116 results about "Coenzyme A biosynthesis" patented technology

An artificial synthesis method for malonyl-CoA and use thereof are provided. By means of heterologous expression of an aminotransferase and a malonyl-CoA reductase, an artificial synthesis pathway for synthesizing malonyl-CoA by using β-alanine (β-ala) as a precursor is constructed as follows: firstly, under catalysis of a transaminase, β-ala transfers amino groups to α-ketonic acid (such as pyruvic acid, oxaloacetic acid, or α-ketoglutaric acid, etc.), to form an intermediate product 3-oxopropanoate and a corresponding amino acid; the 3-oxopropanoate generates malonyl-CoA under the action of the malonyl-CoA reductase. This pathway addresses the defects of the natural malonyl-CoA synthesis pathway, such as low carbon utilization, consumption of energy substance ATP, release of greenhouse gas CO2, and strict regulation of pathway enzymes, a pyruvate dehydrogenase (PDH) and an acetyl-CoA carboxylase (ACC), thereby achieving high yielding of products using malonyl-CoA as a precursor, including flaviolin, octanoic acid, phloroglucinol, pentadecaheptaene, natamycin, and spinosad.

The invention provides a genetically engineered bacterium for producing O-succinyl-L-homoserine as well as a construction method and application of the genetically engineered bacterium. In a chassis bacterium genome, the expression of a 2-ketoglutaric acid decarboxylase encoding gene sucA is enhanced, and the expression of a succinyl-coenzyme A synthetase encoding gene sucD is weakened, so that the supply of succinyl-coenzyme A is increased; the method comprises the following steps: increasing the NADPH (Nicotinamide Adenine Dinucleotide Phosphate) reducing capacity and ATP (Adenosine Triphosphate) energy supply of a chassis bacterium, increasing DNA (Deoxyribose Nucleic Acid) in combination with a transcription dual regulatory factor ompR to improve the stress resistance of escherichia coli under high osmotic pressure, and introducing an overexpression plasmid containing a homoserine transsuccinylase coding gene metA to construct the genetically engineered bacterium for producing O-succinyl-L-homoserine. The engineering strain obtained through a systematic metabolic engineering modification strategy can realize effective accumulation of OSH, the shake flask yield of OSH reaches 19.8 g / L, the fed-batch fermentation yield of a 5L fermentation tank reaches 110.5 g / L, the sugar-acid conversion rate reaches 52.6%, and a foundation is laid for subsequent construction of high-yield OSH engineering bacteria.

The invention provides a euphorbia lathyris acyltransferase gene ElBAHD16 and application of a coding protein thereof. The gene is obtained by cloning from euphorbia lathyris for the first time. The invention also provides a recombinant vector and an engineering bacterium containing the gene. Cinnamoyl coenzyme A, benzoyl coenzyme A or acetyl coenzyme A can be used as an acyl donor, and 7-hydroxy euphorbia lathyris diterpenoid alcohol is used as a substrate to generate a plurality of types of euphorbia lathyris diterpenoid esters through biological catalysis. The content of diterpenoid ester substances in plants such as euphorbia lathyris can be increased through a genetic engineering technology, and the method has a good application prospect.

The invention discloses construction and application of a saccharomyces cerevisiae engineering strain for synthesizing vanillin by taking ferulic acid as a substrate, and belongs to the technical field of genetic engineering. The invention provides a recombinant saccharomyces cerevisiae, which is characterized in that a series of genes for producing vanillic acid and vanillyl alcohol from vanillin through oxidation and reduction are knocked out, and feruloyl coenzyme A synthetase FCS and p-hydroxycinnamyl coenzyme A hydratase ECH which are obtained by screening from a metagene library in a West Sichuan hot spring extreme environment are overexpressed. According to the engineering strain VAN002 with high yield of vanillin, the accumulation of vanillin reaches 16.8 g / L, and the molar conversion rate of catalyzing ferulic acid to synthesize vanillin reaches 93%, which is the highest level reported by synthesizing vanillin by saccharomyces cerevisiae at present.

