1026 results about "Mutant strain" patented technology

The invention belongs to the technical field of genetic engineering and metabolic engineering, and discloses an escherichia coli genetically engineered bacterium for fermentation production of L-histidine, a method and application of the escherichia coli genetically engineered bacterium for fermentation production of L-histidine. The escherichia coli genetically engineered bacterium is prepared by taking wild escherichia coli MG1655 as a starting strain, and knocking out a gene lacI and a gene purR on a genome; integrating the gene prs, the gene zwf and the gene gnd; the method comprises the following steps: integrating genes hisG, hisD, hisB, hisC, hisA, hisF / H and hisIE; and a gene cgl2458 is integrated. According to the invention, a molecular biological technology is utilized to integrate histidine operon in a serratia marcescens mutant strain with high histidine yield into an escherichia coli genome, and an escherichia coli genetically engineered strain with high histidine yield is obtained by enhancing precursor PRPP supply, histidine efflux and other strategies, so that the problems of thick fermentation liquor, high histidine yield and high histidine yield can be solved. And the method has a relatively good industrial application potential.

The present invention discloses a mutant strain of Streptomyces parvum and its application in producing glutathione, belonging to the field of genetic engineering. The present invention successfully constructs a mutant strain of Streptomyces parvum by overexpressing the glnA gene in Streptomyces parvum; wherein the nucleotide sequence of the glnA gene is shown in SEQ ID NO: 1. Experiments have shown that compared with the wild-type Streptomyces parvum, the mutant strain of Streptomyces parvum can significantly increase the content of glutathione and glucose in the fermentation product, and can also improve the utilization efficiency of ammonia nitrogen during the fermentation process. The present invention provides new strain resources and methods for mass production of bacterial-derived glutathione, and provides new agricultural antibiotic resources and strategies for preventing and controlling a variety of plant diseases.

The invention discloses a paenibacillus kribbensis spaceflight mutant strain and application of the paenibacillus kribbensis spaceflight mutant strain in preparation of nano-selenium. According to the invention, a paenibacillus kribbensis PS04-2 strain is obtained through space mutation, and the strain has high selenite reducing capacity and can tolerate high-concentration selenite, and the tolerable concentration exceeds 1000mM; the method has the capacity of efficiently converting sodium selenite to generate nano-selenium, the synthesized nano-selenium is high in conversion rate and uniform in nano-selenium particle, and the provided preparation method is simple, convenient, low in cost, high in product purity and environmentally friendly. The nano-selenium synthesized by the PS04-2 strain has a good antagonistic effect on various plant pathogenic fungi, can prevent and treat various plant diseases, and can be used for developing more selenium-enriched microbial preparations. Meanwhile, nano-selenium synthesized by the PS04-2 strain is used for sesame production, so that sesame growth can be promoted, selenium-rich sesame can be obtained, and more effective methods are provided for increasing the selenium content of crops.

The invention provides a microbial source anti-oxidation pigment feed additive for aquaculture and a preparation method of the microbial source anti-oxidation pigment feed additive, the microbial source anti-oxidation pigment feed additive for aquaculture is prepared by the following steps: carrying out low-temperature plasma physical mutagenesis on talaromyces albuminosus CY-G to generate a mutant strain, namely talaromyces albuminosus CY110, and then carrying out semi-solid state fermentation on the mutant strain, namely talaromyces albuminosus CY110 to produce wine red pigment. The pigment product obtained by the invention is high in yield of haematochrome, orange pigment and yellow pigment, low in citrinin content, stable in property and relatively strong in oxidation resistance, can be used as an aquaculture microorganism source anti-oxidation pigment feed additive, and has a wide application prospect. The preparation method disclosed by the invention is simple to operate, low in equipment requirement, high in production efficiency and suitable for large-scale production.

