Publications

characterization of the gene encoding quinohaemoprotein ethanol dehydrogenase of comamonas testosteroni.	the gene encoding quinohaemoprotein ethanol dehydrogenase type i (qh-edhi) from comamonas testosteroni has been cloned and sequenced. comparison of the amino acid sequence deduced from this with that determined for the n-terminal amino acid stretch of purified qh-edhi, suggests that the gene also contains a leader sequence of 31 residues. based on this information, the molecular mass of the apo-enzyme, i.e. the enzyme without the cofactors pyrroloquinoline quinone (pqq) and haem c, and without t ...	1996	8654419
comamonas testosteroni 3-ketosteroid-delta 4(5 alpha)-dehydrogenase: gene and protein characterization.	comamonas testosteroni delta 4(5 alpha)- and delta1-dehydrogenases [delta4(5alpha)- and delta1dh] are key enzymes in the degradation of steroids having an a:b ring fusion in a trans configuration. we previously reported the isolation of the delta1dh gene (p. plesiat, m. grandguillot, s. harayama, s. vragar, and y. michel briand, j. bacteriol. 173:7219-7227, 1991). in this study, the gene encoding delta 4(5 alpha)dh was cloned in escherichia coli on a 16-kbp bamhi fragment by screening a genomic ...	1996	8655514
characterization of bacterial communities from activated sludge: culture-dependent numerical identification versus in situ identification using group- and genus-specific rrna-targeted oligonucleotide probes	the structures of bacterial communities were studied in activated sludge samples obtained from the aerobic and anaerobic zones of a wastewater treatment plant showing enhanced phosphorous removal. samples were analyzed by in situ hybridization with oligonucleotide probes complementary to selected regions of the 16s and 23s ribosomal rna (rrna) characteristic for defined phylogenetic entities (genera and larger groups). the microbial community structures revealed by molecular techniques were comp ...	1996	8688004
comamonas testosteroni colony phenotype influences exopolysaccharide production and coaggregation with yeast cells.	a comamonas testosteroni strain was isolated from activated sludge on the basis of its ability to coaggregate with yeast cells. on agar plates the following two types of colonies were formed: colonies with a mucoid appearance and colonies with a nonmucoid appearance. on plates this strain alternated between the two forms, making sectored colonies. in liquid medium with constant agitation no such change was observed. in the absence of agitation and in contact with a glass surface a culture with p ...	1996	8702260
characterization of active recombinant 2,3-dihydro-2,3-dihydroxybiphenyl dehydrogenase from comamonas testosteroni b-356 and sequence of the encoding gene (bphb).	2,3-dihydro-2,3-dihydroxybiphenyl-2,3-dehydrogenase (b2,3d) catalyzes the second step in the biphenyl degradation pathway. the nucleotide sequence of comamonas testosteroni b-356 bphb, which encodes b2,3d, was determined. structural analysis showed that the dehydrogenases involved in the bacterial degradation of aromatic compounds are related to each other and that their phylogenetic relationships are very similar to the relationships observed for dioxygenases that catalyze the initial reaction ...	1996	8702262
oerskovia turbata and comamonas acidovorans bacteremia in a patient with aids.		1996	8793408
antibiotic resistance and enhanced insecticide catabolism as consequences of steroid induction in the gram-negative bacterium comamonas testosteroni.	the effects of steroid induction on antibiotic resistance against the fungal steroid fusidic acid (ramycin; 16-(acetyloxy)-3 alpha,11 alpha-dihydroxy-29-dammara-17(20), 24-dien-21-oic-acid) as well as on carbonyl reduction and degradation of the novel anti-insect agent nki 42255 (2-(1-imidazolyl)-1-(4-methoxyphenyl)-2-methyl-1-propanone) were studied in the gram-negative soil bacterium comamonas testosteroni strain atcc 11996. cells grown with testosterone as inducing agent showed a 5-6-fold ele ...	1996	8809204
taxonomic identification of streptomyces exfoliatus k10 and characterization of its poly(3-hydroxybutyrate) depolymerase gene.	the poly(3-hydroxyalkanoate) (pha) degrading isolate k10 was identified as streptomyces exfoliatus. this bacterium is distinguished from other pha-degrading strains by its ability to utilize both poly(3-hydroxybutyrate) (phb) and poly(3-hydroxyoctanoate) (pho). a pha depolymerase structural gene of s. exfoliatus (phaz(sex) was cloned, expressed and partially purified from recombinant escherichia coli. the depolymerase was specific for phb and did not hydrolyze pho. this indicated the presence of ...	1996	8810505
degradative pathways for p-toluenecarboxylate and p-toluenesulfonate and their multicomponent oxygenases in comamonas testosteroni strains psb-4 and t-2.	three multicomponent oxygenases involved in the degradation of p-toluenesulfonate and p-toluenecarboxylate and the regulation of their synthesis have been examined in three strains (t-2, psb-4 and ter-1) of comamonas testosteroni. strain t-2 utilizes p-toluenesulfonate as a source of carbon and energy for growth via p-sulfobenzoate and protocatechuate, and p-toluenecarboxylate via terephthalate and protocatechuate, and has the unusual property of requiring the reductase (tsab) of the toluenesulf ...	1996	8828208
sequencing of comamonas testosteroni strain b-356-biphenyl/chlorobiphenyl dioxygenase genes: evolutionary relationships among gram-negative bacterial biphenyl dioxygenases.	in a previous work, all three components of comamonas testosteroni b-356 biphenyl (bph)/chlorobiphenyls (pcbs) dioxygenase (dox) have been purified and characterized. they include an iron-sulphur protein (ispbph) which is the terminal oxygenase composed of two subunits (encoded by bpha and bphe), a ferredoxin (ferbph) encoded by bphf and a reductase (redbph) encoded by bphg. bphg is not located in the neighbourhood of bphaef in b-356. we are reporting the cloning of b-356-bphg and the sequencing ...	1996	8890734
vascular catheter-related comamonas acidovorans bacteremia managed with preservation of the catheter.		1996	8895931
characterization of a 3 alpha-hydroxysteroid dehydrogenase/carbonyl reductase from the gram-negative bacterium comamonas testosteroni.	a new form of the nad(p)-dependent 3 alpha-hydroxysteroid dehydrogenases (3 alpha-hsds), present in the gram-negative bacterium comamonas testosteroni atcc 11996, was isolated from a testosterone-induced bacterial extract and characterized. the enzyme (hsd 28) has a monomeric molecular mass of 28 kda. it belongs to the protein superfamily of short-chain dehydrogenases/reductases (sdr) as established by n-terminal sequence analysis. along with the 3 alpha-hydroxysteroid dehydrogenase and 3-oxo-re ...	1996	8944761
rp4::mu3a-mediated in vivo cloning and transfer of a chlorobiphenyl catabolic pathway.	chromosomal dna fragments encoding the ability to utilize biphenyl as sole carbon source (bph+) were mobilized by means of plasmid rp4::mu3a from strain jb1 (tentatively identified as burkholderia sp.) to alcaligenes eutrophus ch34 at a frequency of 10(-3) per transferred plasmid. the mobilized dna integrated into the recipient chromosome or was recovered as catabolic prime plasmids. three bph+ prime plasmids were transferred from a. eutrophus to escherichia coli and back to a. eutrophus without ...	1996	8969525
