43results about How to "High molar conversion" patented technology

The invention provides a co-enzyme regeneration system and particularly relates to a genetically engineered bacterium of 5 alpha-reductase constructed by tandem of glucose-6-phosphate-dehydrogenase (G6PDH) and 5alpha<Y187F>-reductase recombinant and tandem of NAD kinase and 5alpha<Y187F>-reductase recombinant and application of the 5 alpha<Y187F>-reductase in high-efficiency catalysis of 5 alpha-AD production. The 5 alpha<Y187F>-reductase is electrotransformed into a mycobacterium respectively with mycobacterium-derived G6PDH and NAD kinase recombinant plasmids to subject to heterologous expression, detection on production efficiency of the 5 alpha<Y187F>reductase discovers that the co-expressed genetically engineered bacterium MNR M3 / 261-5 alpha<Y187F>-G6PDH2 on production of the 5 alpha-AD is increased from previous 67.8 percent to 89.5 percent, the co-expressed strain MNR M3 / 261-5 alpha<Y187F>-NAD2 on production of the 5 alpha-AD is increased from previous 67.8 percent to 92.6 percent, the limitation problem of low catalytic activity of the 5 alpha-reductase is effectively solved, and a new thought is provided to molecular improvement of the 5 alpha-reductase.

The invention provides a method for converting echinocandin B (ECB) by using microbial enzyme. The method comprises the steps that: (1) microbes are fermented, such that echinocandin B deacylase is obtained; (2) when fermentation is finished, phosphate is added into the fermentation broth; ultrasonic processing is carried out; and supernatant is obtained by centrifugation, and the supernatant is echinocandin B deacylase crude enzyme solution; (3) the crude enzyme solution is purified, such that echinocandin B deacylase enzyme solution is obtained; (4) echinocandin B is dissolved in ethanol, and is mixed with the deacylase enzyme solution; mixing and stirring are carried out, such that the material is converted into echinocandins B nucleus; when conversion is finished, filtering is carried out; and the filtrate is obtained; and (5) the filtrate is processed by using macroporous adsorption resin; echinocandins B nucleus is absorbed on resin; and echinocandins B nucleus is eluted by using an organic solvent. According to the invention, a molar conversion rate is high, a conversion time is short, an obtained product is easy to separate and to purify, and ECB deacylase can be repeatedly used.

The invention discloses a method for converting echinocandin B into an echinocandin B parent nucleus through microbial fermentation. The method is characterized by comprising the following step of: adding an echinocandin B substrate in a fermentation process to carry out conversion, wherein the echinocandin B substrate is added in batches or added in a flowing manner.

The invention relates to the technical fields of heterocyclic chemistry and microorganisms, in particular to a synthesis process for preparing eslicarbazepine with a microbial method. In view of the defects of high toxicity of all reagents, more reaction steps, difficulty in splitting, low raw material conversion rate and the like in the prior art, the invention provides a novel synthesis process for preparing eslicarbazepine acetate, wherein the eslicarbazepine is prepared through biotransformation reaction by taking oxcarbazepine as a substrate and an enzyme-containing thalli cell, obtained through fermenting saccharomyces cerevisiae CGMCC No.2230, as a biocatalyst.

The invention discloses a catalyst for preparing o-fluoroaniline from o-fluoronitrobenzene by hydrogenation. The catalyst contains an Al2O3 supporter and the following components in percentage by mass: 0.05%-1% of Pt supported on the Al2O3 supporter, 0.05%-3% of metal M1 and 0.01%-3% of metal M2, wherein the metal M1 is Pd, Sn or Zn; the metal M2 is K, Co, Ga, In, Mn, Ag or Ce. Besides, the invention also provides a preparation method of the catalyst. When the catalyst prepared by the preparation method is used for catalyzing o-fluoronitrobenzene hydrogenation, the mole conversion rate of o-fluoronitrobenzene is up to 100%, the mole percentage of a defluorination product is smaller than 0.1%, the amount of o-fluoronitrobenzene treated by the catalyst of unit mass is large, the use amount of the catalyst is small, and the catalyst can be reused after being regenerated.

