Regioselective hydrolysis of aromatic dinitriles using a whole cell catalyst

Room-temperature ionic liquids as replacements for organic solvents in multiphase bioprocess operations

“…The hydration of 1,3-DCB by the nitrile hydratase Rhodococcus 312 is a reaction of scientific and industrial interest-a number of illustrations already exist in the literature (e.g., Crosby et al, 1994;Maddrell et al, 1996;Martinkova et al, 1995). The substrate, however, is very poorly water soluble and the desired product 3-cyanobenzamide can be further hydrated by the second enzyme in the nitrile metabolism pathway, amidase, to yield the corresponding acid.…”

“…As an example of a two-phase biotransformation reaction, we will consider the Rhodococcus R312 catalyzed transformation of 1,3-dicyanobenzene (1,3-DCB) to 3-cyanobenzamide and 3-cyanobenzoic acid. The versatility of the Rhodococci for the biotransformation of nitriles (Bunch, 1998) and the synthetic applications of this enzyme system (Crosby et al, 1994;Maddrell et al, 1996) are well known. As an example of a liquid-liquid extraction process, we will consider the extraction of the polyketide antibiotic erythromycin-A.…”

Biotransformations of aromatic diniitriles using Rhodococcus equi cells

“…Hitherto, owing to the high rate of hydrolysis of the intermediate cyano amide major products obtained from dicyanobenzenes have been cyano acids (1,3-and 1,4-dicyanobenzene; Cohen et al 1990, Crosby et al 1994) or a dicarboxylic acid (1,2-dicyanobenzene; Cohen et al 1990). 1,3-cyanobenzamide has been obtained in a low yield upon 49 hours at 4°C (Crosby et al 1994).…”

“…1,3-cyanobenzamide has been obtained in a low yield upon 49 hours at 4°C (Crosby et al 1994). On the other hand, the use of R. equi A4 enabled us to prepare cyano amides from all dicyanobenzenes and from 2,6-dicyanotoluene at early reaction stages, as well as cyano acids from 1,3-and 1,4-dieyanobenzene after prolonged periods.…”

“…In several studies the substrate specificity of the enzyme complexes NOVO SP 361 and SP 409 from Rhodococcus sp. has been reported (Cohen et al 1990(Cohen et al , 1992, Hrnicke-Schmidt and Schneider 1990, Klempier et aL 1991, Geresh et al 1993, Crosby et al 1994). Owing to a relatively high activity of amidase, these preparations have been preferred for the conversion to acids.…”