144 results about "Sugar acids" patented technology

The invention discloses construction and application of a plasmid-free and auxotrophy-free L-tryptophan production strain, and belongs to the technical field of bioengineering. According to the invention, a plurality of key anti-feedback inhibition enzymes in a tryptophan synthesis route are optimized and combined, and the optimal combination is integrated into an escherichia coli genome by utilizing a CRISPR (clustered regularly interspaced short palindromic repeats)-ASPR (clustered regularly interspaced short palindromic repeats)-trans-spansses (clustered regularly interspaced short palindromic repeats) system. According to the invention, the plasmid-free and nutritional deficiency-free engineering strain ZH-3 for producing the L-tryptophan is successfully constructed, and under the conditions of no use of antibiotics, use of inducers and no addition of additional substances, the total yield of the L-tryptophan reaches 43g / L and the sugar-acid conversion rate is increased to 0.180 g / g after the strain is cultured for 35h in a 3L fermentation tank. The strategy used by the invention is not only suitable for construction of tryptophan genome integration expression strains, but also provides reference for construction of other plasmid-free amino acid production strains.

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 discloses a spermidine synthetase mutant and application of the spermidine synthetase mutant in synthesis of spermidine, and belongs to the technical field of genetic engineering and metabolic engineering. According to the method, the spermidine synthetase is mutated firstly, the efficiency of the spermidine synthetase is improved, and on the basis, the dissolved oxygen and fed-batch concentration are optimally controlled through fermentation, so that the yield of spermidine is improved. The corynebacterium glutamicum provided by the invention is an engineering bacterium with plasmids and without defects, and after the corynebacterium glutamicum is subjected to fed-batch fermentation in a 5L fermentation tank for 68 hours, the yield of spermidine reaches 25.1 g / L, and the sugar-acid conversion rate is 17.9%.

The invention belongs to the technical field of biology, and particularly relates to a method for producing xylitol through two-step enzyme catalysis of hemicellulose hydrolysate, and the method comprises the following steps: taking hemicellulose hydrolysate as a raw material, adding arabinose dehydrogenase, NADH oxidase and coenzyme NADH, and carrying out first-step fermentation until no L-arabinose residue exists in fermentation liquor to obtain fermentation reaction liquor I; and adding xylose reductase and glucose dehydrogenase into the fermentation reaction liquid I, and carrying out second-step fermentation to obtain a fermentation product containing xylitol. According to the two-step enzyme catalysis method provided by the invention, xylitol is prepared, and high-purity xylose does not need to be used as a raw material; according to the present invention, the cheap hemicellulose hydrolysate can be directly adopted as the raw material, the xylose conversion rate and the xylitol yield can exceed 99%, the impurity arabitol content in the product is low, the other impurity saccharic acid is easy to separate, and the problems of complex process, large separation difficulty and high cost in the xylitol refining process are successfully solved.

An engineered bacterium for improving tryptophan yield, a construction method therefor, and a use thereof. A strain capable of tolerating a high concentration of tryptophan was obtained by screening. Genome sequencing and protein sequence analysis of the strain revealed that some proteins in the strain had undergone point mutations, and these mutants can improve the tryptophan yield. In order to further improve the tryptophan yield, modifications are made to a protein sequence expressed by a fadR gene or a protein sequence expressed by a pepD gene in a starting bacterium. Such modifications enable the obtained engineered bacterium to have a higher tryptophan yield than the starting bacterium. In the case of large-scale production, in a 5 L fermentation tank, the tryptophan yield can reach 62.38±5.80 g / L, and the sugar-to-acid conversion rate can reach 24.1%. Compared with the original bacterium, the tryptophan yield is increased by 1.48 folds, and the sugar-to-acid conversion rate is increased by 1.26 folds. The biological material and the use thereof relate to the technical field of molecular biology and have wide practical application value.