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 bacillus pasteurii is preserved in the China Center for Type Culture Collection, and the preservation number of the bacillus pasteurii is CCTCC M 20241864; the urealyticum mutant strain with high urease activity is successfully screened by adopting a normal-pressure and room-temperature plasma technology, and the capability of inducing precipitation of calcium carbonate can be remarkably enhanced, so that the mineralization efficiency of microorganism-induced calcium carbonate deposition and the sandy soil reinforcement effect are improved; in addition, an improved bacterium-mediated microorganism-induced mineralization reaction kinetic model is established, and an improved process and method for reinforcing sandy soil through strains are provided according to the requirement for efficient control of ammonium emission. The research result of the invention has important scientific significance and wide application prospect for improving the practical application effect of the microbial soil reinforcement technology and improving the environmental problem caused by the byproduct waste ammonium solution.

The invention discloses propionibacterium capable of obtaining high-yield propionic acid through compound mutation screening and a method for fermenting propionic acid by using the propionibacterium. The high-yield propionic acid strain YCBS010 (CGMCC No.31160) is obtained by carrying out compound mutagenesis on acid-producing propionibacterium CGMCC 1.2232 serving as an original strain through microwave-ultrasonic combined mutagenesis and compound normal-pressure and room-temperature plasma (ARTP) mutagenesis means. According to the invention, YPA15 is used as a starting strain, microwave and ultrasonic combined mutagenesis is carried out for 100 seconds to screen a bacterial strain with increased propionic acid yield, then ARTP mutagenesis is carried out for 90 seconds to screen out a high-yield mutant strain YCBS010, fermentation in a 1-ton tank verifies that the highest propionic acid yield reaches 65.87 g / L and the fermentation intensity is 0.73 g / L.h after fermentation is carried out for 90 hours, and the bacterial strain has better industrial fermentation potential.

The invention discloses an EMS-ARTP compound mutation chlorella pyrenoidosa mutant strain and an application thereof. The preparation method comprises the following steps: mutagenizing a chlorella pyrenoidosa mutant strain CX41 by adopting an ethyl methanesulfonate (EMS) and normal-pressure and room-temperature plasma (ARTP) composite technology, screening and verifying to obtain a golden yellow chlorella pyrenoidosa mutant strain, naming the golden yellow chlorella pyrenoidosa mutant strain as chlorella pyrenoidosa Y11, and screening and verifying the golden yellow chlorella pyrenoidosa Y11 to obtain the chlorella pyrenoidosa Y11. The strain is preserved in Guangdong Microbial Culture Collection Center (GDMCC) on the fifth floor of the building 59, No. 100 courtyard, Xianlie Middle Road, Guangzhou on October 23, 2024, and the preservation number is GDMCC No: 65324. The chlorella pyrenoidosa mutant strain Y11 has the characteristics of high yield of protein and rich carotenoids, and can be used for fermentation production of microalgae protein and carotenoids.

The invention discloses a chlorella pyrenoidosa white mutant strain FZU65-W1 and application of the chlorella pyrenoidosa white mutant The classification name of the chlorella pyrenoidosa white mutant strain FZU65-W1 is chlorella pyrenoidosa, the chlorella pyrenoidosa white mutant strain is preserved in the China General Microbiological Culture Collection Center on September 11, 2024, the preservation number is CGMCC N0.46151, and the preservation address is No.3, Yard 1, Beichen West Road, Chaoyang District, Beijing. Compared with an original strain FZU65, the chlorella pyrenoidosa white mutant strain FZU65-W1 has the advantages that the growth speed of algae cells under the heterotrophic condition is higher, and meanwhile, the cells are white due to the fact that chlorophyll and carotenoid are not synthesized in the cells. The chlorella pyrenoidosa white mutant strain FZU65-W1 can be used for producing high-quality protein through heterotrophic fermentation, so that not only can a later-stage protein extraction and preparation process be simplified, but also the sensory acceptance of algae powder can be improved, and a high-quality germplasm resource is provided for industrial production and application of microalgae protein.

The invention provides a cordyceps militaris strain with high yield of cordycepin as well as a sporocarp cultivation method and application of the cordyceps militaris strain, and relates to the technical field of microorganisms. The cordyceps militaris strain KN1.6. 778 provided by the invention is a mutant strain obtained in a conventional breeding process, and the preservation number is CGMCC No.40465. The cordyceps militaris strain is cultured and cultivated under proper conditions, and after harvesting, the content of cordycepin in a cordyceps militaris sporocarp reaches 35000mg / Kg or above, the highest content can reach 148000mg / Kg and is far beyond the level of the prior art, and an unexpected technical effect is generated.

