591 results about "Mutant strain" patented technology

The invention discloses a corn kernel size regulation gene X1 as well as an SNP (Single Nucleotide Polymorphism) marker and application thereof. The invention discovers that the X1 gene has the function of regulating and controlling the grain shape and the grain weight for the first time. The invention provides a novel SNP (Single Nucleotide Polymorphism) marker related to the corn grain size, the SNP marker has two alleles AA and GG, and the allele AA is clear to be regarded as an excellent / synergistic allele. The X1 gene provided by the invention can lead to increase of grain types such as the length of a corn grain of a mutant strain compared with that of a control grain; the length and other grain types of the X1 gene overexpression strain are reduced compared with those of the control grain. Precious gene resources are provided for corn breeding, and the application prospect is wide.

The invention discloses an Escherichia coli mutant strain which is classified and named as Escherichia coli, the strain number is CR-TK01, and the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.35554. The invention further discloses a preparation method of the Escherichia coli mutant strain. The Escherichia coli CR-TK01 with high yield of cytidine provided by the invention has the characteristics of high yield and stable high-yield character, glucose is used as a carbon source, the Escherichia coli CR-TK01 is used for fermentation production of cytidine under a certain fermentation condition, and the yield of cytidine is as high as 97.23 g / L; the strain is not degraded after passage for more than 20 generations, the performance of high-yield cytidine is maintained in the passage fermentation process, and the yield of cytidine in passage fermentation is improved. The method for producing cytidine through fermentation is simple in process, high in yield and suitable for industrialization.

According to the haematococcus pluvialis strain and the application thereof, cell wall breaking operation can be carried out more easily when astaxanthin is extracted, astaxanthin can be extracted more effectively, and the cost of natural astaxanthin is reduced. The haematococcus pluvialis RMC16 strain provided by the invention has the preservation number of CCTCC (China Center for Type Culture Collection) NO: M 20241404. The haematococcus pluvialis mutant strain obtained by screening has the characteristics of thin wall, no secondary cell wall, high astaxanthin content and the like, the haematococcus pluvialis mutant strain is high in growth speed and can quickly reach a plateau phase, the individual proportion of parental cells in a population bred by the haematococcus pluvialis mutant strain serving as a parent is higher, the cost required by extraction of natural astaxanthin can be remarkably reduced, and the haematococcus pluvialis mutant strain is suitable for industrial production. The method is suitable for large-scale popularization.

The invention belongs to the technical field of food microorganisms, and particularly discloses a ganoderma lucidum mutant strain capable of producing polysaccharides and triterpenoids at high yield. The strain is named as Ganoderma lucidum in Latin, the preservation number is CGMCC NO: 41680, the preservation unit is China General Microbiological Culture Collection Center, and the preservation date is December 4, 2024. The strain is named as Ganoderma lucidum, the preservation number is CGMCC NO: 41680, and the preservation number is CGMCC NO: 41680. The polysaccharide content in the ganoderma lucidum spore powder produced by the ganoderma lucidum mutant strain is more than or equal to 8%, and the total triterpenoid content is more than or equal to 12%; a culture medium formula of the ganoderma lucidum mutant strain comprises potato leachate, glucose and monopotassium phosphate, the culture temperature is 25-28 DEG C, and the pH value is 5.5-6.5. The ganoderma lucidum mutant strain is high in genetic stability, the content of active ingredients is remarkably higher than that of parent strains, and the ganoderma lucidum mutant strain is suitable for large-scale fermentation production.

The invention discloses an E3 ubiquitin ligase gene ulA, the nucleotide sequence of which is shown as SEQ ID NO: 1. The gene is knocked out from fusarium oxysporum by using a homologous recombination method to obtain a mutant strain ulA; compared with a wild strain, the mutant hulA has the advantages that the spore yield is reduced, the spore germination is delayed, the response capability to various abiotic stresses is reduced, the pathogenicity to panax notoginseng plants is reduced, and the sensitivity to six bactericides is increased, and experimental results show that the gene plays an important role in pathogenicity, drug resistance and the like of fusarium oxysporum. The gene can be used as a target gene for developing an anti-fusarium oxysporum preparation.

