49 results about "Rate limiting enzyme" patented technology

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 application discloses a whitening and freckle-removing composition, conditioner, medicine and cosmetic. The whitening and freckle-removing composition comprises broccoli, ganoderma lucidum and inula japonica in the composition; the broccoli comprises broccoli raw materials and / or broccoli extract, the ganoderma lucidum comprises ganoderma lucidum raw materials and / or ganoderma lucidum extract, and the inula japonica comprises inula japonica raw materials and / or inula japonica extract. The application has significant synergistic activity by scientific compounding of the broccoli and the inula japonica, has significant inhibitory effect on tyrosinase activity, can inhibit the expression and function of the rate-limiting enzyme TYR in the melanin synthesis process, has significant whitening and freckle-removing activity, is safe and efficient, and can be applied to various conditioners, medicines and cosmetics.

The invention discloses a whitening and freckle-removing composition, a conditioner, a medicine and a cosmetic. The whitening and freckle-removing composition is prepared from emblic leafflower fruit, passion fruit and Chinese ladiestresses root and leaf A; the phyllanthus emblica comprises a phyllanthus emblica raw material and / or a phyllanthus emblica extract, and the passion fruit comprises a passion fruit raw material and / or a passion fruit extract. Through scientific compatibility of the Chinese ladiestresses root-ginseng A and the second active component comprising one or more of the emblic leafflower fruit, the passion fruit and the salvia officinalis, the Chinese ladiestresses root-ginseng A has a remarkable inhibition effect on tyrosinase activity, can inhibit expression and functions of rate-limiting enzyme TYR in the melanin synthesis process, has a remarkable whitening and freckle-removing active effect, and has a remarkable whitening and freckle-removing effect. The composition is safe and efficient, and can be applied to various conditioners, medicines and cosmetics.

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 present application relates to the technical field of medicine, and provides a kind of haena polysaccharide and its preparation method and application and target endogenous coagulation pathway anticoagulant and / or antithrombotic drug.The haena polysaccharide provided by the present application is fucosylated chondroitin sulfate polysaccharide, the weight average molecular weight is 9-13 million, the molar ratio of glucuronic acid, N-acetylglucosamine and fucose is 1:0.8-1.2:0.5-0.8, and the mass percentage content of sulfate group is 25-40%.The haena polysaccharide provided by the present application can target endogenous coagulation pathway terminal rate-limiting enzyme (iFXase), and has no obvious effect on coagulation factors in other coagulation pathways, realizes the effect of anticoagulation and non-hemorrhage, and can be widely applied in acute and recovery period treatment of ischemic stroke, solves the safety problem of using anticoagulant and antithrombotic drug for clinical ischemic stroke patients, and opens up a new field of research and development of target endogenous coagulation pathway rate-limiting enzyme anticoagulant drug.

The invention discloses application of a PAPSS2 inhibitor in preparation of a medicine for treating bladder cancer. Based on the principle that PAPSS2 inhibits p53 expression through sulfurylation modification and mediates purine metabolism reprogramming to promote bladder cancer progress, a sulfurylation rate-limiting enzyme PAPSS2 is used as a core target spot for bladder cancer treatment, the target spot is a key upstream molecule for regulating purine metabolism reprogramming, and high expression of the target spot is directly related to poor prognosis of bladder cancer; the PAPSS2 inhibitor is adopted to specifically inhibit expression or activity of PAPSS2, so that the pathway is intervened to block a metabolic reprogramming process of bladder cancer, and the core is to inhibit PAPSS2-mediated p53 sulfurylation modification and recover an inhibition function of p53 on purine metabolism. According to the invention, the feasibility and effectiveness of bladder cancer metabolism targeted therapy are obviously improved.

The invention relates to a hyaluronic acid high-yield strain based on metabolic flow optimization as well as a construction method and application thereof, and belongs to the technical field of genetic engineering. According to the corynebacterium glutamicum, sources of key rate-limiting enzymes UDP-glucose dehydrogenase and glutamine-fructose-6-phosphate aminotransferase are screened, and heterologous expression of hyaluronic acid synthase and overexpression of endogenous inositol permease and glucokinase are combined, so that the corynebacterium glutamicum capable of highly producing hyaluronic acid is constructed in a form of optimizing metabolic flux; according to the invention, the hyaluronic acid is used as a substrate, polyhydroxybutyrate synthase clusters are further overexpressed in the substrate, the glucose uptake and utilization efficiency of a host are improved, the metabolic coupling of cofactors is realized, the yield of the hyaluronic acid reaches 45g / L, the production intensity is 1.25 g / L / h, a brand new tool is provided for the production of the hyaluronic acid, and the method has an excellent application prospect.

