Rhodococcus erythropolis

A very simple and elegant alternative to the use of ion-exchange columns or extraction to separate the mixture of D-amino add amide and the L-amino add has been elaborated. Addition of one equivalent of benzaldehyde (with respect to die D-amino add amide) to the enzymic hydrolysate results in the formation of a Schiff base with die D-amino add amide, which is insoluble in water and, therefore, can be easily separated. Add hydrolysis (H2SQ4, HX, HNO3, etc.) results in the formation of die D-amino add (without racemizadon). Alternatively the D-amino add amide can be hydrolysed by cell-preparations of Rhodococcus erythropolis. This biocatalyst lacks stereoselectivity. This option is very useful for amino adds which are highly soluble in die neutralised reaction mixture obtained after acid hydrolysis of the amide. 

Figure 8.3 Reduction of ketone with alcohol dehydrogenase from Rhodococcus erythropolis using formate as a hydrogen source [4a].

The last example is mediated by a monooxygenase that can be induced by benzene, toluene, and ethylbenzene, and also by xylenes and styrene. A plausibly analogous situation exists for strains of Pseudomonas sp. and Rhodococcus erythropolis that were obtained by enrichment with isopropylbenzene, and that could be shown to oxidize trichloroethene (Dabrock et al. 1992). In addition, one of the pseudomonads could oxidize 1,1-dichloroeth-ene, vinyl chloride, trichloroethane, and 1,2-dichloroethane. 

In addition to these mechanisms, the degradation of thiocarbamates may be carried out in Rhodococcus erythropolis NI86/21 by a herbicide-inducible nonheme haloperoxidase (de Schrijver et al. 1997). 

Hirrlinger B, A Stolz (1997) Formation of a chiral hydroxamic aid with an amidase from Rhodococcus erythropolis MP50 and subsequent chemical Lessen rerarrangement to a chiral amine. Appl Environ Microbiol 63 3390-3393. 

Van der Werf Ml, KM Overkamp, JAM de Bont (1998) Limonene-1,2-epoxide hydrolase imm Rhodococcus erythropolis DCL14 belongs to a novel class of epoxide hydrolases. J Bacteriol 180 5052-5057. 

Sallis PJ, SJ Armfield, AT Bull, DJ Hardman (1990) Isolation and characterization of a haloaUtane halidohy-drolase from Rhodococcus erythropolis Y2. J Gen Microbiol 136 115-120. 

Lenke H, H-J Knackmuss (1992) Initial hydrogenation during catabolism of picric acid by Rhodococcus erythropolis HL 24-2. Appl Environ Microbiol 58 2933-2937. 

Rieger P-G, V Sinnwell, A Preup, W Francke, H-J Knackmuss (1999) Hydride-Meisenheimer complex formation and protonation as key reactions of 2,4,6-trinitrophenol biodegradation by Rhodococcus erythropolis. J Bacterial 181 1189-1195. 

Matsubara T, T Ohshiro, Y Nishina, Y Izumi (2001) Purification, characterization, and overexpression of flavin reductase involved in dibenzothiophene desulfurization by Rhodococcus erythropolis D-1. Appl Environ Microbiol 67 1179-1184. 

Dabrock B, M Ke eler, B Averhoff, G Gottschalk (1994) Identification and characterization of a transmissible linear plasmid from Rhodococcus erythropolis BD2 that encodes isopropylbenzene and trichloro ethylene catabolism. Appl Environ Microbiol 60 853-860. 

An (5)-specific alcohol dehydrogenase gene from Rhodococcus erythropolis and GDH from Bacillus subtilis were ligated into one plasmid, which was expressed in Escherichia coli strain DSM14 459 to provide an (S)-selective whole-cell catalyst. 

Rhodococcus equi XL-1 has also been demonstrated to have superior stability in solutions containing up to 20 mM HCN when compared with several Rhodococcus erythropolis... 

Rhodococcus erythropolis NCIMB 11540 has been employed as biocatalyst for the conversion of (R)- or (.S )-cyanohydrins to the corresponding (R)- or (S)-a-hydroxycarboxylic acids with an optical purity of up to >99% enatiomeric excess (ee) [27-29] the chiral cyanohydrins can separately be produced using hydroxynitrile lyase from Hevea braziliensis or from Prunus anygdalis [30]. Using the combined NHase-amidase enzyme system of the Rhodococcus erythropolis NCIMB 11 540, the chiral cyanohydrins were first hydrolyzed to the... 

By screening 53 Rhodococcus and Pseudomonas strains, an NHase-amidase biocatalyst system was identified for the production of the 2,2-dimethylcyclopropane carboxylic acid precursor of the dehydropeptidase inhibitor Cilastatin, which is used to prolong the antibacterial effect of Imipenem. A systematic study of the most selective of these strains, Rhodococcus erythropolis ATCC25 544, revealed that maximal product formation occurs at pH 8.0 but that ee decreased above pH 7.0. In addition, significant enantioselectivity decreases were observed above 20 °C. A survey of organic solvent effects identified methanol (10% v/v) as the... 

A prochiral bis(cyanomethyl) sulfoxide was converted into the corresponding mono-acid with enantiomeric excesses as high as 99% using a nitrilase-NHase biocatalyst. The whole-cell biocatalyst Rhodococcus erythropolis NCIMB 11540 and a series of commercially available nitrilases NIT-101 to NIT-107 were evaluated in this study. As outlined in Figure 8.18, the prochiral sulfoxide may be transformed into five different products (plus enantiomeric isoforms), of which, three are chiral (A, B, and C) and two achiral (D and E). Only products A, B, and E were observed with the biocatalysts employed in this investigation. Both enantiomerically enriched forms of both A and C could be obtained with one of the catalysts used. The best selectivities are as follows (S)-A 99% ee, (R)-A 33% ee, (S)-C 66% ee, and (R)-C 99% ee, using NIT-104, NIT-103, NIT-108, and NIT-107 respectively. Each of these catalysts produced more... 

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