31 results about "Nitrile hydratase activity" patented technology

The present invention is directed to methods for inducing desired activity in enzymes or microorganisms capable of producing the enzymes. The invention is further directed to methods of stabilizing activity in microorganisms. In specific embodiments, the invention provides methods for inducing and stabilizing nitrile hydratase activity, amidase activity, and asparaginase I activity. The invention further provides compositions comprising enzymes or microorganisms having induced and / or stabilized activity.

The present invention is directed to methods for inducing desired activity in enzymes or microorganisms capable of producing the enzymes. The invention is further directed to methods of stabilizing activity in microorganisms. In specific embodiments, the invention provides methods for inducing and stabilizing nitrile hydratase activity, amidase activity, and asparaginase I activity. The invention further provides compositions comprising enzymes or microorganisms having induced and / or stabilized activity.

The present invention provides: a protein having an improved nitrile hydratase activity, whereby heat resistance has been improved when compared with a wild-type nitrile hydratase activity, wherein the amino acid sequence of a nitrile hydratase is modified; a gene DNA encoding the above protein; a recombinant vector having the above gene DNA; a transformant or transductant having the above recombinant vector; a nitrile hydratase collected from a culture of the above transformant or transductant, and a production method thereof; and a method for producing an amide compound.

The object of this invention is to provide a method which not only maintains the nitrile hydratase activity of a nitrile hydratase-containing cell or a treated material of the cell under conditions where the cell does not grow, but also improves the nitrile hydratase activity of a nitrile hydratase-containing cell or a treated material of the cell whose activity was once reduced. This invention relates to a method of maintaining or improving a nitrile hydratase activity which comprises bringing a nitrile hydratase-containing cell or a treated material of the cell into contact with an oxidizing agent under conditions where the cell does not grow, as well as a method of producing an amide compound from a nitrile compound, which comprises using the cell brought into contact with an oxidizing agent or a treated material of the cell.

This invention provides an aqueous solution of acrylamide that is useful as a starting material for high-quality polyacrylamide. Starting materials for polyacrylamide are an aqueous solution of acrylamide containing a saccharide and an aqueous solution of acrylamide containing a saccharide produced with the use of a biocatalyst having nitrile hydratase activity.

The invention discloses modified nitrile hydratase and application thereof in the technical field of enzyme engineering and industrial microorganisms. A method for obtaining the modified nitrile hydratase disclosed by the invention is that Pro of 133 site of a alpha subunit of an amino acid sequence shown as by a sequence table SEQ ID NO:2 and Asp of 215 site of a beta subunit of an amino acid sequence shown as by a sequence table SEQ ID NO:1 are respectively replaced with Cys, so that a disulfide bond is formed between the two subunits. Stress resistance and heat resistance of the modified nitrile hydratase disclosed by the invention and product tolerance are all obviously improved, and activity of the nitrile hydratase is not lowered. The modified nitrile hydratase can be catalyzed to obtain a high-concentration acrylamide product, and can be recycled repeatedly.

[Problems] The present invention provides a method for efficiently producing a corresponding amide compound from a nitrile compound by a reaction using a nitrile hydratase and a method for producing an amide-based polymer excellent in quality from the amide compound. In addition, the present invention provides a method for more efficiently producing an acrylamide with higher quality by a microbial catalyst containing a nitrile hydratase and the like and a method for producing an acrylamide-based polymer, which is excellent in hue, has a good balance between the water solubility and the high molecular weight and is also excellent in quality, by using the acrylamide.[Means for Solving the Problems] The method for producing an amide compound of the present invention is characterized in that in a method for producing an amide compound from a nitrile compound in an aqueous medium in the presence of a catalyst having a nitrile hydratase activity, the concentration of benzene in the aqueous medium is 4.0 ppm or less. In addition, the method for producing an amide-based polymer of the present invention is characterized by homopolymerizing the amide compound or by copolymerizing the amide compound and at least unsaturated monomer copolymerizable with the amide compound. Further, the method for producing acrylamide of the present invention is characterized by hydrating acrylonitrile having a concentration of acrolein of 1 ppm or less by a microbial cell containing a nitrile hydratase or a processed product of the microbial cell in an aqueous medium. Furthermore, the method for producing an acrylamide-based polymer of the present invention is characterized by homopolymerizing the acrylamide or by copolymerizing the acrylamide and at least one unsaturated monomer copolymerizable with the acrylamide.