biodegradation of the mixtures of 4-chlorophenol and phenol by comamonas testosteroni cpw301.	a 4-chlorophenol (4-cp)-degrading bacterium, strain cpw301, was isolated from soil and identified as comamonas testosteroni. this strain dechlorinated and degraded 4-cp via a meta-cleavage pathway. cpw301 could also utilize phenol as a carbon and energy source without the accumulation of any metabolites via the same meta-cleavage pathway. when phenol was added as an additional substrate, cpw301 could degrade 4-cp and phenol simultaneously. the addition of phenol greatly accelerated the degradati ...	1996	9188195
broviac catheter-related bacteraemias due to unusual pathogens in children with cancer: case reports with literature review.	among 102 episodes of intravenous catheter related bacteraemias documented between january 1989 and july 1996 in children receiving antineoplastic chemotherapy or bone marrow transplantation at g. gaslini children's hospital, genoa, italy, were identified seven episodes due to unusual pathogens: bacillus circulans, bacillus licheniformis, brevibacterium casei, flavimonas oryzihabitans, porphyromonas asaccharolytica, comamonas acidovorans and agrobacterium radiobacter. susceptibility to different ...	1997	9200028
highly efficient control of iron-containing nitrile hydratases by stoichiometric amounts of nitric oxide and light.	the reaction of two iron-containing nitrile hydratases (nhase) with no has been studied: nhase from rhodococcus sp. r312, which is probably similar to the photosensitive n771 nhase, and the new nhase from comamonas testosteroni ni1 whose aminoacid sequence is quite different from those of br312 and n771 nhases. both enzymes are equally inactivated after addition of stoichiometric amounts of no added as an anaerobic solution or produced in situ under physiological conditions by a rat brain no-syn ...	1997	9202148
porin from the halophilic species ectothiorhodospira vacuolata: cloning, structure of the gene and comparison with other porins.	the gene coding for the anion-specific porin of the halophilic eubacterium ectothiorhodospira (ect.) vacuolata was cloned and sequenced, the first such gene so analyzed from a purple sulfur bacterium. it encodes a precursor protein consisting of 374 amino acid (aa)-residues including a signal peptide of 22-aa residues. comparison with aa sequences of porins from several other members of the proteobacteria revealed little homology. only two regions showed local homology with the previously sequen ...	1997	9218724
testosterone-regulated expression of enzymes involved in steroid and aromatic hydrocarbon catabolism in comamonas testosteroni.	the effect of testosterone as the sole carbon source on protein expression was analyzed in comamonas testosteroni. testosterone simultaneously induced the expression of steroid- and aromatic hydrocarbon-catabolizing enzymes and repressed one amino acid-degrading enzyme. it is suggested that steroids play a regulative role in catabolic enzyme synthesis during adaptive growth of c. testosteroni.	1997	9294458
cloning of the gene for poly(3-hydroxybutyric acid) depolymerase of comamonas testosteroni and functional analysis of its substrate-binding domain.	a poly(3-hydroxybutyric acid) (phb) depolymerase gene of comamonas testosteroni ym1004 was cloned on sau3ai fragment from genomic dna into escherichia coli dh5. nucleotide sequence analysis dedicated a 1539 bp open reading frame encoding a protein 513 amino acid with a putative 25 residue signal peptide for secretion. the deduced amino acid sequence was very similar to that of phb depolymerase of comamonas sp. in order to understand the characteristics of substrate-binding domain of the depolyme ...	1997	9297825
phylogenetic characterization of bacteria in the subsurface microbial culture collection.	the subsurface microbial culture collection (smcc) was established by the u.s. dept. of energy (doe) and contains nearly 10,000 strains of microorganisms (mostly bacteria) isolated from terrestrial subsurface environments. selected groups of bacterial isolates from three sample sites situated above geochemically and hydrologically different subsurface environments have been characterized by phylogenetic analysis of 16s ribosomal rna (rrna) gene nucleotide sequences. among these isolates were mem ...	1997	9299704
development and application of monoclonal antibodies for in situ detection of indigenous bacterial strains in aquatic ecosystems.	strain-specific monoclonal antibodies (mabs) were developed for three different bacterial isolates obtained from a freshwater environment (lake plusssee) in the spring of 1990. the three isolates, which were identified by molecular methods, were as follows: cytophaga johnsonae px62, comamonas acidovorans px54, and aeromonas hydrophila pu7718. these strains represented three species that were detected in high abundance during a set of mesocosm experiments in lake plusssee by the direct analysis o ...	1997	9361440
succession and convergence of biofilm communities in fixed-film reactors treating aromatic hydrocarbons in groundwater.	community composition, succession, and performance were compared in three fluidized bed reactors (fbr) operated to test preemptive colonization and the influence of toluene compared with a mixture of benzene, toluene, and p-xylene (btx) as feeds. one reactor was inoculated with toluene-degrading strains pseudomonas putida paw1, burkholderia cepacia g4, and b. pickettii pko1. paw1 outcompeted the other two strains. when groundwater strains were allowed to challenge the steady-state biofilm develo ...	1997	8979355
active site directed mutagenesis of 3 beta/17 beta-hydroxysteroid dehydrogenase establishes differential effects on short-chain dehydrogenase/reductase reactions.	mutagenetic replacements of conserved residues within the active site of the short-chain dehydrogenase/reductase (sdr) superfamily were studied using prokaryotic 3 beta/17 beta-hydroxysteroid dehydrogenase (3 beta/17 beta-hsd) from comamonas testosteroni as a model system. the results provide novel data to establish ser 138 as a member of a catalytically important "triad" of residues also involving tyr151 and lys155. a ser-->ala exchange at position 138 results in an almost complete (> 99.9%) lo ...	1997	8993315
characterization of the p-toluenesulfonate operon tsambcd and tsar in comamonas testosteroni t-2.	comamonas testosteroni t-2 uses a standard, if seldom examined, attack on an aromatic compound and oxygenates the side chain of p-toluenesulfonate (ts) (or p-toluenecarboxylate) to p-sulfobenzoate (or terephthalate) prior to complete oxidation. the expression of the first three catabolic enzymes in the pathway, the ts methyl-monooxygenase system (comprising reductase b and oxygenase m; tsamb), p-sulfobenzyl alcohol dehydrogenase (tsac), and p-sulfobenzaldehyde dehydrogenase (tsad), is coregulate ...	1997	9006050
identification of burkholderia cepacia isolates from patients with cystic fibrosis and use of a simple new selective medium.	we evaluated 819 isolates referred to us as "burkholderia cepacia" from cystic fibrosis (cf) clinics and research laboratories from five countries; 28 (3.4%) were not b. cepacia. a further 12 (1.5%) organisms appeared to be other burkholderia species, but identification could not be confirmed by conventional means. the most prevalently misidentified organisms were stenotrophomonas maltophilia, alcaligenes xylosoxidans, and comamonas acidovorans. many of these organisms grew on oxidation-fermenta ...	1997	9041399
