826 results about "Biosynthesis" patented technology

The invention discloses a biosynthesis system for high-yield 1, 6-hexamethylenediamine and application of the biosynthesis system, and belongs to the technical field of biology. According to the method, key genes which are excavated and optimized in a 1, 6-hexamethylenediamine biosynthetic pathway are co-expressed in a single cell module or a multi-cell module, and different enzyme elements expressed by the cell module are subjected to enzyme cascade reaction, so that 1, 6-hexamethylenediamine can be efficiently synthesized by taking caprolactam or 6-aminocaproic acid as a substrate; furthermore, after the carboxylic acid reductase MaCAR is mutated, the catalytic activity of the carboxylic acid reductase MaCAR can be remarkably improved, and the yield of the 1, 6-hexamethylenediamine is further improved; in addition, the biosynthesis system disclosed by the invention directly takes the cell module as a whole-cell catalyst, and an enzyme purification step is avoided, so that the biosynthesis system has the advantage of low cost.

The invention relates to the technical field of biology, in particular to a beta-1, 4-galactosyl transferase mutant and a method for biologically synthesizing lactose-N-neotetraose by using the beta-1, 4-galactosyl transferase mutant. The invention discloses a protein, which is a protein HpgalT-186 or a protein HpgalT-146-186, a protein HpgalT-146 and a protein HpgalT-146. The protein HpgalT-186 is a protein obtained by mutating an amino acid residue at the 186th site of a wild type HpgalT; the protein HpgalT-146-186 is a protein obtained by carrying out mutation on an amino acid residue at the 186 site and an amino acid residue at the 146 site of wild type HpgalT. On the basis, a series of escherichia coli is constructed and optimized, the yield of the LNnT synthesized through shake flask fermentation of the finally obtained strain reaches 1.73-4.1 g / L, the highest yield in a 5L fermentation tank reaches 20-45.2 g / L, and efficient synthesis of the LNnT is achieved.

The invention discloses an indole-benzothiadiazole derivative as well as a preparation method and application thereof. The general structural formula of the indole-benzothiadiazole derivative provided by the invention is shown in the specification, wherein R is selected from one of methyl piperazinyl, diethylamino, azetidinyl and pyrrolidinyl. The derivative can be specifically combined and fluorescently labeled with mitochondrial RNA in cells, and has good selectivity, high fluorescence signal-to-noise ratio and excellent anti-interference capability in a complex biological system. Meanwhile, the indole-benzothiadiazole derivative provided by the invention is simple in synthetic route, easily available in raw materials, good in stability and convenient to store and use, can be specifically combined with RNA and generate strong fluorescence response, is suitable for real-time detection and imaging of in-vitro and in-vivo mitochondrial RNA, and is an efficient mitochondrial RNA micromolecular fluorescent probe.

The invention provides a biosynthesis inhibitor of migratory locust aggregation pheromone 4-vinyl anisole and application of the biosynthesis inhibitor. The biosynthesis inhibitor of migratory locust aggregation pheromone 4-vinylanisole reduces the activity of 4-vinylphenol methyltransferase, and the 4-vinylphenol methyltransferase contains an amino acid sequence selected from the following sequences: (a) a sequence as shown in any one of SEQ ID No.1 and SEQ ID No.3; and (b) a sequence which is obtained by deleting, inserting and / or substituting one or more amino acid residues in the sequence shown in any one of SEQ ID No.1 and SEQ ID No.3 and has the activity of catalyzing generation of migratory locust aggregation pheromone 4-vinyl anisole. The inhibitor can be applied to biological prevention and control of migratory locusts, can keep locusts in a harmless scattered state instead of killing the locusts, provides a new method for biological prevention and control of migratory locusts, and has a wide application prospect.

