98 results about "Xylose isomerase" patented technology

The invention provides a method for producing ethanol by synchronizing saccharification, isomerization and fermentation of lignocellulose. In the method, cellulase, xylanase and xylose isomerase are used to enzymolyze the lignocellulose, and enzymolysis products are fermented to obtain the ethanol. The method adopts the synchronous saccharification, isomerization and fermentation of the lignocelluloses to produce the ethanol, and has the advantages of reducing the negative feedback inhibition of the enzymolysis products on the cellulase and the xylanase, increasing enzymolysis rate, shortening a fermentation period, reducing production cost and the like.

The present invention describes the expression cassette for transforming eukaryotic cell which comprises the peptide encoding non-natural sequence of nucleotides with xylose isomerase feature (SEQ ID NO: 1), optionally also comprising other genes of pentose phosphate route. Additionally, it is described the microorganism filed under the number DSM28739, which, in addition to the above-mentioned modifications, also present genetic modifications from adaptive evolution. The described microorganism shows efficient consumption of xylose and conversion of ethanol when compared to its correspondent without said genetic modifications and mutations from evolution. It is also described the process for producing biofuels e biochemicals, preferably ethanol, mainly from the lignocellulosic portion of the vegetal biomass. Biofuels, preferably ethanol, and biochemicals produced by the process of the invention are also described.

The present invention relates to the field of the methods for obtaining yeast strains producing ethanol, of the thereby produced strains, and of the industrial production of ethanol from said strains.

More particularly, the present invention describes in its most general aspect, a method for preparing yeasts from Saccharomyces cerevisiae strains by integration into the genome of the yeast of at least one gene coding for xylose isomerase and of at least one gene coding for xylitol dehydrogenase.

The strain of the invention is useful for producing ethanol from a medium comprising at least one pentose, preferably xylose or a xylose and arabinose mixture.

The invention relates to a xylose isomerase and the coded protein and the application thereof, pertaining to the technical field of enzyme genetic engineering. A coded xylose isomerase DNA sequence is obtained from mutation at partial positions of a xylose isomerase gene xylA(Genebank EU643621) in Sorangium cellulosum 157-2. The invention also relates to enzyme coded by the DNA sequence and the application of the coded enzyme in the fields of chemical industry, food and medicine. In addition, compared with the traditional xylose isomerase, the activity of xylose isomerase of the invention in saccharomyces cerevisiae is increased by 2.8 times.

Disclosed herein is a microorganism capable of producing ethane-1,2-diol from D-xylose, and a method for producing ethane-1,2-diol using the same. More specifically, the present invention relates to an engineered Escherichia coli (E. coli) prepared by knocking out a D-xylose isomerase gene and/or an aldehyde dehydrogenase gene within the genomic DNA of E. coli and transforming an expression vector including a D-xylose dehydrogenase gene into the E. coli, and an efficient method for producing ethane-1,2-diol from D-xylose using the engineered E. coli.

The invention discloses a method for producing D-1,2,4-butantriol through bio-converting cellulosic hydrolyzate. The method comprises the steps of constructing genes for cloning and expressing 2-keto acid decarboxylase, D-xylitol dehydrogenase, D-xylonic acid dehydrase and D-alcohol dehydrogenase, shifting the constructed genes into cells of host bacteria for knocking out xylose isomerase so as to obtain genetic engineering strains, culturing the genetic engineering strains, inoculating the genetic engineering strains to the cellulosic hydrolyzate, and carrying out fermentation so as to produce the D-1,2,4-butantriol. The method disclosed by the invention is easy and feasible, is high in yield and is applicable to industrialization.

It is an object of the disclosure of the present description to provide an eukaryotic cell having xylose utilization ability. The disclosure of the present description provides a novel eukaryotic cell having xylose utilization ability by transforming a yeast or other eukaryotic cell using DNA that codes a xylose isomerase from a termite protist.

The invention discloses mutated xylose isomerase, its coding gene and application. The amino acid sequence of the xylose isomerase is SEQ ID NO.1, SEQ ID NO.3, SEQ ID NO.5 or SEQ ID NO.7. The xylose isomerase has higher activity than wild one, and can be used for high fructose syrup production. The coding gene of the mutated xylose isomerase can be used for the construction of recombinant bacterium utilizing xylose.

