217 results about "Heterologous expression" patented technology

The invention discloses a Pseudomonas putida high-yield rhamnolipid fermentation medium based on a step-by-step optimization strategy, an optimization method and application thereof, through the step-by-step strategy of component screening-single-factor optimization-multi-factor interactive optimization, a mixed carbon source and a mixed nitrogen source are taken as cores, and a Plackett-Burman test, a steepest climbing test and Box-Behnken response surface design are combined, so that the high-yield rhamnolipid fermentation medium for the pseudomonas putida high-yield rhamnolipid is obtained. Optimizing to obtain a special fermentation culture medium; two genetic engineering strains estA-2 and estA-3 are constructed by heterologous expression of key genes, and the supply and extracellular transport efficiency of a rhamnolipid synthesis precursor is enhanced; the recombinant strain is applied to the optimized culture medium, and efficient production of a shake flask and a 5L fermentation tank is achieved. The rhamnolipid yield of the estA-3 strain in a 5L fermentation tank reaches 35.59 + / -2.18 g / L, the conversion rate is 0.282 g / g, the productivity is 0.404 g / L / h, the rhamnolipid yield, the conversion rate and the productivity are obviously superior to those in the prior art, and a key technical support is provided for industrial production of rhamnolipid.

The application provides a recombinant Aspergillus niger with high trans-aconitic acid yield and a construction method and application thereof, and relates to the technical field of genetic engineering. Specifically, the recombinant Aspergillus niger heterogeneously expresses aconitate isomerase TbrA and / or Adi1. The application provides a new engineering strain for efficient production of trans-aconitic acid, solves the source predicament of needing plant extraction or needing chemical synthesis in traditional production of trans-aconitic acid, and greatly improves the yield of trans-aconitic acid.

The invention discloses an escherichia coli engineering bacterium for producing 5-ALA by an anaerobic fermentation method as well as a construction method and a fermentation method of the escherichia coli engineering bacterium. The engineering bacterium is constructed by taking escherichia coli (E. coli) ZX11 as a host and performing heterologous expression on 5-ALA synthetase (HemA) from rhodobacter capsulatus. In order to improve the soluble expression level of the HemA, the HemA is subjected to fusion expression with a maltose binding protein (MBP) tag. Furthermore, the engineering bacterium can also heterologously express a visual purple protein (PR) fused with the MBP tag. The construction method of the engineering bacteria comprises the following steps: sequentially cloning the MBP-HemA fusion gene and the PR gene to an expression vector and transferring into host bacteria. By utilizing the engineering bacteria provided by the invention, anaerobic fermentation can be carried out in a culture medium taking glucose as a carbon source, and 5-ALA can be efficiently synthesized. The invention provides an effective way for realizing green and energy-saving anaerobic biological manufacturing of 5-ALA.

The invention discloses a pennisetum purpureum CpERF37 transcription factor and cold-resistant application thereof, and relates to the technical field of plant genetic engineering. According to the invention, the Pennisetum purpureum-sourced ERF transcription factor CpERF37 is cloned and functionally identified for the first time, and heterologous expression verification in a model plant arabidopsis thaliana proves that the Pennisetum purpureum-sourced ERF transcription factor CpERF37 has a remarkable effect on improving the low-temperature tolerance of plants, and functional gene resources related to low-temperature stress response are enriched. The method not only has theoretical innovation, but also has a definite application prospect, and can provide effective gene resources and technical support for cold-resistant improvement of pasture and crops.

The invention provides application of Ustilaginoidea virens secretory protein UvWMT and a coding gene thereof in prevention and control of plant diseases. The gene sequence of the Ustilaginoidea virens secretory protein UvWMT is researched, found and cloned for the first time, and the new application of the Ustilaginoidea virens secretory protein UvWMT in disease-resistant breeding of crops such as rice is developed. Research finds that the protein is a key pathogenic factor in the process that rice is infected by ustilaginoidea virens, heterologous expression experiments further find that heterologous expression of UvWMT in rice can significantly improve the resistance of crops to various pathogenic bacteria such as ustilaginoidea virens, magnaporthe oryzae and xanthomonas oryzae, and has no significant difference in key agronomic traits compared with a wild type. An important theoretical basis is provided for rice disease-resistant breeding, crops can be safely and effectively endowed with broad-spectrum disease resistance by heterologous expression of the gene, and the gene has great application prospects and economic values in the aspects of crop breeding disease resistance improvement, rice disease prevention and control and crop yield increase and pesticide reduction.

