156 results about "Microbial genetics" patented technology

The invention relates to a saccharomyces cerevisiae strain for efficiently synthesizing cordycepin as well as a construction method and application of the saccharomyces cerevisiae strain, and belongs to the technical field of microbial genetic engineering. The construction method provided by the invention comprises the following steps: carrying out multi-copy genome integrated expression on heterologous codon optimized 2 '-carbonyl-3'-deoxyadenosine reductase genes and 3 '-adenosine monophosphate phosphohydrolase genes, so as to increase the dosage of key enzymes; and supplementing the defective gene of the engineering strain to obtain the saccharomyces cerevisiae strain B5U3 with high yield of cordycepin. According to the obtained saccharomyces cerevisiae strain for efficiently synthesizing the cordycepin, the cordycepin yield reaches 2.92 g / L after shake flask fermentation, the cordycepin yield reaches 7.5 g / L after fermentation in a fermentation tank, and a foundation is laid for safer and more reliable industrial production of the cordycepin.

The invention relates to the technical field of microbial genetic engineering, in particular to a sialyltransferase mutant with high yield of 3 '-sialyllactose as well as a construction method and application of the sialyltransferase mutant. The sialyltransferase mutant is selected from at least one of an NST protein or a mutant and a 406 NST protein or a mutant, the NST protein comprises an amino acid residue site in a sequence as shown in SEQ ID NO.1, and the 406 NST protein comprises an amino acid sequence in a sequence as shown in SEQ ID NO.2. The sialyltransferase mutant has the advantages that the sialyltransferase mutant can be used for preparing sialyltransferase, and the sialyltransferase mutant can be used for preparing sialyltransferase. The invention also provides a nucleic acid molecule containing the sialyltransferase mutant, an expression cassette, a recombinant vector, a recombinant microorganism and a construction method and application thereof, and has great significance in large-scale industrial production of 3-sialyllactose.

The invention discloses a method for traceless gene editing of gram negative bacteria, a carrier and application of the carrier, and belongs to the technical field of microbial genetic engineering. The invention provides a vector for performing traceless gene editing on bordetella pertussis. The vector simultaneously comprises an antibiotic positive screening gene expression box and a sacB and galk negative screening gene expression box. According to the method, the sacB gene and the galk genome are synthesized into the double-reverse-screening system for the first time, and compared with a single-reverse-screening system, the reverse-screening efficiency is remarkably improved, and the dosage of a reverse-screening reagent is remarkably reduced. The invention provides a novel gene editing method for non-mode bacteria such as pertussis bordetella and the like, and has a good application prospect.

The invention relates to the technical field of microbial genetic engineering, in particular to a method for improving cordycepin synthesized by saccharomyces cerevisiae and saccharomyces cerevisiae engineering bacteria. According to the invention, codon-optimized 2 '-carbonyl-3'-deoxyadenosine reductase gene and 3 '-adenosine monophosphate phosphohydrolase gene from cordyceps militaris are expressed by using plasmids, and then the plasmids are transformed into host cells to obtain the saccharomyces cerevisiae engineering bacteria. And inoculating a seed solution obtained by seed culture of the activated saccharomyces cerevisiae engineering bacteria into a fermentation culture medium containing a metabolic effector, and carrying out fermentation culture to synthesize cordycepin. Metabolic effectors (Cu < 2 + >, Fe < 2 + >, Mg < 2 + >, Zn < 2 + >, citric acid, cysteine, aspartic acid, glycine, VB1 and tea polyphenol) are added into a fermentation culture medium strain, and the variety and concentration of the metabolic effectors are optimized, so that the yield and synthesis efficiency of cordycepin are remarkably improved. By using the combination of the strain obtained by the invention and the optimal effector, the yield of cordycepin in a fermentation tank reaches 2.9 g / L.