The invention relates to the technical field of gene engineering, in particular to an L-rhamnose isomerase mutant, a recombinant plasmid, a mutant strain and application. The amino acid sequence of the mutant is as shown in SEQ ID NO.4, and the nucleotide sequence of the coding gene is as shown in SEQ ID NO.3. A specific mutant gene sequence is designed, a recombinant plasmid pET28a (+)-L-Rhi is successfully constructed, the gene sequence is connected between enzyme cutting sites BamH I and Hind III of an escherichia coli expression vector pET-28a (+) to construct a mutant expression vector (the recombinant plasmid pET-28a (+)-L-Rhi), the mutant expression vector is transformed into an escherichia coli BL21 competent cell, a mutant strain is obtained, and the recombinant plasmid pET-28a (+)-L-Rhi is obtained. The obtained mutant strain can overexpress L-rhamnose isomerase, the conversion rate of D-allose is remarkably improved, the thermal stability of the enzyme is remarkably improved through the design of mutation sites, and the half-life period is effectively prolonged.

The invention relates to a Kluyveromyces marxianus strain with high protein yield and application of the Kluyveromyces marxianus strain, which is characterized in that the Kluyveromyces marxianus strain is firstly cultured on a slant, then is transferred into a seed culture medium for seed preparation, and then is inoculated into a fermentation tank, and yeast protein is obtained by adopting index feeding; the bacterial strain is a dominant mutant strain Kluyveromyces marxianus YWX-1, the protein content in a dry thallus reaches 55% or above and is increased by 26% or above compared with that of an original bacterial strain, the bacterial strain can be used for production of single-cell protein, the essential amino acid index (EAAI) value in the protein reaches 1.2, and the bacterial strain is rich in arginine, threonine and lysine and can be applied to production of single-cell protein. These amino acids play a key role in immune regulation, intestinal mucosal barrier function and muscle protein synthesis of young animals. The YWX-1 kluyveromyces marxianus strain has a wide application prospect in the production of neoplasm protein.

The invention discloses a method for improving the synthesis level of L-tryptophan in escherichia coli based on ARTP mutagenesis high-throughput screening, and belongs to the technical field of bioengineering. According to the invention, the L-tryptophan biosensor pSensor-trp3 is constructed, and the L-tryptophan biosensor pSensor-trp3 is good in response under the condition that the exogenous addition concentration range of L-tryptophan is 0-300mg. L <-1 >. High-throughput screening is performed by using a flow cytometry, a dominant mutant strain YB-2 is obtained through iterative mutagenesis, and the shake flask L-tryptophan yield and the sugar-acid conversion rate of the dominant mutant strain YB-2 are 5.68 g.L <-1 > and 0.103 g.g <-1 > respectively and are increased by 11.4% and 10.7%. Through second-generation whole genome re-sequencing comparative analysis, it is speculated that the genes ynfB and waaO possibly have a promoting effect on synthesis of L-tryptophan. The L-tryptophan biosensor used in the invention also provides reference for high-throughput screening and transformation of other related L-tryptophan production strains.

The invention relates to the technical field of gene engineering, in particular to an L-rhamnose isomerase mutant, a recombinant plasmid, a mutant strain and application. The amino acid sequence of the mutant is as shown in SEQ ID NO. 2, and the nucleotide sequence of the coding gene is as shown in SEQ ID NO. 1. A specific mutant gene sequence is designed, a recombinant plasmid pET28a (+)-L-Rhi is successfully constructed, the gene sequence is connected between enzyme cutting sites BamH I and Hind III of an escherichia coli expression vector pET-28a (+) to construct a mutant expression vector (the recombinant plasmid pET-28a (+)-L-Rhi), the mutant expression vector is transformed into an escherichia coli BL21 competent cell, a mutant strain is obtained, and the recombinant plasmid pET-28a (+)-L-Rhi is obtained. The obtained mutant strain can overexpress L-rhamnose isomerase, the conversion rate of D-allose is remarkably improved, the thermal stability of the enzyme is remarkably improved through the design of mutation sites, and the half-life period is effectively prolonged.