The present application relates to the field of molecular biology, in particular to a kind of molecular marker related to the ascorbic acid content of tomato fruit development and its application, the present application is by screening the expression of ascorbic acid related gene-eGWAS data, identify a significant correlation with the ascorbic acid of tomato fruit structural variant (SV). The SV is located at the downstream 397bp of the rate-limiting enzyme GDP-L-galactose phosphorylase gene (GGP2, Solyc06g073320) of ascorbic acid synthesis pathway, it is a 25bp insertion / deletion at 42845487 of tomato chromosome 6. The present application further verifies the existence of the SV in resequencing tomato germplasm and develops molecular marker, and the results show that the molecular marker can be applied to the parent selection of high ascorbic acid tomato fruit selection.

The invention relates to the technical field of gene engineering, and discloses a high-strength promoter, a schizochytrium limacinum engineering bacterium based on the promoter and application of the schizochytrium limacinum engineering bacterium. Phosphoric acid pantetheinyl transferase (PPTase) is a key rate-limiting enzyme for biosynthesis of docosahexaenoic acid. Four high-strength promoters which can be strongly expressed in a schizochytrium limacinum chassis are obtained through screening and comprise a P3431 promoter, a P5659 promoter, a P6631 promoter and a P4862 promoter, and the nucleotide sequences of the promoter are shown as SEQ ID NO.1, SEQ ID NO.2, SEQ ID NO.3 and SEQ ID NO.4 respectively; furthermore, the high-strength promoter is connected with PPTase and is integrated into a schizochytrium limacinum genome, so that the yield of the docosahexaenoic acid is remarkably increased. After a P3431 promoter, a P5659 promoter, a P6631 promoter and a P4862 promoter are respectively connected with PPTase and are transferred into schizochytrium limacinum for expression, the docosahexaenoic acid yield is respectively increased by 25%, 37.5%, 43% and 36.5% compared with that of a wild type.

The invention relates to an application of oligosporine in preparation of a weight-reducing medicine. The invention finds that the oligosporine B can reduce the weight of mammals. Moreover, the further research finds that the weight loss of mammals can be realized due to the fact that triglyceride in fat cells is hydrolyzed into free fatty acid and glycerol by mainly enhancing the activity of a key rate-limiting enzyme responsible for lipid metabolism in the fat cells so as to reduce the blood fat level and lipid accumulation in the fat cells, so that the weight loss of the mammals can be realized. Therefore, the weight loss is realized by reducing the adipose tissue mass.

The invention relates to a homoserine-O-succinyltransferase mutant and application thereof, and belongs to the technical field of enzyme engineering. In order to solve the problem of low activity of a rate-limiting enzyme MetA for producing L-methionine through biological fermentation-enzyme catalysis coupling in the prior art, the homoserine-O-succinyl transferase mutant provided by the invention is obtained by carrying out site-directed mutagenesis on an amino acid sequence of escherichia coli wild type homoserine-O-succinyl transferase as shown in SEQ ID NO.1; comprising single mutation or multiple mutation of 25th, 65th and 113th amino acids. The OSH yield of the obtained mutant is remarkably improved compared with that of a wild type metA. According to the recombinant genetically engineered bacterium disclosed by the invention, the homoserine can be efficiently converted into the O-succinyl-L-homoserine, and sufficient precursor substances are provided for subsequent biosynthesis of L-methionine. The fermentation process of the recombinant genetically engineered bacterium is stable and reliable, is easy for large-scale production, and has a wide industrial application prospect.

The invention discloses a muscle-building dietary flavone compound protein composition as well as a preparation method and application thereof, and belongs to the field of dietary supplements. The composition is prepared from the following components in parts by weight: 50 to 80 parts of concentrated whey protein powder, 5 to 20 parts of separated whey protein powder, 0.01 to 3 parts of hydrolyzed whey protein powder, 0.1 to 1 part of bovine colostrum powder, 0.01 to 0.05 part of kaempferol and 0.01 to 0.1 part of glucomannan. The composition can improve the muscle synthesis and growth rate, inhibit muscle reduction caused by sarcopenia, improve the muscle oxidation resistance, accelerate the muscle repair speed and activate the protein synthesis rate-limiting enzyme AKT and the growth kinase ERK. The composition can be used for preparing food, special diet and health food.