diversity within bacterial isolates hybridizing with comamonas probe ppt.	diversity within bacteria isolated from activated sludge and the baltic sea and recognized by the rrna targeted oligonucleotide probe ppt (designed by braun-howland et al., 1993 to recognize c. testosteroni) was studied. the partial nucleotide sequences of 16s genes of the isolates revealed that the activated sludge and baltic sea isolates each formed a separate group distinct from c. testosteroni. the analysis of phage and bacteriocin sensitivity as well as whole cell protein patterns revealed ...	1997	9151425
d-lysine production from l-lysine by successive chemical racemization and microbial asymmetric degradation.	in order to develop a practical process for d-lysine production from l-lysine, successive chemical racemization and microbial asymmetric degradation were investigated. the racemization of l-lysine proceeded quantitatively at elevated temperatures. a sample of 1000 strains of bacteria, fungi, yeast and actinomyces were screened for the ability to degrade l-lysine asymmetrically. microorganisms belonging to the achromobacter, agrobacterium, candida, comamonas, flavobacterium, proteus, providencia, ...	1997	9163947
conjugative plasmids and the degradation of arylsulfonates in comamonas testosteroni.	comamonas testosteroni t-2 degrades p-toluenesulfonate (tsa) via p-sulfobenzoate (psb) and protocatechuate and degrades toluenecarboxylate via terephthalate (ter) and protocatechuate. the appropriate genes are expressed in at least five regulatory units, some of which are also found in c. testosteroni psb-4 (f. junker, r. kiewitz, and a. m. cook, j. bacteriol. 179:919-927, 1997). c. testosteroni t-2 was found to contain two plasmids, ptsa (85 kbp) and pt2t (50 kbp); a tsa- mutant (strain ter-1) ...	1997	9172362
biochemical and molecular characterization of the polyhydroxybutyrate depolymerase of comamonas acidovorans ym1609, isolated from freshwater.	comamonas acidovorans ym1609 secreted a polyhydroxybutyrate (phb) depolymerase into the culture supernatant when it was cultivated on poly(3-hydroxybutyrate) [p(3hb)] or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [p(3hb-co-3hv)] as the sole carbon source. the phb depolymerase was purified from culture supernatant of c. acidovorans by two chromatographic methods, and its molecular mass was determined as 45,000 da by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. t ...	1997	9406404
degradation of tetrahydrofurfuryl alcohol by ralstonia eutropha is initiated by an inducible pyrroloquinoline quinone-dependent alcohol dehydrogenase.	an organism tentatively identified as ralstonia eutropha was isolated from enrichment cultures containing tetrahydrofurfuryl alcohol (thfa) as the sole source of carbon and energy. the strain was able to tolerate up to 200 mm thfa in mineral salt medium. the degradation was initiated by an inducible ferricyanide-dependent alcohol dehydrogenase (adh) which was detected in the soluble fraction of cell extracts. the enzyme catalyzed the oxidation of thfa to the corresponding tetrahydrofuran-2-carbo ...	1997	9406410
a new comamonas testosteroni steroid-inducible gene: cloning and sequence analysis.	comamonas testosteroni can grow on a variety of steroid compounds as the sole carbon and energy source. in a previous study, we cloned and sequenced the testosterone-inducible betahsd gene from c. testosteroni (genti-raimondi, s., tolmasky, m., patrito, l., flury, a. and actis, l., molecular cloning and expression of the beta-hydroxysteroid dehydrogenase gene from pseudomonas testosteroni. gene, 1991, 105, 43-49.). herein we report the cloning and characterization of another steroid-inducible ge ...	1997	9449210
cloning and sequence analysis of a catechol 2,3-dioxygenase gene from the nitrobenzene-degrading strain comamonas sp js765.	comamonas sp strain js765 utilizes nitrobenzene as a carbon and nitrogen source. the initial attack on nitrobenzene is carried out by nitrobenzene 1,2-dioxygenase, which converts nitrobenzene to an unstable nitrohydrodiol that spontaneously decomposes to form catechol and nitrite. catechol is then degraded via a meta cleavage pathway. we now report the cloning of a dna fragment carrying a catechol 2,3-dioxygenase gene from js765. nucleotide sequence analysis revealed three open reading frames (o ...	1997	9451836
genetics of naphthalene and phenanthrene degradation by comamonas testosteroni.	naphthalene and phenanthrene have long been used as model compounds to investigate the ability of bacteria to degrade polycyclic aromatic hydrocarbons. the catabolic pathways have been determined, several of the enzymes have been purified to homogeneity, and genes have been cloned and sequenced. however, the majority of this work has been performed with fast growing pseudomonas strains related to the archetypal naphthalene-degrading p. putida strains g7 and ncib 9816-4. recently comamonas testos ...	1997	9451837
enrichment, isolation and characterization of dialkyl sulfosuccinate degrading bacteria comamonas terrigena n3h and comamonas terrigena n1c.		1997	9508556
performance of three phase fluidized bed reactor for quinoline degradation on various supports at steady state and dynamic conditions.	quinoline degradation by comamonas acidovorans was investigated in a three phase fluidized bed reactor at dilution rates below and above the critical value (micro(max) = 0.42 h(-1)). quinoline was used as the sole source of carbon, nitrogen, and energy. two attachment carriers, polyurethane foam (bayvitec) and modified cellulose (aquacel), and a gel entrapment carrier (polyvinyl alcohol) were studied and compared with regard to their effectiveness to immobilize cells. attachment and biofilm form ...	1997	18636645
microbial succession during a field evaluation of phenol and toluene as the primary substrates for trichloroethene cometabolism.	microbial community composition and succession were studied in an aquifer that was amended with phenol, toluene, and chlorinated aliphatic hydrocarbons to evaluate the effectiveness of these aromatic substrates for stimulating trichloroethene (tce) bioremediation. samples were taken after the previous year's field studies, which used phenol as the primary substrate, and after three successive monthly treatments of phenol plus 1,1-dichloroethene (1,1-dce) plus tce, phenol plus tce, and toluene pl ...	1997	16535576
degradation of 4-chlorophenol via the meta cleavage pathway by comamonas testosteroni jh5.	comamonas testosteroni jh5 used 4-chlorophenol (4-cp) as its sole source of energy and carbon up to a concentration of 1.8 mm, accompanied by the stoichiometric release of chloride. the degradation of 4-cp mixed with the isomeric 2-cp by resting cells led to the accumulation of 3-chlorocatechol (3-cc), which inactivated the catechol 2,3-dioxygenase. as a result, further 4-cp breakdown was inhibited and 4-cc accumulated as a metabolite. in the crude extract of 4-cp-grown cells, catechol 1,2-dioxy ...	1997	16535738
purification and properties of a polyester polyurethane-degrading enzyme from comamonas acidovorans tb-35.	a polyester polyurethane (pur)-degrading enzyme, pur esterase, derived from comamonas acidovorans tb-35, a bacterium that utilizes polyester pur as the sole carbon source, was purified until it showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page). this enzyme was bound to the cell surface and was extracted by addition of 0.2% n,n-bis(3-d-gluconamidopropyl)deoxycholamide (deoxy-bigchap). the results of gel filtration and sds-page showed that the pur esteras ...	1998	16349494
