55results about How to "Release feedback inhibition" patented technology

The invention utilizes a microbial fermentation technology to improve the forage nutritional value of the cottonseed meal, so as to improve the forage quality of the cottonseed meal, increase the addition proportion in the forage and realize the promotion of the protein nutritional value and the feeding value of the cottonseed meal, aiming at the disadvantages that cottonseed meal is rich in antinutritional factors of free gossypol, cellulose, oligosaccharide, phytic acid and the like, the protein quality is relatively poor and the content of essential amino acids of methionine and the like is low and unbalanced, so that the large-scale forage of cottonseed meal is restricted. The method for improving forage nutritional value of cottonseed meal through the microbial fermentation adopts the technology of 'composite enzymatic hydrolysis and multi-strain three-step solid-state fermentation', so as to prepare the fermented cottonseed meal product that is high in the free gossypol, cellulose degradation degree and the protein content; the cottonseed meal product is rich in nutritional ingredients of probiotics, vitamins, enzyme, amino acid, short peptide, high-grade protein and the like; the method for improving the forage nutritional value of cottonseed meal through the microbial fermentation has the advantages of prompting growth and development, improving the utilization ratio of the forage, enhancing immunization, improving intestinal micro ecology, preventing diseases and the like. The method for improving forage nutritional value of cottonseed meal through the microbial fermentation adopts the solid-state fermentation; the manufacturing technology is simple; the energy consumption is low; zero environmental pollution is generated; and the investment is small. Therefore, mass production is easy.

A two-stage fermenting process for preparing composite biologic flocculant includes such steps as physically and chemically pretreating cellulose, preparing culture liquid, adding inorganic salt, regulating pH value, sterilizing, adding cellulose gradating bacteria to convert cellulose to glucose and cellodiase, and adding flocculant generating bacteria.

The invention discloses methane dry fermentation compound bacteria, which comprise 25% to 45% of cellulose decomposing bacteria, 9% to 15% of protein decomposing bacteria, 8% to 15% of fat decomposing bacteria, 8% to 12% of hydrogen-producing acetogenic bacteria, 18% to 31% of sulfate reducing bacteria and 2.5% to 9.5% of methanogenic archaea according to bacterium number percentages. The compound bacteria of microorganisms with a complete methane fermentation function are capable of processing methane dry fermentation raw materials with TS content as 20% to 30% and stable in methane production effect and apt to control methane production.

The invention discloses tetrahydropyridine high-yield Corynebacterium glutamicum and application thereof and belongs to the field of bioengineering. Feedback inhibition is relieved through site-directed mutagenesis of Corynebacterium glutamicum aspartokinase gene lysC, and expression of mutational LysC is intensified through promoter replacement. Further, pentose phosphate pathway of host bacteriais further intensified through promoter replacement to meet needs on reducing power NADPH in efficient synthesis of tetrahydropyridine. Finally, tetrahydropyridine high-yield Corynebacterium glutamicum is obtained by transferring tetrahydropyridine synthetic gene cluster ectABC of P. stutzeri into recombinant bacteria. By recombinant Corynebacterium glutamicum, tetrahydropyridine can be efficiently synthesized by utilizing cheap raw materials like glucose and maize plasm; compared with recombinant Escherichia coli produced strains, tetrahydropyridine high-yield Corynebacterium glutamicum hasbetter bio-safety and is of great significance to industrial production and large-scale application of tetrahydropyridine.

A novel modified polypeptide having an isopropylmalate synthase activity, a polynucleotide encoding the same, a microorganism comprising the polypeptide, and a method of producing L-leucine by culturing the microorganism.

