15 results about "Cysteine synthesis" patented technology

The invention provides a high-yield L-cysteine engineering bacterium accumulated by sulfur donor 3 '-phosphoadenosine-5'-phosphoryl sulfuric acid as well as a construction method and application of the high-yield L-cysteine engineering bacterium. According to the method, the copy number of key genes in a cysteine synthesis route in an escherichia coli organism is changed, heterologous genes are introduced, the expression level of the key genes in the cysteine synthesis route in the escherichia coli organism is enhanced, and sulfur flux is further made to flow to synthesis of L-cysteine. On the basis that the chassis bacteria enhance the carbon flux, in order to maintain the balance of carbon and sulfur in the strain and continuously enhance the synthesis of the sulfur flux flowing to the L-cysteine, the synthesis of the product is promoted by enhancing the synthesis capability of a sulfur donor PAPS in a sulfate pathway, and finally, the plasmid-free and antibiotic-free engineering strain for high yield of the L-cysteine is obtained. Finally, the shake flask titer of the L-cysteine reaches 6.06 g / L and is increased by 49.2% compared with that of an original strain.

The present invention relates to the field of biotechnology, and more particularly to a highly active S-sulfo-L-cysteine ​​synthetase mutant and its applications. The present invention screened and identified a preferred SSC03 enzyme through cluster analysis and phylogenetic analysis, and further engineered mutations thereof. The resulting SSC03-S256PΔCT achieved a 24-hour conversion rate of 56% and produced 84 mM of S-sulfo-L-cysteine, demonstrating its applicability to further purification process development.

The application discloses a mutant of glutamate-cysteine synthetase and application of the mutant in synthesis of glutathione. Single-site mutation is carried out on amino acid residues at positions 150, 188, 235, 236, 241, 300, 301, 302 and 330 of wild-type glutamate-cysteine synthetase (Glutamate-cysteine ligase [EC:6.3.2.2]) from Citrobacter koseri (strain ATCC BAA-895), and mutant sites at positions 150, 236, 302 and 330 are screened. Mutants M1-M6 are obtained by combination mutation of the mutant sites screened above, and the enzyme activity of the mutant M4 with the highest activity is increased by 477% compared with that of the wild-type glutamate-cysteine synthetase. The mutant M4 is used to catalyze synthesis of glutathione, and the highest concentration reaches 23 g / L, which is increased by 4.2 times compared with the wild type, and the production cost is greatly reduced, so the mutant has important application value.

The invention discloses a novel low-temperature curing epoxy curing agent and a preparation method thereof, and belongs to the technical field of epoxy curing agents. The formaldehyde adsorbent is prepared from eugenol, cysteine and formaldehyde. Raw materials are screened through a large number of experiments, new raw materials-eugenol and cysteine are adopted, and eugenol molecules contain a phenolic hydroxyl group, an allyl group and a methoxyl group; a cysteine molecule contains an amino group, a carboxyl group and a sulfydryl group (-SH). The groups increase the reaction activity of the curing agent, especially sulfydryl, so that the curing speed of the curing agent in a low-temperature environment can be greatly increased. Compared with a common cardanol phenolic aldehyde amine curing agent, the phenolic aldehyde amine curing agent synthesized from eugenol and cysteine has the advantages that the low-temperature curing speed is higher, the good heat deformation resistance is achieved, and the good technical effect is achieved.

The invention discloses a hydrophilic two-dimensional nano composite material and a preparation method thereof. The material is used for enriching phosphorylated and glycosylated peptides at the same time. The hydrophilic two-dimensional nano composite material is MOLs (at) PEI (at) Au (at) L-Cys and is a lamellar material synthesized by taking a metal organic lamellar material (MOLs) as a substrate material and polyethyleneimine (PEI) as a reducing agent and a stabilizing agent, loading gold nanoparticles (AuNPs) on the surface of the MOLs and then fixing L-cysteine through an Au-S bond. The material has specific hydrophilic interaction with a hydroxyl group on a glucoside chain and a phosphate group of phosphopeptide, so that enrichment of phosphorylated and glycosylated peptides, especially N-phosphorylated peptides, is realized under a neutral condition (pH = 7-7.5). A high-resolution and high-sensitivity liquid chromatography-mass spectrometry system is combined, so that qualitative and quantitative analysis of deep-coverage proteome is realized.