The application belongs to the technical field of genetic engineering, and discloses a kind of saccharomyces cerevisiae for producing rare ginsenoside by seaweed biomass and a construction method and application thereof.The saccharomyces cerevisiae has the following characteristics: overexpression of agarase, neojuncanohydrolase, hydroxymethylglutaryl coenzyme A reductase, isopentenyl diphosphate delta isomerase, dammaradienol synthase, protopanaxadiol synthase, cytochrome P450 reductase, protopanaxatriol synthase and glycosyltransferase.The application combines enzymolysis of seaweed biomass with fermentation of rare ginsenoside, which not only endows wild-type yeast with the ability to degrade seaweed biomass that it originally does not have, but also effectively improves the yield of squalene and downstream terpenes (rare ginsenoside Rh1) by overexpression of tHMG1 and IDI1.The saccharomyces cerevisiae can effectively utilize seaweed biomass to obtain squalene and rare ginsenoside Rh1, and has the characteristics of simplicity, economy and ecological friendliness, can convert cheap biomass into high-value products, and provides a way for the development of marine bioeconomy.

The invention belongs to the field of strigose hydrangea juvenile leaf genetic engineering, particularly relates to separation and functional analysis of strigose hydrangea juvenile leaf cinnamoyl-coenzyme A reductase (CCR) and chalcone synthase (CHS) genes, and also relates to in-vitro synthesis of phloretin by using the strigose hydrangea juvenile leaf CCR and CHS genes. The invention discloses application of a strigose hydrangea juvenile leaf CCR gene coded protein. The strigose hydrangea juvenile leaf CCR gene coded protein catalyzes oxidation of 4-hydroxyphenylpropanal to form phloretin synthesis precursor dihydrop-coumaroyl coenzyme A; the phloretin is synthesized under the combined action of the protein coded by the strigose hydrangea juvenile leaf CHS gene. The nucleotide sequence of the strigose hydrangea juvenile leaf CCR gene is shown as SEQ ID No: 1, and the nucleotide sequence of the strigose hydrangea juvenile leaf CHS gene is shown as SEQ ID No: 2.

The invention discloses a rice ACCase mutant protein and a preparation method thereof. The amino acid sequence of the ACCase mutant gene encoding protein has the following mutations: the 2052nd site corresponding to the amino acid sequence of wild rice ACCase is mutated, isoleucine (I) is changed into asparagine (N), or isoleucine (I) is changed into glutamine (Q), or isoleucine (I) is changed into cysteine (C), or isoleucine (I) is changed into cysteine (C), or isoleucine (I) is changed into cysteine (C), or isoleucine (I) is changed into cysteine (C), or isoleucine (I) is changed into cysteine (C). And the plant can have extremely strong resistance (tolerance) to acetyl-coenzyme A carboxylase inhibitor herbicides. After the rice containing the rice ACCase mutant protein disclosed by the invention is applied with an acetyl-coenzyme A carboxylase inhibitor herbicide with 8 times of recommended use concentration, plants still grow normally, and the tolerance of the herbicide is greatly enhanced, so that the rice ACCase mutant protein can be widely applied to breeding of herbicide-resistant plants.

The invention discloses candida tropicalis engineering bacteria for high yield of (-)-alpha-bisabolol and a construction method of the candida tropicalis engineering bacteria, and belongs to the technical field of microorganisms. According to the invention, chassis cell candida tropicalis DC04-WG04-2 is constructed, a gene Cat2 of catalase derived from saccharomyces cerevisiae and a gene ERG10 of 3-hydroxy-3-methylglutaryl coenzyme A reductase are expressed on the basis of the chassis cell candida tropicalis DC04-WG04-2, and a PEX15 motif is anchored on the surface of peroxisome for co-expression; the genes ADH1, GPD1 and GPD2 are further knocked out, so that the accumulation of ethanol is reduced, and the generation of glycerol is reduced. According to the method disclosed by the invention, the yield of the (-)-alpha-bisabolol of the recombinant candida tropicalis reaches 461.7 mg / L by optimizing fermentation conditions. The preparation method has the characteristics of low cost, high efficiency, simplicity in operation, wide prospect and the like.