biphenyl-associated meta-cleavage dioxygenases from comamonas testosteroni b-356.	in addition to 2,3-dihydroxybiphenyl 1,2-dioxygenase (b1,2o), biphenyl-grown cells of comamonas testosteroni b-356 were shown to produce a catechol 2,3-dioxygenase (c2,3o). b1,2o showed strong sequence homology with b1,2os found in other biphenyl catabolic pathways, while partial sequence analysis of the c2,3o of b-356 suggested a relationship with xyleii-encoded c2,3o. the coexistence of two meta-cleavage dioxygenases in this strain prompted a comparison between the catalytic properties of the ...	1998	9522448
population dynamics of phenol-degrading bacteria in activated sludge determined by gyrb-targeted quantitative pcr.	a method for quantifying bacterial populations introduced into an activated-sludge microbial community is described. the method involves extraction of dna from activated sludge, appropriate dilution of the extracted dna with dna extracted from nonintroduced activated sludge, pcr amplification of a gyrb gene fragment from the introduced strain with a set of strain-specific primers, and quantification of the electrophoresed pcr product by densitometry. the adequacy of the method was examined by an ...	1998	9546154
is1491 from pseudomonas alcaligenes ncib 9867: characterization and distribution among pseudomonas species.	a new insertion sequence, is1491, has been cloned and sequenced. the 2489-bp is1491 was isolated from a pseudomonas alcaligenes ncib 9867 (strain p25x) 4.8-kb psti chromosomal fragment. is1491 is flanked by an imperfect inverted repeat of 23 bp and carries two overlapping open reading frames, orf1 and orf2. both orf1 and orf2 displayed homology to the ista-like and istb-like transposases encoded by the is21 family of insertion sequences, which include two is elements previously isolated from p. ...	1998	9571135
grazing pressure by a bacterivorous flagellate reverses the relative abundance of comamonas acidovorans px54 and vibrio strain cb5 in chemostat cocultures	the response of the bacterial strains comamonas acidovorans px54 (beta subclass of the class proteobacteria) and vibrio strain cb5 (gamma subclass of the class proteobacteria) to grazing by the bacterivorous flagellate ochromonas sp. was examined in one-stage chemostat experiments under conditions of low growth rates with a complex carbon source. the two bacterial strains were cultured together; they were cultured without flagellates in the first phase of the experiments and in the presence of t ...	1998	9572971
the adsorption of substrate-binding domain of phb depolymerases to the surface of poly(3-hydroxybutyric acid).	the binding characteristic of phb depolymerase has been studied by using glutathione s-transferase (gst) fusion proteins with substrate-binding domain of three bacterial phb depolymerases, alcaligenes faecalis, comamonas acidovorans and comamonas testosteroni. analysis using immuno-gold labeling technique and transmission electron microscopy indicated that a novel gst fusion protein derived from a. faecalis enzyme adsorbed to the surface of poly(3-hydroxybutyric acid) (p(3hb)) single crystals li ...	1998	9585889
homology model of the quinohaemoprotein alcohol dehydrogenase from comamonas testosteroni.	a molecular model of qh-adh, the quinohaemoprotein alcohol dehydrogenase from comamonas testosteroni, has been built by homology modelling. sequence similarity of n-terminal residues 1-570 with the alpha-subunit of quinoprotein methanol dehydrogenases (mdhs) from methylophilus methylotrophus w3a1 and methylobacterium extorquens provided a basis for the design of the pqq-binding domain of qh-adh. minimal sequence similarity with cytochrome c551 from ectothiorhodospira halophila and cytochrome c5 ...	1998	9613842
high-efficiency incorporation in vivo of tyrosine analogues with altered hydroxyl acidity in place of the catalytic tyrosine-14 of delta 5-3-ketosteroid isomerase of comamonas (pseudomonas) testosteroni: effects of the modifications on isomerase kinetics.	versions of the y55f/y88f modified form of delta 5-3-ketosteroid isomerase in which the active-site tyrosine-14 is replaced by 2-fluorotyrosine, 3-fluorotyrosine, and 2,3-difluorotyrosine, amino acids having progressively greater acidity of their phenolic hydroxyls, have been expressed in an escherichia coli host and purified to high homogeneity. the steady-state kinetic properties of y55f/y88f ksi and its fluorotyrosine modified forms have been determined. the mechanistic implications of the re ...	1998	9657686
the regulated outer membrane protein omp21 from comamonas acidovorans is identified as a member of a new family of eight-stranded beta-sheet proteins by its sequence and properties.	omp21, a minor outer membrane protein of the soil bacterium comamonas acidovorans, was purified from a spontaneous mutant lacking a surface layer and long-chain lipopolysaccharide. omp21 synthesis is enhanced by oxygen depletion, and the protein has a variable electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gel electrophoresis due to its heat-modifiable behavior. the structural gene omp21 encodes a precursor of 204 amino acids with a putative signal peptide of 21 amino acids. m ...	1998	9683466
molybdopterin radical in bacterial aldehyde dehydrogenases.	the epr spectra of three different molybdoprotein aldehyde dehydrogenases, one purified from comamonas testosteroni and two purified from amycolatopsis methanolica, showed in their oxidized state a novel type of signal. these three enzymes contain two different [2fe-2s] centers, one flavin and one molybdopterin cytosine dinucleotide, as cofactors all of which are expected to be epr silent in the oxidized state. the new epr signal is isotropic with g = 2.004 both at x-band and q-band frequencies, ...	1998	9698384
genetic analysis of comamonas acidovorans polyhydroxyalkanoate synthase and factors affecting the incorporation of 4-hydroxybutyrate monomer.	the polyhydroxyalkanoate (pha) synthase gene of comamonas acidovorans ds-17 (phacca) was cloned by using the synthase gene of alcaligenes eutrophus as a heterologous hybridization probe. complete sequencing of a 4.0-kbp smai-hindiii (sh40) subfragment revealed the presence of a 1,893-bp pha synthase coding region which was followed by a 1,182-bp beta-ketothiolase gene (phaaca). both the translated products of these genes showed significant identity, 51.1 and 74.2%, respectively, to the primary s ...	1998	9726894
nonlinear and asymmetric open channel characteristics of an ion-selective porin in planar membranes.	the open channel characteristics of the bacterial porin omp32 from comamonas acidovorans were investigated by means of conductance measurements in planar lipid bilayers of the montal-mueller type. particularly at low salt conditions (< or = 30 mm kcl) omp32 exhibited some unusual asymmetric and nonlinear functional properties. current-voltage relationship measurements showed that conductance depends on the orientation of porin molecules and is a nonlinear function of the applied membrane potenti ...	1998	9726928
microvirgula aerodenitrificans gen. nov., sp. nov., a new gram-negative bacterium exhibiting co-respiration of oxygen and nitrogen oxides up to oxygen-saturated conditions.	a denitrifier micro-organism was isolated from an upflow denitrifying filter inoculated with an activated sludge. the cells were gram-negative, catalase- and oxidase-positive curved rods and very motile. they were aerobic as well as anoxic heterotrophs that had an atypical respiratory type of metabolism in which oxygen and nitrogen oxides were used simultaneously as terminal electron acceptors. the g&c content was 65 mol%. our isolate was phenotypically similar to comamonas testosteroni, accordi ...	1998	9734031