The invention discloses a method for extraction of xylose isomerases by taking brown hot crack loving spore fungus as sources and the activity expression and application of the brown hot crack loving spore fungi xylose isomerases in Saccharomyces cerevisiae. The molecule weight of the brown hot crack loving spore fungi xylose isomerases is 43 kilodaltons; the most suitable reaction temperature of the xylose isomerases is 80 to 85 DEG C; and the most suitable reaction pH of the xylose isomerases is 7.0. The xylose isomerases can convert xyloses into xyluloses under normal biochemical reaction conditions; genes of the xylose isomerases can be recombined into the Saccharomyces cerevisiae in which the activity expression is realized, and the xyloses or other carbon sources such as lignocellulose hydrolysate and so on can be utilized for production of various fermentation products such as alcohols and so on. The method utilizes the genetic engineering means to expand substrates which are converted by the alcohols and has important theoretical significance and application value on full utilization of lignocellulose resources.

The invention relates to a recombinant escherichia coli, a preparation method and a method for synthesizing 3,4-dihydroxybutyric acid, and belongs to the field of biosynthesis. The recombinant escherichia coli is obtained through knocking out xylose isomerase gene xylA, 2-keto acid aldolase gene yjhH, 2-keto acid aldolase gene yagE and alcohol dehydrogenase gene in escherichia coli, overexpressing xylose dehydrogenase gene and/or 2-keto acid decarboxylase gene, and overexpressing aldehyde dehydrogenases gene. By taking xylose as a basic substrate, a compound substrate can be formed by adding glucose and/or glycerinum on the basis of the xylose, and the 3,4-dihydroxybutyric acid is biologically synthesized through the recombinant escherichia coli; by-products are extremely less, and the formation of the by-products can be interdicted through passage metabolism optimization. The recombinant escherichia coli, the preparation method and the method for synthesizing the 3,4-dihydroxybutyric acid have the advantages that the preparation method is simple, the production cycle is short, the cost is low, later continuous optimizing and transformation are realized, and the good industrial development and application prospect is realized.

The invention provides recombinant saccharomyces cerevisiae for producing ethanol by xylose fermentation and a construction method thereof. In the invention, candida boidinii is led to the saccharomyces cerevisiae to metabolize a DNA fragment of a coding gene of related enzymes of the xylose, so that the saccharomyces cerevisiae can secrete and express xylose isomerase the enzymatic reaction conditions of which are close to growth conditions of the saccharomyces cerevisiae, so the recombinant saccharomyces cerevisiae can effectively utilize the xylose to produce the ethanol, thus solving the technical problem that the saccharomyces cerevisiae can not utilize the xylose to produce the ethanol. The invention lays a foundation for industrial application of the saccharomyces cerevisiae for producing the ethanol by using xylose fermentation, thus having great economic benefit and social benefit.

The invention relates to a cell which comprises a nucleotide sequence encoding a xylose isomerase, wherein the amino acid sequence of the xylose isomerase has at least about 70% sequence identity to the amino acid sequence set out in SEQ ID NO: 3 and wherein the nucleotide sequence is heterologous to the host. A cell of the invention may be used in a process for producing a fermentation product, such as ethanol. Such a process may comprise fermenting a medium containing a source of xylose with a cell of the invention such that the cell ferments xylose to the fermentation product.

The invention relates to a novel xylose isomerase gene from fungi, and an application thereof. A nucleotide sequence of the xylose isomerase gene is shown as SEQ ID No.2. A novel yeast engineering bacterium is obtained by introducing recombinant plasmids containing the gene into saccharomyces cerevisiae. Experiments demonstrate that the saccharomyces cerevisiae that has no capability for conversing xylose to xylosone originally gains a conversion capability for conversing xylose to xylosone after the gene is expressed in the saccharomyces cerevisiae. The engineering bacterium can prepare ethanol and other fermentation products by fermenting a medium comprising the xylose.

The invention discloses a method for extracting xylitol and D-galactitol from xylose mother solution, which adopts a homologous exchange method to construct a bacillus subtilis 168 xylose isomerase gene (xylA) deficient strain Bsxyl, utilizes the engineering strain Bsxyl to purify xylose mother solution to obtain xylose and D-galactose and further carries out catalytic hydrogenation and crystallization separation to obtain xylitol and galactitol. The Bsxyl strain is already stored in the China General Microbiological Culture Collection Center on March 25, 2010, the strain accession number of the Bsxyl strain is CGMCC No.3692, and the strain can purify xylose mother solution to obtain xylose and D-galactose. The strain can purify fermentation culture solution containing xylose mother solution, so that the total purity of xylose and galactose can reach more than 88.8 percent, and after further catalytic hydrogenation and crystallization separation, obtaining xylitol and D-galactitol the purity of which is more than 98 percent.