The invention belongs to the field of biosynthesis, and in particular relates to LBD (Levandanenediol Pyrophosphate) synthase and engineered yeast for producing sclareol. In order to solve the problem that in the prior art, the sclareol biosynthesis yield is generally low, LSLPPs mutant containing at least one mutation of D730L, D374L, N674L or G379M is obtained by performing mutation and optimization on LSLPPs pyrophosphate synthase, and the mutant is used for sclareol synthesis. Meanwhile, in order to solve the problem of genetic instability caused by free plasmid expression of part of saccharomyces cerevisiae strains, a sclareol synthesis pathway is constructed in a yeast genome, and meanwhile, an acetyl coenzyme A synthesis pathway, an MVA pathway and a sclareol synthesis pathway are enhanced; chassis bacteria for synthesizing sclareol are modified in a manner of knocking out part of transcription inhibition factors, and the yield of a 5L fermentation tank reaches 26.11 g / L and is greatly improved compared with the prior art.

The invention discloses a flavonoid glycoside glycosyltransferase LbUGT71BX1 in laportea bulbifera as well as the coding gene and the use thereof. The amino acid sequence of the flavonoid glycoside glycosyltransferase LbUGT71BX1 is shown as SEQ ID NO: 2. The nucleotide sequence of the coding gene of the flavonoid glycoside glycosyltransferase LbUGT71BX1 is shown as SEQ ID NO: 1. According to the invention, on the basis of relevant results of the second-generation transcriptome and the third-generation full-length transcriptome sequencing of the laportea bulbifera, the last-step key enzyme LbUGT71BX1 for the synthesis of the flavonoid glycoside in the laportea bulbifera is screened and identified by using a reverse genetics method, filling the terminal blank of the biosynthesis pathway of the flavonoid glycoside in the laportea bulbifera.

The invention discloses application of an apple MdMYS1 gene in regulating and controlling the wax content of plant fruits and leaves, and belongs to the technical field of plant genetic engineering. According to the invention, the MdMYS1 gene with high expression quantity in apple varieties with more waxiness is separated, and the nucleotide sequence of the MdMYS1 gene is shown as SEQ ID NO. 1. Through subcellular localization, the transcription factor expressed by the MdMYS1 gene is found to be localized on a cell nucleus. Experimental results show that overexpression of the MdMYS1 gene can significantly increase the wax content of the apple fruits and leaves by promoting biosynthesis of wax, which indicates that the MdMYS1 gene plays a key role in regulation and control of the wax content of the apple fruits and leaves. The invention provides an efficient and rapid way for apple breeding, provides a gene material for improving apple quality, and has a wide application prospect in improving economic benefits and ecological benefits of apple planting.

The invention belongs to the field of biosynthesis, and particularly relates to sclareol synthase and engineered yeast for producing sclareol. In order to solve the problem that in the prior art, sclareol biosynthesis yield is generally low, sclareol synthase is mutated and optimized, an SsScs mutant containing at least one mutation of Y491F, G307L or N269F is obtained, and the mutant is used for sclareol synthesis. Meanwhile, in order to solve the problem of genetic instability caused by free plasmid expression of part of saccharomyces cerevisiae strains, a sclareol synthesis pathway is constructed in a yeast genome, and meanwhile, an acetyl coenzyme A synthesis pathway, an MVA pathway and a sclareol synthesis pathway are enhanced; chassis bacteria for synthesizing sclareol are modified in a manner of knocking out part of transcription inhibition factors, and the yield of a 5L fermentation tank reaches 21.13 g / L and is greatly improved compared with the prior art.

The present invention discloses a yeast engineering bacterium containing a (-)-α-bisabolol synthase mutant and its application. By designing (-)-α-bisabolol synthase, the present invention obtains a mutant with high expression level, co-expresses the mutant with ERG20, highly expresses the key rate-limiting enzymes in the metabolic pathway, deletes the promoter to reduce the side reaction pathway, and adopts a multi-copy strategy to improve the metabolic flux in the (-)-α-bisabolol biosynthesis pathway. The shake-flask fermentation yield of the yeast engineering bacterium constructed by the present invention is close to 70 mg / L, which is about 35 times higher than that of the starting strain, and has broad application prospects in the biological fermentation production of (-)-α-bisabolol.