The present invention relates to a recombinant Escherichia coli producing 5-methylpyrazine-2-carboxylic acid, in particular to a method for adjusting the ratio of xylene monooxygenase disubunits to increase 5-methylpyrazine-2-carboxylic acid . Said adjustment of xylene monooxygenase disubunit ratio refers to Escherichia coli ( E. coli BL21(DE3)) was used as a starting strain to construct 5-methylpyrazine-2-carboxylic acid by integrating the genes of xylene monooxygenase, benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase by using CRISPR / cas9 homologous recombination Synthetic pathway. The bacterial strain of the present invention can increase the yield of 5-methylpyrazine-2-carboxylic acid in recombinant Escherichia coli to 15.6 g / L, laying a foundation for the industrial production of 5-methylpyrazine-2-carboxylic acid.

The invention relates to a method for preparing r-4-chloro-3-hydroxybutyrate ethyl by coupling extraction with an enzyme-membrane reactor, comprising an enzyme-membrane reactor, an organic solvent barrel and a substrate barrel, the enzyme-membrane reactor The interior of the enzyme membrane reactor is distributed with a filter membrane, and the upper end of the enzyme membrane reactor is connected to a feed liquid outlet, one side of the enzyme membrane reactor is provided with an organic solvent outlet, and the lower end of the enzyme membrane reactor is connected to a feed liquid inlet, An organic solution inlet is installed on the other side of the enzyme membrane reactor. The method is simple in process, reduces the emulsification phenomenon in the reaction and extraction process, improves the yield, reduces the loss of the organic solvent, does not need to extract multiple times, is simple and convenient to operate, is conducive to large-scale industrial production, and can continuously collect products. The inhibition of the product to the enzyme or the toxicity to the cell is removed, and the molar conversion rate is improved, which is more conducive to industrial production.

The invention discloses a method for preparing R-mandelic acid by the aid of two-step microbial transformation processes. The method includes carrying out transformation reaction on ethyl benzoylformate, first thalli and buffer solution with a pH (potential of hydrogen) value of 6-8 under conditions of the temperature of 20-45 DEG C and the speed of 100-200 rpm to obtain R-ethyl mandelate; carrying out reaction on the R-ethyl mandelate, second thalli, organic solvents and buffer solution with a pH value of 7-9 under conditions of the temperature of 20-40 DEG C and the speed of 100-200 rpm to obtain the R-mandelic acid. The ethyl benzoylformate is used as a substrate during the transformation reaction, the first thalli are obtained by means of fermentation cultivation by the aid of saccharomyces cerevisiae and are used as catalysts during the transformation reaction, and the buffer solution with the pH value of 6-8 is used as a reaction medium during the transformation reaction. The R-ethyl mandelate is used as a substrate during the reaction, the second thalli are obtained by means of fermentation cultivation by the aid of bacillus cereus and are used as catalysts during the reaction, the organic solvents are used as complex solubilizers during the reaction, and the buffer solution with the pH value of 7-9 is used as a reaction medium during the reaction. The method has the advantages that the method is low in cost and is environmentally friendly, and the reaction conditions are mild; the R-mandelic acid is easy to industrially produce on a large scale; the method is easy and convenient to implement and high in molar transformation rate; the yield can be increased and can reach 99.8%, and the ee value can be increased and can reach 100%.

The invention belongs to the technical field of biocatalysis, and in particular relates to a method for improving the activity of a steroid drug-producing strain and efficiently fermenting and producing a steroid drug precursor. The present invention improves the activity of the steroid drug production strain by overexpressing the type II NADH dehydrogenase gene and efficiently ferments the steroid drug precursor to solve the problems of long fermentation period and low production efficiency in the production of the steroid drug precursor by microbial method. The reduction in the cost of production of steroid precursors provides new methods.