Nitriles pseudomonas chlororaphis

Rhodococcus sp. N-774 and Pseudomonas chlororaphis B23 resting cells have been used at industrial scale (as first- and second-generation biocatalysts) for the biological production of acrylamide from acrylonitrile since the 1980s [21]. Currently Rhodococcus rhodochrous J1 is being adopted as a third-generation biocatalyst (Mitsubishi Rayon Co.). The industrial production of nicotinamide from 3-cyanopyridine is also operated with this strain (Lonza AG). However, despite the enormous potentiality of nitrile-hydrolyzing biocatalysts for industrial applications, only a few commercial processes have been realized [22]. 

The degradation of nitriles by nitrilases (EC 3.5.5.1) has been the subject of intense study, especially as it relates to the preparation of the commodity chemical acrylamide. Nitrilases catalyze the hydrolysis of nitriles to the corresponding acid plus ammonia (Figure 1 reaction 5), whereas nitrile hydratases (EC 4.2.1.84) add water to form the amide. Strains such as Rhodococcus rhodo-chrous Jl, Brevibacterium sp., and Pseudomonas chlororaphis have been used to prepare acrylamide from acrylonitrile, which contain the hydratase and not nitrilase activity [12]. A comparison of these strains has been discussed elsewhere [98]. Other uses of nitrilases, however, have primarily been directed at resolution processes to stereoselectively hydrolyze one enantiomer over another or regiose-lectively hydrolyze dinitriles [99-101]. 

In recent years nitrile hydratases have been studied intensively. Enzymes from a wide range of microorganisms have been isolated and characterized and the corresponding genes have been cloned and overexpressed. Nitrile hydratases can be subdivided into two classes enzymes requiring Fe3+ (for example from Rhodococcus sp.(9 12, Pseudomonas chlororaphis B231131 and Comamonas testosteroni Nil[u ) and... 

Recently, an industrial application of the chemoselective hydration of a dinitrile, adiponitrile, has been introduced. A Pseudomonas chlororaphis B23 nitrile hydratase... 

Iron-dependent nitrile hydratases, for example from Rhodococcus R312 or Pseudomonas chlororaphis, exhibit a remarkable dependency on light. 

Synthesis of 5-Cyano Valeramide by Nitrile Hydratase from Pseudomonas chlororaphis B23 (E. C. 4.2.1.84)[106, 1071... 

Cyanovaleramide is used as intermediate for the synthesis of the DuPont herbicide azafenidine (Fig. 19-39). The whole cells from Pseudomonas chlororaphis are immobilized in calcium alginate beads. The biotransformation itself is catalyzed by a nitrile hydratase that converts a nitrile into the corresponding amide by addition of water. Nitrile hydratases belonging to the enzyme class of lyases (E.C. 4) are not be... 

E = nitrile hydratase, whole cells from Pseudomonas chlororaphis... 

H. Yamada, K. Ryuno, T. Nagasawa, K. Eno-moto, I. Watanabe, Optimum culture conditions for production by Pseudomonas chlororaphis B23 of nitrile hydratase, Agric. Biol. Chem. 1986, 50, 2859-2865. 

T. Nagasawa, H. Nanba, K. Ryuno, K. Takeuchi, H. Yamada, Nitrile hydratase of Pseudomonas chlororaphis B23. Purification and characterization, Eur. J. Biochem. 162 (1987) 691-698. 

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