The invention discloses a novel biosynthesis path for producing 3 '-phosphoadenosine-5'-phosphosulfuric acid and application, and belongs to the technical field of bioengineering. According to the invention, through recombinant expression and purification of ribose kinase, ribose phosphate pyrophosphate kinase, ribose phosphate transferase, adenine thiotransferase, adenosine phosphate sulfate kinase and polyphosphate kinase 2, a six-enzyme cascade reaction taking ribose and adenosine as substrates in vitro is constructed, the molar conversion rate reaches 22.85%, and the escherichia coli and bacillus subtilis PAPS cell factory can be used for preparing the recombinant ribose phosphate pyrophosphate kinase, the ribose phosphate transferase, the adenine thiotransferase, the adenosine phosphate sulfate kinase and the polyphosphate kinase 2. The yield of PAPS in a 5-L fermentation tank reaches 7.60 g / L and 5.03 g / L respectively. The PAPS synthesis route provided by the invention provides an extensible, economical and efficient solution for the production of sulfated compounds.

The invention focuses on the fields of biotechnology and sanitary disinfection, and successfully separates five brand-new small molecule peptides (small molecule peptides K, L, M, N and O) from herba violae and spica prunellae. According to the innovative extraction method from raw material pretreatment, mixed extraction to multi-step purification, a disinfection action mechanism of destroying pathogen cell membranes, interfering energy metabolism and inhibiting biosynthesis by small molecular peptides is defined. The small molecule peptides show the advantages of efficient disinfection activity, high safety, good stability and difficult generation of drug resistance. On the basis, a series of products such as hygienic disinfection spray, wet tissues and hand sanitizer are developed, the market application prospect is wide, remarkable economic and social benefits can be brought, and a brand-new and high-quality solution is provided for the field of hygienic disinfection.

The invention belongs to the technical field of genetic engineering breeding, and particularly relates to application and a method of a transcription factor CaBTF3 for regulating capsorubin synthesis. According to the capsicum transcription factor CaBTF3 and the coding gene thereof provided by the invention, the biosynthesis of capsorubin can be influenced by adjusting the expression level of a key enzyme gene in a capsorubin synthesis route and regulating and controlling the development and quantity of fruit chloroplast, the expression of the CaBTF3 gene in capsicum fruits is inhibited, the accumulation amount of capsorubin in the capsicum fruits can be reduced, and the yield of capsorubin is increased. The color of the pepper fruit is further influenced. By enhancing the expression level of the CaBTF3 gene, the content of capsorubin in capsicum fruits can be increased, the gene is applied to plant genetic engineering breeding, a new effective way is provided for creating capsicum varieties with high capsorubin content, and the gene plays an important role in improving the economic benefits of the capsicum industry and popularizing and applying the capsorubin.

The invention relates to a diacylglycerol acyltransferase capable of synthesizing triglyceride as well as a coding gene and application of the diacylglycerol acyltransferase, and belongs to the field of enzymology, the nucleotide sequence of the gene for coding the diacylglycerol acyltransferase is as shown in SEQ ID NO.1, and the amino acid sequence of the diacylglycerol acyltransferase is as shown in SEQ ID NO.2. The invention also provides a recombinant plasmid and a recombinant engineering bacterium containing the gene of the enzyme. Diglyceride and an acyl donor are used as substrates, and triglyceride is catalytically synthesized through an acyl transfer reaction by using the enzyme. The invention provides an efficient tool for realizing enzymatic biosynthesis and large-scale production of natural triglyceride.