The invention provides a screening method for using xylose isomerase genes for peanut genetic transformation. The screening method comprises the following steps of: constructing a recombinant vector with target genes; transforming the recombinant vector into peanut embryo lobule explants; transferring the transformed embryo lobule explants to an induction culture medium with sucrose and xylose for culturing until embryos are induced; transferring the embryos to a germination culture medium for culturing until seedlings are induced; performing PCR(polymerase chain reaction) detection on regrowth to obtain transgene positive plants; and transplanting the transgene positive plants to fields by a grafting method. According to the screening method, the culture medium with the 5 g/L of sucrose and the 10 g/L of xylose is used for culturing, so that the transgene plants can be screened, and hidden danger possibly caused by screening by using antibiotics is avoided, and the transformation efficiency is high, and the screening method is a safe and high-efficient screening method.

The invention discloses a discontinuous xylo-pfan isomerase and its genes. The discontinuous xylo-pfan isomerase selects form Thermus thermophilus and its amino acid sequence is indicated by SEQ ID NO.2. The said discontinuous xylo-pfan isomerase has improved specificity to the substrate D-wood sugar without changing original heat endurance. The discontinuous xylo-pfan isomerase can be used in miscible liquids including wood sugar and amylaceum to specially detect the wood sugar content and can be used in constructing recombination bacteria with wood sugar.

This disclosure relates to novel xylose isomerases and their uses, particularly in fermentation processes that employ xylose-containing media.

The invention discovers that a xylose isomerase gene of non-glutinous rice has the function of converting xylose into xylulose. According to the invention, a recombinant plasmid containing the gene is constructed and is introduced into saccharomyces cerevisiae to obtain new engineered saccharomyces cerevisiae. Experiments prove that the saccharomyces cerevisiae which does not have the function ofconverting xylose into xylulose obtains the conversion capacity after the xylose isomerase gene is expressed in a host cell.

The invention relates to a construction method for streptomycete expression plasmids and a production method for keratinase. The construction method for streptomycete expression plasmids includes the following steps: a promoter Xi of actinoplanes missouriensis xylose isomerase and a terminator of streptomycete avermitilis amylase are sleeved, and the promoter-shine-dalgarno (SD) sequence comes from 90 to 269bp of an actinoplanes missouriensis xylose isomerase gene; a cloned src family kinases (sfks) gene is inserted in a construction expression frame structure of a synthetic Xi promoter-SD-amyA2 terminator fragment, and then a conventional method is used for constructing the streptomycete expression plasmids. The production method for keratinase includes: leading the streptomycete expression plasmids into an expression host of streptomycete lividans TK24 through conjugal transfer, performing recombinant expression and generating the keratinase. Specific activity of a crude enzyme solution is 1700 U/mg after expression of the expression plasmids in the streptomycete lividans TK24 and is improved by 50 times compared with specific activity of starting strain streptomycete fradiae varieties S-221, and yield of the keratinase is much higher than starting strains after the expression.

The invention discloses a xylose isomerase producing method and belongs to the technical field of biology. The xylose isomerase producing method includes: firstly, cloning xylose isomerase genes of thermus, streptomyces and escherichia coli; secondly, constructing a pichia pastoris expression vector, a saccharomyces cerevisiae expression vector and a bacillus subtilis expression vector which include three xylose isomerase gene expression cassettes, and transforming the vectors to corresponding host bacteria respectively; thirdly, respectively screening recombinants of over-expression xylose isomerases as engineering bacteria; and finally, fermenting the pichia pastoris engineering bacteria, the saccharomyces cerevisiae engineering bacteria and the bacillus subtilis engineering bacteria to produce a recombinant mixed xylose isomerase. Different from a traditional single-gene-coded xylose isomerase, the recombinant mixed xylose isomerase is wide in suitable reaction temperature and pH (potential of hydrogen) range and suitable for various purposes, and yield of the xylose isomerase expressed by the engineering bacteria including the polygene expression cassettes is obviously higher than that of the xylose isomerase expressed by engineering bacteria including single genes, so that production cost is reduced.

The invention relates to a method for expressing xylose isomerase by applying pGAP regulation of Pichia pastoris, belonging to the biotechnology field. Firstly, pGAP promoters are amplificated in Pichia pastoris, a Pichia pastoris expression vector of which xylose isomerase is regulated by the pGAP is built, and then the Pichia pastoris expression vector is transformed into Pichia pastoris genome. High copy recons are selected as engineering bacterial strain according to resistance genes on the Pichia pastoris expression vector, and the engineering bacterial strain is inoculated into liquid culture medium containing carbon source to ferment engineering bacteria for secreting and expressing the xylose isomerase. The invention has the advantages of low production cost and short fermenting period. The using of the pGAP regulation of Pichia pastoris to express the xylose isomerase is favorable to purifying the product, and the problems of high production cost and hard product purification caused by using natural bacterial strains produced xylose isomerase to produce xylose isomerase can be solved. The invention is favourable for mass production of xylose isomerase.