The invention provides an application of a Ustilaginoidea virens UvWSC1 gene in improvement of plant disease resistance. The invention develops a new application of the Ustilaginoidea virens UvWSC1 gene in improving the broad-spectrum disease resistance of crops such as rice for the first time, and the UvWSC1 gene is subjected to heterologous high expression in the rice, so that the broad-spectrum resistance of the rice to various pathogenic bacteria such as Ustilaginoidea virens, Magnaporthe oryzae and Xanthomonas oryzae can be obviously enhanced, and the agronomic traits of the rice are not influenced; an important theoretical basis is provided for rice disease-resistant breeding. By heterologous expression of the UvWSC1 gene, broad-spectrum disease resistance can be safely and effectively endowed to crops, a broad-spectrum disease-resistant rice variety is obtained for production, and the broad-spectrum disease-resistant rice gene has great application prospects and economic values in the aspects of crop breeding disease resistance improvement, rice disease prevention and control and crop yield increase and pesticide reduction.

The invention discloses a method for synthesizing alpha-arbutin through biotransformation, and belongs to the technical field of biochemistry. A gene cloning technology is utilized, sucrose phosphorylase Spase in leuconostoc mesenteroides and sucrose phosphorylase gtfa in bifidobacterium adolescentis are screened and found through a Deep Molecules and DLKcat algorithm on a Uniprot database, novopro is utilized for codon optimization, then the sucrose phosphorylase Spase and the sucrose phosphorylase gtfa are expressed on a plasmid vector PET-28a and are converted into an escherichia coli BL21 (DE3) strain, and the sucrose phosphorylase Spase and the sucrose phosphorylase gtfa in the bifidobacterium adolescentis are obtained. An engineering strain for heterologous expression of the gene is constructed by taking the gene as a chassis cell. According to the process, sucrose and hydroquinone are taken as co-substrates, and bioconversion is carried out under the action of sucrose phosphorylase from different sources to obtain alpha-arbutin.

This invention relates to the fields of bioengineering and fermentation engineering, and discloses a genetically engineered *Streptomyces albopictus* strain that produces high levels of ε-polylysine and its fermentation production process. This genetically engineered strain uses *Streptomyces albopictus* strains acclimated to ε-polylysine tolerance as a chassis, and its genome integrates... ppc and dapf Through expression box, heterogeneous asd Expression cassettes, containing secretory signal peptides lysp Fusion expression cassettes and D404A / K499A point mutations pls Expression cassette. The fermentation process employs a two-stage pH control strategy, maintaining a neutral environment during the cell growth phase and adjusting to an acidic environment during product synthesis. This invention improves ε-polylysine yield through a synergistic strategy of enhancing precursor supply, constructing efflux detoxification channels, and increasing synthase activity; combined with an acidic fermentation process, it effectively inhibits product degradation, yielding a high-molecular-weight and highly uniform target product suitable for industrial production.

The invention discloses a method for increasing the fermentation yield of mernomycin A based on a reinforced chassis strain glycosyl donor. Specifically, in the heterologous expression process of a sirnomycin A biosynthetic gene cluster in a chassis strain Streptomyces albus J1074, a glycosyl donor synthesis module gene and a resistance gene (MaPBP) are introduced at the same time, and on the basis of improving a glycosyl biosynthetic donor, the physiological tolerance of the chassis strain is also enhanced. Compared with a high-yield strain Streptomyces albus LX03 (CGMCC NO. 20985) of which the tolerance is only optimized, the yield of the strain Streptomyces albus LX02: pJQK610 subjected to genetic engineering optimization is improved by 285%, and the yield reaches 114 mg / L. The strain disclosed by the invention has the advantages that the yield of the strain Streptomyces albus LX02: pJQK610 is improved by 285%, and the yield of the strain Streptomyces albus LX02: pJQK610 is improved by 285%. The invention provides a high-yield technology for improving heterologous expression of the mernomycin A through collaborative optimization of precursor supply and physiological tolerance, and provides reference for efficient production of the medicine.