The invention belongs to the technical field of biosynthesis, and particularly relates to a strain for producing sclareol as well as a construction method and application of the strain. In order to solve the problem of microbial synthesis of sclareol, phosphoketolase in an NOG pathway is mutated and optimized, phosphoketolase NaXpk from nanoarchaea archaeon is subjected to site-directed mutagenesis, a sclareol synthesis pathway is constructed in an escherichia coli host, the influence of NaXpk before and after mutation on the yield of sclareol is compared, and the yield of sclareol is improved. The S472F mutant and the S472Y mutant are determined, the S472F mutant and the S472Y mutant are applied to a sclareol production path, the sclareol yield of the finally obtained production strains can reach 623.3 mg / L and 655.2 mg / L, and the effect is remarkable.

The invention belongs to the technical field of synthetic biology, and particularly relates to recombinant escherichia coli for efficiently producing O-acetyl-L-homoserine as well as a construction method and application of the recombinant escherichia coli. According to the invention, CRISPR-Cas9 gene editing is combined with metabolic modification, so as to precisely integrate OAH biosynthesis key nodes: introducing and overexpressing a mutant metX gene at a genome pseudogene site to enhance the expression of homoserine acetyltransferase, knocking out byproducts such as poxB and mgsA to synthesize genes, and carrying out high-yield synthesis of OAH. Corynebacterium glutamicum thrA (anti-feedback inhibition), aspB and bacillus subtilis acsA-acuA genes (construction of an acetic acid switch) are introduced, gene expression of gltA, tpiA and the like is optimized to increase supply of precursors such as acetyl CoA and the like, and finally a stable strain without plasmids, antibiotics and inducers is obtained. The production cost is effectively reduced, and the method has the advantage of high genetic stability and shows a good application prospect in OAH industrial production.

The utility model discloses a medicine fermentation device for biosynthesis, which is characterized in that a stirring shaft is of a hollow pipe structure, a stirring blade is of a jacket structure communicated with the inside of the stirring shaft, and a plurality of exhaust gaps are formed in the stirring blade; a rotary sealing joint is arranged at the lower end of the stirring shaft and is hermetically communicated with an air pump through an air guide pipe; wherein liquid stored in the buffering agent storage box and liquid stored in the weak base storage box are fed into the tank body through a micropump and a guide pipe respectively. According to the utility model, aeration and the stirrer are integrated together, specifically, the air pump is used for providing air for the stirring shaft, the stirring motor is used for driving the stirring shaft to rotate at the same time, and in the process that the stirring shaft drives the stirring blades to rotate, the air in the stirring blades is dispersed into the fermentation liquid through the exhaust gaps; through the hidden design of the aeration structure, the complexity of the aeration equipment is reduced, and subsequent cleaning is facilitated.

The invention discloses a method for biological high-density synthesis of retinaldehyde and a synthetic strain thereof. The synthetic strain is obtained by expressing ATP citrate lyase ACL, acetyl-CoA synthase ACS, choline kinase CK, inositol polyphosphate kinase IPK and vitreoscilla hemoglobin VHb in host bacteria. Wherein the host bacterium is a pichia pastoris gene modified bacterial strain PP-B2C. The retinaldehyde production performance of the recombinant strain is verified on the basis of a precursor supply pathway, an IUP pathway and a dissolved oxygen level, and the retinaldehyde production capacity of the pichia pastoris is further improved. The construction method of the recombinant pichia pastoris is simple, the synthesis of retinaldehyde can be better promoted, and the retinaldehyde can be efficiently synthesized by the engineering strain by utilizing glucose and methanol through amplification fermentation of a 5L fermentation tank, so that the recombinant pichia pastoris is beneficial to industrial production.

