Pseudomonas sp. NCIMB

Whole-cell enantioselective oxidation of sulfides is in fast development and of preparative interest. Additional examples with Acinetobacter sp NCIMB 9871, Pseudomonas sp. NCIMB 9872, and Xanthobacter autotrophicus DSM 431 have been reported [113,114]. 

All these degradation pathways were shown to involve a Baeyer-Villiger oxidation of a cycloalkanone that led to formation of the corresponding lactone. Further degradation then occured via hydrolysis of this lactone by a lactone hydrolase which has, in some cases, been isolated. As an example, the reaction sequence for the degradation of cyclopentanol by Pseudomonas sp. NCIMB 98721351 is shown in Fig. 16.5-7. 

Figure 2.10. Cyclopentanol-induced enzymes involved in alicyclic ring cleavage in Pseudomonas sp. NCIMB 9872...

Hours after inoculation of Pseudomonas sp. NCIMB 9872 into a medium containing cyclopentanol at 2 g-r as the sole source of carbon and energy... 

An example illustrating both problems, and some suitable solutions, is provided by the Baeyer-Villiger mono-oxygenase-dependent biotransformation of bicyclo(3.2.0.)hept-2-en-6-one to synthetically useful lactones by a resting culture of the cyclopentanol-grown bacterium Pseudomonas sp. NCIMB 9872 (Figure 2.10). 

It has been noted in Section 4.4.1.1 that naphthalene dioxygenase from a strain of Pseudomonas sp. also carries out enantiomeric monooxygenation of indan and dehydrogenation of indene (Gibson et al. 1995), and the stereospecific hydroxylation of (R)-l-indanol and (S)-l-indanol to rfs-indan-l,3-diol and trans (lS,3S)-indan-l,3-diol (Lee et al. 1997) the indantriols are also formed by further reactions. Essentially comparable reactions have been observed with Rhodococcus sp. strain NCIMB 12038 (Allen et al. 1997). 

However, production of 2,6-difluorobenzamide (Scheme 12.1-18) was effected in 99.5% n-heptane using the nitrile hydratase from Rhodococcus sp. NCIMB 12 21 81841. The enzymatic reaction was found to be activated by light (see 12.1.3.4). More recently, Layh and Willetts have studied nitrile transformations in various organic solvents and biphasic mixtures using a nitrilase from Pseudomonas sp. DSM 11387 and a nitrile hydratase from Rhodococcus sp. DSM 113971 51. The enzymes exhibited good stabilities in biphasic mixtures with hydrophobic solvents when dispersed in... 

Further studies also been performed on the bicydo[3.2.0]heptan-6-one series of compounds1124, 125]. These results are summarised in Fig. 16.5-35. Oxidation of this ketone with Pseudomonas NCIMB 9872 gave the (IS, 5 R)-lactone of low optical purity (23% ee) with only small amounts (5%) of the isomeric lactone, whereas its oxidation with an Acinetobacter sp. gave these lactones in a 9 1 ratio and a modest yield, a result quite different from the one described previously. However, oxidation of 7-mdo-methylbicydo[3.2.0]hept-2-en-6-one using either Pseudomonas sp. or Acinetobacter sp. produced optically pure (ee > 96 %) of both lactones in equal quantities... 

Haywood G W, Anderson A J, Ewing D E and Dawes E A (1990) Accumulation of a polyhydroxyalkanoate containing primarily 3-hydroxydecanoate from simple carbohydrate substrates by Pseudomonas sp. Strain NCIMB 40135, Appl Environ Microbiol 56 3354-3359. 

Cycloalkonone oxygenase from Pseudomonas putida ASl and Acinetobacter sp. NCIMB 9871 has been used to catalyze the regio- and stereoselective Baeyer-Villiger type of oxidation of [3.2.0]hept-2-en-6-one. The enantiomerically pure lactones prepared by this enzymatic reaction are chiral synthons for prostaglandin synthesis [248,249]. 

Epoxide hydrolases have been purified from mammalian liver cells [63-66] but also from microbial sources such as Bacillus megaterium [67], Corynebacterium [45,46,68], Pseudomonas sp. [46,69], and dematiaceous fungi such as Ulocladium atrum and Zopfiella karachiensis [70]. However, some of these enzymes were only partially purified [67,68], or their enantioselectivity was not investigated [69] or was very low [45,46]. More recently, two bacterial epoxide hydrolases with high activity and high enantioselectivity were purified and characterized from Rhodococcus sp. NCIMB 11216 [71] and Nocardia TBl [72]. 

Purified CHMOs from Acinetobacter sp. NCIB 9871 and Pseudomonas NCIMB 10007 coupled with dehydrogenases to generate NADPH/NADH in situ was used to prepare (1R,5S)- and (i5, 5/ )-lactones [29,30]. These chiral lactones are important synthons used in the synthesis of prostaglandins. 

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