The invention discloses ganoderic acid mass production and application based on cytochrome P450 enzyme CYP512W6, the cytochrome P450 enzyme CYP512W6 in ganoderma lucidum is converted into a corresponding saccharomyces cerevisiae strain for heterologous expression, and three kinds of ganoderic acid, namely TLTOA, 3 beta-TLTOA and DLDOA, are obtained after fermentation. The invention provides a new implementation mode for heterologous biosynthesis of ganoderic acid in saccharomyces cerevisiae.

The application belongs to the field of enzyme genetic engineering, and particularly relates to application of a sesquiterpene synthase and a mutant thereof in synthesis of enantiomeric-drimenol compounds, wherein the sesquiterpene synthase is a sesquiterpene synthase from Chenopodium quinoa Willd., and includes CqDMDS1 or CqDMDS2; the mutant of the sesquiterpene synthase is a mutant CqDMDS1 in which an amino acid at position 443 of CqDMDS1 is mutated F443A / G The application realizes heterologous expression of the sesquiterpene synthase and the mutant thereof from Chenopodium quinoa Willd. in an Escherichia coli and a N. benthamiana expression system, catalyzes synthesis of (-)‑8,11-driman-diol or (+)‑drimenol. It is found through activity test that the sesquiterpene synthase from Chenopodium quinoa Willd. has a significant inhibitory effect on plant pathogenic fungi Phytophthora nicotianae, Phytophthora sojae and Fusarium graminearum. The sesquiterpene synthase and the mutant thereof and the biological preparation of the catalytic product have important significance for development of biological pesticides.

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

The application belongs to the field of genetic engineering and biosynthesis, and particularly relates to biosynthesis of a class of diterpenoids. The application provides genes having a key role in the formation of a 5-8-5 tricyclic mother nucleus and a five-membered heterocyclic ring in biosynthesis of the class of diterpenoids, which are respectively named as PrcA and PrcB and polypeptides encoded by the genes, expression of PrcA and PrcB is carried out through a heterologous expression system of Aspergillus oryzae, and five diterpenoids with novel structures and anti-metabolic related fatty liver disease activity are obtained. The application provides application of the polypeptides in biosynthesis of the class of diterpenoids, and enriches a diterpenoid library, thereby providing lead compound resources for discovering new anti-metabolic related fatty liver disease medicinal raw materials.

The present application belongs to the field of biotechnology, and particularly relates to a biosynthesis gene cluster of fungal polyketide compounds and application thereof. The present application provides a heterologous expression method of an aspertaichunol compound biosynthesis gene combination, and a compound aspertaichunol B is obtained through the method, and a compound aspertaichunol A is prepared through acid hydrolysis of the aspertaichunol B, which has important significance for future research and development of an efficient biosynthesis method for preparing the aspertaichunol compound.

The invention relates to the technical field of plant genetic engineering and agricultural planting, in particular to application and method of an SlGRXC9 gene in improvement of tomato cadmium stress tolerance, the number of the SlGRXC9 gene is Solyc07g053550, the core coding region sequence of the SlGRXC9 gene is SEQ ID NO.1, and the coded protein sequence is SEQ ID NO.2; through construction of SlGRXC9 overexpression transgenic tomatoes, heterologous expression of protein encoded by the gene in plant cells or use of the gene as a molecular breeding target, the system activity of antioxidant enzymes such as SOD, POD, CAT and GR in tomatoes can be enhanced, cadmium stress induced H2O2 and O2-accumulation and membrane lipid peroxidation damage are reduced, and absorption and accumulation of the tomatoes to cadmium ions are not affected; according to the method, the growth ability and physiological stability of the tomatoes under cadmium stress are remarkably improved, the risk of nutrient imbalance is avoided, the hereditary stability is high, and the method can be widely applied to safe production of the tomatoes in cadmium-contaminated soil and creation of stress-tolerant germplasm.