The invention relates to a genetic engineering bacterium for producing L-leucine, and application of the genetic engineering bacterium, and belongs to the field of metabolic engineering. The genetic engineering bacterium is obtained by an isopropylmalate synthetase encoding gene leuA[M] capable of relieving L-leucine feedback inhibition through overexpression in a host cell, an acetolactate synthase encoding gene ilvBN[M] capable of relieving L-leucine feedback inhibition, a 3-isopropylmalate dehydrogenase encoding gene leuB and a 3-isopropylmalate dehydratase encoding gene leuCD. Acetohydroxyacid synthase encoded by the leuA[M] relieves the feedback inhibition function of the L-leucine for the acetohydroxyacid synthase, in addition, the activity of the acetohydroxyacid synthase is not obviously lowered than wild leuA encoded isopropylmalate synthetase. The L-leucine genetic engineering bacterium does not have nutritional deficiencies, is quick in growth, and has a short fermentation period, a high yield and a high conversion rate. After fermentation is conducted for 40-44h, the concentration of the L-leucine in fermentation liquor achieves 60.5-69.6g/L.

The invention belongs to the technical field of culture of enterococcus faecalis and relates to a high-density fermentation medium for the enterococcus faecalis for feed and a fermentation method of the medium. The strategy that addition of sucrose is controlled according to pH feedback is adopted, and meanwhile, the concentration of lactic acid in fermentation broth is reduced, so that the feedback inhibition effect of lactic acid is relieved; the bacterium density of the enterococcus faecalis fermented by the aid of the high-density fermentation medium with the fermentation method of the medium is remarkably higher than that of enterococcus faecalis fermented with a common fermentation method, the number of living bacteria is not less than 10<10> cfu/mL and is 40 times or more that of enterococcus faecalis cultured by the aid of a common MRS medium, and high-density fermentation of the enterococcus faecalis is realized; thus, the separation cost of biomass can be reduced, the production cycle can be shortened, the production cost can be reduced, and the production efficiency can be improved.

The invention discloses a method for preparing biodiesel by directly using cellulose through mixed fermentation. The mixed fermentation is performed by using a plant fiber degrading strain and a grease producing strain, and ethanol is produced by directly using natural plant fiber such as straws. The method comprises the following steps of: designing a culture medium for the mixed fermentation by optimization methods such as a response surface method, and optimizing to obtain the fermentation conditions such as the optimum temperature of mixed fermentation, optimum mixing proportion of strains and optimum mixing time of the strains by utilizing the methods such as orthogonal test and response surface methodology; according to the optimized fermentation conditions, by using the plant fiber as a carbon source, degrading the cellulose into fermentable sugar by using a cellulase producing strain, and adding grease-producing microorganisms into the culture system for the mixed fermentation; and by using the sugar which is produced by the constant enzymolysis of the plant fiber as the carbon source, fermenting to produce grease by using the grease producing strain, and performing methyl esterification reaction of the microbial grease to obtain the biodiesel.

The invention discloses 2-keto-L-gulonic acid high tolerance type gluconobacteroxydans TL-1045 and also provides application of the bacterial strain in vitamin C fermentation production. The gluconobacteroxydans TL-1045 can tolerate the 2-keto-L-gulonic acid which has high concentration, the feedback inhibition of a product for a thallus in a second step during vitamin C fermentation production is eliminated, the output of 2-keto-L-gulonic acid can reach above 125g/L, the production efficiency of the vitamin C is improved remarkably and the production cost of the vitamin C is reduced effectively.

The invention belongs to the field of fermentation engineering, and discloses a composite extracting agent and a method for promoting production of monascus pigments by using of the composite extracting agent, wherein the method comprises the steps of: inoculating a monascus liquid seed in the logarithmic growth phase into a fermentation medium according to the inoculum size of 3%-8% by volume, adding peanut oil into the fermentation medium according to the amount of 70 mL/L fermentation liquid to 180 mL/L fermentation liquid; performing shake-flask culture at temperature of 27 DEG C to 33 DEGC; adding non-ionic surfactant Span80 into the fermentation system containing the Monascus liquid seed and the peanut oil according to the amount of 2.8 g/L fermentation liquid to 3.4 g/L fermentation liquid, performing shake-flask culture again, and the like. The final yields of red, orange and yellow pigments in the fermentation liquid with the composite extracting agent added are increased by76%, 85% and 89%, respectively, compared with the control group.

