40results about How to "Improve conversion yield" patented technology

A process for the production of synthesis gas for obtaining compounds such as ammonia or methanol, in which hydrocarbons and steam are reacted first in a primary reforming section (11) and then-together with oxygen-in a secondary reforming section (12), thus obtaining CO, CO2, H2 and possibly N2 which are then fed to a carbon monoxide conversion section (13, 14), is distinguished by the fact of reacting hydrocarbons, steam and oxygen in an autothermal reforming section (20) provided in parallel with respect to other reforming sections (11, 12), and feeding the so produced CO, CO2, H2 and possibly N2 to the carbon monoxide conversion section (13, 14).

The invention discloses a recombinant Pichia pastoris producing small molecule hyaluronic acid and a construction method thereof, belonging to the technical field of bioengineering. The present invention adopts hyaluronic acid synthase hasA derived from Streptococcus zooepidemicus and UDP-glucose dehydrogenase tuaD derived from Bacillus subtilis, expressed in the recombinant Pichia pastoris GS115 host to realize the production of hyaluronic acid; Hyaluronidase is integrated into the Pichia pastoris genome, secreted and expressed under constitutive promoters of different strengths, and small molecule hyaluronic acid products with different molecular weights are prepared by controlling the secretion and expression of hyaluronidase. There are differences in the molecular weight ranges of the products, which have important guiding significance for the direct production of specific ranges of small molecule hyaluronic acid by microorganisms. The invention lays a certain foundation for efficient preparation of small molecule hyaluronic acid and is suitable for industrial production and application.

The invention discloses L-aspartase recombinant escherichia coli free of malic acid byproducts. The genes fumA, fumB and fumC of encoded fumarase in ammonium-tolerant escherichia coli BEW308 are inactivated, then encoded L-aspartase genes are inserted into the positions of encoded fumarase fumAC genes, and the L-aspartase recombinant escherichia coli free of the malic acid byproducts is obtained. The preservation number of a strain of the ammonium-tolerant escherichia coli BEW308 is CCTCC NO:M2013157. The invention further discloses a construction method and application of the strain. The constitutive high-activity expression of L-aspartase can be achieved, and cells or crude enzyme obtained after fermental cultivation has low fumarase activity.

The invention discloses a Mycobacterium parafortuitum strain producing 4-HP, which is classified as Mycobacterium parafortuitum BK12 and has been preserved in the China Center for Type Culture Collection with a preservation number of CCTCC NO.M2017084; The new strain obtained after variable screening can efficiently transform sterols to produce 4-HP, produce a fermentation broth with 4-HP as the main product, simplify subsequent separation and extraction steps, and have high production stability. The present invention also discloses a preparation method for obtaining high-yield 4-HP by using said Mycobacterium parafortuitously; the preparation method of high-yield 4-HP of the present invention can make up to 3 parts of sterol in the fermentation medium When the species is converted into 4-HP, and the sterol input is 3 parts, the conversion rate reaches 90%, thereby increasing the single production yield on the basis of ensuring the single conversion rate.

The invention discloses a 5-azacytosine synthesis method .The method comprises the following steps that 1, dicyandiamide, formic acid and a catalyst p-toluenesulfonic acid are added into an airtight reaction device and heated to react to obtain emulsion matter; 2, the product obtained in the step 1 is refined through hydrochloric acid to obtain the 5-azacytosine .A high-pressure reaction kettle is utilized, under the p-toluenesulfonic acid catalysis condition, the dehydration reaction temperature of guanylurea formate is effectively lowered, anhydrous formic acid in a system is directly utilized as a dehydrating agent, the steps of a synthesis process are simplified, side reactions are reduced, the product quality is ensured, the productivity is improved, and reaction yield is higher than 80% based on dicyandiamide .

The invention discloses a method for preparing hydroxy spironolactone by microbial transformation, which comprises: forming a transformation system in the original fermentation liquid or a phosphate buffer with a pH of 6.8 by using wet bacteria obtained by fermentation culture of cunninghamella elegans ATCC 9245 as catalysts, using spironolactone as a substrate, and using anhydrous alcohol as a cosolvent, performing a transformation reaction under a constant temperature vibration condition of 25-32 DEG C and 150-300 r / min, after the reaction, separating and purifying the reaction liquid to obtain 12[beta]-hydroxy-spironolactone and 2[alpha]-hydroxy-spironolactone. The microbial transformation method of the invention synthesizes two hydroxy spironolactones which have a certain degree of improvement in diuretic effect when compared with original spironolactone; the microbial strain used as the catalyst is safe and nontoxic, simple in culture condition, strong in mixed bacterium contamination resistance, and suitable for large-scale culture; the transformation operation is simple; no other reagent is necessary in the reaction process; the method is high in transformation yield, low in cost, and easy to realize industrial application.