[development of microbiological technology of air deodoration in laboratory-industrial conditions using a pilot plant].	laboratory tests were performed to select a complex of bacterial strains capable of effective deodoration of waste air produced by an animal formulated feed works under elevated temperature with the presence of numerous organic pollutants. the complex included species from the general nocardia, rhodococcus, and comamonas. the biocatalyst was tested in a real industrial process with the use of a pilot plant for microbiological deodoration of waste air. the test lasted for over six months and conf ...	1998	9749432
biodegradation of dimethylterephthalate by comamonas acidovorans d-4.	comamonas acidovorans d-4, capable of utilizing dimethylterephthalate (dmt) as the sole carbon source, was isolated from the activated sludge of petrochemical wastewater treatment plant. almost complete utilization of as high as 0.5% (w/v) dmt was observed in 72 hr. growth kinetics followed a parallel relation between the growth, dmt utilization and cell associated esterase activity. a cell free broth of dmt grown cells showed an extracellular esterase activity. during the dmt degradation an ext ...	1998	9754068
distribution and life strategies of two bacterial populations in a eutrophic lake	monoclonal antibodies and epifluorescence microscopy were used to determine the depth distribution of two indigenous bacterial populations in the stratified lake plusssee and characterize their life strategies. populations of comamonas acidovorans px54 showed a depth distribution with maximum abundances in the oxic epilimnion, whereas aeromonas hydrophila pu7718 showed a depth distribution with maximum abundances in the anoxic thermocline layer (metalimnion), i. e., in the water layer with the h ...	1998	9758799
crystallization and preliminary x-ray crystallographic studies of the native and chemically modified anion-selective porin from comamonas acidovorans.	omp32, the strongly anion-selective porin from comamonas acidovorans, has been crystallized. two crystal forms were observed, both of which belong to space group r3, but exhibit different cell dimensions a = b = 106.7, c = 140.6 a (crystal form i) and a = b = 87.1, c = 135.3 a (crystal form ii) with one trimer per asymmetric unit. the crystals diffract to 2.2 and 2.3 a resolution, respectively. omp32 was chemically modified by introducing negative charges through succinylation. the number and po ...	1998	9761864
in situ detection of bacteria in continuous-flow cultures of seawater sediment suspensions with fluorescently labelled rrna-directed oligonucleotide probes.	rrna-targeted and fluorescently labelled oligonucleotide probes were used to study the composition of natural bacterial populations in continuous-flow cultures of seawater sediment suspensions. the cultures were run as enrichment cultures with increasing dilution rates, and hexadecane as the sole carbon source. total cell numbers were analysed by counting dapi (4',6-diamidino-2-phenylindole)-stained cells. to differentiate the population composition, oligonucleotide probes for eubacteria, for cy ...	1998	9802019
adaptation of comamonas testosteroni ta441 to utilize phenol: organization and regulation of the genes involved in phenol degradation.	comamonas testosteroni ta441 was not able to grow on phenol as a sole carbon and energy source, but it gained the ability to utilize phenol after a 2-3-week incubation in a medium containing phenol. phenol hydroxylase (ph) and catechol 2,3-dioxygenase (c230) were highly induced by phenol in the adapted strain designated as strain p1, suggesting that phenol was degraded via the meta-pathway. gene clusters for phenol degradation were isolated from both strains ta441 and p1. the structural genes en ...	1998	9802031
involvement of the terminal oxygenase beta subunit in the biphenyl dioxygenase reactivity pattern toward chlorobiphenyls.	biphenyl dioxygenase (bph dox) oxidizes biphenyl on adjacent carbons to generate 2,3-dihydro-2,3-dihydroxybiphenyl in comamonas testosteroni b-356 and in pseudomonas sp. strain lb400. the enzyme comprises a two-subunit (alpha and beta) iron sulfur protein (ispbph), a ferredoxin (ferbph), and a ferredoxin reductase (redbph). b-356 bph dox preferentially catalyzes the oxidation of the double-meta-substituted congener 3,3'-dichlorobiphenyl over the double-para-substituted congener 4,4'-dichlorobiph ...	1998	9811638
molecular cloning, overexpression, and characterization of steroid-inducible 3alpha-hydroxysteroid dehydrogenase/carbonyl reductase from comamonas testosteroni. a novel member of the short-chain dehydrogenase/reductase superfamily.	3alpha-hydroxysteroid dehydrogenase/carbonyl reductase (3alpha-hsd/cr) from comamonas testosteroni, a bacterium that is able to grow on steroids as the sole carbon source, catalyzes the oxidoreduction at position 3 of a variety of c19-27 steroids and the carbonyl reduction of a variety of nonsteroidal aldehydes and ketones. the gene of this steroid-inducible 3alpha-hsd/cr was cloned by screening a c. testosteroni gene bank with a homologous dna probe that was obtained by polymerase chain reactio ...	1998	9812981
operation of mixed-culture immobilized cell reactors for the metabolism of meta- and para-nitrobenzoate by comamonas sp. js46 and comamonas sp. js47	the treatment of meta- and para-nitrobenzoic acid in an industrial wastestream by comamonas sp. js46 and comamonas sp. js47 is investigated. the most important feature of the wastestream is the constantly changing concentration ratio of the two isomers. the most extreme occurrence is considered here: the complete change in feed carbon source from one isomer to the other. a series of immobilized cell airlift reactor experiments are described to examine the operation and response of the system to ...	1998	10099310
dynamic modeling of meta- and para-nitrobenzoate metabolism by a mixed co-immobilized culture of comamonas spp. js46 and js47	a model describing the transient activity of a mixed immobilized culture of comamonas spp. js46 and js47 growing on mixed substrates is presented. the transient periods considered are those following changes in the feed carbon source, which alternated between meta- and para-nitrobenzoate. the feed profile alternately starved one of the species in the mixed culture. the response of the system, as quantified by the reactor effluent substrate concentrations, is dictated by the activity of the bioma ...	1998	10099365
analysis of changes in congener selectivity during pcb degradation by burkholderia sp. strain tsn101 with increasing concentrations of pcb and characterization of the bphbcd genes and gene products.	we isolated and characterized a gram-negative bacterium, burkholderia sp. strain tsn101, that can degrade polychlorinated biphenyls (pcbs) at concentrations as high as 150 microg kaneclor 300/ml, a pcb mixture equivalent to aroclor 1242. growing cells of strain tsn101 degraded most of the tri- and tetrachlorobiphenyls in medium containing 25 microg kaneclor 300/ml. using pcb concentrations of 50-150 microg of kaneclor 300/ml, the congener selectivity pattern was different and the pattern of chlo ...	1998	9396836
an attempt to use selected strains of bacteria adapted to high concentrations of petroleum oil to increase the effective removal of petroleum products in excess activated sludge in laboratory conditions.	forty two strains of bacteria were isolated from excess activated sludge from petroleum wastewater treatment plant. the strains were identified and classified to the following groups: enterobacteriaceae (7 strains), anitratum (3 strains), pseudomonas (13 strains), micrococcus (12 strains), comamonas (2 strains), xanthomonas (2 strains), achromobacter (1 strain) and vibrio-aeromonas (1 strain). one of the isolates was found to be a yeast strain. following preliminary selection ten strains, showin ...	1998	9990713
