Sphingomonas

The chiral intermediate (S)-l-(2 -bromo-4 -fluorophenyl) ethanol was prepared by the enantioselective microbial reduction of 2-bromo-4-fiuoroacetophenone [lObj. Organisms from genus Candida, Hansmula, Pichia, Rhodotcnda, Saccharomyces, Sphingomonas, and baker s yeast reduced the ketone to the corresponding alcohol in... 

For the deracemization of phenylethanol derivatives using G. candidum under aerobic conditions (Figure 8.41b), the (S)-specific enzyme was reversible and (R) enzyme was irreversible, so (R)-alcohol accumulated when the cell and racemic alcohols were mixed [31b,c]. Para-substituted phenylethanol derivatives gave better results than meta-substituted derivatives. Sphingomonas was used for... 

Several suitable whole-cell systems have been identified for deracemization biotransformations on a large diversity of substrates, as compiled recently [48]. In particular, heterocyclic alcohols were successfully converted by Sphingomonas [55]. Access to enantiocomplementaiy products was achieved with various strains of Aspergillus [56] or Rhizopus [57]. Biotransformations can even be accomplished with yacon and ginger [58]. Substrate titers were reported up to 8gl for Candida parapsUosis mediated biotransformations [59]. 

Only the R(+) enantiomer of the herbicide 2-(2-methyl-4-chlorophenoxy)propionic acid was degraded (Tett et al. 1994), although cell extracts of Sphingomonas herbicidovorans grown with the R(-) or S -) enantiomer, respectively, transformed selectively the R -) or S(-) substrates to 2-methyl-4-chlorophenol (Nickel et al. 1997). 

The a-isomer of hexachlorocyclohexane exists in two enantiomeric forms, and both are degraded by Sphingomonas paucimobilis strain B90A by dehydrochlorination to 1,3,4, 6-tetrachlorocyclohexa-l,4-diene that is spontaneously degraded to 1,2,4-trichlorophenol. 

The degradation of 4-chlorobiphenyl by Sphingomonas paucimobilis strain BPSl-3 formed the intermediates 4-chlorobenzoate and 4-chlorocatechol. Fission products from the catechol reacted with NH4+ to produce chloropyridine carboxylates (Davison et al. 1996) (Figure 2.2c). 

A taxonomic note there have been substantial developments in the taxonomy of pseudomonads, and many new genera have been proposed including, for example, Sphingomonas, Comamonas, and Variovorax, while denitrifying organisms described as pseudomonads have been referred to the general Thauera and Azoarcus (Anders et al. 1995). 

The Major Genera within the Former Genus Sphingomonas and Their Role in Degradation... 

Davison AD, P Karuso, DR Jardine, DA Veal (1996) Halopicolinic acids, novel products arising through the degradation of chloro- and bromobiphenyl by Sphingomonas paucimobilis BPSl-3. Can J Microbiol 42 66-71. 

Nickel K, MJ-F Suter, H-PE Kohler (1997) Involvement of two 3-ketoglutarate-dependent dioxygenases in enantioselective degradation of R)- and (S)-mecoprop by Sphingomonas herbicidovorans MH. Appl Environ Microbiol 63 6674-6679. 

Suar M et al. (2005) Enantioselective transformation of a-hexachlorocyclohexane by the dehydrochlorinases LinAl and LinA2 from the soil bacterium Sphingomonas paucimobilis B90A. Appl Environ Microbiol 71 8514-8518. 

Takeuchi M, K Hamana, A Hiraishi (2001) proposal of the genus Sphingomonas sensu stricto and three new genera, Sphingobium, Novosphingobium and Sphingopyxis, on the basis of phylogenetic and chemotaxonomic analyses. Int J Syst Evol Microbiol 51 1405-1417. 

The degradation of bisphenol-A by Sphingomonas sp. strain AOl is initiated by hydroxylation to intermediates that undergo fission to 4-hydroxyacetophenone and 4-hydroxybenzoate. The components have been purified, and consist of cytochrome P450, ferredoxin reductase, and ferredoxin (Sasaki et al. 2005). 