The invention relates to the technical field of bioinformatics, in particular to a nano-drug curative effect biomarker mining system based on multi-omics data. The method comprises the following steps: firstly, acquiring multiple omics data of a subject, calculating an initial flux capacity corresponding to each enzymatic reaction, and constructing a directed graph model; further driving the directed graph model to synchronously execute supply-demand bidirectional rate updating at each temperature of the simulated temperature stepping sequence, locking the failure temperature and extracting a speed-limiting enzymatic reaction set limiting the global flux at the failure temperature; finally, mapping the rate-limiting enzymatic reaction set into a sensitive patient screening index combination; according to the method, multiple omics data are obtained to construct an enzymatic reaction directed graph, network supply and demand are deduced through temperature stepping, the failure temperature is locked, the rate-limiting enzymatic reaction is recognized, and the screening index combination is mapped, so that the mining accuracy of the nano-drug curative effect related biomarkers is improved; the technical problem that in the prior art, a sensitive patient screening index combination related to the nano-drug curative effect is difficult to determine is solved.

The invention discloses yarrowia lipolytica genetically engineered bacteria for producing linalool as well as a construction method and application of the yarrowia lipolytica genetically engineered bacteria. According to the invention, an optimized linalool synthase gene AaLIS from kiwi fruit is assembled by using polypeptide interaction tags RIAD-RIDD and ERG20WW, the assembled gene is converted into a mevalonic acid pathway enhanced chassis strain Yl-19, the Yl19 is used as an original strain, and the linalool synthase is obtained by overexpressing a key rate-limiting enzyme in a metabolic pathway, knocking out a key enzyme in a side reaction pathway and a multi-copy strategy. And the metabolic flux in the biosynthetic pathway of the yarrowia lipolytica alcoholysis is improved. The shake flask fermentation yield of the constructed engineering strain Li-6 can reach 41.8 mg / L, the shake flask fermentation yield of Li-27 reaches up to 178.4 mg / L and can be further increased to 665.8 mg / L by optimizing fermentation conditions, and the method is suitable for large-scale industrial production of linalool.

A strain of Yarrowia lipolytica was engineered to overexpress β-hydroxy β-methylglutaryl-CoA reductase and farnesyl pyrophosphate synthase, as rate-limiting enzymes in the mevalonate and sesquiterpenoid synthesis pathways respectively. Metabolite extracts from this strain were run on LC-MS and showed a number of novel compounds being produced, including terpenoids varying in lengths and oxidation states. Upon NMR and MS / MS structure validation as well as biochemical assays, these compounds were determined as a new class of non-natural compounds, bifunctional terpenoids. Studies on the overexpression of P450 enzymes, alcohol oxidase, aldehyde dehydrogenase, and alcohol dehydrogenase showed that expression of these enzymes in addition to β-hydroxy β-methylglutaryl-CoA reductase and farnesyl pyrophosphate synthase increase the production of bifunctional terpenoids. Bioactivity assays demonstrate the application of bifunctional terpenoids.

The application discloses a serine palmitoyltransferase mutant and application thereof, and belongs to the technical field of biological medicines. The amino acid sequence of the serine palmitoyltransferase mutant is shown as SEQ ID NO. 1, and the mutant can be applied to synthesis of tetraacetyl phytosphingosine. In the application, the yeast is used as a host, a plasmid coding the serine palmitoyltransferase mutant lcb1m is introduced, a synthesis path of tetraacetyl phytosphingosine is constructed, and then a high-yield strain of tetraacetyl phytosphingosine is obtained, and the yield is as high as 30.2+ / -0.8 g / L. The application improves the binding capacity of the serine palmitoyltransferase with a substrate serine by mutating the serine palmitoyltransferase which is a rate-limiting enzyme of the synthesis path of tetraacetyl phytosphingosine, effectively improves the synthesis efficiency of tetraacetyl phytosphingosine, and has extremely high industrial application value.