The invention relates to rhodosporidium toruloides with high grease yield and application of the rhodosporidium toruloides. The rhodosporidium toruloides mutant strain with high grease content and high grease yield is obtained through a compound mutation method. According to the invention, a wild rhodosporidium toruloides strain RT is taken as a starting strain, a method of combining normal-pressure and room-temperature plasma mutagenesis with genome rearrangement is adopted, a stable genetic mutant strain RT-55 with the oil content and the yield obviously improved is obtained through oil content screening, and under the condition of a nitrogen-limited culture medium, the oil content of the mutant strain reaches 70.1% and is improved by 14.2%, and the yield of the mutant strain is greatly improved. The biomass is 4.11 g / L and is reduced by 0.8%, and the grease yield reaches 2.832 g / L and is improved by 10.9%. The rhodosporidium toruloides mutant strain provided by the invention can be used as a substitute of a grease raw material and is applied to the fields of aquatic feed additives and the like.

An epigenetic regulatory factor ZmULT1 related to corn grain size regulation and heat stress response and the use thereof, which solve the technical problems of how to increase the grain size and / or heat resistance and / or lodging resistance of corn. Use of a substance for reducing the content of the protein ZmULT1 or a substance for inhibiting the expression of the encoding gene of the protein ZmULT1, which use is any one of the following: P1, the use in increasing the grain size of corn; P2, the use in improving the heat resistance of corn; P3, the use in increasing the lodging resistance of corn; and P4, the use in plant breeding. The homozygous mutant strain with knockout of the ZmULT1 gene has a reduced plant height and an increased grain size, and exhibits significant heat stress resistance, this indicates that the research on the gene can further enrich the use of epigenetics in crops and is of important significance for improving the grain size, heat resistance and lodging resistance of corn.

The invention discloses a tryptophan response type promoter as well as a construction method and application thereof. A tryptophan specific biosensor is created by constructing a tryptophan response type hybrid promoter, and a tryptophan high-throughput screening platform is established in combination with a flow cytometry sorting technology. And the mutant strain TrpES94N beneficial for improving the yield of the L-tryptophan is successfully screened from a random mutation library of the key enzyme TrpE for synthesizing the L-tryptophan. The strain is over-expressed in an engineering strain TRP30, and after the strain is cultured in a 5L fermentation tank for 48h, it is determined that the yield of L-tryptophan is increased to 50.8 g / L and is increased by 19.53% compared with the yield of L-tryptophan of a control strain.

The invention discloses a method for obtaining and culturing ED pathway regulated and controlled engineering bacteria for fermentation production of vitamin B12, a mutant strain is based on ensifer adhesion, an ED pathway key gene edd gene in the ensifer adhesion of a vitamin B12 production strain is overexpressed by a homologous recombination single exchange method, an edd gene overexpressed mutant strain is constructed, and the edd gene overexpressed mutant strain is used for producing the vitamin B12. The purpose of disturbing the ED pathway to realize the metabolic migration of central carbon is achieved, and the method is applied to the production of vitamin B12. A shake flask fermentation experiment proves that overexpression of the edd gene can remarkably promote synthesis of a VB12 product, and the edd gene has good commercial and scientific research values.

The invention provides a phaffia rhodozyma mutant strain for high yield of astaxanthin as well as a screening method and application of the phaffia rhodozyma mutant strain, belongs to the technical field of fermentation microorganism screening, and can solve the problems of low astaxanthin yield, high cost and low growth temperature of wild type phaffia rhodozyma existing in synthesis of astaxanthin from a phaffia rhodozyma strain. The invention provides a phaffia rhodozyma mutant strain capable of producing astaxanthin at high yield, the phaffia rhodozyma mutant strain is a phaffia rhodozyma AA0529 mutant strain, the phaffia rhodozyma AA0529 mutant strain is preserved in China Center for Type Culture Collection in Wuhan, Hubei on September 7, 2023, and the preservation number is CCTCC (China Center for Type Culture Collection) NO: M20231637. According to the method, the yield of the astaxanthin can be increased, and the yield of the astaxanthin is increased to 3.3 mg / g at 26 DEG C.

The invention is suitable for the technical field of molecular biology, and provides a rice transcription factor OsGATA16 and application thereof in regulation and control of rice blast resistance of rice. The method comprises the following steps: firstly, cloning a rice OsGATA16 gene, then constructing an overexpression vector and a mutant vector, and transforming rice to obtain a corresponding strain. Research finds that after a mutant strain with OsGATA16 knocked out is inoculated with germs, the number of scabs is obviously smaller than that of a wild type control group, the disease resistance of rice can be accurately regulated and controlled, and the rice blast resistance is obviously improved. The regulation and control mode can effectively reduce pesticide use and reduce environmental pollution and residual risk. Meanwhile, the successfully constructed stable genetic regulation material can be stored for a long time and used for multiple times in molecular and phenotype levels through verification. Besides, the OsGATA16 gene can be used as a disease-resistant molecular marker or a functional gene to be applied to various breeding systems, a new target is provided for breeding new rice materials with high rice blast resistance, and the OsGATA16 gene has a wide practical application prospect.