The invention discloses a 13-hydroxyglucopiericidin A heterologous expression engineering strain, a construction method of the 13-hydroxyglucopiericidin A heterologous expression engineering strain and an application of the 13-hydroxyglucopiericidin A heterologous expression engineering strain. According to the engineering strain, Streptomyces avicularis SUKA17 is taken as a host, and heterologous synthesis of the chalicimycin glycoside, especially 13OH-GPA, is realized by introducing a biological synthesis gene cluster of the chalicimycin glycoside; the bacterial strain is classified and named as Streptomyces sp. SK-SA23E, and the preservation number of the bacterial strain is GDMCC NO.67271. The invention further discloses a preparation method of the bacterial strain. According to the invention, the efficient heterologous expression of the biological synthesis gene cluster of the chalcone glycoside is realized for the first time, the yield of the 13OH-GPA in the engineering strain is increased by 2.8 times compared with that of the original production strain, the relative content of the 13OH-GPA in the chalcone glycoside is increased to 48.1% from 23.6%, and the method is suitable for large-scale preparation of the 13OH-GPA.

The invention discloses a recombinant bacterium for producing mevalonic acid by taking glucose and acetone as co-substrates as well as a construction method and application of the recombinant bacterium, and belongs to the technical field of genetic engineering. The problems that an existing mevalonic acid biosynthesis mode is low in carbon atom economy, limited in theoretical yield and the like are solved. According to the invention, acetone carboxylase, acetoacetyl coenzyme A synthetase, 3-hydroxy-3-methylglutaryl coenzyme A reductase and hydroxymethyl glutaryl-CoA synthetase are subjected to heterologous expression in escherichia coli with an acetyl coenzyme A acetyltransferase gene atoB and a histidine protein kinase gene atoS knocked out, and self carbonic anhydrase is over-expressed; and a new way for synthesizing MVA by using glucose and acetone as a co-substrate is constructed. According to the method, one molecule of CO2 can be fixed in the biosynthesis of mevalonic acid, the yield of carbon atoms in the synthesis process of mevalonic acid is increased, the problem of low yield of carbon atoms in the synthesis process of mevalonic acid by taking glucose as a single substrate is solved, and a new thought is provided for constructing a carbon neutralization type biological manufacturing technology.

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 invention discloses an application of a recombinant thuricella Cry21A protein in preparation of an active medicine for resisting baylisascaris of pandas and pandas. The application comprises the following steps: generating the recombinant thuricella Cry21A protein Bt2-56 in a cloning and heterologous expression mode; the ED50 values of the recombinant Cry21A protein on the L4-stage larvae and adults of panda schroederleinii on the third day are respectively 12.5 g / mL and 9.2 g / mL, and the ED50 values of the recombinant Cry21A protein on the seventh day are respectively 0.15 g / mL and 0.08 g / mL; the ED50 values of the recombinant Cry21A to the L4-stage larvae and adults of the baylisascaris lisascaris of the pandas on the third day are 9.7 g / mL and 6.6 g / mL respectively, the ED50 values of the recombinant Cry21A to the L4-stage larvae and adults of the baylisascaris lisascaris of the pandas on the seventh day are 0.11 g / mL and 0.07 g / mL respectively, and it is proved that the recombinant Cry21A protein has higher insecticidal activity to the baylisascaris lisascaris of the The results provide data reference for subsequent research and development of recombinant Cry21A protein as a novel and environment-friendly candidate drug for resisting ascariasis of wild animals such as pandas, pandas and the like.