The invention relates to the field of microbial genetic transformation, and discloses a preparation method of Ilyonectria fungus protoplast and a construction method of a genetic transformation system.The preparation method comprises the following steps that S11, Ilyonectria fungus hyphae are prepared, Ilyonectria fungi are cultured on a PDA solid culture medium for 14 d, then the Ilyonectria fungi are inoculated to a CMC liquid culture medium to be subjected to shake-flask culture for 4 d and filtered, filtrate is centrifuged for 10 min at the speed of 10000 rpm, and spores are collected; diluting the concentration of spores to 107 pieces / mL, inoculating the spores into a YEPD liquid culture medium, carrying out shake-flask culture for 2 days, and filtering and collecting hyphae; and S12, preparing the Ilyonectria fungus protoplast, namely adding the hypha prepared in the step S11 into the enzymatic hydrolysate, performing enzymolysis in a shaker at the temperature of 30 DEG C at the rotating speed of 150-200rpm for 3-5 hours, filtering, centrifuging filtrate at the temperature of 4 DEG C, discarding supernate, adding 0.7 M NaCl for centrifuging, and discarding the supernate, thereby obtaining the Ilyonectria fungus protoplast. The genetic transformation constructed by the invention can be used for exploring the specific action and mechanism of a specific pathogenic gene in the pathogenic process of Ilyonectria fungi through gene knockout or overexpression experiments.

The invention belongs to the technical field of microbial genetic engineering, and particularly relates to an alpha-2, 3-sialyltransferase mutant and application thereof. The a-2, 3-sialyltransferase mutants V175N, P198A, G173D, D174Q, F196K and A315H are obtained by performing site-specific mutagenesis on six amino acids in an a-2, 3-sialyltransferase amino acid sequence coded by a gene derived from Campylobacter jejuni (OH4384), the yield of 3 '-sialyllactose is remarkably increased by single-point mutagenesis of the V175N, the yield of 3'-sialyllactose is remarkably increased by single-point mutagenesis of the V175N, the yield of 3 '-sialyllactose is remarkably increased by single-point mutagenesis of the P198A, the G173D, the D174Q, the F196K and the A315H, the optimal recombinant microbial strain 3 '-SL-09 (V175N / P198A / D174Q) is obtained through combination of multiple mutation sites, the yield can reach 5.91 g / L, the bottleneck problem of low catalytic efficiency of sialyltransferase is effectively solved, and an enzyme element with excellent performance is provided for high-efficiency and low-cost biological manufacturing of 3'-SL.

The invention discloses a transport protein of Stemphylium solanol A as well as a coding gene and application thereof, and relates to the technical field of microbial genetic engineering. The transporter is any one of (1), (2) and (3): (1) SvMFS1 protein, the amino acid sequence of which is as shown in SEQ ID NO.3; (2) carrying out substitution, deletion and / or addition of one or more amino acid residues on the amino acid sequence of the SvMFS1 protein to obtain a protein which has more than 90% of identity with the SvMFS1 protein and is related to crosslink solanol A transport; and (3) a fusion protein obtained by connecting a protein tag to the N terminal or / and C terminal of (1) or (2). Research finds that overexpression of the coding gene of the transporter in Stemphylium cystosum can significantly improve the yield of interlinked solanol A, thereby providing a new direction for developing microbial-sourced interlinked solanol A.

The invention belongs to the field of application of microbial genetic engineering and metabolic engineering, and particularly relates to a method for improving the biosynthesis efficiency of sclareol. Specifically, in a host strain, gene knockout is realized through a CRISPR / Cas9 technology, or / and a DNA fragment is introduced, and a strain metabolic pathway is adjusted to obtain a corresponding engineering strain; carrying out biosynthesis by utilizing the obtained engineering strain to obtain sclareol; the gene knockout is realized by introducing donor DNA (Deoxyribose Nucleic Acid) containing upstream and downstream homologous arms of a coding frame; the DNA fragment sequentially comprises an upstream homologous arm, a promoter, a gene, a terminator and a downstream homologous arm from upstream to downstream, the host strain is selected from any one of saccharomyces cerevisiae. According to the method, the cell life is associated with product synthesis, and meanwhile, metabolic balance is coupled, so that the synthesis efficiency of a target product is improved, and a foundation is laid for industrial fed-batch fermentation.