The invention discloses a method for improving the synthesis level of L-tryptophan in escherichia coli based on ARTP mutagenesis high-throughput screening, and belongs to the technical field of bioengineering. According to the invention, the L-tryptophan biosensor pSensor-trp3 is constructed, and the L-tryptophan biosensor pSensor-trp3 is good in response under the condition that the exogenous addition concentration range of L-tryptophan is 0-300mg. L <-1 >. High-throughput screening is performed by using a flow cytometry, a dominant mutant strain YB-2 is obtained through iterative mutagenesis, and the shake flask L-tryptophan yield and the sugar-acid conversion rate of the dominant mutant strain YB-2 are 5.68 g.L <-1 > and 0.103 g.g <-1 > respectively and are increased by 11.4% and 10.7%. Through second-generation whole genome re-sequencing comparative analysis, it is speculated that the genes ynfB and waaO possibly have a promoting effect on synthesis of L-tryptophan. The L-tryptophan biosensor used in the invention also provides reference for high-throughput screening and transformation of other related L-tryptophan production strains.

The invention relates to the technical field of tomato juice processing, in particular to flavor-improved NFC tomato juice, a preparation method thereof and compound juice. The invention provides flavor-enhanced NFC tomato juice, a preparation method thereof and composite fruit juice. The tomato NFC beverage prepared by the preparation method is bright in color, mellow and fine in taste, appropriate in sugar-acid ratio, moderate in viscosity and weakened in layering phenomenon by utilizing specific ultrasonic treatment and ultrahigh-pressure non-thermal sterilization processes, and the flavor of tomato raw materials and the flavor of tomato juice, especially the characteristic flavor of tomatoes, are enhanced under the condition of no additives. In addition, various nutrient substances in the tomatoes are reserved to the maximum extent, and the special color, flavor and nutrient components of the product are still kept in the storage period.

The invention discloses a production strain for fermenting L-histidine and application of the production strain, and belongs to the technical field of biological engineering. According to the invention, escherichia coli E.coli CICC 10243 is taken as an original strain, histidine synthesis operon genes hisDCB-cg2302-cg2301-HA-impA-FI, hisN and hisEG from corynebacterium glutamicum are integrated on a genome of the escherichia coli E.coli CICC 10243, a pyruvate dehydrogenase AceE mutant coding gene is introduced, and an escherichia coli transcription factor SlyA coding gene slyA is inactivated. The novel strain E.coli His08 for fermentation production of L-histidine is prepared and fermented in a 5L fermentation tank for 60 h, the histidine yield reaches 58.39 g / L, the sugar-acid conversion rate is 0.15 g / g, and the strain E.coli His08 has important application value.

Escherichia coli is modified by means of metabolic engineering, a genetically engineered bacterium for high yield of O-succinyl-L-homoserine is obtained, and a construction method of the genetically engineered bacterium comprises the following steps: weakening a synthetic route of an organic acid metabolic byproduct of a chassis strain E.coli W3110 [delta] metI [delta] metJ [delta] thrB [delta] metB; wherein the synthetic route of the organic acid metabolic byproducts is selected from at least one of a formic acid synthetic route, a lactic acid synthetic route and an ethanol synthetic route. The constructed genetically engineered bacterium is applied to microbial fermentation production of the O-succinyl-L-homoserine, effective accumulation of the O-succinyl-L-homoserine is achieved, the sugar acid conversion rate reaches 46.8%, and a foundation is laid for subsequent construction of high-yield O-succinyl-L-homoserine engineering bacteria.

The invention discloses a fermentation production process for improving the conversion rate of L-arginine and a strain used by the fermentation production process, and belongs to the technical field of fermentation engineering. According to the method, the content of residual sugar and ammonia nitrogen in the fermentation process of the L-arginine is accurately regulated and controlled, so that the growth speed of thalli and the sugar-acid conversion capacity are controlled, the fermentation period is shortened, meanwhile, the fermentation period of the L-arginine is 44-55 hours, the produced acid reaches 130 g / L or above, and the conversion rate is 50% or above by supplementing materials in the fermentation process and controlling other processes. According to the process, the acid production and conversion rate of the strain are greatly improved, and the production cost is reduced.

