719 results about "Biocatalysis" patented technology

The invention relates to the technical field of biological catalysis, and discloses an L379A mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: leucine of the 379th amino acid sequence is mutated into alanine; the enzyme can be applied to RA in-vitro conversion preparation of RI with higher utilization value, the conversion rate is higher than 50%, and the enzyme activity is remarkably improved by 7 times compared with the original enzyme catalytic conversion enzyme activity. The UGT76G1 mutant disclosed by the invention has the advantages that (1) the blank is filled, and a special enzyme catalyst capable of realizing efficient in-vitro synthesis of rebaudioside I (RI) is provided for the first time; 2) efficiency jump: the catalytic conversion rate is greatly increased from original about 7% to more than 50% (increase gt; and 3) stability and reliability: in the cross-scale reaction of 10mL to 5L, the catalyst has stable catalytic performance, shows excellent industrial application potential, and is suitable for popularization and application.

The invention discloses a carbonyl reductase mutant as well as a preparation method and application thereof, and belongs to the technical field of enzyme engineering. According to the invention, on the basis of carbonyl reductase BcKRED from Bacillus cereus, a series of dominant mutants are obtained through a method of directed evolution in the field of enzyme engineering. The carbonyl reductase dominant mutant obtained by the invention has high catalytic activity, thermal stability and chiral selectivity reversed with wild-type carbonyl reductase. A green and efficient way is provided for industrial production of chiral alcohol by taking carbonyl reductase as a biocatalyst, and the method has a wide application prospect.

Glycosyltransferase UGT76G1 and UGT91C1 mutants and a method for catalytic synthesis of rebaudioside A, D, and M by using same, pertaining to the technical field of biocatalytic synthesis. The glycosyltransferase UGT76G1 mutant can effectively synthesize rebaudioside A using stevioside STV as a substrate. The glycosyltransferase UGT91C1 mutant is obtained by mutation screening of wild-type glycosyltransferase UGT91C1, has higher enzyme activity and catalytic rate, and can effectively synthesize rebaudioside D using rebaudioside A as a substrate. The glycosyltransferase UGT76G1 mutant can also be obtained by mutation and subsequent screening of glycosyltransferase UGT76G1, has higher catalytic activity, and can effectively synthesize rebaudioside M using rebaudioside D and UDPG as substrates.

The invention relates to the technical field of biological catalysis, and discloses an M88V mutant enzyme for preparing rebaudioside I. The M88V mutant enzyme is obtained by the following mutations generated by UGT76G1: M88V: methionine of the 88th amino acid sequence of UGT76G1 is mutated into valine. Aiming at the technical bottlenecks of low RI yield and poor selectivity in the existing RA biotransformation process, an efficient solution is provided for the UGT76G1 mutant developed by the invention. The mutant can specifically catalyze conversion from RA to RI, and the conversion rate of a target product is remarkably increased to 65% or above from general less than 7%. The excellent catalytic performance of the catalyst is verified in milliliter-level to upgraded reaction systems, the key problems of conversion efficiency and process amplification are solved, and a foundation is laid for large-scale green manufacturing of a high-added-value product RI.

The invention discloses a p-nitrophenyl ethyl esterase mutant with high enantioselectivity as well as a construction method and application of the p-nitrophenyl ethyl esterase mutant. The p-nitrophenyl ethyl esterase mutant is obtained by mutating an amino acid sequence of wild p-nitrophenyl ethyl esterase pnbA as shown in SEQ ID NO.1 according to one or a combination of more of the following modes: leucine at the 273rd site is mutated into aspartic acid, phenylalanine at the 314th site is mutated into histidine, and leucine at the 362nd site is mutated into arginine. The mutant pnbA-L273D / F314H / L362R provided by the invention shows optimal catalytic performance (E = 47.16) for racemization-acetic acid pinyl hydrate, the enantiomeric excess value of the mutant is 95.13%, the conversion rate of 1S, 5R-acetic acid pinyl hydrate is 90.42%, the enantioselectivity of the mutant is obviously higher than that of a wild type, and the mutant has great application potential in biological catalytic synthesis of monocyclic monoterpenoid chiral alcohols.