The invention relates to the field of microbial genetic transformation, and discloses a preparation method of Ilyonectria robus fungus protoplast and a construction method of a genetic transformation system.The preparation method comprises the following steps that S11, I.robus hyphae are prepared, after I.robus is cultured on a PDA solid culture medium for 14 days, the I.robus hyphae are inoculated to a CMC liquid culture medium to be subjected to shake-flask culture, and spores are filtered and collected; diluting the spore concentration, inoculating into a YEPD liquid culture medium, carrying out shake-flask culture, filtering and collecting hyphae; and S12, preparing enzymatic hydrolysate, namely adding the hyphae prepared in the step S11 into the enzymatic hydrolysate prepared in the step S12, carrying out shake flask enzymolysis, filtering, centrifuging filtrate, discarding supernate, adding a 0.7 M NaCl solution, centrifuging, and discarding the supernate, so as to obtain the I.robus fungus protoplast. The protoplasts with proper quantity and good quality can be efficiently obtained, and the transformation efficiency of a subsequent genetic transformation system is improved; and the constructed genetic transformation system can be used for construction of a mutant library of the I.robusta strain, interaction of a host plant and the I.robusta strain and research on the pathogenesis of the I.robusta strain.

The invention discloses a 5 'UTR library, a recombinant expression vector and a genetically engineered bacterium for improving the yield of folamin in pathogenic bacterium Badei and application of the 5' UTR library and the genetically engineered bacterium, and belongs to the technical field of microbial genetic engineering. The method comprises the following steps: designing an SD region based on a 16S rRNA (ribosomal Ribonucleic Acid) 3'end complementary sequence of a Buddei pathogenic bacterium XBD101 serving as an original strain, regulating and controlling the number of bases between the SD sequence and an initiation codon AUG and optimizing an UTR secondary structure to construct a library containing 14 UTR sequences, and replacing three sequences N4A, N7A and N18A with the strongest translation ability in the library to the UTR region of a folamin synthesis key gene fclC, so as to obtain the folamin peptide. And finally, the capacity upgrading of the folamin chassis strain is realized, and an important support is provided for the industrial production of agricultural antibiotics.

The invention belongs to the field of microbial genetic engineering, and provides schizochytrium limacinum with high DHA content and low DPA content and application of the schizochytrium limacinum. According to the strain, an n3 front-end desaturase gene derived from crypthecodinium cohnii is integrated to a 18S rDNA site of schizochytrium limacinum ALS01, and omega-6 type DPA is converted into DHA by utilizing an extension-desaturation way. Under the optimized conditions of a 5L fermentation tank (the inoculation amount is 5-20%, the temperature is 25-28 DEG C, the ventilation ratio is 1.0-2.0 vvm, and fermentation is performed for 72-168 hours), the biomass is larger than or equal to 150g / L, the total grease is larger than or equal to 60%, the DHA total grease proportion is larger than or equal to 53%, the DPA total grease proportion is smaller than or equal to 2%, and the DHA yield is larger than or equal to 47.82 g / L. The invention solves the problems of unstable fish oil resource and insufficient DHA purity in the traditional DHA production, provides a new strain for the industrial production of high-purity DHA, and has important application value.

The invention discloses a pathogenicity-related sclerotinia sclerotiorum gene SsVSP19 and application thereof, and belongs to the technical field of microbial genetic engineering, the pathogenicity-controlling gene SsVSP19 from sclerotinia sclerotiorum provided by the invention has a DNA sequence as shown in SEQ ID No: 1, and consists of 1298 nucleotides; the amino acid sequence of the protein coded by the provided SsVSP19 gene is as shown in SEQ ID No: 2, and the protein consists of 332 amino acids; the SsVSP19 gene can be applied to the field of plant sclerotinia sclerotiorum gene engineering. The gene SsVSP19 for controlling pathogenicity of sclerotinia sclerotiorum is knocked out, so that the pathogenicity of the gene SsVSP19 has defects, and the gene SsVSP19 can be applied to reducing the pathogenicity of sclerotinia sclerotiorum.