The invention provides a high-yield O-succinyl-L-homoserine engineering bacterium as well as a construction method and application of the high-yield O-succinyl-L-homoserine engineering bacterium. According to the invention, O-succinyl-L-homoserine genetically engineered bacteria with high yield of O-succinyl-L-homoserine are constructed by introducing O-succinyl-homoserine transferase from Vibrio cholera into a chassis strain in an exogenous manner and obtaining a gene mutant metAVc (T242A) of the O-succinyl-L-homoserine transferase, and further increasing the expression of the O-succinyl-L-homoserine transferase by adopting a Trc promoter. The engineering strain obtained through a systematic metabolic engineering modification strategy can realize effective accumulation of OSH, the shake flask yield of OSH reaches 18.8 g / L, the fed-batch fermentation yield of a 5L fermentation tank reaches 105.4 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 discloses recombinant escherichia coli capable of increasing the yield of L-homoserine and a preparation method of the recombinant escherichia coli, and belongs to the technical field of biology. By constructing a multi-way glucose transport system, L-homoserine synthesis precursor supply is enhanced, high-energy-consumption genes are knocked out, ATP regeneration is enhanced, ATP availability is improved, an acetic acid conversion way is established, and an L-homoserine degradation way is blocked, so that a metabolic flow of a synthesis way is further enhanced; a pyruvate carboxylase mutant and a designed promoter are introduced to weaken expression of citrate synthase and reconstruct key metabolic nodes, and fed-batch fermentation conditions of the strain in a 5L bioreactor are optimized according to metabolic characteristics of the strain; the genetically engineered bacterium which is clear in genetic background, does not carry plasmids, does not need induction and can stably and efficiently produce the L-homoserine is obtained, the yield of the L-homoserine reaches 141.5 g / L after the L-homoserine is fermented for 56h in a 5L fermentation tank, the saccharic acid conversion rate reaches 40%, and the genetically engineered bacterium has a certain application prospect.

The invention belongs to the technical field of microorganisms, and particularly relates to a strain for producing high-optical-purity L-lactic acid and application of the strain. The strain is preserved in the China General Microbiological Culture Collection Center (CGMCC) on May 13, 2025, and the preservation number of the strain is CGMCC No. 34537; the preservation address is Institute of Microbiology, Chinese Academy of Sciences, No.3, Yard 1, Beichen West Road, Chaoyang District, Beijing. When the strain is used for fermentation production of L-lactic acid, the fermentation period is short, the sugar-acid conversion rate is high, the yield of L-lactic acid is high, and the optical purity is high. In addition, the strain also has excellent growth and metabolism stability, lactic acid with optical purity can still be efficiently produced after passage to the tenth generation, and the strain is suitable for industrial production of high-purity L-lactic acid.

The invention belongs to the technical field of genetic engineering breeding, and particularly relates to application of an SC8 gene in regulating accumulation of soluble solids in tomato fruits and a breeding method. The SC8 gene provided by the invention plays an important role in tomato saccharic acid metabolism and soluble solid synthesis and accumulation, and plays a role in negative regulation of tomato fruit soluble solid synthesis and accumulation. The SC8 gene is applied to plant genetic engineering breeding, and a new functional site and a new breeding thought are provided for cultivating high-quality flavor tomato varieties. By inhibiting the expression of the SC8 gene, soluble solids and sugar acid metabolites thereof such as cane sugar, fructose, glucose, malic acid and citric acid in the red ripe tomato fruits can be increased, and by enhancing the expression level of the SC8 gene, synthesis and accumulation of the soluble solids in the tomato can be reduced; therefore, the implementation of the invention provides a feasible way for cultivating and producing tomatoes with various flavors and qualities, and plays an important role in improving the economic benefits of the tomato industry.