The present application relates to the technical field of biocatalysis and biosynthesis, and specifically discloses a natural blue pigment and a biosynthesis method therefor. The present application uses metabolically engineered bacteria to express indigoidine synthetase and phosphopantetheinyl transferase, to catalyze glutamine and N-acetylglutamine to biosynthesize a natural blue pigment N-acetylindigoidine, and deduces its molecular structure by means of mass spectrometry, nuclear magnetic resonance and other methods. The present application achieves catalytic synthesis of N-acetylindigoidine from glutamine and N-acetylglutamine in Escherichia coli, Corynebacterium glutamicum, Saccharomyces cerevisiae and Streptomyces. Compared with indigoidine, N-acetylindigoidine has a maximum absorption wavelength of 584 nm, possesses better color brightness, and has more stable coloration that is not easily faded, with a very broad application range and industrial production application prospects.

The invention relates to the technical field of biological catalysis, and discloses an M88A mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: M88A: methionine of the 88th amino acid sequence of UGT76G1 is mutated into alanine; the key conversion rate of RI is greatly increased from 7% to 85% (increased by more than 12 times), and the utilization rate and economical efficiency of raw materials are remarkably improved; the method can be perfectly reproduced under any test scale (10mL, 100mL and 5L), the conversion rate is always anchored to be more than 85%, and incomparable stability and amplification potential are shown.

The present application relates to the technical field of biocatalysis and biosynthesis, and specifically discloses a blue pigment and a biosynthesis method thereof. In the present application, an indigoidine synthetase and a 4′-phosphopantetheinyl transferase are expressed by a metabolically engineered strain to catalyze the biosynthesis of the blue pigment N-acetyl-indigoidine from glutamine and N-acetylglutamine, and a molecular structure of the blue pigment is inferred by mass spectrometry, nuclear magnetic resonance spectroscopy, etc. The present application achieves the catalytic synthesis of N-acetyl-indigoidine from glutamine and N-acetylglutamine in Escherichia coli (E. coli), Corynebacterium glutamicum (C. glutamicum), Saccharomyces cerevisiae (S. cerevisiae), and Streptomyces. Compared with indigoidine, N-acetyl-indigoidine has a maximum absorption wavelength of 584 nm, and a stable color having high brightness that is not easy to fade. Thus, the blue pigment shows an extensive application range and a promising industrial production prospect.

The invention belongs to the technical field of catalytic materials, and particularly relates to high-entropy alloy nanoparticles used as a biocatalyst and application of the high-entropy alloy nanoparticles. The PtFeCuCoNi high-entropy alloy nano-particles with pH adaptability are developed through a one-step solvothermal synthesis method, it is found that the PtFeCuCoNi high-entropy alloy nano-particles can serve as potent oxidase, can generate reactive oxygen species (ROS) and effectively kill bacteria such as MRSA under the acidic condition, and can play the functions of superoxide dismutase and catalase under the neutral condition, so that the PtFeCuCoNi high-entropy alloy nano-particles with the pH adaptability can be used for effectively killing bacteria such as MRSA. Active oxygen in cells is efficiently removed, oxidative stress is relieved, and the cell protection effect is achieved.

The invention discloses a method for biosynthesizing epigallocatechin gallate glucoside, and belongs to the technical field of biocatalytic synthesis. According to the method, a sucrose phosphorylase mutant is adopted as a catalyst, the sucrose phosphorylase mutant is subjected to single-point mutation or combined mutation on the basis of an amino acid sequence SEQ ID NO.1, and the enzyme activity of the sucrose phosphorylase is improved through mutation; the mutant is utilized to realize efficient catalytic synthesis of epigallocatechin gallate glucoside, and in the whole catalytic process, the synthesis method is mild in condition, simple to operate, short in reaction time and high in catalytic efficiency, and has a good application prospect.