The invention discloses a primer probe combination for identifying a group A streptococcus M1UK strain and application of the primer probe combination, and belongs to the technical field of streptococcus mutant strain detection. The primer probe combination provided by the invention can specifically amplify the target gene of the M1UK strain. Furthermore, a method for identifying the M1UK strain is designed according to the primer probe combination, the M1UK strain and other group A streptococcus can be effectively distinguished, and besides the advantages of being high in specificity and accurate in detection result, the method is easy, convenient and rapid to operate and high in detection efficiency, labor cost and time cost are reduced, and the method is suitable for popularization and application. The method can realize rapid and effective non-sequencing-dependent variant strain detection, and has important significance in disease prevention and control and improvement of disease treatment efficiency.

The invention discloses an application of an SCAB82331 gene or a protein coded by the SCAB82331 gene in regulation and control of synthesis of thaxtominA, and belongs to the technical field of gene engineering. According to the application disclosed by the invention, the SCAB82331 gene in the streptomyces scabies is deleted through a genetic engineering way, so that the high-yield strain of the thaxtominA is obtained, and the yield of the thaxtominA in the streptomyces scabies is increased. When the SCAB82331 gene is deleted in the streptomyces scabies, the yield of the thaxtominA is obviously increased by 66.2%; after the SCAB82331 gene is supplemented in the delta SCAB82331 mutant strain, the yield of the thaxtominA is recovered, and the yield of the thaxtominA is recovered; the deletion of the SCAB82331 gene can be used for directionally improving the biosynthesis yield of the thaxtominA in streptomyces scabies.

The invention relates to the technical field of plant genetic engineering, in particular to application of a rice OsERF141 protein and a coding gene thereof in improving low-temperature tolerance of plants. Experiments show that the low-temperature resistance of an OsERF141 function deletion mutant strain is remarkably reduced, and the low-temperature resistance of an overexpressed OsERF141 transgenic strain is remarkably improved. The invention provides a new gene resource for the cold resistance problem of rice, and has important significance for the molecular mechanism research of low-temperature stress and the cultivation of new low-temperature-resistant varieties.

The invention discloses application of protein TaTDM and related biological materials thereof, and belongs to the field of plant breeding. The amino acid sequence of the protein TaTDM is as shown in SEQ ID NO: 2 or SEQ ID NO: 4 or SEQ ID NO: 6. The TaTDM gene knockout homozygous mutant strains tatdmm1 and tatdmm2 are obtained by carrying out gene knockout on wild type wheat Fielder, and it is found that at the temperature of 25 DEG C, the total floret number of each spike of the Fielder, the tatdmm1 and the tatdmm2 and the survival rate under the water shortage treatment condition are remarkably higher than those of the wild type wheat Fielder. The protein TaTDM has an important application value in regulation and control of wheat ear type characters and stress tolerance, provides a high-quality germplasm resource, and is of great significance in cultivation of drought-enduring plant varieties and improvement of crop yield.

The invention discloses construction and application of a streptococcus suis serotype 2 cps2C gene knockout mutant strain. The invention relates to a streptococcus suis serotype 2 cps2C gene knockout mutant strain 05ZYH33 delta cps2C. A coding gene, from the 31st site to the 1000th site, of the cps2C gene in the strain 05ZYH33 is replaced by a spectinomycin resistance gene cassette SpcR. The mutant strain 05ZYH33 delta cps2C is applied to preparation of a streptococcus suis type 2 attenuated vaccine and a subunit vaccine. The capsule of the mutant strain 05ZYH33 delta cps2C is obviously reduced; in-vitro experiments show that the macrophage phagocytosis resistance of the mutant strain 05ZYH33 delta cps2C is reduced, and animal toxicity test results show that the toxicity of the mutant strain is obviously reduced. The mutant strain provides an important clue for screening of protective antigens of multivalent subunit vaccines, and can be applied to development of S.suis attenuated vaccines and multivalent subunit vaccines.