The invention discloses a modified aureobasidium pullulans strain based on reduction of malic acid pathway consumption and application of the modified aureobasidium pullulans strain. Gene for coding NADPH dependent malic enzyme and phosphoenolpyruvate carboxykinase in an aureobasidium pullulans genome is directionally knocked out. The transformation blocks a key consumption branch for synthesis and accumulation of the cytoplasmic malic acid, and effectively guides a central carbon metabolic flow to be more efficiently guided to a target product. Experimental results show that the polymalic acid yield and the saccharic acid conversion rate of the double-knockout engineering strain D3N5-delta3617 / deltapepck in fermentation are remarkably improved compared with those of an original strain, and the biomass is also increased. The invention provides a high-performance strain with important application value for industrial efficient fermentation production of polymalic acid.

The invention provides a method for improving fermentation yield and sugar-acid conversion rate of 5-hydroxytryptophan, alpha-ketoglutaric acid ferrous salt, alpha-ketoglutaric acid zinc salt, alpha-ketoglutaric acid cobalt salt and alpha-ketoglutaric acid manganese salt are added into a fermentation culture medium according to a specific proportion, alpha-ketoglutaric acid directly participates in TCA circulation, circulation operation can be accelerated, generation of NADH and FADH2 is increased, the yield of 5-hydroxytryptophan is increased, and the yield of 5-hydroxytryptophan is increased. The ATP synthesis efficiency is improved, and more energy is provided for cell growth; the alpha-ketoglutaric acid can balance amino acids required in the growth process of escherichia coli, promote the generation of proteins and nucleic acids and accelerate the growth of thalli; the alpha-ketoglutaric acid metal salt can improve the utilization efficiency of microelements by thalli; ferrous ions are cofactors of 5-hydroxytryptophan hydroxylase and can accelerate the hydroxylation process of tryptophan. Through the synergistic effect of the added components, the yield of the 5-hydroxytryptophan and the sugar-acid conversion rate are improved.

The invention belongs to the field of synthetic biology, and particularly relates to a genetically engineered bacterium for producing O-succinyl-L-homoserine at high yield as well as a construction method and application of the genetically engineered bacterium. According to the invention, the large intestine probiotic Nissle 1917 is used as a chassis strain, and compared with other expression hosts, the large intestine probiotic Nissle 1917 can grow and breed more quickly and is safer. The expression of the gene thrB is regulated by using the self-regulation promoter PfliA, so that the synthesis route of threonine is dynamically regulated, the efficient utilization of a carbon source is realized, and the sugar acid conversion rate of OSH synthesis is improved; in addition, by introducing site mutation, feedback inhibition suffered by OSH synthesis key enzyme HST is relieved, the enzyme activity of consumption pathway key enzyme CGS is reduced, and the carbon flow is effectively driven to be redirected to a target product synthesis pathway. According to the microbial cell factory constructed by the invention, the production efficiency of OSH is remarkably improved, the fermentation period is shortened, the production cost is reduced, and the economic feasibility of industrial production is realized.

The invention discloses a nutrition regulating agent for regulating the mature period of citrus fruits and application of the nutrition regulating agent. The nutrition regulating agent is prepared from potassium nitrate, monopotassium phosphate, magnesium sulfate, ferric sodium ethylenediaminetetraacetate, zinc sodium ethylenediaminetetraacetate, boric acid, ammonium molybdate, gibberellin, abscisic acid and diatomite which is supplemented to 100 parts. The invention further provides a preparation method of the nutrition regulating agent and application of the nutrition regulating agent in regulating the mature period of citrus fruits, and the application mode is that when the diameter of the citrus fruits is 40-50 mm, the preparation is diluted by 600-800 times to be sprayed on leaf surfaces, once every 7 days and twice continuously. Through the synergistic effect of mineral nutrient elements and low-concentration hormones, bidirectional precise regulation and control of the citrus mature period are achieved, fruits can be promoted to mature in advance or later for 7-15 days, the sugar-acid ratio and color of the fruits can be remarkably improved, meanwhile, the problems of tree vigor decline and quality decline caused by single hormone treatment are solved, and the method is suitable for large-scale popularization and application. The method has the characteristics of high efficiency, safety and simple operation.