The invention relates to the technical field of biological catalysis, and discloses an L204A mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: L204A: leucine of the 204 amino acid sequence of UGT76G1 mutates into alanine; the high-efficiency in-vitro enzymatic preparation of the rebaudioside I (RI) is realized for the first time, the catalytic efficiency of the rebaudioside I (RI) is improved by more than 7 times (from about 7% to more than or equal to 50%) compared with that of an original enzyme, the high-efficiency performance can be stably maintained under different scales of 10mL to 5L, a solid foundation is laid for industrial application of the RI, and the preparation method is simple, controllable in process condition and suitable for popularization and application.

The invention relates to the technical field of enzyme engineering, in particular to an acylase mutant and a biosynthesis method of (R)-2-aminobutanol.The acylase mutant comprises at least one of mutation of the following sites relative to wild type acylase with the amino acid sequence being SEQ ID NO: 1: T106, A625 and S413. The acylase mutant disclosed by the invention is used for synthesizing (R)-2-aminobutanol through biological catalysis, and the reaction route is as follows: the catalytic efficiency of a product is remarkably improved by the mutant, and the ee value of a chiral product is improved; according to the synthesis method, the problem of chiral resolution in the prior art is solved, the production cost is reduced, and pollution is reduced.

This invention relates to the field of biocatalysis technology, and more particularly to an aflatoxin oxidase, its preparation method, and its applications. This invention utilizes a self-designed artificial intelligence enzyme design workflow to de novo design a novel aflatoxin oxidase, DnD-AFO. Compared to the traditional wild-type AFO, DnD-AFO exhibits enhanced activity, better thermal stability (its activity is significantly superior to the wild-type after high-temperature granulation), and improved resistance to pepsin and acid. Furthermore, it further enhances the detoxification efficiency against aflatoxin, making it well-suited as a food or feed additive for applications in agriculture and food engineering, among other related industries, demonstrating significant commercial and added value.

The invention discloses a heme oxygenase mutant and application of the heme oxygenase mutant in preparation of bilirubin through multienzyme coupling, and belongs to the field of biological catalysis engineering. The forward mutant of the heme oxygenase is obtained through a directed evolution technology, and heme can be efficiently catalyzed to synthesize biliverdin; the bilirubin is synthesized by further introducing biliverdin reductase, coupling cytochrome P450 reductase and formate dehydrogenase, and coupling the two core enzymes with foreign assistant enzymes to construct recombinant escherichia coli to catalyze heme to synthesize bilirubin. In the system, NADPH does not need to be exogenously added, the reaction time is about 4 h, the yield of bilirubin reaches 2.10 g / L, accumulation of intermediate products is not observed in the catalysis process, and the highest yield and the shortest reaction time in bilirubin synthesis reported at home and abroad at present are achieved. Compared with the traditional pig bile extraction, the method disclosed by the invention breaks through the resource limitation, is simple to operate and high in yield, and realizes efficient and green synthesis of bilirubin.

The application discloses a light-controlled nitric oxide releasing hollow single-atom nanoscale enzyme, a preparation method and application, and belongs to the technical field of biomedical materials. In the application, spherical silica nanoparticles are used as a template, and a structure of copper ion-polydopamine coated silica nanoparticles is formed on the surface of the silica nanoparticles through self-polymerization of dopamine and chelation of copper ions, and the spherical structure is maintained with the support of the silica nanoparticles. The copper ion-polydopamine coated silica nanoparticles are pyrolyzed to obtain a copper-based single-atom nanoscale enzyme with a carbon skeleton, and a hollow spherical single-atom nanoscale enzyme is obtained after etching. Nitric oxide donor molecules are loaded into the hollow of the hollow spherical single-atom nanoscale enzyme to obtain the light-controlled nitric oxide releasing hollow single-atom nanoscale enzyme. The application can realize the synergistic treatment effect of photothermal therapy, nitric oxide gas therapy and biological catalytic therapy, is used for efficiently removing bacteria and biofilms at an infected wound site, and effectively promotes the healing of the bacteria-infected wound.