Rhodococcus globerulus P6 Burkholderia cepacia LB 400 Pseudomonas pseudoalcaligenes KF 707 Pseudomonas sp. KKS 102 Sphingomonas paucimobilis SYK 6 Pseudomonas sp. CA 10 Escherichia coli C Escherichia coli Alcaligenes eutrophus IMP 222 Sphingomonas paucinwbilis SYK 6... 

Eaton SL, SM Resnick, DT Gibson (1996) Initial reactions in the oxidation of 1,2-dihydronaphthalene by Sphingomonas yanoikuyae strains. Appl Environ Microbiol 62 4388-4394. 

Endo R, M Kamakura, K Miyauchi, M Fukuda, Y Ohtsubo, M Tsuda, Y Nagata (2005) Identification and characterization of genes involved in the downstream degradation pathway of y-hexachlorocyclohexane in Sphingomonas paucimobilis UT26. J Bacterial 187 847-853. 

Miyauchi K, H-S Lee, M Fukuda, M Takagi, Y Nagata (2002) Cloning and characterization of linR, involved in regulation of the downstream pathway for y-hexachlorocyclohexane degradation in Sphingomonas paucimobilis UT26. Appl Environ Microbiol 68 1803-1807. 

Ohtsubo Y, K Miyauchi, K Kanda, T Hatta, H Kiyohara, T Senda, Y Nagata, Y Mitsui, M Takagi (1999) PcpA, which is involved in the degradation of pentachlorophenol in Sphingomonas chlorophenolica ATCC 39723, is a novel type of ring-cleavage dioxygenase. FEBS Lett 459 395-398. 

Sasaki M, A Akahira, L-i Oshiman, T Tsuchid, Y Matsumura (2005) Purification of cytochrome P450 and ferredoxin involved in bisphenol. A degradation from Sphingomonas sp. stain AOl. Appl Environ Microbiol 71 8024-8030. 

Wergath J, H-A Arfmann, DH Pieper, KN Timmis, R-M Wittich (1998) Biochemical and genetic analysis of a gentisate 1,2-dioxygenase from Sphingomonas sp. strain RW 5. J Bacterial 180 4171-4176. 

Xun L, J Bohuslavek, M Cai (1999) Characterization of 2,6-dichloro-p-hydroquoinone 1,2-dioxygenase (PcpA) of Sphingomonas chlorophenolica ATCC 39723. Biochem Biophys Res Commun 266 322-325. 

Keck A, J Ran, T Reemtsma, R Mattes, A Stolz, 1 Klein (2002) Identification of quinoide redox mediators that are formed during the degradation of naphthalene-2-sulfonate by Sphingomonas xenophaga BN6. Appl Environ Microbiol 68 4341-4349. 

Two strains of Sphingomonas sp. that could degrade pentachlorophenol maintained their levels of ATP even in the presence of high concentrations of pentachlorophenol. Analysis of the lipids using P NMR showed that this could be attributed to the increased levels of cardiolipin (Lohmeier-Vogel et al. 2001). 

C subfamily of type 1 extradiol dioxygenases (Mars et al. 1999). The alternative extradiol fission of 3-chlorocatechol may take place between the 1 and 6 positions (distal fission), and this has been shown for the 2,3-dihydroxybiphenyl 1,2-dioxygenase from the naphthalene sulfonate degrading Sphingomonas sp. strain BN6 (Riegert et al. 1998). 

Basta T, A Keck, J Klein, A Stolz (2004) Detection and characterization of conjugative plasmids in xenobiotic-degrading Sphingomonas strains. J Bacteriol 186 3862-3872. 

Zipper C, M Bunk, AJB Zehnder, H-PE Kohler (1998) Enantioselective uptake and degradation of the chiral herbicide dichloroprop [(R5)-2-(2,4-dichlorophenoxy)propionic acid] by Sphingomonas herbicidov-orans MH. J Bacteriol 180 3368-3374. 

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