The invention belongs to the technical field of tea tree gene application, and particularly relates to application of a tea tree CsPHT gene in improving tea geometrid and colletotrichum gloeosporioides resistance of a tea tree. The invention discloses a tea tree CsPHT gene, the nucleotide sequence of the tea tree CsPHT gene is as shown in SEQ ID NO.1, the tea tree CsPHT gene codes 434 amino acid residues, and the amino acid sequence of the tea tree CsPHT gene is as shown in SEQ ID NO.2. The CsPHT gene is proved to be capable of catalyzing biosynthesis of tea tree defense related compounds such as feruloyl putrescine, coumaroyl putrescine and cinnamoyl putrescine for the first time, and the conservation of the catalytic function of the CsPHT gene is proved through heterologous expression. An in-vivo instantaneous function verification result of a tea tree shows that the over-expression of the CsPHT gene can significantly improve the resistance of the tea tree to tea geometrid and tea anthracnose bacteria. The CsPHT gene is proved to be a key positive regulation factor for regulating the resistance of the tea tree to the tea geometrid and the tea anthracnose fungus. The invention provides important gene resources and molecular targets for cultivating new varieties of high-resistance and multi-resistance tea trees.

The invention relates to the technical field of biology, in particular to a recombinant pichia pastoris engineering bacterium, a construction method of the recombinant pichia pastoris engineering bacterium and application of the recombinant pichia pastoris engineering bacterium in secretory expression of ovotransferrin. The heterologous expression of ovotransferrin is effectively realized by optimizing ovotransferrin genes and utilizing molecular chaperone genes to strengthen the regulation and control capability of hosts, and meanwhile, by optimizing signal peptides and constructing high-copy recombinant pichia pastoris expression strains, the low-copy expression condition is verified and compared by utilizing fermentation expression, so that the heterologous expression of ovotransferrin is realized. According to the high-copy recombinant pichia pastoris engineering bacteria constructed by the invention, the ovotransferrin expression quantity is obviously improved and reaches 140 mg / L, the secretory expression efficiency of the ovotransferrin is effectively improved, and theoretical guidance is provided for heterologous expression and industrial production of the ovotransferrin.

The present invention relates to an adenovirus genome comprising a heterologous expression cassette encoding a circular RNA and uses thereof.

The application provides a myo-inositol production strain and a construction method and application thereof. The strain is deficient in ackA, adhE, ldhA, lacI, poxB, pgi, pgm, pfkA, pykF and ptsG genes, down-regulates a Zwf gene, up-regulates glk and glf genes, heterologously expresses an IPS gene from Thermococcus and an IMP gene from Thermotoga, and carries a high-copy plasmid pTrcII. The strain has good myo-inositol synthesis capacity, can efficiently and stably synthesize myo-inositol from glucose as a carbon source by fermentation, has low production cost, high strain stability, no toxic metabolic by-products, and has high economic benefits and excellent industrial application prospect.

The invention relates to a method for improving the gamma-aminobutyric acid yield of heterologous expression coffee GAD recombinant escherichia coli through ultrasonic and ultraviolet combined mutagenesis, and belongs to the technical field of microbial breeding. The method comprises the following steps: mutagenizing recombinant escherichia coli for heterologous expression of coffee-derived GAD by adopting an ultrasonic and ultraviolet sequential compound mutagenesis strategy, screening out bacterial colonies with good growth vigor through mutagenesis, finally inoculating the screened bacterial colonies into a fermentation culture medium for fermentation, and screening out bacterial strains with the highest GABA yield and conversion rate; the GABA yield of the mutagenized strain is improved by 31.3% compared with that of an initial strain, and the conversion rate is improved by 22.1%. The GABA yield, the GAD activity, the GAD gene expression quantity and the passage stability of the high-yield mutant strain UT-UV-3 are tested, the GABA yield, the conversion rate, the GAD activity and the GAD gene expression quantity of the high-yield mutant strain UT-UV-3 are remarkably improved, passage is stable, and the high-yield mutant strain UT-UV-3 has a good application prospect.

The present disclosure provides compositions comprising a glycoside hydrolase and one or both of hesperidin and hesperetin, wherein an active site of the glycoside hydrolase comprises first, second, third, fourth, and fifth regions as described herein. The present disclosure also relates to methods for producing a polyphenol aglycone, comprising contacting a phenolic glycoside with a glycoside hydrolase described herein. Also provided are host cells and heterologous expression systems capable of expressing a heterologous glycoside hydrolase, and nucleic acids encoding the glycoside hydrolase.