The invention belongs to the technical field of microbial genetic engineering, and particularly relates to an alpha-2, 6-sialyltransferase mutant and application thereof. The a-2, 6-sialyltransferase mutants M133L, E140D, D228H, N289D and G322Q are obtained by carrying out site-specific mutagenesis on five amino acids in an a-2, 6-sialyltransferase amino acid sequence coded by a gene derived from Photobacterium sp.JT-ISH-224, and compared with wild type alpha-2, 6-sialyltransferase, the yield of the single-point mutant 6 '-SL of the E140D and the yield of the single-point mutant 6'-SL of the G322Q are increased by 87.80% and 78.01% respectively. The yield of the optimal recombinant microbial strain 6 '-SL-7 (E140D / G322Q) obtained by mutation site combination can reach 1.471 g / L, the bottleneck problem of low catalytic efficiency of sialyltransferase is effectively solved, and an enzyme element with excellent performance is provided for high-efficiency and low-cost biological manufacturing of 6'-SL.

The invention relates to a construction method and application of recombinant escherichia coli for increasing the yield of lactoyl-N-tetrasaccharide, and belongs to the field of microbial genetic engineering. According to the invention, three genes tauB, nikD and livM screened by using a transcriptome technology are proved to be capable of promoting the generation of LNT and LNTri II. An engineering strain MG-LNT-09 is used as a starting strain, the biosynthesis efficiency of endogenous transporter genes tauB, nikD, livM, LNT and LNTri II derived from Escherichia coli K-12 derivative bacteria MG1655 is remarkably improved through single plasmid overexpression, the yield of the LNT in shake-flask culture is as high as 7.77 g / L, and the yield of the LNTri II is as high as 3.03 g / L. The optimized strain MG3WB of which the tauB gene is integrated to the hlyE site obtains the maximum LNT titer of 40.35 g / L in a 5L bioreactor without using any antibiotics or plasmids, has a good industrial prospect, and lays a foundation for further industrial production and synthesis of other complex breast milk oligosaccharides.

The invention discloses a method for producing phloretin by using saccharomyces cerevisiae, and belongs to the technical field of microbial genetic engineering. A natural metabolic phloretin path in a plant is successfully constructed in the saccharomyces cerevisiae BY4741, synthesis of phloretin in microorganisms is achieved, synthesis of the phloretin in the microorganisms is enhanced by enhancing synthesis path genes of tyrosine and phenylalanine in the saccharomyces cerevisiae, including elimination of tyrosine feedback inhibition and introduction of exogenous genes, synthesis of prerequisite tyrosine and phenylalanine is enhanced, and the yield of the phloretin is increased. And the yield of the phloretin is further improved by enhancing the expression of a key gene in a phloretin synthesis pathway. The yield of phloretin synthesized from the beginning by the engineering yeast can reach 246.21 mg / L, the synthesis problem of phloretin serving as a carbohydrase inhibitor is effectively solved, and a foundation is laid for synthesizing phloretin through efficient fermentation of microorganisms.

The invention discloses a Stemphylium alcohol dehydrogenase as well as a coding gene and application thereof, and relates to the technical field of microbial genetic engineering. The alcohol dehydrogenase is any one of (1), (2) and (3): (1) SvADH1 protein, the amino acid sequence of which is as shown in SEQ ID NO.3; (2) carrying out substitution, deletion and / or addition of one or more amino acid residues on the amino acid sequence of the SvADH1 protein to obtain a protein which has more than 70% of identity with the SvADH1 protein and is related to cross-linked solanol A redox; and (3) a fusion protein obtained by connecting a protein tag to the N terminal or / and C terminal of (1) or (2). Research finds that overexpression of the coding gene of the alcohol dehydrogenase in Stemphylium cystosum can significantly improve the yield of the interlinked solanol A, so that a new direction is provided for developing the interlinked solanol A from microorganisms.