The invention discloses a saccharomyces cerevisiae strain for de novo synthesis of fucoxanthine precursor neoxanthine and application of the saccharomyces cerevisiae strain, and belongs to the technical field of biology. According to the recombinant saccharomyces cerevisiae disclosed by the invention, the 3-hydroxy-3-methylglutaryl coenzyme A reductase, the isopentenyl pyrophosphate isomerase, the farnesyl pyrophosphate synthase and the endoplasmic reticulum size regulation factor are expressed in an enhanced manner; according to the method, geranyl geranyl diphosphate synthase, phytoene dehydrogenase, 15-cis-phytoene synthase, bifunctional lycopene cyclase / phytoene synthase, beta-carotene hydroxylase, zeaxanthin epoxidase truncated mutant and violaxanthin deep oxidase-like protein are subjected to heterologous expression, so that the zeaxanthin deep oxidase-like protein is obtained; the ROX1 and GAL80 genes in the saccharomyces cerevisiae are knocked out, and the expression of squalene synthase ERG9 is down-regulated. When the strain is subjected to shake flask fermentation, the contents of neoxanthine and violaxanthin of the strain respectively reach 1.78 mg / L and 26.77 mg / L, so that the strain has a wide application prospect.

The invention belongs to the technical field of biological engineering, and discloses a schizochytrium limacinum engineering strain co-expressing a PDC-ACC gene, a construction method and application, and the genetic engineering strain is obtained by taking schizochytrium limacinum as an original strain and expressing a pyruvate decarboxylase compound gene PDC and an acetyl-coenzyme A carboxylase gene ACC in yarrowia lipolytica. The PDC and ACC genes in the schizochytrium limacinum genetic engineering strain disclosed by the invention are cloned to yarrowia lipolytica, namely Po1f. The yield of traditional fermented grease is 43.90 g / L. The engineering strain performs overexpression on PDC and ACC genes, so that the grease content of the schizochytrium limacinum engineering strain is increased by 53.13% and reaches 67.22 g / L, and the DHA content is increased by 36.97% and is increased from 40.71% to 55.76%.

The invention discloses a Chimonobambusa chensinensis CuCCoAOMT1 gene as well as a protein and application thereof, belongs to the technical field of plant genetic engineering, and particularly relates to a Chimonobambusa chensinensis caffeoyl-coenzyme A-O-methyltransferase CuCCoAOMT1 gene, and a nucleotide sequence of the CuCCoAOMT1 gene is shown as SEQ ID NO.1. The invention further discloses a preparation method of the CuCCoAOMT1 gene. The invention further discloses application of the CuCCoAOMT1 gene in regulation and control of the drought resistance of gramineous plants. By overexpressing the caffeoyl-coenzyme A-O-methyltransferase CuCCoAOMT1 gene in the rice, the lignin content in the rice can be effectively increased, the thickening of rice cell walls is promoted, the drought resistance of rice plants is improved, and a new gene resource is provided for plant material property improvement gene engineering.

The invention discloses yarrowia lipolytica with high yield of beta-carotene as well as a construction method and application of the yarrowia lipolytica. According to the yarrowia lipolytica engineering bacterium, geranyl diphosphate synthase gene xdGPS, phytoene dehydrogenase gene CarB, phytoene cyclization / phytoene synthesis bifunctional enzyme mutant gene GarRPY27R, acetyl-coenzyme A synthetase mutant gene ACSL641P and pyruvate ferredoxin oxidoreductase gene nifJ are integrated and expressed on a chromosome, and the yarrowia lipolytica engineering bacterium is obtained. Meanwhile, a 3-hydroxy-3-methylglutaryl CoA reductase gene HMGR (3-hydroxy-3-methylglutaryl CoA reductase) derived from the yarrowia lipolytica strain is subjected to overexpression; the yield of the beta-carotene is increased to 13.186 g / L, and the production efficiency is 0.14 g / L / h.

A method for preparing glycine by using threonine relates to a fermentation process in which threonine is decomposed into glycine and acetaldehyde by aldolase. Glycine and acetyl coenzyme A can be produced in a fermentation process, in which acetaldehyde is reduced into acetyl coenzyme A or an acetyl coenzyme A derivative by acetylating acetaldehyde dehydrogenase; or threonine is dehydrogenated by threonine dehydrogenase to obtain 2-amino-3-ketobutyric acid, which is then ligated by 2-amino-3-ketobutyrate CoAligase to obtain acetyl coenzyme A. Coenzyme A can be converted into an acetyl coenzyme A derivative under different fermentation conditions.