The invention belongs to the technical field of synthetic biology, and particularly relates to recombinant escherichia coli for efficiently biosynthesizing lanosterol as well as a construction method and application of the recombinant escherichia coli. The method comprises the following steps: introducing exogenous squalene synthase (SQS), squalene epoxidase (SE) and oxidized squalene cyclase (OSC) genes into escherichia coli to construct a complete lanosterol synthesis route; the method comprises the following steps of: enhancing MEP pathway rate-limiting enzymes, namely 1-deoxy-D-xylulose-5-phosphate synthase (DXS), isopentenyl pyrophosphate isomerase (IDI) and farnesyl pyrophosphate synthase (FPS), so as to increase precursor supply, and further regulating and controlling the expression of key enzyme genes by adopting an arabinose promoter (PBAD). The lanosterol yield of the constructed engineering bacterium BW-2 reaches 8.02 mg / L and is increased by 40 times compared with that of an initial strain, and a brand new technical scheme is provided for green and efficient industrial production of lanosterol.

The invention discloses a serine palmitoyl transferase mutant and application thereof, and belongs to the technical field of biological medicine. The amino acid sequence of the serine palmitoyl transferase mutant provided by the invention is shown as SEQ ID NO. 1, and the mutant can be applied to synthesis of tetraacetyl phytosphingosine. According to the invention, saccharomyces cerevisiae is taken as a host, and plasmids for expressing and coding the serine palmitoyl transferase mutant lcb1m are introduced, so that a synthetic route of the tetraacetyl phytosphingosine is constructed, a high-yield strain of the tetraacetyl phytosphingosine is further obtained, and the yield is up to 30.2 + / -0.8 g / L. The serine palmitoyl transferase serving as a rate-limiting enzyme in a synthetic route of the tetraacetyl phytosphingosine is mutated, so that the combining capacity of the serine palmitoyl transferase and a substrate serine is improved, the synthetic efficiency of the tetraacetyl phytosphingosine is effectively improved, and the tetraacetyl phytosphingosine has extremely high industrial application value.

The present invention discloses a genetically engineered bacterium that uses the key enzymes SrfAD and YbdT to synergistically improve the high-yield production of surfactin by Bacillus. The genetically engineered bacterium is obtained by transforming the key rate-limiting enzyme genes of SrfAD and / or YbdT into the Bacillus velezensis mutant strain ΔRapF+SerA, which is used as the starting strain. The genetically engineered bacteria ΔRapF+SerA+SrfAD and ΔRapF+SerA+SrfAD+YbdT constructed in the present invention are used for the high-efficient production of surfactin under fermentation conditions. The constitutive expression of the two key rate-limiting enzyme genes has successfully further increased the surfactin production. Under the optimal medium conditions, about 18.2 g / L and 19.6 g / L of surfactin can be stably produced in a 5 L fermenter for 40-50 h. This genetically engineered bacterium provides raw materials for accelerating the industrialization of surfactin.

The application discloses a method for increasing drought adaptability of plant osmotic regulation substance accumulation, and belongs to the field of plant genetic engineering and drought-resistant molecular breeding. First, a plant to be transformed is combined with 13C-glutamic acid and 15N-choline double isotope labels to quantize carbon and nitrogen flow redistribution of proline synthesis pathways and glycine betaine synthesis pathways in leaf cells and vascular bundle companion cells, and to identify rate-limiting enzyme nodes. Second, a multi-cistronic plant expression vector is constructed. A first expression box is driven by a leaf-specific promoter and a drought response cis-element composite promoter to drive P5CS. A second expression box is driven by a companion cell-specific promoter and a drought response cis-element composite promoter to drive BADH. Positive transformants are obtained through Agrobacterium mediation or gene gun transformation and molecular screening. The expression quantity of the positive transformants is increased by 5 to 50 times under stress and falls back to a baseline within 72 hours of rehydration. Root activity is significantly improved, and yield is preserved.

The invention discloses an actinobacillus succinogenes gene engineering strain for highly producing succinic acid as well as a construction method and application of the actinobacillus succinogenes gene engineering strain. According to the actinobacillus succinogenes, rate-limiting enzymes, namely phosphoenolpyruvate carboxylase PPC and formate dehydrogenase FdoG, in a succinic acid synthesis route are overexpressed in series in the actinobacillus succinogenes, formic acid accumulation is reduced to provide more CO2 and NADH, and phosphoenolpyruvate is reinforced to fix CO2 to be converted into succinic acid, so that the yield of succinic acid is increased, and meanwhile, the yield of byproduct formic acid is reduced.