The present application relates to a pyridoxal kinase mutant, a recombinant expression vector and a microbial cell and their applications, and belongs to the technical field of biological catalysis. In order to solve the problem of low product concentration in existing enzyme catalysis, a pyridoxal kinase mutant is provided, the amino acid sequence is selected from the amino acid sequence shown in SEQ ID NO. 1, the lysine at position 229 is mutated to alanine, phenylalanine, methionine, arginine, threonine, histidine, serine, tyrosine, valine, leucine, isoleucine, proline, asparagine, aspartic acid or glutamic acid; the pyridoxal kinase mutant is used for catalyzing pyridoxal to synthesize pyridoxal phosphate, and a recombinant expression vector and a microbial cell can be further formed. The present application has good enzyme activity, high product conversion rate, high concentration of pyridoxal phosphate obtained, and the concentration of the product catalyzed by the wild-type pyridoxal kinase to phosphorylate pyridoxal is obviously improved.

The invention discloses a marine-derived carboxylesterase and an application of the marine-derived carboxylesterase in degradation of PET (Polyethylene Terephthalate) plastics. The amino acid sequence of the enzyme is as shown in SEQ ID NO.1, experiments show that Tm of RbCE1 is 79.5 DEG C, 40 mM of depolymerization monomers can be generated after the enzyme treats low-crystallinity PET powder at 60 DEG C for 4 hours, the catalytic activity is equivalent to that of LCC, and good degradation activity is shown. Through escherichia coli heterologous expression, 0.4 g / L high expression quantity can be achieved in a shake flask, and the potential of remarkably reducing the enzyme production cost is achieved. Therefore, the novel carboxylesterase RbCE1 is suitable for degrading PET plastics and composite materials thereof, and is a potential enzyme preparation for efficient biological catalysis of a waste PET plastic waste enzymatic depolymerization recovery treatment process.

The invention discloses a progesterone 5beta-reductase mutant and application thereof in synthesis of 5beta-dihydrosteroid, relates to the technical field of biology, and in particular relates to application of gene mining and engineering modification of progesterone 5beta-reductase derived from bacteria in asymmetric synthesis of 5beta-dihydrosteroid. According to the progesterone 5 beta-reductase LpP5beta R disclosed by the invention, the progesterone 5 beta-reductase LpP5beta R from bacteria psoromais is obtained by a gene mining method, and the progesterone 5 beta-reductase LpP5beta R can be subjected to soluble expression in escherichia coli. The mutant obtained by mutating the wild type LpP5beta R has obviously improved catalytic ability on progesterone, and can efficiently catalyze delta 4-3-carbonyl steroids such as hydrocortisone, dinorcitol and the like to generate corresponding 5beta-dihydrosteroids. According to the invention, the technical bottlenecks of poor heterologous expression and low catalytic efficiency of plant-derived progesterone 5beta-reductase are solved, and a potential biocatalyst is provided for green manufacturing of 5beta-dihydrosteroid drugs.

The invention discloses a preparation process of a moxidectin pouring solution. The preparation process comprises the following steps: S1, respectively preparing a moxidectin initial solution and a thickener premixed solution; s2, the moxidectin initial solution and the thickener premixed solution are stirred and mixed uniformly at the temperature of 25-35 DEG C to form a mixture A, the stirring speed is 150-250 rpm, and the mixing time is 10-20 min; s3, adding auxiliary materials into the mixture A, and uniformly mixing to form a mixture B; s4, supplementing the second solvent into the mixture B to the total amount, uniformly mixing, and filtering to obtain a moxidectin pouring solution; the method comprises the following steps: dissolving a moxidectin raw material in a first solvent to obtain a moxidectin initial solution, and synthesizing the moxidectin raw material by using biological catalysis; the first solvent is a nano-emulsion formed after homogenization. According to the preparation method, the solubility of the medicament, the stability of the preparation and the transdermal drug delivery efficiency are improved by improving the solvent system and controlling the process in the preparation process of the moxidectin pouring solution.

The invention discloses a synthesis method of 2 '-fluoro-2'-deoxyguanosine. According to the method, thymine nucleoside phosphorylase and purine nucleoside phosphorylase are used as biocatalysts, and 2 '-fluoro-2'-deoxyuridine and guanine are used as substrates to synthesize the 2 '-fluoro-2'-deoxyguanosine. Compared with a chemical method, the production cost is greatly reduced; meanwhile, the synthesis method can effectively solve the problem that the product is difficult to separate.