This invention belongs to the field of microbial technology and provides a space-mutated *Bacillus paralichrysiformis* strain with high synthetic selenocysteine ​​and high sodium selenite tolerance, obtained through space mutagenesis, and its applications. The *Bacillus paralichrysiformis* G1-m strain is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 36525, deposited on November 11, 2025. This strain has significant core advantages: firstly, it possesses extremely high sodium selenite tolerance, able to withstand sodium selenite stress up to 440 mM; secondly, its selenocysteine ​​and nano-selenium synthesis efficiency is significantly improved, not only significantly increasing the strain's resistance threshold to selenium stress but also directionally enhancing the activity of the selenocysteine ​​biosynthetic pathway. Its application potential covers multiple fields, such as selenium-enriched probiotic preparations, nano-drug carriers, functional food additives, and high-efficiency selenium nutritional supplements, laying the foundation for the high-value utilization of selenium resources and the industrial application of functional microorganisms.

Provided is a multienzyme complex assembly system for producing L-cysteine at high yield. A reasonable metabolic modification target is determined by means of screening of critical pathway enzymes CysE, CysM, NrdH, and CysK in a L-cysteine synthesis pathway and L-cysteine transport-related channel proteins EamA and EamB, two affinity short peptides RIDD and RIAD are respectively fusion-expressed with the critical pathway enzymes and the channel proteins, and by means of combination optimization, the assembly of the critical pathway enzymes and the channel proteins is implemented, thereby accelerating the reaction rate of the L-cysteine synthesis pathway, improving the metabolic flux, and enhancing the degree of aggregation of products in the vicinity of a cell membrane. On the basis of the construction and application strategy of the multienzyme complex assembly system, further provided are a genetically engineered bacterium for producing L-cysteine at high yield and a construction method therefor, implementing efficient synthesis of L-cysteine.

The invention discloses a bacillus licheniformis recombinant strain with high yield of L-cysteine, and belongs to the technical field of synthetic biology and microbial metabolism engineering. The cysteine synthesis flux is enhanced through multiple knockout and combined overexpression. An efficient engineering strain is constructed by knocking out a serine hydroxymethyltransferase coding gene glyA and an L-serine ammonolysis enzyme coding gene sdaAA of a serine catabolism key pathway, knocking out a cysteine catabolism gene metC and combining gene overexpression to introduce a feedback inhibition removal mutant cysEf and a transporter eamA, and the efficient engineering strain is used for preparing a recombinant strain. Finally, the yield of the L-cysteine reaches 1.075 g / L in shake flask fermentation (the conversion rate is 18.69%), and the application potential of the bacillus licheniformis in sulfur metabolism engineering is highlighted.

The invention provides application of taurine and hypotaurine in inhibiting synthesis of plant cysteine. According to the invention, taurine and hypotaurine are used for directly inhibiting the catalytic function and activity of two cysteine synthesis key enzymes, namely SAT and OAS, in plants, so that synthesis of plant cysteine is hindered. The technology can be used for preparing a plant cysteine inhibitor, so that the amino acid metabolism process of plants is seriously disturbed, the growth of the plants is hindered, and then the technology has the potential of developing novel safe and non-toxic herbicides, can enrich the biological application in the field of agricultural weeding, and further lays a foundation for the application of exogenous compounds to plant amino acid synthesis inhibition. Meanwhile, the invention also provides a method for rapidly synthesizing the taurine and the hypotaurine in the nicotiana benthamiana leaves by utilizing an instantaneous conversion method, so that the synthesis cost of the taurine and the hypotaurine is reduced, and a basis is provided for later wide application.

The application discloses a novel low-temperature curing epoxy curing agent and a preparation method thereof, and belongs to the technical field of epoxy curing agents. The novel low-temperature curing epoxy curing agent is made of eugenol, cysteine and formaldehyde. The application selects raw materials through a large number of experiments, adopts new raw materials, i.e. eugenol and cysteine. The eugenol molecule contains a phenolic hydroxyl group, an allyl group and a methoxyl group; the cysteine molecule contains an amino group, a carboxyl group and a sulfydryl group (-SH). These groups increase the reactivity of the curing agent, and especially the sulfydryl group can greatly improve the curing speed of the curing agent in a low-temperature environment. The phenolic aldehyde amine curing agent synthesized by using eugenol and cysteine has a faster low-temperature curing speed than a general cardanol phenolic aldehyde amine curing agent, and also has a good heat deformation resistance, and thus a good technical effect is achieved.