This invention relates to the field of biotechnology, specifically to the construction and application of a Benzodiacetic tobacco chassis for synthesizing isoflavones. This invention reconstructs the upstream pathway for isoflavone synthesis in Benzodiacetic tobacco, further identifies and screens key rate-limiting enzymes for isoflavone synthesis in Benzodiacetic tobacco, and utilizes 2A peptides to co-express multiple key genes, further introducing flavonoid synthesis transcription factors to construct a Benzodiacetic tobacco chassis for synthesizing isoflavones. This Benzodiacetic tobacco chassis can efficiently synthesize daidzein and genistein. Furthermore, based on the constructed high-yield Benzodiacetic tobacco platform for daidzein and genistein, various isoflavones can be further synthesized, such as daidzein, genistein, puerarin, gentiopicrin, chickpea extract A, and stigmosiderin, paving the way for the industrialization of plant biosynthesis of various bioactive isoflavones and thus possessing broad application prospects.

The invention relates to a construction method and application of high-yield lactyl-N-difucotetraose engineering bacteria, and belongs to the technical field of bioengineering and food biology. According to the method, genes in a GDP-1-fucose synthesis path are combined and regulated in host bacteria by utilizing a synthetic biological means, alpha-1, 2-fucosyltransferase and alpha-1, 3-fucosyltransferase are heterologously expressed on the basis, and then construction of a DFL high-yield strain is realized through modification strategies such as site-specific mutagenesis and random saturated mutation of rate-limiting enzyme. The invention also provides a method for synthesizing a high-added-value product DFL by taking glycerol as a substrate. The method has reference significance for solving the technical bottleneck of the DFL, provides an effective way for industrial production of the DFL, and has relatively high theoretical research value and social and economic benefits.

The invention provides a genetically engineered bacterium for synthesizing monoterpene and a construction method and application thereof, and relates to the field of bioengineering, in particular to a gene combination, an expression vector, a host and application thereof. According to the engineering bacteria provided by the invention, Pseudomonasputida KT2440 which can tolerate various monoterpenes is taken as a chassis cell, endonuclease coding genes endA and endX are knocked out, and a heterologous fragrant folic acid synthesis module is introduced. On the basis, key rate-limiting enzyme gene modules of different biological sources are screened to systematically strengthen an endogenous MEP metabolic pathway. After metabolism enhancement, the engineering strain successfully realizes heterologous biosynthesis of the aromatic folic acid, and the yield of the engineering strain is greatly improved compared with that of an original strain. According to the method, the yield of the aromatic folic acid is increased by systematically optimizing the MEP approach for the first time, and an optimized scheme is provided for producing the monoterpenoids by a microbiological method. The construction method of the recombinant pseudomonas putida is efficient, simple and high in operability.

The present application belongs to the field of genetic engineering, and particularly relates to a cotton leaf-off precise regulation method based on CPD gene regulation. The present application finds that the brassinosteroid (BR) biosynthesis pathway is the key metabolic pathway for regulating the sensitivity of TDZ by analyzing the sensitivity difference of different cotton varieties to thidiazuron (TDZ) leaf-off agent, and the rate-limiting enzyme gene GhCPD is the core gene for determining the leaf-off sensitivity difference between varieties. The present application can early predict the leaf-off agent sensitivity of cotton varieties by detecting the expression level of GhCPD gene or the endogenous BR content; further, by regulating the expression level of GhCPD gene or applying exogenous 24-epibrassinolide (EBR), the leaf-off response of cotton to TDZ can be significantly enhanced.

The invention discloses a genetically engineered bacterium for improving rate-limiting enzyme to promote xanthophyll synthesis and application of the genetically engineered bacterium, and belongs to the technical field of genetic engineering. According to the genetically engineered bacterium, a lycopene-producing strain is taken as a starting bacterium, and coding genes of a lycopene epsilon-cyclase mutant, lycopene beta-cyclase, a carotene beta-hydroxylase mutant and carotene epsilon-hydroxylase are extrinsic introduced; according to the invention, a lycopene epsilon-cyclase mutant with higher enzymatic activity and / or a carotene beta-hydroxylase mutant with higher enzymatic activity are / is utilized to improve the limitation of a rate-limiting enzyme in the lutein synthesis process, and further, the lutein synthesis route is subjected to compartment regulation and control; and the lycopene epsilon-cyclase and / or the lycopene beta-cyclase are / is positioned in the intracellular lipid droplets, so that the synthesis of the lutein is comprehensively enhanced.

