9 results about "Xylose fermentation" patented technology

The invention provides a method for synthesizing D-psicose through fermentation of escherichia coli by using D-glucose and D-xylose. The method comprises the following steps: by taking escherichia coli as a host cell, over-expressing a galactose permease gene galP, a glucokinase gene glk, a 6-phosphate glucose isomerase gene pgi, a D-psicose-6-phosphate epimerase gene alsE with an SUMO tag and a D-psicose-6-phosphate phosphatase gene a6PP, and constructing a path for synthesizing D-psicose by taking D-glucose and D-xylose as substrates; the synthetic route of D-psicose is optimized by knocking out a D-glucose phosphorylation transport pathway gene ptsG, knocking out D-fructose-6-phosphokinase genes pfkA and pfkB, silencing a glucose-6-phosphate dehydrogenase gene zwf, overexpressing glutamate transhydrogenase genes gdh1 and gdh2, knocking out a UDP-glucose-4-epimerase gene galE and knocking out a transport protein key gene fryA in D-psicose; and finally, the optimal proportion of mixed sugar fermentation is explored, so that efficient synthesis of D-psicose from escherichia coli through mixed sugar fermentation of D-glucose and D-xylose is realized.

The invention relates to the technical field of galactose separation, in particular to a method for separating galactose from xylose mother liquor, which comprises the following steps: diluting the xylose mother liquor, and inoculating active dry yeast powder into the diluted xylose mother liquor for fermentation to obtain xylose fermentation liquor; filtering and concentrating the xylose fermentation liquor to obtain a raw material; and controlling the sample loading flow and the eluent flow in the two-dimensional liquid chromatography separation process of the raw materials, and separating the stock solution to obtain a galactose component solution. The invention aims to improve the purity of galactose in the separation process.

An engineered yeast strain capable of efficient fermentation of xylose to ethanol, and methods of making and using the strain, are provided

The invention belongs to the technical field of fermentation, and particularly relates to pediococcus acidilactici capable of efficiently utilizing xylose to produce lactic acid and application of the pediococcus acidilactici. The xylose metabolism capability of the pediococcus acidilactici JDYJY4.1805-2401 provided by the invention is greatly improved compared with that of an initial strain, and xylose in a culture medium can be fully utilized to grow, metabolize and produce lactic acid; the high-light pure lactic acid can be produced by efficiently utilizing the lignocellulose hydrolysate through fermentation, and a technical guarantee is provided for large-scale production of lactic acid from straw sugar. 46.2 g / L of lactic acid can be obtained by fermenting pediococcus acidilactici JDYJY 4.1805-2401 with 50g / L of xylose, and the conversion rate of the lactic acid to the xylose is greater than 90%; the corn straw and miscanthus sinensis straw enzymolysis mixed liquor (containing 109.1 g / L of glucose and 50.9 g / L of xylose) is used for fermentation, the fermentation period is 36-42 h, the acid yield can reach 142 g / L, the residual sugar in the fermentation liquor is 0.45%-1%, and the lactic acid light purity is 98.0%-99.92%.

The present invention discloses a genetically engineered bacterium, characterized in that the starting strain of the genetically engineered bacterium is Corynebacterium glutamicum, and the genetically engineered bacterium comprises phaC gene, phaA gene and phaB gene, and the nucleotide sequences thereof are shown in SEQ ID NO:38, SEQ ID NO:37 and SEQ ID NO:36, respectively. The modified strain obtained by the present invention can produce PHB by using glucose and xylose in wheat straw hydrolyzate without adding antibiotics, thereby realizing that Corynebacterium glutamicum produces PHB by fermenting glucose and xylose in lignocellulose.

The invention belongs to the technical field of microorganisms and fermentation engineering, and particularly relates to a method for promoting the co-utilization efficiency of glucose and xylose of saccharomyces cerevisiae and application of the method. Specifically, it is accidentally found through research that the co-fermentation efficiency of the saccharomyces cerevisiae glucose and xylose can be effectively improved by activating a TORC1 signal channel, and the method is achieved by adding a TORC1 signal channel activator into a fermentation system. And the typical activating agent comprises leucine and glutamine. According to the technical scheme, the xylose fermentation efficiency can be remarkably improved, the overall fermentation time is shortened, a foundation is laid for effective utilization of biomass resources such as lignocellulose, and therefore the method has good practical application value.

The invention belongs to the technical field of genetic engineering, and particularly relates to recombinant foal foal xylose as well as a construction method and application thereof. The recombinant foal foal capable of improving the bacterial cellulose yield and the xylose utilization amount is constructed by taking the foal foal foal as an original strain and overexpressing a xylose isomerase gene xylA, a xylulokinase gene xylB, a phosphopentose pathway key gene TKL and a structural gene BcsD. Under the fermentation conditions of pure xylose and xylose and glucose, the bacterial cellulose yields of the bacterial strain can reach 9.51 g / L and 8.1 g / L respectively and are increased by 553.23% and 44.75% respectively compared with original bacteria, and the highest xylose consumption of the bacterial strain under the fermentation conditions of pure xylose can reach 11.18 g / L. According to the method, the utilization rate of xylose is remarkably increased, the production efficiency of bacterial cellulose is improved, and a feasible solution is provided for replacing efficient conversion of traditional biomass resources with glucose as a carbon source.

An engineered yeast strain capable of efficient fermentation of xylose to ethanol, and methods of making and using the strain, are provided.

The present invention relates to novel nucleic acid sequences encoding bacterial xylose isomerases which, upon transformation of a eukaryotic microbial host cell, such as yeast, confer upon the host cell the ability to isomerize xylose into xylulose. The nucleic acid sequences encode xylose isomerases originating from bacteria such as Eubacterium sp., Clostridium cellulosii, and others. The invention further relates to fermentation processes in which the transformed host cells ferment a medium containing xylose to produce ethanol or other fermentation products.