Gerrit J Poelarends

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Halohydrin dehalogenases, also known as haloalcohol dehalogenases or halohydrin hydrogen-halide lyases, catalyze the nucleophilic displacement of a halogen by a vicinal hydroxyl function in halohydrins to yield epoxides. Three novel bacterial genes encoding halohydrin dehalogenases were cloned and expressed in Escherichia coli, and the enzymes were shown to(More)
Bacterial dehalogenases catalyse the cleavage of carbon-halogen bonds, which is a key step in aerobic mineralization pathways of many halogenated compounds that occur as environmental pollutants. There is a broad range of dehalogenases, which can be classified in different protein superfamilies and have fundamentally different catalytic mechanisms.(More)
The haloalkane-degrading bacteria Rhodococcus rhodochrous NCIMB13064, Pseudomonas pavonaceae 170, and Mycobacterium sp. strain GP1 share a highly conserved haloalkane dehalogenase gene (dhaA). Here, we describe the extent of the conserved dhaA segments in these three phylogenetically distinct bacteria and an analysis of their flanking sequences. The dhaA(More)
Three mutants of Lactococcus lactis subsp. lactis MG1363, termed EthR, DauR, and RhoR, were selected for resistance to high concentrations of ethidium bromide, daunomycin, and rhodamine 6G, respectively. These mutants were found to be cross resistant to a number of structurally and functionally unrelated drugs, among which were typical substrates of the(More)
The sequences of the 16S rRNA and haloalkane dehalogenase (dhaA) genes of five gram-positive haloalkane-utilizing bacteria isolated from contaminated sites in Europe, Japan, and the United States and of the archetypal haloalkane-degrading bacterium Rhodococcus sp. strain NCIMB13064 were compared. The 16S rRNA gene sequences showed less than 1% sequence(More)
The gram-negative bacterium Pseudomonas cichorii 170, isolated from soil that was repeatedly treated with the nematocide 1, 3-dichloropropene, could utilize low concentrations of 1, 3-dichloropropene as a sole carbon and energy source. Strain 170 was also able to grow on 3-chloroallyl alcohol, 3-chloroacrylic acid, and several 1-halo-n-alkanes. This(More)
The Pseudomonas aeruginosa PAO1 genome has at least two genes, pvdQ and quiP, encoding acylhomoserine lactone (AHL) acylases. Two additional genes, pa1893 and pa0305, have been predicted to encode penicillin acylase proteins, but have not been characterized. Initial studies on a pa0305 transposon insertion mutant suggested that the gene is not related to(More)
To genetically dissect the drug extrusion systems of Lactococcus lactis, a chromosomal DNA library was made in Escherichia coli and recombinant strains were selected for resistance to high concentrations of ethidium bromide. Recombinant strains were found to be resistant not only to ethidium bromide but also to daunomycin and tetraphenylphosphonium. The(More)
The newly isolated bacterial strain GP1 can utilize 1, 2-dibromoethane as the sole carbon and energy source. On the basis of 16S rRNA gene sequence analysis, the organism was identified as a member of the subgroup which contains the fast-growing mycobacteria. The first step in 1,2-dibromoethane metabolism is catalyzed by a hydrolytic haloalkane(More)
By selective enrichment, we isolated a bacterium that can use β-phenylalanine as a sole nitrogen source. It was identified by 16S rRNA gene sequencing as a strain of Variovorax paradoxus. Enzyme assays revealed an aminotransferase activity. Partial genome sequencing and screening of a cosmid DNA library resulted in the identification of a 1,302-bp(More)