Provided is a novel improved nitrile hydratase with improved resistance to amide compounds under high temperatures. Specifically provided is a nitrile hydratase having at least one amino acid mutation selected from (a) to (d) below, in the amino acid sequence expressed in SEQ ID NO:50 (X.sub.1 to X.sub.27 represent independent arbitrarily-defined amino acid residuals). (a) X.sub.1 is valine or glycine (b) X.sub.9 is valine or threonine (c) X.sub.23 is an amino acid selected from a group consisting of isoleucine, leucine, methionine and threonine, (d) X.sub.24 is leucine.

The present invention provides methods for catalyzing the conversion of an olefin to any compound containing one or more cyclopropane functional groups using heme enzymes. In certain aspects, the present invention provides a method for producing a cyclopropanation product comprising providing an olefinic substrate, a diazo reagent, and a heme enzyme; and admixing the components in a reaction for a time sufficient to produce a cyclopropanation product. In other aspects, the present invention provides heme enzymes including variants and fragments thereof that are capable of carrying out in vivo and in vitro olefin cyclopropanation reactions. Expression vectors and host cells expressing the heme enzymes are also provided by the present invention.

The present invention provides methods for catalyzing the conversion of an olefin to any compound containing one or more cyclopropane functional groups using heme enzymes. In certain aspects, the present invention provides a method for producing a cyclopropanation product comprising providing an olefinic substrate, a diazo reagent, and a heme enzyme; and admixing the components in a reaction for a time sufficient to produce a cyclopropanation product. In other aspects, the present invention provides heme enzymes including variants and fragments thereof that are capable of carrying out in vivo and in vitro olefin cyclopropanation reactions. Expression vectors and host cells expressing the heme enzymes are also provided by the present invention.

The present invention relates to means and methods for producing an amide compound from a nitrile compound with less acrylic acid as by-product using a Nitrile hydratase (NHase) and Amidase producing microorganism as biocatalyst. Also provided is an aqueous amide compound obtained by the methods of the invention as well as a composition comprising acrylamide or polyacrylamide as well as a dried microorganism exhibiting a NHase/Amidase activity ratio of at least 400 when being brought into contact with a nitrile compound to convert said nitrile compound into an amide compound.

The present invention relates to means and methods for producing an amide compound from a nitrile compound with less acrylic acid as by-product using a Nitrile hydratase (NHase) and Amidase producing microorganism as biocatalyst. Also provided is an aqueous amide compound obtained by the methods of the invention as well as a composition comprising acrylamide or polyacrylamide as well as a dried microorganism exhibiting a NHase/Amidase activity ratio of at least 400 when being brought into contact with a nitrile compound to convert said nitrile compound into an amide compound.

Recombinant microorganisms comprising DNA molecules in a deregulated form which improve the production of cadaverine or N-acetylcadaverine, as well as recombinant DNA molecules and polypeptides used to produce the microorganisms are provided. Said microorganisms comprise an intracellular lysine decarboxylase activity and a deregulated cadaverine export activity, or comprise a decreased cadaverine export activity and an enhanced N-acetylcadaverine forming activity. Processes for the production of cadaverine N-acetylcadaverine using the recombinant microorganisms are also provided.

Recombinant microorganisms comprising DNA molecules in a deregulated form which improve the production of cadaverine or N-acetylcadaverine, as well as recombinant DNA molecules and polypeptides used to produce the microorganisms are provided. Said microorganisms comprise an intracellular lysine decarboxylase activity and a deregulated cadaverine export activity, or comprise a decreased cadaverine export activity and an enhanced N-acetylcadaverine forming activity. Processes for the production of cadaverine N-acetylcadaverine using the recombinant microorganisms are also provided.

Provided is an improved nitrile hydratase with improved catalytic activity. Also provided are DNA for coding the improved nitrile hydratase, a recombinant vector that contains the DNA, a transformant that contains the recombinant vector, nitrile hydratase acquired from a culture of the transformant, and a method for producing the nitrile hydratase. Also provided is a method for producing an amide compound that uses the culture or a processed product of the culture. The improved nitrile hydratase contains an amino acid sequence represented by SEQ ID NO: 50 (GX.sub.1X.sub.2X.sub.3X.sub.4DX.sub.5X.sub.6R) in a beta subunit, and is characterized in that X.sub.4 is an amino acid selected from a group comprising cysteine, aspartic acid, glutamic acid, histidine, isoleucine, lysine, methionine, asparagine, proline, glutamine, serine and threonine.

Provided is an improved nitrile hydratase with improved catalytic activity. Also provided are DNA for coding the improved nitrile hydratase, a recombinant vector that contains the DNA, a transformant that contains the recombinant vector, nitrile hydratase acquired from a culture of the transformant, and a method for producing the nitrile hydratase. Also provided is a method for producing an amide compound that uses the culture or a processed product of the culture. The improved nitrile hydratase contains an amino acid sequence represented by SEQ ID NO: 50 (GX.sub.1X.sub.2X.sub.3X.sub.4DX.sub.5X.sub.6R) in a beta subunit, and is characterized in that X.sub.4 is an amino acid selected from a group comprising cysteine, aspartic acid, glutamic acid, histidine, isoleucine, lysine, methionine, asparagine, proline, glutamine, serine and threonine.

A regulation method for preparing γ-polyglutamic acid by sludge substrate fermentation includes: 1) extraction of glutamic acid from sludge protein (high pressure hydrothermal treatment, gravity pressure filtration treatment), 2) secondary metabolic synthesis of γ-polyglutamic acid (activation of domesticated strains and secondary metabolic fermentation strains); and 3) preparation of pure γ-polyglutamic acid (acidification, centrifugation, filtration, precipitation based on polar repulsion, purification, impurity removal and drying). The present invention realizes a recycling of high-value carbon and nitrogen sources of sludge without secondary pollution, and has advantages of simplified operation, good feasibility, and low preparation cost. The synthesized γ-polyglutamic acid has high economic value and broad application prospect.