interactions of "limax amoebae" and gram-negative bacteria: experimental studies and review of current problems.	free-living amoebae can harbour bacteria inside their cysts giving them a microhabitat and protecting them from disinfectants. the aim of this study was to evaluate the potential importance of "limax amoebae" as vectors for environmental and nosocomial bacteria in a hospital. it was shown that free-living amoebae are ubiquitous in the investigated hospital, occur syntopically with facultative human pathogens (comamonas acidovorans and pseudomonas aeruginosa) and may serve as hosts not only for t ...	1998	10622622
peritonitis due to comamonas acidovorans in a capd patient.		1998	10505573
adaptation of comamonas testosteroni ta441 to utilization of phenol by spontaneous mutation of the gene for a trans-acting factor.	comamonas testosteroni ta441 adapts to utilization of phenol upon incubation with phenol as the major carbon source. strain ta441 has a cluster of genes (aphklmnopqb) encoding the catabolic enzymes phenol hydroxylase and catechol 2,3-dioxygenase, and a divergently transcribed regulatory gene (aphr), but these genes are silent until adaptation occurs. we found another regulatory gene (aphs) downstream of aphr. aphs belongs to the gntr family of transcriptional regulators. all adapted strains were ...	1999	10510228
a cole1-compatible expression vector for the production of his-tagged fusion proteins.	plasmid pdb31 is a cole1-compatible expression vector based on the p15a origin of replication. it is designed to express his-tagged fusion proteins in cells co-hosting a compatible expression vector. it was constructed by assembling the operator/promoter region plus the 6xhis and the multiple cloning site of pqe31 (qiagen) with the p15a origin of replication plus kanr of pgp1-2. the plasmid was found to be stable in escherichia coli strains bl21 and dh11s. it was used to produce and purify the f ...	1999	10510716
genetic organization and characteristics of the 3-(3-hydroxyphenyl)propionic acid degradation pathway of comamonas testosteroni ta441.	comamonas testosteroni ta441 degrades 3-(3-hydroxyphenyl)propionate (3hpp) via the meta pathway. a gene cluster required for degradation of 3hpp was cloned from strain ta441 and sequenced. the genes encoding six catabolic enzymes, a flavin-type hydroxylase (mhpa), extradiol dioxygenase (mhpb), 2-keto-4-pentenoate hydratase (mhpd), acetaldehyde dehydrogenase (acylating) (mhpf), 4-hydroxy-2-ketovalerate aldolase (mhpe) and the meta cleavage compound hydrolase (mhpc), were found in this cluster, en ...	1999	10537203
endotoxins and igg antibodies as indicators of occupational exposure to the microbial contaminants of metal-working fluids.	the aim of this study was to evaluate workers' exposure to microbes and bacterial endotoxins during the use of metal-working fluids (mwf).	1999	10541909
flagellate predation on a bacterial model community: interplay of size-selective grazing, specific bacterial cell size, and bacterial community composition.	the influence of grazing by the bacterivorous nanoflagellate ochromonas sp. strain ds on the taxonomic and morphological structures of a complex bacterial community was studied in one-stage chemostat experiments. a bacterial community, consisting of at least 30 different strains, was fed with a complex carbon source under conditions of low growth rate (0.5 day(-1) when nongrazed) and low substrate concentration (9 mg liter(-1)). before and after the introduction of the predator, the bacterial co ...	1999	10543797
genetic and biochemical comparison of 2-aminophenol 1,6-dioxygenase of pseudomonas pseudoalcaligenes js45 to meta-cleavage dioxygenases: divergent evolution of 2-aminophenol meta-cleavage pathway.	nitrobenzene is degraded to pyruvate and acetaldehyde by pseudomonas pseudoalcaligenes js45 via a reductive pathway, and by comamonas sp. js765 via an oxidative pathway. although the initial reactions in the degradation of nitrobenzene by the two bacteria are totally different, the lower pathways are similar and converge at the level of 4-oxalocrotonate. in order to further investigate the biochemical properties and reveal the evolutionary relationships between the two lower pathways, the genes ...	1999	10550475
crystal structure of delta(5)-3-ketosteroid isomerase from pseudomonas testosteroni in complex with equilenin settles the correct hydrogen bonding scheme for transition state stabilization.	delta(5)-3-ketosteroid isomerase from pseudomonas testosteroni has been intensively studied as a prototype to understand an enzyme-catalyzed allylic isomerization. asp(38) (pk(a) approximately 4.7) was identified as the general base abstracting the steroid c4beta proton (pk(a) approximately 12.7) to form a dienolate intermediate. a key and common enigmatic issue involved in the proton abstraction is the question of how the energy required for the unfavorable proton transfer can be provided at th ...	1999	10551849
characterization of a high-affinity phenol hydroxylase from comamonas testosteroni r5 by gene cloning, and expression in pseudomonas aeruginosa pao1c.	comamonas testosteroni strain r5 is a phenol-degrading bacterium which expresses a phenol-oxygenating activity that is characterized by low ks (the apparent half-saturation constant in haldane's equation) and low k(si) (the apparent inhibition constant) values. we have now cloned the gene cluster encoding a phenol hydroxylase (phcklmnop) and its cognate regulator (phcr) from strain r5. transformation of pseudomonas aeruginosa pao1c (phenol catechol+) with pror502, a derivative of pro1614 contain ...	1999	10589844
desulfonation of propanesulfonic acid by comamonas acidovorans strain p53: evidence for an alkanesulfonate sulfonatase and an atypical sulfite dehydrogenase	evidence is presented for the presence in propanesulfonate-grown comamonas acidovorans strain p53 of a cytoplasmically located sulfonatase that does not sediment at 100,000 x g. this enzyme catalysed the sulfonate-dependent oxidation of nadh or nadph, indicating a monooxygenase that effects the addition of molecular oxygen to c(3)-c(6) 1-alkanesulfonates. enzyme activity was proportional to protein concentration only above approximately 2 mg cytoplasmic fraction protein ml(-1), suggesting that t ...	1999	10591848
a study on the prevalence of gram-negative bacteria in bulk tank milk.	bulk tank milk from 131 dairy herds in eastern south dakota and western minnesota were examined for coliforms and noncoliform bacteria. coliforms were detected in 62.3% of bulk tank milk samples. counts ranged from 0 to 4.7 log10 cfu/ml. the mean count was 3.4 log10 cfu/ml. gram-negative noncoliform bacteria were observed in 76.3% of bulk tank milk. counts ranged from 0 to 6.2 log10 cfu/ml. the mean count was 4.8 log10 cfu/ml. a total of 234 isolates from bulk tank milk were examined to species ...	1999	10629809
microbial degradation of polyurethane, polyester polyurethanes and polyether polyurethanes.	polyurethane (pur) is a polymer derived from the condensation of polyisocyanate and polyol and it is widely used as a base material in various industries. pur, in particular, polyester pur, is known to be vulnerable to microbial attack. recently, environmental pollution by plastic wastes has become a serious issue and polyester pur had attracted attention because of its biodegradability. there are many reports on the degradation of polyester pur by microorganisms, especially by fungi. microbial ...	1999	10091317