The invention relates to a method for producing biotin, dethiobiotin (DTB), or a mixture thereof, characterised in that a microbial production strain is cultivated which recombinantly expresses at least one coenzyme A feedback-resistant enzyme with the enzymatic activity of a pantothenate kinase (enzymatic activity of proteins of class EC 2.7.1.33), and biotin or DTB or a mixture thereof is subsequently isolated.

The invention discloses recombinant saccharomyces cerevisiae for producing protopanoxadiol by metabolizing glycerol and a construction method thereof, and the construction method comprises the following steps: introducing a dammarendiol synthase DS gene expression cassette, a PPD synthase and reductase fusion protein PPDS-ATR1 gene expression cassette and a squalene oxidase ERG1 gene expression cassette into saccharomyces cerevisiae to obtain a recombinant bacterium 1; introducing a glycerol transport protein CjFPS1 gene expression cassette, a glycerol dehydrogenase OpGDH gene expression cassette, a dihydroxy acetone kinase DAK1 gene expression cassette and a 3-hydroxy-3-methylglutaryl coenzyme A reductase HMGR gene expression cassette into the recombinant bacterium 1 to obtain a recombinant bacterium 2; introducing citric acid lyase AnACLa and AnACLb gene expression cassettes and citric acid transporter protein YHM2 and CTP1 gene expression cassettes into the recombinant bacterium 2 to obtain a recombinant bacterium 3; experiments prove that the yield of the recombinant bacteria 2, 3PPD is 124 mg / L and 220 mg / L.

The present disclosure relates to multi-enzyme pathways for the in vitro cell-free biosynthesis of the cofactor, coenzyme A ("CoA") from lower-cost substrates, such as D-pantothenate, L-cysteine, and ATP, and the use of these pathways in CoA-dependent cell-free systems for the biobased production of chemicals, such as acetyl-CoA, hexanoyl-CoA, malonyl-CoA, and cannabigerolic acid (CBGA).

The invention discloses saccharomyces cerevisiae engineering bacteria for efficiently synthesizing mogroside V on the basis of cytoplasm and lipid droplet double-cell area compartment and a construction method of the saccharomyces cerevisiae engineering bacteria. The construction method comprises the following steps: integrating truncated 3-hydroxy-3-methylglutaryl coenzyme A reductase tHMG1, pentenyl pyrophosphate isomerase IDI1, epoxy squalene cyclization enzyme ERG1, squalene synthetase ERG9, choline kinase ScCK, isopentenyl phosphokinase AtIPK, cucurbitadienol synthetase SgCDS, cyclic epoxy hydrolase SgEPH3, cytochrome P450 enzyme CYP87D18 and cytochrome P450 enzyme reductase AtCPR1 at the site of a saccharomyces cerevisiae genome GAL80; an ABC efflux protein PDR11, a glycosyl transferase UGTMG1, a sucrose synthase Susy and a glycosyl transferase SgUGT94-289-3 are integrated at a site Exg1 of a saccharomyces cerevisiae genome. The yield of mogroside V produced by shake flask fermentation of the saccharomyces cerevisiae engineering strain provided by the invention reaches 96.3 mg / L, so that mogroside V is efficiently synthesized from the beginning in the saccharomyces cerevisiae, and the saccharomyces cerevisiae engineering strain has important practical significance for promoting sustainable development of the mogroside industry.

Described is a recombinant organism or microorganism which is capable of enzymatically converting acetyl-CoA into isobutene, (A) wherein in said organism or microorganism: (i) acetyl-CoA is enzymatically converted into acetoacetyl-CoA, (ii) acetoacetyl-CoA is enzymatically converted into 3-hydroxy-3-methylglutaryl-CoA, (iii) 3-hydroxy-3-methylglutaryl-CoA is enzymatically converted into 3-methylglutaconyl-CoA, (iv) 3-methylglutaconyl-CoA is enzymatically converted into 3-methylcrotonyl-CoA, and (v) wherein said 3-methylcrotonyl-CoA is converted into isobutene by: (a) enzymatically converting 3-methylcrotonyl-CoA into 3-methylcrotonic acid which is then further enzymatically converted into said isobutene; or (b) enzymatically converting 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyryl-CoA which is then further enzymatically converted into 3-hydroxy-3-methylbutyric acid which is then further enzymatically converted into 3-phosphonoxy-3-methylbutyric acid which is then further enzymatically converted into said isobutene; (B) wherein said recombinant organism or microorganism has an increased pool of coenzyme A (CoA) over the organism or microorganism from which it is derived due to: (i) an increased uptake of pantothenate; and / or (ii) an increased conversion of pantothenate into CoA. Moreover, described is the use of such a recombinant organism or microorganism for the production of isobutene. Further, described is a method for the production of isobutene by culturing such a recombinant organism or microorganism in a suitable culture medium under suitable conditions.