The invention belongs to the field of enzyme engineering, and relates to a glycosyl transferase mutant and application thereof in synthesis of salidroside. On the basis of a glycosyl transferase amino acid sequence as shown in SEQ ID NO: 1, iterative saturated mutation is carried out through a molecular modification technology, and the enzymatic activity and catalytic efficiency of the modified glycosyl transferase mutant are greatly improved. The mutation at a specific site can significantly promote the glycosylation activity of a tyrosol substrate. The mutant enzyme is obtained by carrying out induced expression and protein purification on the obtained mutant strain. The substrate conversion rate of the transformed glycosyl transferase mutant for catalyzing the tyrosol glycosylation reaction can reach 95% or above, the yield reaches 55.0 g / L, and an efficient and green new way is provided for salidroside production.

The invention discloses application of OsHTT4 protein in regulation and control of heat resistance and yield of rice. According to the invention, a CRISPR / Cas9 gene editing system is utilized to perform mutation on a rice OsHTT4 gene, and an OsHTT4 protein function deletion mutant strain is constructed. The heat stress of the obtained mutant strain shows that the tolerance of the rice to the heat stress can be remarkably improved by inhibiting the expression of the OsHTT4 protein. In addition, by inhibiting the expression of the OsHTT4 protein, the grain number per ear, the yield per plant, the tiller number and the maturing rate of the rice can be remarkably improved, and the rice yield is improved. On the basis, the invention further provides a method for improving the heat stress tolerance and / or yield of the rice, and the method is beneficial to cultivation of heat stress-resistant and high-yield rice varieties.

The invention discloses a porcine reproductive and respiratory syndrome virus recombinant nanoparticle vaccine and a preparation method and application thereof, the vaccine contains a recombinant nanoparticle protein, and the protein comprises: (1) a recombinant protein designed based on a PRRSV structural protein epitope; (2) nano-particle protein designed on the basis of ferritin derived from bacteria; and (3) realizing the self-assembly of the recombinant nano particles by virtue of a SpyCatcher-SpyTag system. The vaccine can prevent and control NADC30PRRSV-like strains which are popular in China in recent years, and is used for suppressing propagation of PRRSV variants.

The invention belongs to the technical field of plant genetic engineering, and particularly relates to an elongation factor subunit OsRAV9 gene for regulating and controlling resistance of rice to rice blast and application of the elongation factor subunit OsRAV9 gene. The elongation factor subunit OsRAV9 gene induced to express by magnaporthe oryzae is screened, and the nucleotide sequence of the elongation factor subunit OsRAV9 gene is as shown in SEQ ID NO: 1; the sequence of the protein coded by the gene is as shown in SEQ ID NO: 2. By means of agrobacterium tumefaciens-mediated transformation, an OsRAV9 over-expression transgenic strain and a CRISPR / Cas9 mutant strain are obtained. The rice blast inoculation identification on the transgenic material finds that the resistance of the OsRAV9 over-expression strain to the rice blast is enhanced, and the mutant strain is more susceptible to the rice blast bacteria, which indicates that the OsRAV9 is a positive regulation factor of the rice to the rice blast resistance. The OsRAV9 gene plays a positive regulation role in the rice blast resistance, and the resistance of rice to the rice blast can be remarkably improved by over-expression of the gene.

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.

The invention relates to a novel coronavirus SARS-CoV-2 mutant vaccine and application, the vaccine comprises a fusion protein, and the fusion protein comprises: (1) interferon or a functional fragment thereof; (2) a novel coronavirus SARS-CoV-2Omicron mutant strain S protein or a functional fragment of the novel coronavirus SARS-CoV-2Omicron mutant strain S protein; and (3) an immunoglobulin Fc region. Molecule and process optimization of the fusion protein comprises improvement of process developability and immunogenicity, and the vaccine can improve immunogenicity and antibody titer of a mutant new crown antigen through convergence mutation design, efficiently generate a neutralizing antibody, significantly improve defense ability to a variant strain, and can be massively and industrially produced.