The disclosure relates to rare earth element (REE) phosphates and methods for making the same. The REE phosphates can be formed by combining a REE sulfate with a phosphate source and a biological catalyst, for example an acid phosphatase.

The invention discloses a method for converting rutin into quercetin through biological catalysis, and belongs to the technical field of biological catalysis. The method comprises the following steps: mixing rutin and a solvent to obtain a quasi-solid rutin suspension; mixing the paraphlonia plant endogenous enzyme and the quasi-solid rutin suspension for enzymolysis, and then filtering, washing and drying to obtain quercetin; the solvent is methanol with the concentration of 5-50%, ethanol with the concentration of 5-50% or acetone with the concentration of 10-50%. The method is mild in biological catalytic reaction condition, does not generate pollutants such as acid waste liquid, and meets the environmental protection requirement. Efficient conversion of quercetin is realized by adopting a quasi-solid rutin strategy (rutin suspension reaction system), and the problem of substrate solubility limitation is solved. High-purity quercetin can be obtained through simple washing, the product purity is larger than 95%, and food and clinical application can be met.

The invention relates to the technical field of biological catalysis, and discloses an M88F mutant enzyme for preparing rebaudioside I. The enzyme is obtained by the following mutations generated by UGT76G1: M88F: methionine of the 88th amino acid sequence of UGT76G1 is mutated into phenylalanine; and the substrate rebaudioside A (RA) can be efficiently and directionally converted into rebaudioside I (RI) with higher value. In an optimized reaction system, the conversion rate stably reaches 40%, and the catalytic efficiency is improved by more than 5-8 times compared with the common reference enzyme. The enzyme preparation has the characteristics of high catalytic activity, mild reaction conditions, simplicity and convenience in operation and the like, shows good stability and reproducibility in laboratory research and large-scale production, and has a wide industrial application prospect.

Described herein are biocatalytic methods of producing terpene degradation products useful as starting material for the production of perfumery ingredients, such as, for example, ambrox. In particular novel terpene degrading polypeptides (enal-cleaving polypeptides) and novel peptides converting terpenes compounds to oxygenated derivatives (oxygenases) and mutants and variants derived therefrom are described which may be applied in novel types of fully enzymatic multistep degradation pathways allowing the controlled, stepwise conversion and degradation of linear or cyclic terpene substrates. Said novel biosynthetic strategies allow the fully biochemical synthesis of valuable terpene-derived compounds, like for example manooloxy or gamma ambrol. Also described herein are recombinant host organisms carrying the required set of genetic information for the functional expression of the set of enzymes necessary for catalyzing the combination of enzymatic conversion and degradation steps.

The invention discloses a multi-site mutant of glucosyltransferase and an application of the multi-site mutant. A GT 1 family O-glycosyl transferase UGT73C33 derived from liquorice is mutated, an excellent multi-site mutant of the O-glycosyl transferase is obtained through screening, the multi-site mutant contains three mutation sites, F148 is mutated into W, F388 is mutated into W, and A389 is mutated into T. The novel O-glycosyl transferase mutant C33-F148W-F388W-A389T is high in specificity, the selectivity of the novel O-glycosyl transferase mutant C33-F148W-F388W-A389T for generating luteolin-4 '-O-glucoside through specific conversion of luteolin reaches 80%, the novel O-glycosyl transferase mutant is high in catalytic activity, and the yield of luteolin-4'-O-glucoside reaches 156.8 mg / L under suitable conditions. The invention provides a unique biocatalyst and a conversion process thereof for the preparation of luteolin-4 '-O-glucoside with high activity and high added value.

