Construction of library of useful nitrile hydratase for various industrial needs

该生物催化剂在温和的反应条件下非常有效且特异性地工作。使用生物催化剂的生产工艺通常被评价为环境可接受的生产工艺。传统的化学工业往往在高压或强酸碱条件下使用有毒的重金属催化剂，造成严重的环境污染。有毒的有机溶剂，包括卤代有机溶剂如氯仿和二氯甲烷已被经常使用。生物催化剂在化学工业中的应用有望在21世纪实现。腈水合酶是一种非常有应用前景的生物催化剂。紫红红球菌J1腈水合酶用于丙烯酰胺和烟酰胺的工业生产。然而，J1并不总是完美的。进一步的工业用途需要进一步的特定腈水合酶。例如，需要更热稳定、更pH稳定和更耐溶剂的腈水合酶。腈水合酶在较高浓度的腈和酰胺中起作用，并在氰离子存在下催化，也是必要的。对映选择性腈水合酶也有很大的需求。因此，我们通过新的富集培养技术和新的筛选程序，开始了新的腈水合酶的调查。总之，我们已经成功地分离了新的腈水合酶产生菌，它们被鉴定为拟无枝酸菌和马杜拉放线菌。我们对这些菌株进行了纯化和鉴定。此外，我们还进一步分离了几株独特的腈水合酶产生菌。虽然目前它们的活性仍然很低，但它们独特的特性似乎非常有趣，并有希望用于工业应用。

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.