The invention discloses application of a transcription factor ZmbZIP27 in regulation and control of corn plant height and ear height, and belongs to the technical field of plant genetic engineering and corn molecular breeding. The invention reveals that the bZIP transcription factor family member ZmbZIP27 has an important biological function of regulating and controlling the corn plant height and lodging resistance for the first time. A ZmbZIP27 knockout vector is constructed through a CRISPR / Cas9 gene editing technology, and an obtained homozygous mutant strain shows remarkable plant type improvement characteristics compared with a wild type: the plant height is reduced by 8-12%, and the ear height is reduced by 15-22%. And a new gene target and a breeding strategy are provided for creating a new high-yield lodging-resistant corn variety suitable for mechanical harvesting.

The invention discloses a rape grain weight regulation gene NGAL3 based on whole genome screening and a breeding application thereof, based on the seed size and grain weight phenotypic value of a cabbage type rape germplasm resource, a candidate gene interval is positioned by using GWAS; the method comprises the following steps: selecting large-grain-weight and small-grain-weight extreme phenotypic materials, performing transcriptome sequencing in a critical period of seed development, and screening differential expression genes; and performing cross comparison on the GWAS candidate gene and the differential expression gene to obtain a key gene for jointly regulating and controlling the size and the grain weight of the seed, and performing functional verification on the key gene. The thousand seed weights of the created homozygous three mutant strains L1-sg1-1-4-5 and L2-sg1-4-8-16 are obviously increased by 46% and 29% compared with those of the wild type strains. The invention provides a new target for high-yield rape breeding, and non-transgenic high-grain-weight germplasm can be created through gene editing or beneficial allelic variation of NGAL3 is selected and enriched under the assistance of molecular markers.

Provided are an Aeromonas dhakensis mutant strain with deletion of a surface polysaccharide synthesis gene, a complemented strain, a construction method therefor, and the use thereof. The mutant strain is obtained by deleting one or more of ugd, ugd2, and cap1J from the Aeromonas dhakensis wild strain A. dhakensis C160501.

The invention provides a tomato cytokinin receptor gene SlHK2 and an application of a knockout vector of the tomato cytokinin receptor gene SlHK2 in regulating and controlling the size of tomato fruits. The cytokinin receptor gene SlHK2 is identified from tomatoes. The knockout vector disclosed by the invention is targeted to an sgRNA sequence as shown in SEQ ID NO.1, namely a fragment with the length of 20bp in a 6370-6389bp region of an SlHK2 gene sequence. The invention also provides a transgenic engineering bacterium transfected with the knockout vector of the tomato cytokinin receptor gene SlHK2 and application of the transgenic engineering bacterium in regulation and control of tomato fruit size. According to the invention, a target sgRNA fragment of a CRISPR / Cas9 gene edited tomato cytokinin receptor gene SlHK2 is obtained through screening, a CRISPR / Cas9 gene edited vector pYLCRISPRCas9Pubi-N-SlHK2 of the SlHK2 is obtained through construction, then transgenic engineering bacteria are transfected and transferred into tomatoes, and the size of tomato fruits of an obtained homozygous mutant strain of the SlHK2 gene is obviously increased.

The invention belongs to the technical field of medicines, and provides a method for screening a mutant strain and a high-virulence Seneca virus A mutant strain. The method for promoting Senecavirus A mutation provided by the invention comprises the following steps: inserting an RNAi target sequence between 3Dpol and a 3'untranslated region of an SVA starting strain; the target sequence of the RNAi contains a complementary sequence of an endogenous sequence of the miRNA. According to the research, mutagenesis is carried out on SVA by constructing a high RNAi pressure system, and a method for screening the mutant strain SVA is carried out by simulating an antiviral RNAi mechanism in a host, so that a natural evolution process of the virus is better met, a large number of stably inherited mutant strains can be obtained, and an efficient research and development means is provided for vaccine research and development aiming at the virus.