The application provides a compound microbial fertilizer, a preparation method and application thereof. The compound microbial fertilizer comprises the following components in parts by weight: 10-30 parts of a compound microbial agent, 20-50 parts of an agent carrier, 30-50 parts of a compound fertilizer slow-release agent and 10-30 parts of modified urea aldehyde. The compound microbial fertilizer prepared by the application can be applied to growth tests of tomatoes, and higher yield, stem thickness growth value, vitamin C content and sugar acid ratio can be obtained. The compound microbial fertilizer has long-term effect, can release phosphorus, nitrogen and potassium and the like, has the effects of moisturizing and loosening soil, can increase the yield and quality of tomato fruits, promote the robustness of roots and stems and improve the eating taste.

Provided is a composition for inhibiting the proliferation of bacteria belonging to the genus Collinsella, the composition containing at least one selected from sugar acid-containing oligosaccharides and salts thereof. The sugar acid is preferably selected from aldonic acid, uronic acid, and aldaric acid.

The invention discloses a method for synergistically improving the lycopene content and the sugar-acid ratio in tomato fruits, belongs to the technical field of biology, and particularly relates to a method for knocking out or silencing an INVINH1 gene to synergistically improve the lycopene content and the sugar-acid ratio in the tomato fruits, and a nucleotide sequence of a protein coding region of the INVINH1 gene is shown as SEQ ID NO.1. The invention further discloses a method for synergistically improving the lycopene content and the sugar-acid ratio in the tomato fruits. A carrier for knocking out or silencing the INVINH1 gene is constructed by utilizing a CRISPR / Cas9 gene editing technology, the carrier is transferred into tomato cotyledons through agrobacterium tumefaciens mediation, INVINH1 gene knockout homozygous strains invinh1-1 and invinh1-2 are obtained through screening by utilizing a tissue culture technology, the lycopene content and saccharic acid in tomato fruits of a mutant plant are remarkably improved compared with those of wild plants, and the gene knockout or silencing method is suitable for industrial production. The invention provides an important gene resource for cultivating tomato varieties for synergistically improving lycopene and sugar-acid ratio.

According to the method for improving the flavor of the Huangguo pear juice beverage, provided by the invention, the Huangguo pear residues can be effectively utilized to extract aroma components, and the original fruit flavor of the Huangguo pear juice beverage is greatly improved through scientific process steps such as composite enzymolysis, reasonable adjustment of the sugar-acid ratio and strict sterilization treatment; the loss of aroma substances is reduced, so that the product has higher typicality and high quality, and a new technical support and a new development direction are brought to the processing industry of the Huangguo pears in the same kernel region.

Aiming at a lactic acid return loss phenomenon existing in a process for producing lactic acid by microbial fermentation, the invention firstly provides application of a target gene in inhibiting lactic acid return loss in lactic acid production by a microbial fermentation method, and the target gene is a lactic acid permease gene lutP and / or an iron-sulfur oxidase gene cluster lutABC. On the basis of the application, the invention also provides a method for inhibiting lactic acid return consumption in lactic acid production by a microbial fermentation method, and a bacillus coagulans engineering strain with low lactic acid return consumption and high sugar-acid conversion rate. According to the method, effective inhibition of intracellular transport and / or metabolism of lactic acid is realized, so that the problem of lactic acid return consumption in a process for producing lactic acid through microbial fermentation is solved, and the technical effect is remarkable. According to the engineering strain, a LutR palindromic sequence in a lactic acid permease gene lutP promoter region is modified, and / or an iron-sulfur oxidase gene cluster lutABC is inactivated, so that transmembrane transport and / or intracellular metabolism of lactic acid are / is effectively inhibited, a lactic acid return loss phenomenon is remarkably weakened, the sugar-acid conversion efficiency is improved, the fermentation process flow is simplified, the production cost is reduced, and the engineering strain is suitable for industrial production. And the method has important value for large-scale production.

