517 results about "Recombinant yeast" patented technology

Described are recombinant yeast which ferment xylose to ethanol and which maintain their ability to do so when cultured for numerous generations in non-selective media. The preferred yeast contain multiple copies of integrated genes encoding xylose reductase, xylitol dehydrogenase, and xylulokinase fused to promoters which are non-glucose inhibited and which do not require xylose for induction. Also described are preferred methods for integrating multiple copies of exogenous DNA into host cells by transforming cells with replicative/integrative vectors, and then replicating the cells a number of times under selective pressure to promote retention of the vector in subsequent generations. The replicated vectors thus serve to integrate multiple copies of the exogenous DNA into the host cells throughout the replication/selection phase. Thereafter the selective pressure can be removed to promote loss of the vector in subsequent generations, leaving stable integrants of the exogenous DNA.

The present invention provides one kind of improved high specific activity phytase and its coding gene, and the improved phytase has even higher heat stability. The present invention also provides recombinant yeast cell containing the phytase gene of the present invention. The recombinant yeast of the present invention has phytase expressing amount up to 6.5E6 U in each ml of fermented liquid. The phytase of the present invention may be used widely in feed and food industry.

The invention relates to the technical field of gene engineering, and discloses a recombinant yeast strain, and a construction method and application thereof. In the recombinant yeast strain, gal1, gal7, gal10 and ypl062w genes are knocked out, and the recombinant yeast strain comprises 9 gene segments which are integrated to the genome by yeast homologous recombination. The construction method comprises the following steps: constructing a four-knock-out yeast strain to provide an optimized host cell for producing beta-carotin, selecting lycopene cyclases crtY from different sources, and carrying out modular design to integrate functional genes crtE crtB and crtI of the specific-source synthetic lycopene, specific yeast endogenous genes and the like to the four-knock-out yeast strain genome, thereby obtaining a brand-new recombinant strain capable of producing beta-carotin at high yield.

Recombinant Saccharomyces cerevisiae produced by transformation with heterologous polynucleotide sequences coding for xylulokinase (XKS) from Yersinia pestis and xylose isomerase (XI) are capable of xylose utilization. The transformants express these heterologous polynucleotides at a sufficient functional level to grow aerobically on xylose as the sole carbon source. Further transformation of the recombinant yeasts to overexpress one or more of the S cerevisiae genes PIP2, IMG2, MAK5, VPS9, COX10, ALE1, CDC7, and MMS4, permits the yeast to grow anaerobically on xylose as the sole carbon source. When grown under anaerobic conditions on a culture medium comprising both glucose and xylose, the transformed yeast exhibit increased ethanol productivity, with the yeast growing on the xylose to increase their biomass and fermenting the glucose to ethanol.

The invention relates to the technical field of gene engineering, and discloses a recombinant yeast strain, and a construction method and an application thereof. The recombinant yeast strain is obtained through the following steps: knocking out gal1, gal7, gal10 and ypl062w genes, integrating three gene fragments a genome through yeast homologous recombination, further knocking out an rox1 gene, and further integrating two gene fragments to the yeast genome. The gene knockout yeast strain constructed in the invention provides optimized host cells for production of lycopene; and combined functional genes crtE, crtB and crtI having specific sources and used for synthesizing the lycopene and specific yeast endogenous genes are selected and are integrated to the gene knockout strain genome through modular designing, so the brand new recombinant strain for highly yielding lycopene is obtained.

The present invention relates to a process for preparing a nutritional, therapeutic or organoleptic product by growing non-recombinant yeast under aerobic conditions, in a medium that includes crude glycerol, as one possible carbon source to produce a yeast product. The yeast product can be processed to obtain such nutritional, therapeutic or organoleptic products as yeast paste, yeast metabolites, carbohydrates, proteins, functional proteins, nucleotides, yeast autolysates, yeast extract, yeast cell walls, beta-glucans, mannans or a product derived from a mineralized yeast product.

The invention relates to the technical field of gene engineering, and discloses a recombinant yeast strain, and a building method and application thereof. The recombinant yeast strain includes two specific gene segments recombined and integrated onto a genome in a homologous way through yeast. By selecting the specific group for forming a promoter combination and matching phaffia rhodozyma sourced phytoene synthetase and lycopene cyclase dual-function enzyme gene CrtYB, GGPP synthase CrtE, phytoene desaturase CrtI and specific yeast endogenous gene and the like, the substances are integrated onto the yeast strain genome through modular design; the yp1062w gene is knocked away through homologous recombination; one strain of fire-new recombinant yeast without an inducing agent is obtained; the high yield of the beta-renieratene is ensured.

Disclosed are xylose-fermenting recombinant yeast strains comprising heterologous PsXYL1, Ps XYL2, and PsXYL3, as well as methods of fermenting xylose to obtain ethanol using the recombinant yeast strain.