This invention relates to the fields of microbial genetic engineering and fermentation biomanufacturing technology, specifically disclosing a recombinant Corynebacterium glutamicum with high 5-aminolevulinic acid (ALA) production and its applications. Addressing the problems of existing strains such as crude enzyme activity regulation, inhibited cell growth, the need for external inhibitors, and low yield, this invention uses Corynebacterium glutamicum as a host and removes the gdhA gene without scarring to reduce precursor competitive metabolism. Site-directed mutations of the endogenous hemB gene (S288A, D128E, R231K) are performed to moderately reduce dehydratase activity. A high-expression plasmid pXMJ19-hemA containing the hemA gene from Rhodopsinus capsulatum is constructed and introduced into the modified strain to obtain a recombinant strain with optimized triple metabolism. This strain reduces product degradation without the need for external dehydratase inhibitors, does not affect cell growth, and achieves a yield up to 4.30 times higher than the control after 42 hours of fermentation, with ALA accumulation exceeding 8.9 g / L. The strain exhibits stable characteristics, the process is simple, and it has good industrial application value.

The invention belongs to the technical field of microbial genetic transformation, and particularly relates to a method for high-yield production of pleurotus ostreatus transformants, a genetic transformation system and application of the genetic transformation system. Through optimization of protoplast preparation conditions, the number of the obtained protoplast is 4.95 * 10 < 8 > CFU.mL <-1 >, and the regeneration rate of the protoplast in an OM-YEPS regeneration culture medium is 12.7%. A method for producing high-yield pleurotus ostreatus transformants is researched by using a PEG-mediated protoplast transformation method, a set of efficient and stable genetic transformation and screening method is established, about 200-300 positive transformants with stably expressed exogenous genes are obtained, and the transformation efficiency is 65.38%. The genetic transformation system of the high-yield Pleurotus ostreatus transformant, constructed by the invention, lays a solid technical foundation for subsequent gene function verification, metabolic engineering transformation and molecular breeding with excellent characters, and further accelerates the biological research and industrial application process of Pleurotus ostreatus and even other macro fungi.

The invention belongs to the field of microbial genetic engineering. The invention particularly relates to a tylosin industrial high-yield strain as well as a construction method and application thereof. The sequence of the ALDH interfering gene is as shown in SEQ ID NO: 3. The industrial high-yield strain of tylosin is obtained by regulating and controlling the ALDH gene of an original strain. The strain is applied to fermentation production of tylosin and related derivatives thereof. The CRISPR i technology is utilized to inhibit in streptomyces fradiae to regulate and control ALDH gene expression, the gene is knocked out by using the homologous recombination technology, and then an engineering strain for high-yield tylosin is obtained. The engineering strain can improve the fermentation yield of tylosin by 6.8% and 9.9%.

The invention provides a CcUOX gene of Colletotrichum camelliae and an application thereof. The CcUOX gene is related to pathogenicity and purine metabolism, belongs to the technical field of microbial genetic engineering, comes from Colletotrichum camelliae, and its cDNA sequence consisting of 906 nucleotides is shown in SEQ ID NO:1; a protein encoded by the provided CcUOX gene has an amino acid sequence consisting of 301 amino acids as shown in SEQ ID NO:2; the CcUOX gene can be applied in the field of tea tree anthracnose resistance genetic engineering, and can be applied in the fields of food science and engineering; an engineering strain expressing the CcUOX gene can be used for the degradation, utilization and environmental restoration of caffeine waste, and can be applied to uric acid degradation; and CcUOX can be used as a gene target in the design and screening of fungicidal bacteria for Colletotrichum camelliae.