The invention relates to flavored fruit vinegar and a preparation method thereof, and the flavored fruit vinegar has the beneficial effects that the coexistence of flavor and nutrition is realized through the matching of apples and roxburgh roses; wherein the apple juice is used as a fermentation substrate, so that stable sugar-acid ratio and mellow feeling are provided; the rosa roxburghii tratt greatly enriches active ingredients such as vitamin C, SOD, polyphenol and the like, and lays a health-care foundation of the product. In the fermentation process, the synergistic effect of saccharomycetes, acetic bacteria and lactic acid bacteria is adopted, the saccharomycetes efficiently complete alcoholic fermentation, the acetic bacteria dominate acid production, the lactic acid bacteria not only can generate soft lactic acid, more importantly, metabolites of the lactic acid bacteria can effectively complex and convert tannin astringency in the roxburgh roses, and the taste is fundamentally improved. The final product successfully integrates the mellowness of the apples and the high nutrition of the roxburgh roses and is free of obvious bitter and astringent taste, and the taste, flavor and nutritional value are comprehensively improved.

The invention discloses an application of indole-3-acetamide in storage and preservation of postharvest oranges, and belongs to the technical field of food preservation. A variety of indole-3-acetic acid analogues are selected, a postharvest storage and fresh-keeping test is carried out by taking citrus reiculata Blanco as an experimental material, and the screened indole-3-acetamide has stronger fresh-keeping activity and can greatly prolong the storage period of citrus reiculata Blanco. Then, Wenzhou mandarin oranges are used as experimental materials to further verify the effect of the indole-3-acetamide in citrus preservation, and it is proved that the indole-3-acetamide can significantly reduce the pedicel aging rate and rotting rate; the accumulation of peel reactive oxygen species (ROS) is inhibited, and the SOD activity is improved; and the fruit hardness, soluble solids and sugar-acid ratio are maintained, and the internal quality is maintained. Therefore, as an indole-3-acetic acid analogue, the indole-3-acetamide has excellent storage and fresh-keeping effects after the citrus is picked.

The present invention provides a tegoprazan sugar acid salt and a preparation method therefor, the salt being pharmaceutically usable for gastroesophageal disease, gastroesophageal reflux disease, gastritis, peptic ulcer, gastric ulcer, duodenal ulcer, NSAID-induced ulcer, non-erosive reflux disease (NERD) and the like. The tegoprazan sugar acid salt of the present invention has excellent water solubility and stability of tegoprazan, and thus can be particularly useful as a pharmaceutical injection preparation.

The invention relates to a monophase gel consisting of a non-polar liquid mixed with a non-ionic surfactant selected from ester surfactants of formula ROC(O)R1 or RC(O)OR2 or ether surfactants of formula ROR2, wherein RO denotes the radical of a sugar or sugar alcohol, RC(O)O denotes a sugar acid, C(O)R1 denotes the radical of a fatty acid and R2 denotes the radical of a fatty acid alcohol. In the afore-mentioned non-ionic surfactants, the sugar is a C5 or C6 sugar, and the sugar acid and the sugar alcohol are a sugar acid derived therefrom or a sugar alcohol derived therefrom. The fatty acid or fatty acid alcohol has a C chain length of at least 6 and the non-ionic surfactant has an OH group to C atom ratio in the range of 1: 3 to 1: 8. The invention further relates to methods for producing corresponding monophase gels and to the use of corresponding gels for texturing food or cosmetic products or for formulating pharmaceuticals.

The application discloses a kind of high-yield O-succinyl-L-homoserine recombinant escherichia coli and its construction method and application, belong to genetic engineering and fermentation engineering technical field.The recombinant escherichia coli is expressed by expressing anti-feedback inhibition homoserine O-succinyltransferase metA fbr , aspartate ammonia-lyase aspA, aspartate transaminase aspC, 2 ketoglutarate decarboxylase sucA, dihydrothioctic acid succinyltransferase sucB and efflux protein yjeH, knock out metJ, improve intracellular NADPH availability, to enhance OSH synthesis pathway metabolic flow, precursor succinyl coenzyme A supply and product efflux.Using 5 L bioreactor for fed-batch fermentation, after fermentation 60 h, OSH production is as high as 137.4 g / L, and sugar acid conversion rate reaches 50.5%.The application provides engineering strain and technical realization path for the efficient fermentation of OSH.