The invention discloses application of thiamine in preparation of a product for treating subclinical ketosis of dairy cows, and belongs to the field of biological medicines. Tests prove that compared with dairy cows suffering from subclinical ketosis (SCK), by adding thiamine, the content of beta-hydroxybutyric acid (BHBA), the number of bacteria in milk and the number of somatic cells can be remarkably reduced, and the milk yield, the milk fat content, the acetic acid content and the A / P ratio are remarkably increased; the microbial diversity of rumen and excrement of the dairy cow can be adjusted; a metabonomics result shows that metabolite up-regulated after the thiamine is added mainly focuses on pyruvic acid metabolism, glycolysis or gluconeogenesis, tyrosine metabolism, glycerophospholipid metabolism and biosynthetic pathways of phenylalanine, tyrosine and tryptophan. The conclusion is that when thiamine is added into the SCK dairy cow, synthesis and catabolism of BHBA of an organism can be effectively regulated and controlled by adjusting the content of succinyl-coenzyme A, then subclinical ketosis is relieved, rumen fermentation is promoted, and therefore the milk yield and the milk quality are improved.

The invention discloses an application of a succinyl-coenzyme a synthetase subunit alpha (SUCLG1) as a drug target in prevention and treatment of renal fibrosis, belongs to the technical field of biological medicines, and proves that the expression of SUCLG1 in renal fibrosis tissues is down-regulated, renal fibrosis occurs after the SUCLG1 in normal kidney tissues is selectively knocked down, and the renal fibrosis cannot be affected. And the degree of renal fibrosis can be relieved by over-expression up-regulation of SUCLG1 in renal tubular epithelial cells, so that the SUCLG1 can be determined to be used as an important target for preventing and treating renal fibrosis, and drugs for regulating and increasing the expression of SUCLG1 can be researched and developed in the field, so that the drugs are used for intervening the occurrence and development of renal fibrosis, and new potential therapeutic targets and therapeutic strategies are provided for renal fibrosis.

The present disclosure relates to the use of a switch for the production of heterologous non-catabolic compounds in microbial host cells. In one aspect, provided herein are genetically modified microorganisms that produce non-catabolic compounds more stably when serially cultured under aerobic conditions followed by microaerobic conditions, and methods of producing non-catabolic compounds by culturing the genetically modified microbes under such culture conditions. In another aspect, provided herein are genetically modified microorganisms that produce non-catabolic compounds more stably when serially cultured in the presence of maltose followed by the reduction or absence of maltose, and methods of producing non-catabolic compounds by culturing the genetically modified microbes under such culture conditions.

The present disclosure describes a recombinant yeast host cell having a first engineered metabolic pathway to convert fructose-6-phosphate (F-6-P) into acetyl-coenzyme A. The first engineered metabolic pathway comprises: a genetic modification for expressing a heterologous phosphoketolase capable of converting fructose-6-phosphate into erythrose-4-phosphate, and at least one genetic modification for decreasing native 6- phosphofructo-2-kinase activity classified under Enzyme Commission No. 2.7.1.105. Optionally, the recombinant yeast host cell comprises a second engineered metabolic pathway for convert acetyl-coA into a fermentation product. The present disclosure further describes a process for making a fermentation product. The process comprises contacting the recombinant yeast host cell described herein with a carbohydrate source under a condition allowing the conversion of at least a part of the carbohydrate into a fermentation product.