The present invention belongs to the field of microbial technology and discloses a microbial preparation for sludge anaerobic fermentation. The microbial preparation comprises a mixed bacteria liquid and a carrier, wherein the mixed bacteria liquid is prepared from Bacillus pumilus, enterobacter cloacae, denitrifying bacteria, paracoccus denitrificans, bacillus amyloliquefaciens, and lactococcus lactis. The microbial preparation can greatly increase the amount of methane generated by sludge, increase the utilization rate of the sludge, and recycle the sludge.

The invention belongs to the fields of microorganism breeding and fermentation engineering, and concretely relates to a Corynebacterium glutamicum, and a key tryptophan synthesis gene thereof. The above high-yielding strain is obtained through editing the genome of Corynebacterium glutamicum CGMCC No.12302 through a gene engineering means, and integrating the trpDCB mutation site in a tryptophan operon to the genome of the CGMCC No.12302. The Corynebacterium glutamicum provides a new mutation site for tryptophan synthesis related gene, and provides a new research direction for biosynthesis of the tryptophan; and a shaking bottle fermentation result shows that the tryptophan output of the obtained strain is about 3.4 times original output, so the tryptophan production performance of the strain is greatly improved.

The invention discloses a method for preparing a feed protein from alcohol waste liquid and crop straws, aiming at phenomena that the utilization rate of crops straw feed is not high and alcohol waste liquid pollution is caused, so as to meet straw comprehensive utilization requirements, requirements of animal husbandry feed proteins and objective requirements of alcohol waste liquid harmless treatment and utilization. The method disclosed by the invention mainly comprises the following three steps: ammonifying, carrying out compound enzymatic hydrolysis and carrying out multi-strain three-step solid-state fermentation. The method disclosed by the invention has the advantages of promoting growth and development, improving the feed utilization rate, improving the intestinal micro-ecology, preventing diseases and the like; recycling high-value utilization of the crops straws and harmless treatment and resource utilization of the alcohol waste liquid are realized; healthy, green and scientific development of a feed processing industry is facilitated, and the method has a wide application prospect.

The invention relates to a method for making composite microbio beta-glucanase and beta-glucosidase. The invention includes mixed fermentation of trichoviridin and aspergillus niger to prepare composite microbio beta-glucanase and beta-glucosidase, preparation of solid enzyme preparation and liquid enzyme preparation, and inclined-plane bacterial, shake flask shake culture, liquid seed tank enrichment culture of the trichoviridin and aspergillus niger, mixed input of the trichoviridin and aspergillus niger after enrichment culture into solid fermentation tank to perform fermentation, after fermentation, by digestion, filtration and ultrafilter membrane concentration, obtaining liquid enzyme preparation after adding protecting agent; obtaining solid enzyme preparation by adding British gum in concentrated enzymatic solution with dehumidification and granulation. The inventiom is of scientific and fair industrial design, the trichoviridin and aspergillus niger obtained by mixed culture and screening of strains of fungus can perform paragenetic mixed culture and mutually have no antagonistic reaction, the cost is low, the energy consumption is small, and the invention is of no devil liquor and waste slag discharge, which has a wide applicability of an invention and fills up our zymin breed margin, and has large market foreground.

The invention discloses a method for preparing D-xylosone by microbial transformation of glucose, comprising the following steps: firstly, respectively preparing an osmophilic yeast seed liquid and a gluconobacter oxydans seed liquid by using glucose as a raw material, then inoculating the osmophilic yeast seed liquid to conduct arabitol fermentation, and then in middle and later stage inoculating the gluconobacter oxydans seed liquid to conduct mixed culture fermentation, simultaneously controlling the glucose content in the broth to be 5-10g/L, and converting arabitol into D-xylosone. According to the method, the feedback inhibition of arabitol is removed, and the efficiency of preparing D-xylosone from glucose is raised. The invention further discloses a method for preparing xylitol by microbial transformation of glucose, comprising the following steps: firstly converting glucose into D-xylosone by the above method, then converting D-xylosone into D-xylose by isomerization of enzyme, extracting and refining, and conducting catalytic hydrogenation to obtain xylitol. According to the method, the production efficiency of xylitol is raised, and the cost of preparing xylitol by biological method is reduced.