comamonas acidovorans strain mc1: a new isolate capable of degrading the chiral herbicides dichlorprop and mecoprop and the herbicides 2,4-d and mcpa.	a gram-negative prototrophic bacterial species, strain mc1, was isolated from the vicinity of herbicide-contaminated building rubble and identified by 16s rdna sequence analysis, its physiological properties, gc content, and fatty acid composition as comamonas acidovorans. this strain displays activity for the productive degradation of the two enantiomers of dichlorprop [(rs)-2-(2,4-dichlorophenoxy-)propionate; (rs)-2,4-dp] and mecoprop [(rs)-2-(4-chloro-2-methyl-) phenoxypropionate; (rs)-mcpp] ...	1999	10652787
diversity and correlation of specific aromatic hydrocarbon biodegradation capabilities.	this work investigated the biodegradation capabilities of indigenous microorganisms exposed to different combinations of aromatic hydrocarbons. considerable diversity was found in the catabolic specificity of 55 strains. toluene was the most commonly degraded compound, followed by p-xylene, m-xylene and ethylbenzene. strains capable of degrading o-xylene and benzene, which were the least-frequently-degraded compounds, exhibited broader biodegradation capabilities. kappa statistics showed a signi ...	1999	10870549
degradation of anaerobic reductive dechlorination products of aroclor 1242 by four aerobic bacteria.	we studied the aerobic degradation of eight pcb congeners which comprise from 70 to 85% of the anaerobic dechlorination products from aroclor 1242, including 2-, 4-, 2,4-, 2,6-, 2,2'-, 2,4'-, 2,2', 4-, and 2,4,4'-chlorobiphenyl (cb), and the biodegradation of their mixtures designed to simulate anaerobic dechlorination profiles m and c. strains comamonas testosteroni vp44 and rhodococcus erythreus ny05 preferentially oxidized a para-substituted ring, while rhodococcus sp. rha1, similar to well k ...	1999	10870552
[studies on the metabolism pathway of aniline degradation by comamonas acidovorans an3].	all of the enzymes relating to aniline degradation in c. acidovorans an3 were inducible ones. when growing on aniline as sole carbon, nitrogen and energy sources, the cells of c. acidovorans an3 contained aniline dioxygenase, catechol-2, 3-dioxygenase, 2-hydromuconic semialdehyde dehydrogenase, 4-oxalocrotonic acid decarboxylase and 4-hydroxy-2-oxovalerate acid aldolase. the km and vmax of aniline dioxygenase were 292 mumol/l and 3.57 mumol.mg-1. min-1, respectively. the km and vmax of catechol- ...	1999	12555527
urinary tract infection associated with comamonas acidovorans.		1999	11853571
analyses of a polyhydroxyalkanoic acid granule-associated 16-kilodalton protein and its putative regulator in the pha locus of paracoccus denitrificans.	the polyhydroxyalkanoic acid (pha) granule-associated 16-kda protein (ga16 protein) of paracoccus denitrificans was identified, and its corresponding gene was cloned and analyzed at the molecular level. the n-terminal amino acid sequence of ga16 protein revealed that its structural gene is located downstream from the pha synthase gene (phacpd) cloned recently (s. ueda, t. yabutani, a. maehara, and t. yamane, j. bacteriol. 178:774-779, 1996). gene walking around phacpd revealed two new open readi ...	1999	10217786
construction and characterization of two recombinant bacteria that grow on ortho- and para-substituted chlorobiphenyls.	cloning and expression of the aromatic ring dehalogenation genes in biphenyl-growing, polychlorinated biphenyl (pcb)-cometabolizing comamonas testosteroni vp44 resulted in recombinant pathways allowing growth on ortho- and para-chlorobiphenyls (cbs) as a sole carbon source. the recombinant variants were constructed by transformation of strain vp44 with plasmids carrying specific genes for dehalogenation of chlorobenzoates (cbas). plasmid pe43 carries the pseudomonas aeruginosa 142 ohb genes codi ...	1999	10224015
isolation of poly(beta-l-malic acid)-degrading bacteria and purification and characterization of the pma hydrolase from comamonas acidovorans strain 7789.	several bacteria were isolated which were able to utilize poly(beta-l-malic acid) as sole carbon source for growth. the poly(beta-l-malic acid) hydrolyzing enzyme of comamonas acidovorans strain 7789 was detected in the membrane fraction. the enzyme was purified by isolation of crude cell membranes by ultracentrifugation of disrupted cells, solubilization of the membrane fraction with octylglucoside, selective precipitation with 50% saturated ammonium sulfate and preparative isolectric focusing. ...	1999	10227166
phylogenetic relationships among members of the comamonadaceae, and description of delftia acidovorans (den dooren de jong 1926 and tamaoka et al. 1987) gen. nov., comb. nov.	the phylogenetic relationships among members of the family comamonadaceae and several unclassified strains were studied by direct sequencing of their pcr-amplified 16s rrna genes. based on the 16s rrna gene sequence analysis, members of the family formed a coherent group. the closest relatives are species of the rubrivivax sub-group: leptothrix discophora, ideonella dechloratans and rubrivivax gelatinosus. the genus hydrogenophaga formed two subclusters, as did the species of acidovorax, whereas ...	1999	10319477
cloning and sequencing of a new comamonas testosteroni gene encoding 3 alpha-hydroxysteroid dehydrogenase/carbonyl reductase.		1999	10352711
linear alkanesulfonates as carbon and energy sources for gram-positive and gram-negative bacteria.	several bacteria from soil and rainwater samples were enriched and isolated with propanesulfonate or butanesulfonate as sole carbon and energy source. most of the strains isolated utilized nonsubstituted alkanesulfonates with a chain length of c3-c6 and the substituted sulfonates taurine and isethionate as carbon and energy source. a gram-positive isolate, p40, and a gram-negative isolate, p53, were characterized in more detail. phylogenetic analysis grouped strain p40 within group iv of the gen ...	1999	10369899
cis-2,3-dihydro-2,3-dihydroxybiphenyl dehydrogenase and cis-1, 2-dihydro-1,2-dihydroxynaphathalene dehydrogenase catalyze dehydrogenation of the same range of substrates.	pseudomonas putida strain g7 cis-1,2-dihydro-1, 2-dihydroxynaphthalene dehydrogenase (nahb) and comamonas testosteroni strain b-356 cis-2,3-dihydro-2,3-dihydroxybiphenyl dehydrogenase (bphb) were found to be catalytically active towards cis-2,3-dihydro-2,3-dihydroxybiphenyl (specificity factors of 501 and 5850 s-1 mm-1 respectively), cis-1,2-dihydro-1, 2-dihydroxynaphthalene (specificity factors of 204 and 193 s-1 mm-1 respectively) and 3,4-dihydro-3,4-dihydroxy-2,2',5, 5'-tetrachlorobiphenyl (s ...	1999	10381363
comparison of the downstream pathways for degradation of nitrobenzene by pseudomonas pseudoalcaligenes js45 (2-aminophenol pathway) and by comamonas sp. js765 (catechol pathway).	nitrobenzene is degraded by pseudomonas pseudoalcaligenes js45 via 2-aminophenol to 2-aminomuconic semialdehyde, which is further degraded to pyruvate and acetaldehyde. comamonas sp. js765 degrades nitrobenzene via catechol to 2-hydroxymuconic semialdehyde. in this study we examined and compared the late steps of degradation of nitrobenzene by these two microorganisms in order to reveal the biochemical relationships of the two pathways and to provide insight for further investigation of their ev ...	1999	10382261