The invention relates to ribozyme for labeling biotin on target RNA (Ribonucleic Acid) as well as a screening method and application thereof. The RNA labeling technology is one of core tools for modern molecular biology research and clinical diagnosis. A specific marker is covalently linked to a target RNA molecule, so that accurate tracking, efficient detection and functional analysis of RNA can be realized. A biotin-streptavidin system becomes one of the technical routes which are most widely applied due to extremely high affinity and signal amplification capability of the biotin-streptavidin system. At present, common biotin-labeled RNA technical methods mainly comprise a chemical solid-phase synthesis method, an enzymatic method and a chemical labeling method. However, the methods have the limitations of poor site specificity, low efficiency, complex manipulation and the like in the use process. The engineering ribozyme for catalyzing RNA biotinylation is obtained by taking 12: 0 biotin coenzyme A as a biotin donor through an in-vitro screening technology. The ribozyme provided by the invention can efficiently and specifically carry out biotin labeling on target RNA, the reaction process is simple, and the labeling activity is up to 90% or above.

This invention belongs to the fields of fermentation and genetic engineering technology, and provides a high-yield hexanoic acid-producing engineered *Escherichia coli* strain, its construction method, and its applications. This engineered strain is *Escherichia coli*... E. coli w3110 was the starting strain, overexpressing the acetyl-CoA transferase gene. act and β-ketothiolase gene bktB Overexpression of trans-enoyl-CoA reductase gene ter 3-Hydroxybutyryl-CoA dehydrogenase gene hbd, and 3-hydroxybutyryl coenzyme A dehydratase gene crt Or, simultaneously not expressing the pyruvate formate lyase gene. pflB or lactate dehydrogenase gene ldhA This engineered bacteria can convert glucose into hexanoic acid, a high-value product, with a yield of 4.968 g / L after 18 hours of fermentation. It adopts aerobic fermentation, resulting in rapid cell growth, a short fermentation cycle, and a high acid production rate. The fermentation process is simple, easy to control, and has low production costs, which is conducive to its promotion and application in industrial production.

The invention provides a genetic engineering strain of high-yield immunosuppressant mycophenolic acid as well as a preparation method and application of the genetic engineering strain. The invention firstly provides a method for constructing the penicillium with the effect of high yield of mycophenolic acid. The method comprises the step of replacing an indigenous promoter of acyl-coenzyme A oxidase PbACOX323 protein participating in beta oxidation in peroxisome of a penicillium strain with a promoter PgpdA of 3-phosphoglycerol dehydrogenase with an amino acid sequence of SEQ ID NO: 1. According to the method disclosed by the invention, the genetically engineered bacterium with high yield of mycophenolic acid is constructed, the yield of mycophenolic acid is positively increased by replacing a promoter of acyl-coenzyme A oxidase PbACOX323, and the method has a good industrial application value.

The invention discloses a compound enzyme preparation-containing nutritional feed for regulating and controlling intramuscular fat of black pigs and a preparation method of the compound enzyme preparation-containing nutritional feed, and relates to the technical field of livestock and poultry breeding feeds. The invention discloses a black pig skeletal muscle cell fat directional transport feed which is prepared from the following components in parts by weight: 850-920 parts of basal feed, 5-12 parts of fat directional deposition compound enzyme group, 25-40 parts of amino acid-enzymatic synthesis substrate combination and 2-6 parts of lipolytic enzyme specific inhibitor. According to the black pig skeletal muscle cell fat directional transport feed, fat precursor directional transport is realized through the compounded fat directional deposition compound enzyme group, a fat synthesis pathway targeting black pig skeletal muscle cells and lipoprotein lipase; acetyl-coenzyme A carboxylase and fatty acid synthetase catalyze fat synthesis step by step, only intramuscular fat generation pathways are activated, subcutaneous and abdominal fat deposition paths are blocked, the technical defects that fat deposition of an existing single enzyme preparation is non-directional, and the body fat rate is caused to be abnormally increased are overcome, meanwhile, an exclusive amino acid-enzymatic synthesis substrate combination is matched, and the body fat synthesis efficiency is improved. Sufficient adaptive substrates are supplied to enzyme group catalytic reaction, and the problem that a single enzyme preparation is insufficient in catalytic efficiency is solved.