The application discloses a whitening and freckle-removing composition, conditioner, medicine and cosmetic. The whitening and freckle-removing composition comprises a composition of Phyllanthus emblica, Passiflora edulis and discodermolide A; the Phyllanthus emblica comprises Phyllanthus emblica raw materials and / or Phyllanthus emblica extract, and the Passiflora edulis comprises Passiflora edulis raw materials and / or Passiflora edulis extract. The application has a significant inhibitory effect on tyrosinase activity by scientifically compounding discodermolide A and the second active component comprising one or more of Phyllanthus emblica, Passiflora edulis and Salvia, can inhibit the expression and function of the rate-limiting enzyme TYR in the melanin synthesis process, has a significant whitening and freckle-removing activity, is safe and efficient, and can be applied to various conditioners, medicines and cosmetics.

The invention provides a construction method and application of a bacillus amyloliquefaciens chassis strain, bacillus amyloliquefaciens HZ12 is taken as a starting strain, two key genes of a non-PTS system are screened and identified from a glucose transport pathway, and the bacillus amyloliquefaciens chassis strain is obtained. According to the present invention, the L-tyrosine genes are respectively a glucose osmose gene Bao-glcP1 derived from bacillus amyloliquefaciens and a glucokinase gene Cgb-glK derived from corynebacterium glutamicum, and after the genes are subjected to overexpression, the L-tyrosine yields of the engineering bacteria respectively achieve 395.82 mg / L and 385.37 mg / L, and are increased by 36% and 33% compared with the original strain; then, by strengthening a non-PTS system, weakening the PTS system and reconstructing glucose uptake and phosphorylation pathways of the strain, the phosphorylation process of glucose and PEP are decoupled, a chassis strain with high yield of L-tyrosine is obtained, and the yield of L-tyrosine is increased to 407.16 mg / L and is increased by 43% compared with that of an original strain. Key rate-limiting enzyme genes aroA and tyrA for synthesizing L-tyrosine are further overexpressed in the chassis strain, so that the yield of the L-tyrosine is increased to 1400.53 mg / L and is increased by 3.82 times compared with that of an original strain.

The application discloses a method for synthesizing natural products by using methanol yeast chassis cells and an engineering strain, relates to the technical field of genetic engineering, and comprises a squalene engineering strain.The construction of the squalene engineering strain comprises the following steps: cloning a rate-limiting enzyme gene in Pichia pastoris GS115 into a vector pPICZA with a PAOX1 promoter, electrically transforming a linearized recombinant plasmid into the Pichia pastoris GS115, integrating the linearized recombinant plasmid into a genomic HIS4 site, screening positive transformants, and obtaining a first strain.The first strain is synthesized, the squalene synthesis capacity is established in the chassis cells, the problem that the wild-type Pichia pastoris has a very low endogenous mevalonate pathway flow is solved, the rate-limiting bottleneck of the squalene synthesis pathway is eliminated, and the precursor supply level is improved.

The invention discloses application of para aminobenzoic acid synthase and / or hydroxymethyl dihydropterin pyrophosphate kinase-dihydropterioic acid synthase in regulation and control of coccidium drug resistance, and through comparative analysis of whole transcriptome level, only in DZR strain, the para aminobenzoic acid synthase and / or hydroxymethyl dihydropterin pyrophosphate kinase-dihydropterioic acid synthase can be used for regulating and controlling coccidium drug resistance. A key rate-limiting enzyme coding gene of a folic acid biosynthetic pathway, namely para aminobenzoic acid synthase (EtpABAS), is specifically associated with the expression level of hydroxymethyl dihydropterin pyrophosphate kinase-dihydropteroic acid synthase (EtHPPK-DHPS), and the drug resistance of diclazuril is specifically associated with the expression level of the hydroxymethyl dihydropterin pyrophosphate kinase-dihydropteroic acid synthase (EtHPPK-DHPS). The invention reveals that the molecular mechanism of E.tenella for generating drug resistance to diclazuril is closely related to the folic acid synthesis pathway for the first time, and defines the core regulation effect of the key metabolic enzyme EtpABAS in the folic acid synthesis pathway in the process. Meanwhile, the invention provides a strategy for intervening generation of the drug resistance of the coccidiosis by regulating and controlling a folic acid metabolic pathway, a new theoretical basis and a new practice direction are provided for research, development and precise medication of novel anti-coccidiosis drugs, and the method has remarkable scientific value and industrial application prospect.