The invention belongs to the technical field of microorganism mutation breeding, and particularly relates to a nisin high-yield mutant strain with enhanced production performance. The mutant strain is specifically lactococcus lactis 2686, and the preservation number of the mutant strain is CCTCC (China Center for Type Culture Collection) NO: M 2023219. The strain has relatively high osmotic pressure tolerance, can still normally grow and produce nisin when the osmotic pressure is higher than 0.66 osM / kg H2O, meanwhile, the strain has excellent nisin production capacity, the titer reaches 9834 IU / mL when the strain is fermented in a shake flask for 21 hours, and the titer reaches 21000 IU / mL when the strain is fermented in a fermentation tank for 22 hours. The method is high in yield, good in stability, low in production cost and suitable for further industrial application.

The invention provides a carbonyl reductase mutant and an application of the carbonyl reductase mutant in synthesis of S-glassine. The mutant protein is a non-natural protein, and the mutant protein can significantly improve the activity of catalyzing the reduction of carbonyl in 1-C-(beta-D-xylopyranosyl)-acetone to generate S-configuration alcohol. When the activity-improved carbonyl reductase mutant strain is applied to the production process of S-configuration glassine, the carbonyl reduction capacity of the S-configuration glassine can be improved, 100-240 g / L of substrate can be completely converted, and the S-configuration glassine is generated.

The invention discloses Pseudomonas protegens for producing nitropyrrole, which is preserved in the China Center for Type Culture Collection, and the preservation number is CCTCC (China Center for Type Culture Collection) M20241968. The invention further discloses a preparation method of the Pseudomonas protegens for producing nitropyrrole. The invention also discloses an engineering bacterium for producing nitropyrrole and a construction method of the engineering bacterium. The engineering bacterium is a mutant strain for blocking a bypass metabolic pathway of the pseudomonas. For example, the pseudomonas is taken as a target, a core gene in a BGC1 biosynthetic gene cluster in the pseudomonas is knocked out through a gene knockout method, or a core gene in a BGC16 biosynthetic gene cluster is knocked out, or a mutant strain of the core genes in two biosynthetic gene clusters of BGC1 and BGC16 is knocked out at the same time. The invention also discloses a biocontrol microbial inoculum containing the pseudomonas or the engineering bacteria. The invention further discloses application of the pseudomonas or the engineering bacteria or the biocontrol microbial agent in prevention and treatment of rhizoctonia solani, and the pseudomonas or the engineering bacteria or the biocontrol microbial agent has a remarkable antibacterial effect.

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 relates to the technical field of gene engineering, and particularly discloses application of a pathogenic gene FpMetR for controlling stem rot pathogenic bacteria Fusarium pseudograminearum, specifically, the colony morphology of a deletion mutant strain of the FpMetR gene is changed, the sporulation quantity is reduced, the spore germination rate is reduced, and the pathogenicity of the mutant strain is completely lost, the DNA sequence of the FpMetR gene is as shown in SEQ ID No: 1, and the DNA sequence of the FpMetR gene is as shown in SEQ ID No: 2. According to the invention, the pathogenic mechanism is clarified: a scientific basis is provided for deeply understanding the pathogenic mechanism of pathogenic bacteria by revealing the key effect of the FpMetR gene in the pathogenic process of the fusarium pseudograminearum, and a new thought and a target gene are provided for the field of plant anti-fusarium pseudograminearum genetic engineering by virtue of the effect of the FpMetR gene in the aspects of regulating and controlling the growth and pathogenicity of wheat. By applying the gene or a regulation mechanism thereof to genetic improvement of crops such as wheat, new varieties with disease resistance are expected to be cultivated, dependence on chemical pesticides is reduced, and environmental friendliness is improved.

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 yeast mutant strain capable of efficiently utilizing acetic acid to generate grease. The strain is named as rhodotorula mucilaginosa in taxonomy. The strain is adaptively domesticated for 211 days, and the obtained mutant strain can grow in a culture medium containing at most 1.4 M of sodium acetate. Under the condition of sodium acetate stress, compared with a wild strain, the hysteresis period of the mutant strain is reduced by at least 24 hours, and the grease yield is increased by 197%. According to the strategy, the glucose and sodium acetate metabolism rate and the grease generation efficiency are improved, and a technical basis is provided for establishment of a cell factory for producing lipid-based chemicals.

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.