The present application discloses a filamentous fungal mutant strain with high-efficient expression of superoxide dismutase and its application. The filamentous fungal mutant strain of the present application is formed by gene knockout of phytochrome genes PaPhy1 and / or PaPhy2 in the wild-type filamentous fungus Podospora anserina. The filamentous fungal mutant strain of the present application is a mutant strain with gene knockout of phytochrome gene PaPhy1, a mutant strain with gene knockout of phytochrome gene PaPhy2, or a mutant strain with gene knockout of phytochrome genes PaPhy1 and PaPhy2. The present application first discovers that the filamentous fungus Podospora anserina with gene knockout of phytochrome genes PaPhy1 and / or PaPhy2 can express superoxide dismutase and peroxidase more efficiently, which is of great significance for the high-efficient expression and preparation of superoxide dismutase and peroxidase.

The invention belongs to the field of poultry infectious diseases, and particularly relates to a riemerella anatipestifer phage mutant strain and a method for quickly mutating riemerella anatipestifer phage. Escherichia coli bacteriophage, riemerella anatipestifer bacteriophage and corresponding host bacteria are mixed, the infection complex number is made to be larger than 100, after culture, supernate is taken and then mixed with the host bacteria for culture, a bacteriophage mutant strain is separated from a secondary culture solution, the phage spectrum of the bacteriophage mutant strain is detected, and the mutant strain with the broadened phage spectrum is screened. At present, no report for widening the bacteriophage spectrum of the riemerella anatipestifer based on similar principles is found, and the research can fill the blank in the related research field.

The invention belongs to the technical field of gene engineering, and particularly relates to application of an OsNAC4 gene in regulation and control of rice salt tolerance. It is found for the first time that mutation of the OsNAC4 gene can improve the salt tolerance of rice seeds in the seedling stage. Under salt stress, the seedling survival rate of the mutant OsNAC4 strain is obviously higher than that of a wild type. Under normal treatment, the proline content, the hydrogen peroxide content and the malondialdehyde content of the wild type strain and the Osnac4 mutant strain have no significant difference, but after salt stress, the proline content of the Osnac4 mutant strain is significantly higher than that of the wild type strain, and the hydrogen peroxide content and the malondialdehyde content are both lower than those of the wild type strain. Therefore, the OsNAC4 gene can be utilized to cultivate an improved rice material suitable for saline-alkali soil planting through a biotechnology, a new thought is provided for cultivating salt-tolerant rice varieties, and a theoretical basis is also provided for increasing the yield of other crops by utilizing a heterologous gene expression technology.

The invention belongs to the technical field of microbial engineering, and discloses a method for producing eicosapentaenoic acid (EPA) with high yield by schizochytrium limacinum based on random mutation and low-temperature screening and application, and the method comprises the following steps: driving overexpression of a G418 resistance gene through a P2520 promoter, constructing a random insertion mutant library, and screening to obtain a schizochytrium limacinum mutant strain with a randomly mutated genome; coating in a culture medium containing G418 resistance for culturing, and screening out strains which are resistant to low temperature and good in growth state at 15 DEG C; and inoculating into a fermentation culture medium, adding MgSO4 with the final mass concentration of 0.1% at the initial stage of fermentation, supplementing MnCl2 with the final mass concentration of 0.05% when fermentation is performed for 72 hours, and culturing to obtain a mutant strain. According to the invention, the G418 resistance gene carried by the plasmid is randomly inserted into the schizochytrium limacinum genome, and low-temperature induced screening is combined, so that the target limitation of traditional homologous recombination is broken through, and a stable strain with multiple mutation superposition can be obtained through enrichment.

The invention provides Saccharomyces cerevisiae for producing squalene as well as a screening method and application of the Saccharomyces cerevisiae. The method comprises the following steps: culturing a Saccharomyces cerevisiae engineering strain ySC782 for synthesizing squalene to obtain a to-be-mutagenized bacterial solution, carrying out ARTP mutagenesis on the to-be-mutagenized bacterial solution, adding the to-be-mutagenized bacterial solution into a YPD liquid culture medium, culturing to obtain a resuscitation bacterial solution, adding the resuscitation bacterial solution into a sucrose solution with gradient concentration distribution, screening, and repeating the ARTP mutagenesis-sucrose solution screening step to obtain the squalene mutant strain. And finally, the saccharomyces cerevisiae strain ySC782-M5 is obtained through screening, and the saccharomyces cerevisiae strain ySC782-M5 is obtained through screening. The yield of squalene produced by the saccharomyces cerevisiae ySC782-M5 reaches 49.83 g / L, so that a solution is provided for breaking through the yield bottleneck of squalene synthesized by yeast.