The invention provides a recombinant O-succinyl-L-homoserine mercaptotransferase mutant, a coding gene thereof, a recombinant vector containing the coding gene of the mutant, a recombinant genetically engineered bacterium obtained by converting the recombinant vector, and application of the recombinant O-succinyl-L-homoserine mercaptotransferase mutant in preparation of L-methionine. The novel recombinant O-succinyl-L-homoserine mercaptotransferase mutant with high activity and high selectivity is used as a catalyst to be applied to catalysis of O-succinyl-L-homoserine for synthesis and preparation of L-methionine, a catalytic reaction system is optimized, the feed ratio and reaction conditions in the reaction are finely regulated and controlled, and the yield of L-methionine is increased. The recombinant O-succinyl-L-homoserine mercaptotransferase mutant has high enzyme activity under the optimal reaction condition, the catalytic efficiency is further improved, the purposes of reducing cost and improving efficiency are achieved, and the method has important significance in promoting industrial application of biological catalysis preparation of L-methionine.

The invention relates to the technical field of polypeptide biosynthesis, in particular to a method for biosynthesizing acetyl tetrapeptide-5, a composition containing the acetyl tetrapeptide-5 and application of the composition. According to the method, low-cost natural amino acid is used as a substrate, specific aminopeptidase or a mutant thereof is used as a biocatalyst, amino acid ligase and polyphosphatase are combined, and acetyl tetrapeptide-5 can be efficiently synthesized through a one-step enzymatic reaction. Compared with a traditional chemical synthesis method, the method has the advantages of low raw material cost, no use of an organic solvent, mild reaction conditions, high regioselectivity, environmental friendliness, low production cost and the like. The invention also provides a composition containing acetyl tetrapeptide-5 and dipeptide-15, the inhibition effect of the composition on grease secretion is obviously better than that of a single component, and the composition has a synergistic oil control effect under a specific ratio.

The invention provides a mutant derived from Clostridium difficile glutamate dehydrogenase and an application of the mutant in preparation of L-glufosinate-ammonium. The glutamate dehydrogenase mutant is a glutamate dehydrogenase single site mutant, a double site mutant or a multi-site mutant. The L-glufosinate-ammonium can be used for preparing L-glufosinate-ammonium from L-glufosinate-ammonium from L-glufosinate-ammonium from L-glufosinate-ammonium from L-glufosinate-ammonium from L-glufosinate-ammonium. The invention effectively solves the problem that glutamate dehydrogenase shows inactivity or low activity in biological catalytic conversion taking 2-carbonyl-4-(hydroxymethylphosphonyl) butyric acid as a substrate, and provides a chemical method for continuously synthesizing the substrate 2-carbonyl-4-(hydroxymethylphosphonyl) butyric acid by a whole-process microchannel reactor.

The invention discloses a salicylic acid decarboxylase mutant and application of the salicylic acid decarboxylase mutant in degradation of salicylic acid. The mutant is obtained by carrying out site-specific modification on salicylic acid decarboxylase NahG, and specifically, valine at the 46th site, tyrosine at the 380th site and leucine at the 382nd site of an amino acid sequence shown in SEQ ID NO.2 are mutated into cysteine, phenylalanine and phenylalanine at the same time. The mutant shows remarkably improved catalytic efficiency, and salicylic acid can be efficiently and thoroughly decarboxylated and converted into catechol under mild conditions. The invention also provides a coding gene, a recombinant vector and an engineering bacterium of the mutant. The mutant not only can be used for efficient bioremediation of salicylic acid pollution, but also can effectively break through and accelerate a naphthalene catabolism pathway due to the characteristic of directionally generating catechol, and has important application value in the fields of environmental pollution abatement and biological catalysis.

The invention discloses a phospholipase D mutant with improved thermal stability and a preparation method thereof. The amino acid sequence of the phospholipase D mutant is as shown in SEQ ID NO.4; according to the phospholipase D mutant A426P with improved thermal stability, the mutant is incubated for 30 min at 55 DEG C and 60 DEG C respectively, the residual enzyme activity is 85% and 58% respectively, the activity of wild-type enzyme is only 56% and 7% under the same treatment condition, the thermal stability of the mutant enzyme is remarkably improved, and the phospholipase D mutant A426P can be used as a phospholipase D mutant. The problem that phospholipase D is not ideal in thermal stability in biological catalytic reaction is solved.