The application discloses a genetically engineered bacterium for efficiently producing itaconic acid by using corn stalk hydrolysate and application thereof, and belongs to the technical field of gene recombination and metabolic engineering. The genetically engineered bacterium for efficiently producing itaconic acid by using corn stalk hydrolysate is characterized by the following aspects: taking a strain BW08 as a starting strain, heterologously expressing a homocentric acid decarboxylase gene CAD, deleting an isocitric acid dehydrogenase gene Icd, heterologously expressing a xylose acid dehydrase gene XD, a 2-keto-3-deoxy-xylose acid dehydrase gene KDXD and an alpha-ketoglutaric acid semialdehyde dehydrogenase gene KGSADH, and heterologously expressing a citric acid synthase gene gltA. In the fed-batch fermentation, the yield of itaconic acid of the genetically engineered bacterium reaches 68.6 g / L, and the conversion rate reaches 0.6 g / g (total sugar). The genetically engineered bacterium can efficiently metabolize corn stalk hydrolysate to produce itaconic acid.

This application discloses a recombinant bacterial strain that highly expresses nonspecific peroxygenase, its construction method, and its applications, relating to the field of microbial engineering technology. The strain of this invention uses *Escherichia coli* BL21(DE3) as the host. First, the key gene *hemA* for heme synthesis is integrated into the genome using the CRISPR-transposon system. Then, a chassis engineered strain A2 with 2 copies of optimal integration is screened and co-transformed with the rDcaUPO-A161C expression plasmid and the molecular chaperone plasmid pG-KJE8. The intracellular heme level of this strain is increased by 2.84 times compared to the original strain, and the total enzyme activity of rDcaUPO-A161C is cumulatively increased by 8.9 times and the specific enzyme activity is increased by 6.21 times compared to the wild type. This fundamentally solves the problems of insufficient cofactors, low folding efficiency, and poor activity in heterologous expression of nonspecific peroxygenases, and can be used for the efficient production of nonspecific peroxygenases.

The invention relates to the technical field of bioengineering bacteria. The invention provides a saccharomyces cerevisiae engineering bacterium capable of synthesizing p-anisaldehyde from the beginning and a construction method of the engineering bacterium. A saccharomyces cerevisiae recombinant strain JS1-15 is used as an original strain; the saccharomyces cerevisiae engineering bacteria are obtained by heterologous expression of 4-hydroxymandelic acid synthetase HmaS, heme oxygenase HMO, benzoyl formate decarboxylase BFD and methyltransferase 4VPMT1. The saccharomyces cerevisiae engineering bacteria are used for preparing the saccharomyces cerevisiae engineering bacteria. The saccharomyces cerevisiae engineering bacterium disclosed by the invention can realize a complete de novo biosynthesis path from 4-hydroxyphenylpyruvic acid to p-anisaldehyde by taking glucose as a unique carbon source, and has good industrial application potential.

This invention discloses an engineered bacterium expressing the sqr gene and its application in aerobic remediation of hexavalent chromium pollution. The construction method of the engineered bacterium includes the following steps: S1. Constructing the pEcgRNA-sqr plasmid; S2. Obtaining donor DNA; S3. Preparing electrocompetent cells; S4. Co-transforming the pEcgRNA-sqr plasmid and donor DNA fragment into the electrocompetent cells, performing resistance screening, and obtaining engineered bacteria integrating the sqr gene. This invention utilizes the constructed engineered bacterium expressing SQR coupled with nano-ferrous sulfide to establish a "sulfur metabolism-FeS regeneration" cycle system, accelerating Cr(VI) reduction. Under aerobic / microaerobic conditions, the removal rate of 50 mg / L Cr(VI) in 1 hour can reach over 95%, while simultaneously alleviating the competitive pressure of intracellular reducing power caused by heterologous expression of the sqr gene, improving remediation efficiency and strain growth stability, and achieving a synergistic effect of biochemistry.