The invention relates to a simultaneous saccharification and fermentation hydrogen-producing reactor accompanied with enzyme recycling. The reactor comprises an enzymolysis unit, a hydrogen-producing unit, an enzyme desorption unit and an enzyme adsorption unit, wherein the enzymolysis unit is located in the hydrogen-producing unit, and is communicated with the hydrogen-producing unit; the lower end of the enzymolysis unit is connected with a feed inlet in the upper end of the enzyme desorption unit; the bottom part of the hydrogen-producing unit is communicated with the top part of the enzyme adsorption unit through a first support pipeline; a discharge hole in the bottom part of the enzyme desorption unit is communicated with the top part of the enzyme adsorption unit through a second support pipeline. The invention also discloses an experimental method of the simultaneous saccharification and fermentation hydrogen-producing reactor accompanied with enzyme recycling. According to the simultaneous saccharification and fermentation hydrogen-producing reactor accompanied with enzyme recycling and the experimental method of the simultaneous saccharification and fermentation hydrogen-producing reactor accompanied with enzyme recycling provided by the invention, cellulase is recycled after a hydrogen-producing process is finished, and the cellulase subjected to enzymatic hydrolysis can be recycled, so that the residual activity of the cellulase is effectively utilized, the sugar yield of unit enzyme is improved, the dosage of the cellulase is further reduced, the process cost can be greatly reduced, and the industrialization production of straw biomass energy conversion is promoted.

The invention provides a composite microbial inoculant capable of efficiently producing methane by grease anaerobic degradation, which comprises the following strains: Anaerovibrio lipolytica DSM 3074, Syntrophomonas erecta DSM 16215, Syntrophomonas bryantii DSM 3014A, Syntrophomonas palmitatica DSM 18709, Desulfovibrio vulgaris DSM 644, Methanospirillum hungatei DSM 13809, Methanobacterium formicicum DSM 1535, Methanobrevibacter smithii DSM861, and Methanosaeta concilii DSM 2139T. The invention also provides a method for preparing the microbial inoculant and application of the microbial inoculant in producing methane by grease anaerobic degradation. The composite microbial inoculant can obviously shorten the start time, enhance the biogas fermentation efficiency and enhance the stability of the fermentation process. The composite microbial inoculant is suitable for different scales of fermentation systems, and has favorable market value.

The invention discloses a fermentation device and method for efficiently fermenting and producing bacteriocin. The fermentation device comprises a fermentation tank, a foam-liquid separation device and a foam recycling device, wherein the foam-liquid separation device is arranged in the fermentation tank; an inlet of the foam recycling device is connected with a foam outlet at the top of the fermentation tank; a vacuum hole of the foam recycling device is communicated with a vacuum generation device; a gas inlet is formed in the bottom of the fermentation tank. The method for fermenting and producing the bacteriocin comprises the following steps: filling a culture medium containing a foaming catalyst into the fermentation tank; pouring a de-foaming agent into a collection tank; inoculating bacteria into the fermentation tank; ventilating and adjusting the pH (Potential of Hydrogen) to be 6 to 7, and fermenting; starting the vacuum generation device and collecting foam at the upper part of the fermentation tank into the collection tank; decomposing the foam into liquid and collecting a fermentation product from liquid in the collection tank. By adopting the fermentation device and method disclosed by the invention, the feedback inhibition effect, caused by the product, on bacterium production and metabolism, can be effectively eliminated in time, so that a target product is efficiently expressed.

The invention relates to a heterologous expression method and an application of L-lysine decarboxylase from thermophilic bacteria. L-lysine decarboxylase from a thermophilic strain is screened and isfused and expressed with the thermophilic strain by utilizing a solubilizing tag, and when the L-lysine decarboxylase from the thermophilic strain is connected with the solubilizing tag, the L-lysinedecarboxylase from the thermophilic strain can be helped to exert a lysine decarboxylation function; and in addition, the use of the solubilizing tag may also explicitly indicate a cell expressing thefusion protein. The invention provides a new strategy for fermentation production of high-yield 1, 5-pentanediamine.