon peptide of the trans-spliced intein, and the exogenous polypeptide is used as the C-terminal exon peptide of the trans-spliced intein. Through local application of the skin wound healing preparation, the cure rate of diabetic foot ulcers, bedsores and hard-to-heal wounds is greatly increased.

The invention provides a formula of an anabaena culture medium, comprising 200-250 mg / L NH4NO3, 500-550 mg / L NaNO3, 400-500 mg / L K2SO4, 150-200 mg / L of CaC12.2H2O, 100-150 mg / L MgSO4.7H2O, 400-500 mg / L K2HPO4, 15-20 mg / L Na2S2O3.5H2O, 20-25 mg / L H3BO3, 2-4 mg / L CuSO4.5H2O, 0.2-0.4 mg / L ammonium ferric citrate, 0.1-0.2 mg / L nicotinic acid, 0.2-0.3 mg / L vitamin B, 0.2-0.3 mg / L vitamin B1, 0.05-0.1 mg / L NNA and 0.03-0.05 mg / L IBA. The culture medium provided by the invention has the advantages of high survival rate and high growth rate while cultivating the anabaena, and are less prone to being polluted by other bacteria.

The invention provides a selenium-rich nutrient solution as well as a preparation method and application thereof. The selenium-rich nutrient solution comprises a selenium-rich nutrient solution A and a selenium-rich nutrient solution B, and the mass ratio of the selenium-rich nutrient solution A to the selenium-rich nutrient solution B is (1-2):(2-3). The selenium-rich nutrient solution A comprises the following raw materials in parts by weight: 8-10 parts of humic acid, 6-8 parts of L-proline, 2-4 parts of magnesium sulfate, 2-4 parts of copper sulfate, 3-6 parts of selenium ore powder, 10-15 parts of straw mushroom powder, 20-30 parts of bran fermentation liquor and 25-35 parts of water; and the selenium-rich nutrient solution B comprises the following raw materials in parts by weight: 7 to 11 parts of cassava starch, 9 to 15 parts of bamboo powder, 4 to 6 parts of sodium selenite, 8 to 15 parts of liquorice root decoction dregs, 12 to 16 parts of radix astragali decoction dregs, 4 to 8 parts of fructus crataegi decoction dregs, 12 to 15 parts of lotus leaf extract and 12 to 18 parts of anabaena culture solution. The prepared selenium-rich nutrient solution is applied to crop cultivation, green and environment-friendly selenium-rich crops with high organic selenium content and less inorganic selenium residues can be harvested, the quality and nutritional value of the crops can be improved, the preparation method is simple, the product is easy to use, and the selenium-rich nutrient solution is quite suitable for large-scale popularization and application.

Polynucleotide, DNA constructs and methods are disclosed for the modification of cellulose content in plant tissues. Plants are transformed with constructs encoding either an active Anabaena sp. sucrose synthase gene or a soybean nodule sucrose synthase gene, which leads to increased cellulose content when over-expressed under the control of a cambium / xylem preferred promoter. Plant transformants harboring an Anabaena sp. or a soybean nodule sucrose synthase gene demonstrated increased content of cellulose, a trait that is thought to improve woody trees for cellulose extraction during pulping and papermaking.

The invention discloses a nostoc high-efficiency cracking phycophage as well as a separation method and application thereof. The nostoc high-efficiency cracking phycophage is characterized in that the phycophage is a novel Myoviridae phycophage, is named as YongM, is preserved in the General Microbiological Center of Microbiological Culture Collection Center on January 13, 2020, and is numbered as CGMCC NO.18383. The YongM has the characteristics of high efficiency and broad spectrum, can be used for efficiently splitting nostoc and can be used for infecting and splitting various microcystis, Chroococcus, Anabaena aquatica, oscillatoria planktonic and floating hylonema adami. According to the nostoc high-efficiency cracking phycophage, with the application of the YongM, the algae liquid of the nostoc FACHB-596, the algae liquid of the anabaena flos-aquae FACHB-245, the algae liquid of the Chroococcus FACHB-193, the oscillatoria planktonic FACHB-708 can be subjected to cracking clarification within 24 h.

The invention discloses a cyanobacteria engineering bacterium capable of efficiently fixing nitrogen and a preparation method and application thereof. Anabaena engineering bacterium delta(FTN) of which the heteromorphic cell volume is about two times of the normal heteromorphic cell volume is obtained by knocking out a gene of a cell division related factor FTN of wild anabaena PCC 7120. The nitrogenase activity of the anabaena engineering bacterium delta(FTN) is 2.3 times that of a wild type, the anabaena engineering bacterium delta(FTN) is high in growth speed, the generation time is about 20 hours, the anabaena engineering bacterium delta(FTN) has the prospect of being popularized and applied in agriculture, and a new choice is provided for application of nitrogen-fixing blue-green algae in agricultural production.