The present invention belongs to the technical field of microbial genetic engineering, and particularly relates to an engineered strain for producing 2'-deoxyadenosine, a preparation method thereof and an application thereof. The engineered strain expresses a ketodeoxyadenosine reductase gene cns1 and an adenylic acid dephosphatase gene cns2 . The engineered strain prepared by the preparation method of the present invention has obvious advantages in the production of 2'-deoxyadenosine. By optimizing the fermentation medium conditions, the present invention improves the yield and efficiency of Corynebacterium glutamicum in synthesizing 2'-deoxyadenosine to varying degrees, and the yield reaches 702.3 mg / L on a 6L bioreactor.

The invention belongs to the technical field of microbial genetic engineering, and particularly relates to an acid-resistant lactobacillus plantarum engineering bacterium as well as a construction method and application thereof. The recombinant lactobacillus plantarum WCFS1-gadA-speA is obtained by constructing a recombinant expression vector pMG36e-gadA-speA and inducing the expression of two key genes, and the recombinant lactobacillus plantarum WCFS1-gadA-speA is obtained. The analysis of the fermentation capacity of the strain finds that compared with a single gene heterologous expression strain, the recombinant lactobacillus plantarum WCFS1-gadA-speA shows higher acid resistance and apple juice fermentation capacity. The recombinant lactobacillus plantarum WCFS1-gadA-speA with higher strong acid tolerance is obtained through a heterologous expression technology, a strain resource with better performance is provided for the food fermentation industry, and the quality and stability of a fermented product are improved.

The present invention discloses a recombinant saccharomyces cerevisiae for efficiently biosynthesizing inositol and its construction method and application, and belongs to the field of microbial genetic engineering. The recombinant saccharomyces cerevisiae of the present invention strengthens the expression of hexokinase gene hxk, inositol 3-phosphate synthase gene ino, inositol monophosphatase gene suhb, and realizes the rearrangement of glucose metabolism by knocking out the transcriptional repressor opi1 of inositol 3-phosphate synthase (Ino1) and glucose 6-phosphate dehydrogenase gene zwf1, and relieves feedback inhibition; In addition, the present invention further increases the yield of inositol by screening inositol external emission protein gene ompf, ompc and knocking out inositol internal transport protein gene itr1, itr2. The present invention realizes the efficient production of inositol (yield is as high as 195.7g / L), with good industrialization prospect.

The invention belongs to the field of microbial genetic engineering, and particularly relates to an efficient homologous recombination method suitable for bifidobacteria and application of the efficient homologous recombination method. Specifically, the invention discloses a method for constructing and screening the combination of the single-chain annealing protein and the single-chain binding protein for the first time. According to the method, a single-chain annealing protein and a single-chain binding protein are jointly constructed in an escherichia coli-bifidobacterium shuttle expression vector, and co-expression of the single-chain annealing protein and the single-chain binding protein in bifidobacterium longum is realized, so that the homologous recombination capability of the bifidobacterium longum is remarkably improved. According to the method disclosed by the invention, the homologous recombination efficiency of genome editing of the bifidobacterium longum is greatly improved, the absolute genome editing efficiency of the bifidobacterium longum is improved to 0.00009792% from the original level which is almost undetectable, and the research and application progress of genome engineering of the strain is remarkably promoted, so that the method has a good practical application value.

The invention belongs to the field of microbial genetic engineering, and particularly relates to a saccharomyces cerevisiae engineering bacterium for producing cinnamyl alcohol as well as a construction method and application of the saccharomyces cerevisiae engineering bacterium. The recombinant saccharomyces cerevisiae comprises a phenylalanine ammonia lyase gene Arval derived from anoectochilus roxburghii, a phosphopantetheine ethylamine phosphotransferase gene Bssfp derived from bacillus subtilis, and a reductase gene Nicar derived from nocardia aralgarica, or a reductase gene Nicar of nocardia otitis media, or a carboxylic acid reductase gene Mpar of mycobacterium phlei. According to the invention, the total synthesis of cinnamyl alcohol in the saccharomyces cerevisiae is realized for the first time, and the cinnamyl alcohol produced by using the recombinant saccharomyces cerevisiae can reach 30.30 mg / L.

