A method is described for producing acrylamide from acrylonitrile by the action of a microorganism having nitrilase activity in an aqueous medium, which comprises conducting the reaction in the presence of an alkali metal sulfate at an ionic activity of from 0.004 to 0.01 mole per liter while controlling the pH of said aqueous medium within a range of from 7 to 9 with an alkali hydroxide.
The invention relates to modified materials based on polyacrylonitrile having amidic groups on their surface. The modification gives the material greater hydrophilic characteristics improving its comfort properties. In addition, it permits the polyacrylonitrile to be dyed also with acidic dyes thus making it possible for it to be used for the preparation of yarns mixed with natural fibres, such as wool for example. The process for their production involves treatment of the material with enzymes of the nitrile hydratasis class obtained from Brevibacterium imperiale.
A method for the cultivation of bacteria of the genus Pseudomonas capable of producing nitrile hydratase is disclosed. The method involves adding a water soluble copper compound in an amount of about 0.5 to 5.0 mg/l as calculated in terms of copper to a culture medium in the preparation of cells of the bacteria under shear force supplied by stirring blades, wherein the circumferential speed of the edges of the stirring blades exceeds about 2.5 m/sec. The water soluble copper compound is preferrably copper chloride, copper sulfate, copper nitrate, copper acetate, copper tartrate, copper (II) acetylacetonate or copper (II) ETDA.
Enzymes derived from the isolated and substantially purified microorganisms of the present invention, designated herein as strains 52 and 56wt, are capable of hydrating nitriles such as 2-hydroxy-4-(methylthio)-butanenitrile (HMB-nitrile) to their corresponding amides, and further, of hydrolyzing amides such as 2-hydroxy-4-(methylthio)-butaneamide (HMB-amide) to their corresponding carboxylic acids. Advantageously, the nitrile hydratase of these strains is not substantially inhibited by the .alpha.-hydroxybutyramide product being formed; rather, this enzyme maintains the ability to hydrate an .alpha.-hydroxybutyronitrile to its corresponding amide even at high amide concentrations, including at saturating amide conditions. As such, enzymes derived from strains 52 and 56wt are particularly suited for commercial use in preparing agrichemical intermediates such as HMB-amide. HMB-amide may, in turn, be hydrolyzed through traditional or enzymatic conversion methods to form HMB-acid or salts thereof, which are useful as methionine substitutes in feeds for domestic animals.
The present invention describes methods for the detoxification of a mixture of nitrile compounds, or a mixture of nitrile and amide compounds by conversion of the nitrile compound(s) to the corresponding amide or acid compounds using a pure culture of an induced microorganism strain capable of converting a nitrile moiety to an amide or acid moiety. If an amide is formed or is present in the mixture, the amide can be further converted, using the present methods for detoxification, to the corresponding acid. The acid can then, if desired, be further degraded to CO.sub.2, H.sub.2 O and biomass. The induced pure cultures are able to detoxify a mixture of nitriles or a mixture of nitriles and amides which are typically present, in high concentration(s), in nitrile production waste streams. The present invention further discloses methods for removing a nitrile compound from an amide preparation, such as an acetamide or acrylamide preparation containing an unwanted nitrile compound, using an induced pure culture of an induced microorganism strain capable of converting a nitrile moiety to an amide or acid moiety. The pure cultures are able to purify or reduce the toxicity of the amide preparation thus improving purity and amide product yield from the amide preparation. The present invention further discloses methods for the conversion of a mixture of amide compounds to the corresponding acid compounds using a pure culture of an induced microorganism strain capable of converting an amide moiety to an acid moiety. This invention also discloses kits, biofilters and methods for use of the kits and biofilters for detoxification containing the useful microorganism strains.
The present invention describes methods for the detoxification of a mixture of nitrile compounds, or a mixture of nitrile and amide compounds by conversion of the nitrile compound(s) to the corresponding amide or acid compounds using a pure culture of an induced microorganism strain capable of converting a nitrile moiety to an amide or acid moiety. If an amide is formed or is present in the mixture, the amide can be further converted, using the present methods for detoxification, to the corresponding acid. The acid can then, if desired, be further degraded to CO.sub.2, H.sub.2 O and biomass. The induced pure cultures are able to detoxify a mixture of nitrites or a mixture of nitriles and amides which are typically present, in high concentration(s), in nitrile production waste streams. The present invention further discloses methods for removing a nitrile compound from an amide preparation, such as an acetamide or acrylamide preparation containing an unwanted nitrile compound, using an induced pure culture of an induced microorganism strain capable of converting a nitrile moiety to an amide or acid moiety. The pure cultures are able to purify or reduce the toxicity of the amide preparation thus improving purity and amide product yield from the amide preparation. The present invention further discloses methods for the conversion of a mixture of amide compounds to the corresponding acid compounds using a pure culture of an induced microorganism strain capable of converting an amide moiety to an acid moiety. This invention also discloses kits, biofilters and methods for use of the kits and biofilters for detoxification containing the useful microorganism strains.
