Pseudomonas sp. strain 9816-4 grows with naphthalene as the sole source of carbon and energy (9). The initial reaction is catalyzed by a multicomponent enzyme system designated naphthalene dioxygenase (NDO) (11,12,23,24). NDO catalyzes the NAD(P)H-dependent enantiospecific incorporation of dioxygen into naphthalene to form (ϩ)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene (cis-naphthalene dihydrodiol) (26, 27) ( Fig. 1). An analogous reaction is catalyzed by toluene dioxygenase (TDO) from Pseudomonas putida F1, where enantiomerically pure (ϩ)-cis-(1S,2R)-dihydroxy-3-methylcyclohexa-3,5-diene (cis-toluene dihydrodiol) is the first detectable oxidation product (17,31,60). TDO also catalyzes the enantiospecific oxidation of naphthalene to (ϩ)-cis-naphthalene dihydrodiol (18,39).In addition to the enantiospecific oxidation of naphthalene and toluene, NDO and TDO from the above strains oxidize many related aromatic compounds to optically active dihydrodiols (10,18,28,30). Other bacterial dioxygenases show similar properties, and more than 130 chiral arene cis-dihydrodiols have been produced from a small number of strains (7,35,48). The high enantiomeric purity of these compounds has led to their use as chiral synthons in the enantiospecific synthesis of a wide variety of biologically active natural products (7,8,46,57). The present studies focus on another facet of this interesting group of dioxygenases, that is, their ability to catalyze reactions other than the formation of arene cis-dihydrodiols. For example, the TDO expressed by P. putida F39/D oxidizes indan to (1R)-indanol and oxidizes indene to cis-(1S,2R)-indandiol and (1S)-indenol (55). Similar reactions have been reported for TDO from P. putida UV4, although the 1-indenol produced by this strain is the (1R)-enantiomer (3, 5).We now report the identification and absolute stereochemistry of the products formed from indan and indene by NDO from Pseudomonas sp. strain 9816-4 and confirm earlier observations on the desaturation of indan to indene by NDO (22). MATERIALS AND METHODSOrganisms. Pseudomonas sp. strain 9816/11 is a mutant which oxidizes naphthalene stoichiometrically to (ϩ)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene (40). This organism is a derivative of Pseudomonas sp. strain 9816-4 (9, 59), which harbors the genes for naphthalene catabolism on an 83-kb NAH plasmid designated pDTG1 (45). Pseudomonas sp. strain 9816/C84, a cured strain, was used as a control in experiments with strain 9816/11. Escherichia coli strain JM109 (DE3)[pDTG141] contains the structural genes (nahAaAbAcAd) for NDO in plasmid pT7-5 (50). Expression of NDO in this strain is inducible by the addition of isopropylthiogalactopyranoside (IPTG). E. coli JM109(DE3)[pT7-5] was used as a control in experiments with strain JM109(DE3) [pDTG141].Biotransformation experiments. Strain 9816/11 was grown at 30ЊC in mineral salts basal medium (MSB) (49) with 0.2% (wt/vol) pyruvate as a carbon source in the presence of 0.05% (wt/vol) salicylate or anthranilate. These aromatic acids induce the s...

A Beijerinckia sp. and a mutant strain, Beijerinckia sp. strain B8/36, were shown to cooxidize the polycyclic aromatic hydrocarbons acenaphthene and acenaphthylene. Both organisms oxidized acenaphthene to the same spectrum of metabolites, which included 1-acenaphthenol, 1-acenaphthenone, 1,2-acenaphthenediol, acenaphthenequinone, and a compound that was tentatively identified as 1,2-dihydroxyacenaphthylene. In contrast, acenaphthylene was oxidized to acenaphthenequinone and the compound tentatively identified as 1,2dihydroxyacenaphthylene by the wild-type strain of Beijerinckia. Both of these products were also formed when the organism was incubated with synthetic cis-1,2-acenaphthenediol. A metabolite identified as cis-1,2acenaphthenediol was formed from acenaphthylene by the mutant Beijerinckia sp. strain B8/36. Cell extracts prepared from the wild-type Beijerinckia strain contain a constitutive pyridine nucleotide-dependent dehydrogenase which can oxidize l-acenaphthenol and 9-fluorenol. The results indicate that although acenaphthene and acenaphthylene are both oxidized to acenaphthenequinone, the pathways leading to the formation of this end product are different.

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A collection of 12 microbial cultures, known to contain cytochrome P-450 monooxygenase or other degradative enzymes, was screened for their ability to degrade the Novartis Crop Protection Inc. developmental fungicide cyprodinil (CGA-219417; 4-cyclopropyl-6-methyl-N-phenyl-2-pyrimidinamine). Ten of the 12 cultures produced a monohydroxylated metabolite in yields ranging from 1.2 to 35.6%. The filamentous fungus, Beauveria bassiana ATCC 7159, produced a methoxylated glycoside of the monohydroxylated metabolite with a yield of 80%. Dihydroxylated metabolites and a molecular cleavage product, 4-cyclopropyl-6-methyl-2-pyrimidamine, were also detected in certain cultures. The overall results of the study indicated that cyprodinil was readily metabolized by a variety of microbial species. Metabolites generated by these cultures can potentially be used as analytical reference standards to support animal, plant, and soil metabolism studies.