Processes for producing L-cysteic acid along with uses for the same. The process includes providing a reaction of O-phospho-L-serine (OPS) with a salt of sulfurous acid (sulfite) and a cysteate synthase (CS enzyme) belonging to enzyme class EC 2.5.1.76 in a biotransformation. Where a concentration of OPS in a batch is at least 1 g / L and the CS enzyme is produced in an enzymatically active form by growth of the microorganism strain E. coli K12 JM105. The biotransformation is carried out under active pH control and the CS enzyme has an amino acid sequence specified in SEQ ID NO: 4 or an amino acid sequence homologous thereto. Where an amino acid sequence homologous to SEQ ID NO: 4 has a sequence identity of at least 50% in relation to SEQ ID NO: 4 and, at the same time, cysteate synthase enzyme activity.

The present invention relates to a method for producing L-cysteic acid, which includes a reaction of O-phospho-L-serine (OPS) with a salt of sulfurous acid (sulfite) and cysteic acid synthase (CS enzyme) belonging to the enzyme class EC 2.5.1.76 in a bioconversion process. The L-cysteic acid according to the present invention can be decarboxylated to form taurine. The present invention also relates to the use of the produced L-cysteic acid for the production of taurine.

The invention discloses a method for synthesizing acetyl coenzyme A by multi-enzyme cascade catalysis of calcium pantothenate, and belongs to the technical field of biological catalysis engineering. According to the invention, a new way for efficiently and catalytically synthesizing the acetyl coenzyme A by adopting a bifunctional enzyme of pantothenate kinase, phosphopantetheine synthetase-phosphopantetheine decarboxylase, phosphopantetheine adenylyltransferase, dephosphorylated coenzyme A kinase, malonyl coenzyme A synthetase and malonyl coenzyme A decarboxylase in a cascade manner is adopted; a coupling system is preferably selected, D-calcium pantothenate, L-cysteine hydrochloride and malonic acid are used as substrates, and the yield of the synthesized acetyl coenzyme A reaches up to 8.3 g / L after 90 min of reaction. According to the method disclosed by the invention, the compound which is cheap and easy to obtain is used as a precursor to construct the multi-enzyme coupled recombinant escherichia coli, and the acetyl coenzyme A is catalytically synthesized, so that the synthesis cost is greatly reduced, and a solid foundation is laid for industrially, green and efficiently preparing the acetyl coenzyme A.

The invention provides an Escherichia coli mutant strain with high yield of L-cysteine and application, and belongs to the technical field of bioengineering, the strain is named as MFAPA45QT, and the preservation number of the strain is CGMCC (China General Microbiological Culture Collection Center) NO: 31970. According to the method, molecular modification means such as metabolic engineering and the like are combined with a traditional breeding method, and through mutation sites existing in 3-phosphoglycerate dehydrogenase and serine acetyltransferase, feedback regulation on key enzymes in the L-cysteine synthesis process is effectively relieved, and the yield of L-cysteine is increased; the escherichia coli mutant strain MFAPA45QT is obtained by carrying out ARTP mutagenesis coupling L-cysteine specific response biosensor high-throughput screening, the L-cysteine yield in a fermentation tank level can reach 31.11 g / L, and the method is suitable for industrial production of L-cysteine.

The invention relates to the technical field of biology, in particular to a high-activity S-sulfo-L-cysteine synthetase mutant and application thereof. The optimized SSC03 enzyme is screened through clustering analysis and phylogenetic analysis, mutation design is further performed on the optimized SSC03 enzyme, the conversion rate of the finally obtained SSC03-S256P delta CT after 24-hour reaction is 56%, 84 mM of S-sulfo-L-cysteine is generated, and it is indicated that the SSC03-S256P delta CT can be used for further purification process development.