The amino acid sequence of a mutant which is obtained by introducing a novel mutation into a Pseudonocardia thermophila JCM3095-derived nitrile hydratase consisting of two types of heterogeneous subunits, and the base sequence of the gene are provided. The nitrile hydratase is modified by specifying the region to be modified in the stereostructure / amino acid sequence of the nitrile hydratase, and applying alteration such as substitution, insertion, deletion or the like, to the amino acids in the amino acid sequence which are corresponding to the amino acid residues forming the region. Also provided is a method for modifying an enzyme having a nitrile hydratase activity.

The present invention provides: a protein having an improved nitrile hydratase activity, whereby heat resistance has been improved when compared with a wild-type nitrile hydratase activity, wherein the amino acid sequence of a nitrile hydratase is modified; a gene DNA encoding the above protein; a recombinant vector having the above gene DNA; a transformant or transductant having the above recombinant vector; a nitrile hydratase collected from a culture of the above transformant or transductant, and a production method thereof; and a method for producing an amide compound.

This invention relates to a process for producing an amide compound from a nitrile compound using a microbial catalyst, wherein a microbial cell having nitrile hydratase activity of 50 U or higher per mg of dry cell at a reaction temperature of 10° C. is brought into contact with a nitrile compound in an aqueous medium without being immobilized. This method utilizes a microbial cell that exhibits high nitrile hydratase activity in the reaction without being entrap-immobilized. Thus, an amide compound can be effectively produced from a nitrile compound without problems of decreased reaction speed or lowered amount produced per unit cell amount, which are caused by entrap-immobilization. Accordingly, an amide compound can be produced within a very short period of time in the case of a batch reaction and with a very small-scale facility in the case of a continuous reaction.

This invention relates to a process for the preparation of a 3-hydroxycarboxylic acid from a 3-hydroxynitrile. More specifically, 3-hydroxyvaleronitrile is converted to 3-hydroxyvaleric acid in high yield at up to 100% conversion, using as an enzyme catalyst 1) nitrile hydratase activity and amidase activity or 2) nitrilase activity of a microbial cell. 3-Hydroxyvaleric acid is used as a substitute for ε-caprolactone in the preparation of highly branched copolyester.

The present invention provides a cheap and simple microbe for replacing that of the prior art, and a preserving method thereof. The invention relates to the preserving method of microbe and is characterized in that: the microbes with nitrile hydratase activity are dispersed in a dispersion medium with a concentration that the mass of dry microbe is 4-20wt%.

The problem is to provide a method for inexpensively and simply preserving an enzyme of a microbial biomass obtained by culturing and improve the enzyme activity during preservation. Provided is a method for preserving nitrile hydratase, characterized in that microbes having nitrile hydratase activity are cultured while being protected from light, and the resulting biomass is crushed using a high-pressure homogenizer and preserved while being protected from light.

A method for storing microbial cells having nitrile hydratase activity in a hermetically sealable container, and a method for transporting microbial cells having nitrile hydratase using the container. The methods are characterized in that the vapor phase portion within the container is set to 2-20% (inclusive) of the total interior volume of the container, said vapor phase portion being filled with a suspension that contains the microbial cells.

The invention discloses a Escherichia coli recombinant strain heterologously expressing heat-resistant nitrile hydratase and application of the Escherichia coli recombinant strain, and belongs to thefield of bioengineering. According to the invention, the Escherichia coli recombinant strain having a high nitrile hydratase activity is obtained by constructing of recombinant Escherichia coli, and the recombinant nitrile hydratase obtained by fermentation has better thermal stability. In addition, the Escherichia coli recombinant strain can be used as a catalyst, and nicotinonitrile or acrylonitrile can be used as a substrate to carry out a whole-cell catalytic reaction to prepare nicotinamide or acrylamide. Compared with a chemical production method, the production process is safe and clean, and has no environmental pollution. Compared with an enzymatic method, the production process employs a cheap substrate, simplifies separation and purification steps of products, has high catalyticefficiency, and has a yield of the final product nicotinamide or acrylamide of 95% or above.

The invention provides a Rhodococcus boritolerans FW815 enriched in soil and sewage and sieving high nitrile hydratase active mircoorganism strain, and a process that applies the strain to biological catalysis methods for the preparation of 2,2-dimethyl cyclopropane formamide. The 2,2-dimethyl cyclopropane formamide is prepared by converting 2,2-dimethyl cyclopropane formonitrile via the nitrile hydratase generated by the strain, wherein, the reaction medium is water, constituents of the reaction system are simple, the biological catalysis efficiency is high, the conversion time is short, theconversion rate for substrates is high, the yield of the 2,2-dimethyl cyclopropane formamide product is high and the extraction and purification processes are simple.