Construction of library of useful nitrile hydratase for various industrial needs

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The biocatalyst works very efficiently and specifically under mild reaction conditions. The production process using the biocatalyst is often evaluated to be environmentally acceptable production process. The conventional chemical industry has often brought about the severe environmental pollution, because toxic heavy metal catalysts are often used under high pressure or strong acidy or basic conditions. Toxic organic solvents including halogenated organic solvent such as chloroform and dichloromethane have been often used. Thus the introduction of biocatalyst into chemical industry is expected to be realized in the 21 centuries. Nitrile hydratase is very useful and promising biocatalyst for the chemical industry. Rhodococcus rhodochrous J1 nitrile hydratase is used for the industrial production of acrylamide and nicotinamide. However, J1 is not always perfect for any situation. Further specific nitrile hydratase is required for each futher industrial uses. For example, more heat stable, more pH stable and more solvent tolerant nitrile hydratase is required. Nitrile hydratase which works at higher concentration of nitriles and amides, and catalyzes in the presence of cyanide ions, are also necessary. Enantioselective nitrile hydratase has also great demand. Thus, we have started the new survey of novel nitrile hydratases through the new enrichment culture technique and new screening procedures. After all, we have succeeded to isolate the novel nitrile hydratase producing strains, which were identified to be Amycolatopsis and Actinomadura strains. We have purified and characterized these strains. In addition, we also isolated further several unique nitrile hydratase producing strains. Although their activity is still low at present, their unique characterization seems to be very interesting and promising for the industrial application.