Host cells, comprising Kluveryomyces expressing heterologous cellulases produce ethanol from cellulose In addition, multiple host cells expressing different heterlogous cellulases can be co-cultured together and used to produce ethanol from cellulose The recombinant yeast strains and co-cultures of the yeast strains can be used to produce ethanol on their own, or can also be used in combination with externally added cellulases to increase the efficiency of sacchanfication and fermentation processes

We disclose a recombinant yeast, wherein the yeast is pyruvate decarboxylase enzyme (PDC) activity negative (PDC-negative) and is functionally transformed with a coding region encoding a pyruvate carboxylase enzyme (PYC) wherein the PYC is active in the cytosol, a coding region encoding a malate dehydrogenase enzyme (MDH) wherein the MDH is active in the cytosol and is not inactivated in the presence of glucose, and a coding region encoding a malic acid transporter protein (MAE). We also disclose a method of producing malic acid by culturing such a yeast in a medium comprising a carbon source and a carbon dioxide source and isolating malic acid from the medium.

The invention discloses a recombinant yeast strain (Saccharomyces cerevisiae)) capable of efficiently metabolizing xylose, which is named SyBE005. The recombinant yeast strain has been collected in Common Microorganism Center of China Committee for Culture Collection of Microorganisms, the collection number is CGMCC No.6634, and the recombinant yeast strain has the capacity of efficiently metabolizing xylose to produce ethanol. The recombinant yeast strain SyBE005 can effectively ferment xylose to generate ethanol. The ethanol yield reaches 64% of the theoretical yield, and the yield of the byproduct xylitol is lower than 12%; and thus, the recombinant yeast strain can efficiently convert xylose into ethanol, and is an excellent strain utilizing cellulose hydrolysate.

Disclosed are xylose-fermenting recombinant yeast strains expressing xylose reductase, xylitol dehydrogenase, and xylulokinase and having reduced expression of PHO13 or a PHO13 ortholog, as well as methods of fermenting xylose to obtain ethanol using the recombinant yeast strains.

The invention relates to the technical field of gene engineering, and discloses a recombinant yeast strain, a construction method thereof and the application thereof. In the recombinant yeast strain, gal1, gal7, gal10 and ypl062w genes are knocked out, and the recombinant yeast strain comprises 6 gene segments which are integrated to the genome through yeast homologous recombination. On the above basis, the recombinant yeast strain is further integrated onto one gene segment of a yeast genome, so that a better recombinant yeast is obtained. According to the technical scheme of the invention, the yeast strain is constructed based on gene knock-out, and an optimized host cell for producing lycopene is provided. Meanwhile, functional genes crtE crtB and crtI of a specific source combination and used for the synthesis of lycopene, specific yeast endogenous genes and specific exogenous genes are selected. The above selected genes are integrated to the gene knock-out genome of the yeast strain, and then a brand-new recombinant strain capable of producing high-yield lycopene is obtained.

The invention provides a modified coding gene of xylanase that has high activity in the condition of high temperature and strong alkali, a recombinant plasmid thereof, a yeast recombination genetic engineering strain containing the gene and a preparation method of the gene. Compared with the original xylanase, the modified xylanase is mutated into cysteine from glycin of the 201 site of amino acid sequence of the original xylanase; and the modified xylanase has higher heat stability, after being processed for 10 minutes at the temperature of 75 DEG C, the residual activity of the modified xylanase reaches 80 percent, while that of the original xylanase is only 15 percent. The activity of the modified xylanase is 1.5 to 2 times of that of the original xylanase at the environment with high temperature and strong alkali and can decompose xylan for a long time at high temperature. The invention also provides the Pichia pastoris yeast recombination genetic engineering strain containing the modified gene. The modified xylanase can be widely applied to industries of paper making, feedstuff and food.

Methods and compositions for treating an iron disorder in a patient are presented, including methods for delivering a therapeutically effective amount of iron to the brain. Iron disorders that may be treated by these methods include iron deficiency disorders and iron overload disorders. A recombinant yeast expressing human H-ferritin and a composition for treating an iron disorder comprising this recombinant yeast are also presented.

Substance productivity is improved by introducing a metabolic pathway for synthesis of acetyl-CoA or acetic acid from glucose-6-phosphate into yeast. Acetic acid productivity, acetyl-CoA productivity, and productivity of a substance made from acetyl-CoA-derived are improved by attenuating genes involved in the glycolytic system of yeast and introducing a phosphoketolase gene into the yeast.

The invention discloses a preparation method for a recombinant coxsackie virus A16 like particle, which comprises the following steps: (1) cloning a P1 gene and a 3CD gene of a coxsackie virus A16 to a target plasmid to obtain a recombinant expression vector; (2) transforming a target yeast cell by using the recombinant expression vector obtained in the step (1) to obtain a recombinant yeast cellfor expressing the P1 gene and the 3CD gene; and (3) cracking the recombinant yeast cell obtained in the step (2), and separating to obtain the recombinant coxsackie virus A16 like particle. The recombinant coxsackie virus A16 like particle can be prepared in a yeast expression system by the method provided by the invention. Compared with a wild-type P1 gene and a wild-type 3CD gene, the yield ofthe coxsackie virus A16 like particle in the yeast expression system is greatly increased through the optimization of codons of the P1 gene and the 3CD gene, and the recombinant coxsackie virus A16 like particle can be further used for producing candidate preventive vaccines and pharmaceutical compositions for infant hand-foot-and-mouth diseases.

Recombinant yeast strains that saccharify, ferment and grow on insoluble and crystalline forms of cellulose are disclosed herein. The yeast strains express tethered cellulases including cellobiohydrolase, endoglucanase and β-glucosidase. The recombinant organisms are particularly suited for consolidated bioprocessing.