The invention belongs to the technical field of biosynthesis, and particularly relates to a method for regulating and controlling stevioside production through a UDPG synthesis route. According to the invention, a high-efficiency stevioside biosynthesis system is constructed through systematic engineering modification: in the aspect of chassis cell optimization, transcription factors (AtWRKY18, AtWRKY40 and AtMYC2) for regulating and controlling MEP pathway and key genes (dxs and / or dxr) of the MEP pathway are over-expressed, so that supply of terpene precursors is enhanced; and a heterologous MVA pathway (over-expression T7-atoB-mvaS-mvaE-mvK / mvKmut-pmK-mvaD-idi) with a modular design is introduced, so that sufficient supply of the terpenoid precursor is realized. Meanwhile, the intracellular concentration of the UDPG is increased by systematically enhancing a UDPG synthesis pathway (knocking out ugd, glgc, ushA, agp, deoA, tdk, udp, or thrA, and overexpressing galU, pgm, pyrE, pyrH, ugpA, or prs), so that the production capacity of the stevioside is remarkably improved.

The invention discloses a high-yield lycopene recombinant rhodobacter sphaeroides strain as well as a construction method and application thereof, and belongs to the technical field of biosynthesis and biological energy sources, the construction method comprises the following steps: knocking out a crtC gene of rhodobacter sphaeroides by using a homologous recombination method to obtain a recombinant strain RS01; the method comprises the following steps: on the basis of a strain RS01, replacing a crtI3 gene on a rhodobacter sphaeroides genome with a crtI4 gene (from rhodospirillum rubrum) by using a homologous recombination method to obtain a recombinant strain RS02; the method comprises the following steps: connecting crtB and crtE genes to a pYYDT vector to construct a plasmid pYYDT-crtB-crtE, transferring the plasmid pYYDT-crtB-crtE into escherichia coli S17, and then introducing the plasmid pYYDT-crtB-crtE into a recombinant rhodobacter sphaeroides RS02 in a conjugational transfer manner to obtain a recombinant strain RS03. The recombinant rhodobacter sphaeroides constructed by the invention can be used for efficiently producing lycopene.

The invention belongs to the technical field of biosynthesis, and particularly relates to a method for regulating and controlling stevioside production by improving the utilization rate of a carbon source. According to the invention, a high-efficiency stevioside biosynthesis system is constructed through systematic engineering modification: in the aspect of chassis cell optimization, transcription factors (AtWRKY18, AtWRKY40 and AtMYC2) for regulating and controlling MEP pathway and key genes (dxs and / or dxr) of the MEP pathway are over-expressed, so that supply of terpene precursors is enhanced; and a heterologous MVA pathway (over-expression T7-atoB-mvaS-mvaE-mvK / mvKmut-pmK-mvaD-idi) with a modular design is introduced, so that sufficient supply of the terpenoid precursor is realized. Meanwhile, by knocking out related genes and bypass metabolism genes (mgsA, iclR, menA or adhE) synthesized by organic acid, a glucose transport and utilization system (fnr, fadR, ppc, zwf or pgi is knocked out, and ACS, fbaA, tpiA, glf, galP or ptsG is overexpressed, so that the utilization rate of a carbon source is further improved, and the production capacity of stevioside is remarkably improved.

Provided are a nerolidol synthetase comprising structural domains having Pfam numbers PF01397 and PF03936, and a use thereof. The amino acid sequence of the nerolidol synthase is as shown in SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 11, or SEQ ID NO: 12, and a nucleotide sequence encoding a nucleic acid molecule is as shown in SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, or SEQ ID NO: 10. The use includes: integrating a coding gene of the nerolidol synthetase into a nucleic acid construct and introducing same into a host cell to obtain a recombinant bacterium, so that the coding gene is expressed in the recombinant bacterium. Thus, biosynthesis of nerolidol is implemented, and the yield of nerolidol is remarkably improved.

