Degradation of diarylethane structures by Pseudomonas fluorescens biovar I

Abstract

Pseudomonas fluorescens biovar I was isolated from a pulp mill effluent based on its ability to grow on synthetic media containing 1,2-diarylethane structures as the sole carbon and energy source. Analysis of samples taken from cultures of this strain in benzoin or 4,4'-dimethoxybenzoin (anisoin), showed that cleavage between the two aliphatic carbons takes place prior to ring fission. Intermonomeric cleavage was also obtained with crude extracts. Substrates of this reaction were only those 1,2-diarylethane compounds that supported growth of the bacterium. The purification and partial characterization of an enzyme that catalyzes the NADH-dependent reduction of the carbonyl group of benzoin and anisoin is also reported.

Benzaldehyde lyase, a novel thiamine PPi-requiring enzyme, from Pseudomonas fluorescens biovar I

“…(Fig. 3D) (6), indicating that the cofactor remains attached to the enzyme after ammonium sulfate precipitation. However, extensive dialysis or DEAE-cellulose chromatography of the extract sufficed to inactivate benzaldehyde lyase unless TPP was added to the assay mnixture.…”

“…The following chemicals were used (roman numerals refer to Fig. 2 (6). The synthesis of 3-hydroxy-1,2-diphenyl-propanone (compound III) and 3-hydroxy-1,2-bis(4'-methoxyphenyl)-propanone (compound III') from desoxybenzoin and desoxyanisoin, respectively, was performed by the method of Kirk and Nakatsubo (11).…”

“…When crude extracts from this bacterium were prepared, they catalyzed the conversion of benzoin and anisoin to benzaldehyde and anisaldehyde, respectively, in the absence of any added cofactor (6). However, we found later that this activity was lost upon extensive dialysis or fractionation of this extract and that it could be restored only by addition of thiamine PP1 (TPP) and a divalent cation salt.…”

“…Pseudomonasfluorescens biovar I, a strain we isolated in enrichment cultures containing the lignin model compound anisoin as the sole carbon and energy source, quantitatively degrades this substrate, producing anisic acid as a metabolic intermediate (5,6). When crude extracts from this bacterium were prepared, they catalyzed the conversion of benzoin and anisoin to benzaldehyde and anisaldehyde, respectively, in the absence of any added cofactor (6).…”

Model-based experimental analysis of enzyme kinetics in aqueous–organic biphasic systems

“…Pseudomonas fluorescens is able to grow on media with benzoin or anisoin as the only carbon source (Gonzalez et al, 1988). BAL is a homo-tetramer of four identical subunits of 563 amino acid residues, corresponding to a molecular mass of 58,919 Da.…”