This invention discloses a method for preparing self-healing concrete based on microbial gene programming, belonging to the field of building materials technology. The method includes: constructing a recombinant engineered strain incorporating a urease gene cluster and a carbonic anhydrase gene; preparing a spore suspension and protecting it with a three-layer microencapsulation system of sodium alginate / chitosan / gelatin; preparing nutrient-releasing microspheres encapsulating calcium lactate and urea in a polylactic acid-glycolic acid copolymer; and mixing cement, standard sand, water, fly ash, microencapsulated spore particles, nutrient-releasing microspheres, nano-silica, and modified bentonite to prepare self-healing concrete. This invention enhances the urease activity of the strain through genetic engineering, protects the spores using a three-layer microencapsulation technology, and combines a nutrient-releasing system and nano-synergists to achieve efficient self-repair of concrete cracks.

This invention discloses a high-yield lactyl-3-4 ...5-4-4-4-4-4- N This invention relates to plasmid-free genetically engineered strains of tetrasaccharides and their applications, belonging to the field of microbial genetic engineering. The invention screened strains with higher activity. β -1,3-galactosyltransferase gene PmgalT Computer-aided enzyme function modification was used to achieve a shake-flask yield of 10.05 g / L for the constructed mutant. Subsequently, genome integration was performed... breast Multi-copy integration PmgalT * V27I / V39I / Y147F ‑galE‑galU A plasmid-free strain was constructed, enabling it to grow in shake flasks with lactoyl- N The yield of tetrasaccharides reached 14.4 g / L. Using glucose as the sole carbon source, the highest yield of 68.19 g / L was achieved at 64.5 h; using glycerol as the sole carbon source, the highest yield of 62.88 g / L was achieved at 60.5 h, providing a basis for its industrial production.

The invention relates to the field of microbial genetic engineering and synthetic biology, and particularly discloses a yersinia pseudotuberculosis temperature-sensitive promoter and application thereof. The screened and identified temperature-sensitive promoter element fills the blank of efficient constitutive promoter resources of yersinia pseudotuberculosis. The promoters can be used as universal gene expression regulation modules to be applied to metabolic engineering and synthetic biology research of yersinia pseudotuberculosis and other prokaryotic hosts, and are beneficial to high-efficiency expression of target protein or biosynthesis of high-value products. According to the method, the expression of the target gene can be regulated and controlled by changing the culture temperature without adding chemical inducers, so that the operation is convenient, the cost is saved, and the method has outstanding advantages in large-scale fermentation production.

The invention provides an arthrobotrys oligospora genetic engineering strain with nematode attracting activity, and belongs to the technical field of microbial genetic engineering, the genetic engineering strain takes arthrobotrys oligospora as a starting strain, and the genetic engineering strain is a strain obtained by knocking out an AoETF beta gene in an arthrobotrys oligospora genome. The arthrobotrys oligospora genetic engineering strain has nematode attraction activity, and can attract nematodes in soil to gather together so as to achieve the effect of efficiently capturing and killing the nematodes, thereby providing a basis for biological control of the nematodes. The invention further provides a construction method and application of the arthrobotrys oligospora genetic engineering strain with nematode attracting activity.

The invention provides application of protein in construction of engineering bacteria for producing 6 '-sialic acid lactose, and relates to the technical field of microbial genetic engineering. According to the invention, new alpha2, 6-sialyltransferase with the potential of producing 6 '-sialyllactose is obtained through screening, and genes for coding precursor CMP-Neu5Ac synthetic pathway enzyme and alpha2, 6-sialyltransferase are introduced into escherichia coli to construct a new biosynthesis pathway of 6'-sialyllactose so as to construct engineering bacteria for efficiently producing 6 '-sialyllactose. Besides, a precursor CMP-Neu5Ac synthetic pathway enzyme and alpha2, 6-sialyltransferase are integrated and expressed in the engineering bacteria, so that the instability problem caused by plasmids is avoided, meanwhile, the dependence on antibiotics in the production process is reduced, and the environmental risk in the production process is reduced.