The invention provides a method for promoting synthesis of microcystis astaxanthin by adjusting the concentration of a stress substance, which comprises the following steps of: firstly, culturing microcystis algal bloom or microcystis aeruginosa to a logarithmic phase by adopting a BG11 culture medium under the conditions of specific temperature, illumination and shaking table rotating speed, and adjusting the cell density by centrifuging and resuspending; then, NaCl, KCl, beta-violet ketone, longifolene and H2O2 with different concentrations are added into the algae liquid respectively, control is set, through multi-dimensional index measurement, the algae cell density, the ROS level, the photosynthetic pigment content, the photosynthetic performance and the level of astaxanthin and a precursor thereof are monitored when treatment is carried out for 0 day, 2 days, 4 days and 6 days, the expression quantity of astaxanthin biosynthesis related genes is further analyzed, and the astaxanthin biosynthesis related genes are obtained. Therefore, the optimal concentration of NaCl, KCl, beta-violet ketone, longifolene and H2O2 is determined, the effect of promoting astaxanthin synthesis is compared, and a theoretical basis and a precise regulation and control method are provided for industrial production of astaxanthin by using microcystis.

The invention relates to the field of synthetic biology, in particular to a high-flux biosynthesis ink-jet printing control method and device, and the method comprises the steps: sequentially extracting base data from an obtained DNA base sequence file, and forming a one-dimensional original array; according to a preset printing width, the one-dimensional original array is converted into a two-dimensional array, meanwhile, visualization processing is carried out, corresponding colors are given to different basic groups, and a basic group distribution array diagram with matched row and column structures is obtained; establishing null arrays which correspond to different bases and are consistent in dimension based on the null arrays, traversing the original arrays and assigning values to the corresponding bases at the corresponding positions of the null arrays to obtain a plurality of single base arrays; converting the arrays into a two-dimensional array according to a preset width, and then converting the two-dimensional array into a monochromatic bitmap; and sending the bitmap according to the corresponding relationship between the basic groups and the nozzles and controlling printing. According to the invention, efficient and accurate printing of the base sequence in high-throughput biosynthesis is realized, and the synthesis efficiency and reliability are improved.

The invention discloses an antibacterial small peptide CsCAPE9 and application of the antibacterial small peptide CsCAPE9 in prevention and control of citrus huanglongbing. The amino acid sequence of the antibacterial small peptide CsCAPE9 is as shown in SEQ ID NO.1; the antibacterial small peptide CsCAPE9 provided by the invention is a small peptide synthesized in a plant body, and the antibacterial small peptide CsCAPE9 can activate biosynthesis of salicylic acid and induce systematic defense reaction of citrus. The antibacterial small peptide CsCAPE9 has a good inhibition effect on pathogenic bacteria of citrus huanglongbing in greenhouses and fields, and has a wide application prospect in comprehensive prevention and control of the huanglongbing.

The invention provides an engineering bacterium and a method for synthesizing sclarediol. Wherein the engineering bacterium comprises a sclareone synthase gene and a Bayer-Villiger monooxygenase gene, and the sclareone synthase comprises: (a1) a protein having any sequence in SEQ ID NOs: 1-25, or (a2) a protein having any sequence in SEQ ID NOs: 2-25, or (a3) a protein having any sequence in SEQ ID NOs: 2-25; (a2) protein which has more than 70% of homology with the amino acid sequence limited in (a1) and has sclareone synthase activity; the Bayer-Villiger monooxygenase comprises: (b1) a protein having any one sequence in SEQ ID NOs: 26-50, or (b2) a protein having any one sequence in SEQ ID NOs: 26-50; (b2) is protein which has more than 70% of homology with the amino acid sequence limited in (b1) and has Bayer-Villiger monooxygenase activity. The method can solve the problem of difficulty in efficient biosynthesis of sclarediol in the prior art, and is suitable for the field of synthetic biology.

The invention discloses arabinose glycosyl transferase PnUGT73B4 and application thereof to preparation of panax japonicus saponin IV, the amino acid sequence of the arabinose glycosyl transferase is shown as SEQ ID NO: 1, under the catalysis of the arabinose glycosyl transferase PnUGT73B4, UDP-arabinose is added to a glucuronic acid group on the C3 site of panax japonicus saponin IVa, and the panax japonicus saponin IV is generated; according to the method, the requirement for raw material plants can be reduced, agricultural land is saved, the product is single, preparation of the panax japonicus saponin IV is facilitated, the biosynthesis route of oleanane type triterpenoid saponin is analyzed, and a breakthrough solution is provided for biosynthesis of the panax japonicus saponin IV.