seasonal dynamics of bacterioplankton community structure in a eutrophic lake as determined by 5s rrna analysis.	community structure of bacterioplankton was studied during the major growth season for phytoplankton (april to october) in the epilimnion of a temperate eutrophic lake (lake plusssee, northern germany) by using comparative 5s rrna analysis. estimates of the relative abundances of single taxonomic groups were made on the basis of the amounts of single 5s rrna bands obtained after high-resolution electrophoresis of rna directly from the bacterioplankton. full-sequence analysis of single environmen ...	1999	10388718
beta-lactamases and outer membrane investigations in beta-lactam-resistant comamonas acidovorans strains.	imipenem-induced beta-lactamase (level of expression, specific activity and kinetic parameters (vmax and km) in response to nitrocefin) and outer membrane proteins (omps) (hydrophobicity, permeability and electrophoretic pattern) were characterized in, one beta-lactam sensitive (pac-9), one resistant (pac-1) and two resistant laboratory mutants (pac-9m, pac-9m2) of comamonas acidovorans strains. beta-lactamases from both mutant strains showed different vmax values compared to the parental strain ...	1999	10389644
substrate and binding specificities of bacterial polyhydroxybutyrate depolymerases.	the substrate specificities of three extracellular polyhydroxybutyrate (phb) depolymerases from alcaligenes faecalis (phaz afa), pseudomonas stutzeri (phaz pst), and comamonas acidovorans (phaz cac), which are grouped into types a and b based on the position of a lipase box sequence in the catalytic domain, were examined for films of 12 different aliphatic polyesters. each of these phb depolymerases used was capable of hydrolyzing poly(3-hydroxybutyrate) (p(3hb)), poly(3-hydroxypropionate) (p(3h ...	1999	10408639
improved production of poly(4-hydroxybutyrate) by comamonas acidovorans and its freeze-fracture morphology.	production of poly(4-hydroxybutyrate) [p(4hb)] by comamonas acidovorans jcm10181 was studied by introducing additional copies of its pha synthase gene and the beta-ketothiolase gene. a multi-copy-number broad-host-range plasmid vector, pjrd215, was modified to contain the strong hybrid trc promoter in order to express these genes in the wild-type c. acidovorans. increased copy-number of genes resulted in significant increase in the activities of corresponding enzymes, which could further be incr ...	1999	10416653
extracellular degradation of medium chain length poly(beta-hydroxyalkanoates) by comamonas sp.	the pha-degrading isolate, strain p37c, was enriched from residential compost for its ability to hydrolyze the medium chain length pha, poly(beta-hydroxyoctanoate) (pho). it was subsequently found to grow on a wide range of phas, including both short chain length and medium chain length phas. the isolate was identified as belonging to the genus comamonas. strain p37c formed clear zones on poly(beta-hydroxybutyrate) (phb), (pho) and poly(beta-hydroxyphenylvalerate) (phpv) overlay plates. pha clea ...	1999	10416660
bioconversion of pyrimidine by resting cells of quinoline-degrading bacteria.	nine quinoline-degrading bacterial strains were tested for their ability to hydroxylate pyrimidine. all strains converted pyrimidine to uracil via pyrimidine-4-one in a cometabolic process. quinoline 2-oxidoreductases (quinors) were the catalysts of fortuitous pyrimidine hydroxylation. whereas in most strains the activity of the quinor towards pyrimidine was very low compared to its activity towards quinoline, quinor in crude extracts from comamonas testosteroni 63 showed a specific activity of ...	1999	10427712
comamonas acidovorans contamination of dental unit waters.	a study was carried out to evaluate the extent of the colonization of dental water systems by comamonas acidovorans and to investigate how the occurrence of these bacteria is related to certain water characteristics. the 152 water samples were collected from the oral rinsing cup, air-water syringe, turbine and supply lines to dental units. comamonas acidovorans was found most frequently and in greatest quantities in samples taken from water entering the units and in samples with a lower total ba ...	1999	10432632
heterologous expression and characterization of the purified oxygenase component of rhodococcus globerulus p6 biphenyl dioxygenase and of chimeras derived from it.	in this work, we have purified the his-tagged oxygenase (ht-oxygenase) component of rhodococcus globerulus p6 biphenyl dioxygenase. the alpha or beta subunit of p6 oxygenase was exchanged with the corresponding subunit of pseudomonas sp. strain lb400 or of comamonas testosteroni b-356 to create new chimeras that were purified ht-proteins and designated ht-alpha(p6)beta(p6), ht-alpha(p6)beta(lb400), ht-alpha(p6)beta(b-356), ht-alpha(lb400)beta(p6), and ht-alpha(b-356)beta(p6). ht-alpha(p6)beta(p6 ...	1999	10438748
differential detection of key enzymes of polyaromatic-hydrocarbon-degrading bacteria using pcr and gene probes.	bacteria with ability to degrade polyaromatic hydrocarbons (pahs), isolated from wastewater and soil samples, were investigated for their taxonomic, physiological and genetic diversity. eighteen isolates able to metabolize naphthalene or phenanthrene as sole carbon source were taxonomically affiliated to different subclasses of the proteobacteria (sphingomonas spp., acidovorax spp., comamonas spp. and pseudomonas spp.) and to phyla of gram-positive bacteria with low and high dna g + c content (p ...	1999	10439412
microbial degradation of nitrobenzene and mono-nitrophenol by bacteria enriched from municipal activated sludge.	using a mixture of three mono nitrophenols as sole carbon, nitrogen and energy sources, mixed cultures were enriched from municipal activated sludge to degrade both nitrophenols and nitrobenzene. bacterial growth and degradation rate could be increased by supplementing the medium with 0.1% ye. microorganisms were isolated from the nitrophenols enrichment, and they were identified as strains of comamonas testosteroni and acidovorax delafieldii. these strains showed broad degradation ability towar ...	1999	10446720
capillary electrophoresis-single-strand conformation polymorphism analysis for rapid identification of pseudomonas aeruginosa and other gram-negative nonfermenting bacilli recovered from patients with cystic fibrosis.	we used capillary electrophoresis-single-strand conformation polymorphism (ce-sscp) analysis of pcr-amplified 16s rrna gene fragments for rapid identification of pseudomonas aeruginosa and other gram-negative nonfermenting bacilli isolated from patients with cystic fibrosis (cf). target sequences were amplified by using forward and reverse primers labeled with various fluorescent dyes. the labeled pcr products were denatured by heating and separated by capillary gel electrophoresis with an autom ...	1999	10488211
mechanistic insights from the three-dimensional structure of 3-oxo-delta(5)-steroid isomerase.	3-oxo-delta(5)-steroid isomerase (ksi) catalyzes the isomerization of beta,gamma-unsaturated 3-oxosteroids to their conjugated isomers through the formation of an intermediate dienolate. the three-dimensional structure of the enzyme from pseudomonas testosteroni was solved by multidimensional heteronuclear magnetic resonance spectroscopy. this protein, a 28-kda symmetric dimer, exhibits a three-dimensional fold with the two independently folded monomers packed together via extensive hydrophobic ...	1999	10496971