The preparation method comprises the following steps: detecting the concentration of cytoplasmic acyl-coenzyme A thioester hydrolase in a sample by adopting an ELISA (Enzyme-Linked Immunosorbent Assay) method, and carrying out regression analysis through Logistic, the correlation between the serum level of the cytoplasm acyl-coenzyme A thioester hydrolase in an AD (Alzheimer's disease) patient and a vascular dementia (VD) patient and the cognitive impairment degree and the A beta 40 content is evaluated, and whether the expression of the cytoplasm acyl-coenzyme A thioester hydrolase is closely related to the AD progress or not is judged. An effective molecular marker is provided for differential diagnosis of an AD patient and a VD patient, a large number of tests prove that the cytoplasm acyl-coenzyme A thioester hydrolase is highly expressed in the AD patient, the cytoplasm acyl-coenzyme A thioester hydrolase serving as an AD serum molecular marker has high diagnostic value, and when the serum content of the cytoplasm acyl-coenzyme A thioester hydrolase is higher than 62.5 pg / ml, the cytoplasm acyl-coenzyme A thioester hydrolase can assist AD diagnosis and can also serve as an auxiliary index for distinguishing AD and VD. The kit is applied to preparation of a kit for differential diagnosis of AD and VD.

Described herein are non-human organisms for producing triacylglycerol wherein the non-human organism is genetically modified to express a lysophosphatidic acid acyltransferase specific for C16:0-Coenzyme A (C16:0 LPAT) and wherein, once expressed, the C16:0 LPAT is localised in the endoplasmic reticulum. Also described are non-human organisms for producing triacylglycerol in which (a) a lysophosphatidic acid acyltransferase specific for C16:0-Coenzyme A (C16:0 LPAT) is localised in the endoplasmic reticulum; and (b) activity of native endoplasmic reticulum lysophosphatidic acid acyltransferase (ER LPAT) is suppressed or prevented. Further described are non-human organisms in which a chloroplast lysophosphatidic acid acyltransferase (LPAT) is expressed, wherein said chloroplast LPAT lacks a functional chloroplast targeting signal. The disclosure also relates to methods for extracting triacylglycerol from the organisms and the use thereof in infant formula.

The invention provides a method for producing DL-2, 4-dihydroxy-3, 3-dimethyl butyric acid (DL-pantoic acid) and / or DL-3-hydroxy-4, 4-dimethyl oxacyclopentane-2-one (DL-pantolactone), in particular to a method for producing DL-2, 4-dihydroxy-3, 3-dimethyl butyric acid and / or DL-3-hydroxy-4, 4-dimethyl oxacyclopentane-2-one (DL-pantolactone) by condensation of hydroxypivalaldehyde and formyl-CoA of C1 source, in particular to a method for producing DL-2, 4-dihydroxy-3, 3-dimethyl oxacyclopentane-2-one (DL-pantoic acid) and / or DL-3-hydroxy-4, 4-dimethyl oxacyclopentane-2-one (DL-pantoic acid). The invention relates to a method for preparing 2, 4-dimethyl oxacyclopentane-2-one. The present invention also provides a genetically engineered microorganism for use in the production of DL-2, 4-dihydroxy-3, 3-dimethylbutyric acid and / or DL-3-hydroxy-4, 4-dimethyl oxacyclopentane-2-one, and also provides a genetically engineered microorganism for use in the production of DL-3-hydroxy-4, 4-dimethyl oxacyclopentane-2-one. In addition, the key enzyme has been engineered to improve its performance in the production of DL-pantoic acid or DL-pantolactone.

The invention relates to a preparation method and application of 6-methyl-3, 5-dioxocapryloyl coenzyme A. According to the preparation method, 2-methylbutyric acid serves as a starting raw material, the 6-methyl-3, 5-dioxocapryloyl coenzyme A is chemically synthesized through the steps of activation, condensation, coenzyme A coupling and the like, and the structure and purity of the 6-methyl-3, 5-dioxocapryloyl coenzyme A are identified through the technologies of LC-MS / MS, 1HNMR and the like. The nine-carbon coenzyme A is successfully prepared and identified through a chemical synthesis method for the first time, the core problem that an intermediate is unstable and cannot be obtained in vitro is solved, and a stable substrate is provided for in-vitro acyl transfer; the QS-21 in-vitro acyl transfer reaction is realized for the first time, an in-vitro catalytic system of a chemical synthesis intermediate and an insect cell expression enzyme is established, and a foundation is laid for development of a QS-21 total synthesis process.