The present invention provides an engineered bacterium with a high yield of a direct precursor of oritavancin and its application. The high-yield engineered bacterium is Amycolatopsis orientalis, which knocks out the potential competitive biosynthesis pathway of the direct precursor of oritavancin (Chloroeremomycin) and highly expresses the rate-limiting enzyme gene of the direct precursor of oritavancin, thereby obtaining a high-yield bacterium of the direct precursor of oritavancin, and optimizes its fermentation process to increase the yield of the direct precursor of oritavancin to 3.1 times that of the starting bacterium, reaching 428 mg / L. The present invention combines the application of knocking out potential competitive metabolic pathways, enhancing the expression of rate-limiting enzymes and optimizing the fermentation process, successfully superimposing multiple high-yield strategies, greatly reducing the production cost of the direct precursor of oritavancin, and improving the biosynthesis efficiency of the direct precursor of oritavancin. This new strain has important application value in the industrial production of oritavancin.

The invention discloses glycosyltransferase in safflower and a related biological material and application thereof. The invention firstly discloses any one of the following proteins: A1) a protein consisting of an amino acid sequence as shown in a sequence 2; a2) a fusion protein obtained by connecting the N end or / and C end of the protein as shown in the sequence 2 with a protein tag. The invention further discloses the protein related biological material and application thereof. The HSYA biosynthesis key glycosyl transferase gene UGT708U5 is obtained from safflower for the first time, it is proved that the protein UGT708U5 coded by the gene can catalyze phloretin to form HSYA precursor compounds, namely phloretin-mono-C-glucoside and phloretin-di-C-glucoside, and the gene plays an important role in biosynthesis and heterologous production of HSYA; the method has important theoretical and practical significance for regulating and producing the quinonechalcone C-glycoside compounds of plants and cultivating high-quality safflower carthamus.

The invention relates to the technical field of synthesis of natural dyes by a biological method, in particular to an antibiotic-demand-free ornamental blue high-yield strain as well as construction and application of the antibiotic-demand-free ornamental blue high-yield strain. Corynebacterium glutamicum is used as an initial strain, a tricarboxylic acid circulating gene is regulated and interfered, and the copy number of exogenous blue pigment synthetase BpsA in a genome is adjusted, so that the ornamental blue high-yield strain is obtained. The strain does not need to use antibiotics in the fermentation process, the yield is stable, the product production capacity equivalent to the level when antibiotics are used can still be achieved through fermentation under the antibiotic-free condition, and the growth performance of the strain is kept. The method for producing the ornamental blue by using the strain provided by the invention ensures that the ornamental blue product is natural and green, also improves the efficient production capacity of the strain, solves the contradiction between green environmental protection and stable high yield of the ornamental blue dye, is green and environment-friendly, and has a remarkable industrial application prospect.

The invention discloses pichia pastoris for efficiently synthesizing lactoferrin as well as a construction method and application of the pichia pastoris, and belongs to the technical field of biosynthesis. The pichia pastoris for efficiently synthesizing the lactoferrin expresses at least one of KAR2, PDI1 and ERO1 in molecular chaperones in a host in an enhanced manner and carries an optimized secretory signal peptide, and the secretory signal peptide is obtained by replacing a leading peptide of alpha-factor with any signal peptide in LacZ, PelB, FLO and alpha-factor. The yield of LF can be effectively increased by enhancing expression of at least one of KAR2, PDI1 and ERO1 molecular chaperones in molecular chaperones in a host; when the lactoferrin expression cassette is integrated into the recombinant pichia pastoris X-33 genome and the copy number is increased to 2-6, the LF yield can be further increased, and when the copy number is 4, the LF yield reaches a peak value.