| crystal structure of quinohemoprotein alcohol dehydrogenase from comamonas testosteroni: structural basis for substrate oxidation and electron transfer. | quinoprotein alcohol dehydrogenases are redox enzymes that participate in distinctive catabolic pathways that enable bacteria to grow on various alcohols as the sole source of carbon and energy. the x-ray structure of the quinohemoprotein alcohol dehydrogenase from comamonas testosteroni has been determined at 1.44 a resolution. it comprises two domains. the n-terminal domain has a beta-propeller fold and binds one pyrroloquinoline quinone cofactor and one calcium ion in the active site. a tetra ... | 2002 | 11714714 |
| nad(p)-dependent aldehyde dehydrogenases induced during growth of ralstonia eutropha strain bo on tetrahydrofurfuryl alcohol. | different aldehyde dehydrogenases (aldhs) were formed during growth of ralstonia eutropha bo on tetrahydrofurfuryl alcohol (thfa). one of these enzymes, aldh 4, was purified and characterized as a homodimer containing no prosthetic groups, showing a strong substrate inhibition, and having an n-terminal sequence similar to those of various nad(p)-dependent aldhs. the conversion rate of thfa by the quinohemoprotein thfa dehydrogenase was increased by aldh 4. | 2001 | 11717302 |
| integration of matrix-assisted laser desorption ionization-time of flight mass spectrometry and molecular cloning for the identification and functional characterization of mobile ortho-halobenzoate oxygenase genes in pseudomonas aeruginosa strain jb2. | protein mass spectrometry and molecular cloning techniques were used to identify and characterize mobile o-halobenzoate oxygenase genes in pseudomonas aeruginosa strain jb2 and pseudomonas huttiensis strain d1. proteins induced in strains jb2 and d1 by growth on 2-chlorobenzoate (2-cba) were extracted from sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels and analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry. two bands gave significant matches ... | 2001 | 11722919 |
| cultivation-independent, semiautomatic determination of absolute bacterial cell numbers in environmental samples by fluorescence in situ hybridization. | fluorescence in situ hybridization (fish) with rrna-targeted oligonucleotide probes has found widespread application for analyzing the composition of microbial communities in complex environmental samples. although bacteria can quickly be detected by fish, a reliable method to determine absolute numbers of fish-stained cells in aggregates or biofilms has, to our knowledge, never been published. in this study we developed a semiautomated protocol to measure the concentration of bacteria (in cells ... | 2001 | 11722938 |
| laribacter hongkongensis gen. nov., sp. nov., a novel gram-negative bacterium isolated from a cirrhotic patient with bacteremia and empyema. | a bacterium was isolated from the blood and empyema of a cirrhotic patient. the cells were facultatively anaerobic, nonsporulating, gram-negative, seagull shaped or spiral rods. the bacterium grows on sheep blood agar as nonhemolytic, gray colonies 1 mm in diameter after 24 h of incubation at 37 degrees c in ambient air. growth also occurs on macconkey agar and at 25 and 42 degrees c but not at 4, 44, and 50 degrees c. the bacterium can grow in 1 or 2% but not 3, 4, or 5% nacl. no enhancement of ... | 2001 | 11724825 |
| case of catheter sepsis with ralstonia gilardii in a child with acute lymphoblastic leukemia. | acute lymphoblastic leukemia was diagnosed in a 7-year-old girl. two months after insertion of a central venous catheter, she developed fever and complained of headache and abdominal pain. physical examination revealed no focus of infection. a gram-negative nonfermenting bacillus was recurrently cultured from blood. extensive biochemical testing and 16s ribosomal dna sequencing led to the identification of ralstonia gilardii. | 2001 | 11724891 |
| biodegradation of aromatic compounds by escherichia coli. | although escherichia coli has long been recognized as the best-understood living organism, little was known about its abilities to use aromatic compounds as sole carbon and energy sources. this review gives an extensive overview of the current knowledge of the catabolism of aromatic compounds by e. coli. after giving a general overview of the aromatic compounds that e. coli strains encounter and mineralize in the different habitats that they colonize, we provide an up-to-date status report on th ... | 2001 | 11729263 |
| meta-cleavage enzyme gene tesb is necessary for testosterone degradation in comamonas testosteroni ta441. | comamonas testosteroni metabolizes testosterone as the sole carbon source via a meta-cleavage reaction. a meta-cleavage enzyme gene, tesb, was cloned from c. testosteroni ta441. the deduced n-terminal amino acid sequence of tesb matched that of the purified meta-cleavage enzyme which is induced in ta441 during growth on testosterone as the sole carbon source. the tesb-disrupted mutant did not show growth on testosterone, suggesting that tesb is necessary for ta441 to grow on testosterone. downst ... | 2001 | 11739769 |
| degradation of aromatics and chloroaromatics by pseudomonas sp. strain b13: cloning, characterization, and analysis of sequences encoding 3-oxoadipate:succinyl-coenzyme a (coa) transferase and 3-oxoadipyl-coa thiolase. | 3-oxoadipate:succinyl-coenzyme a (coa) transferase and 3-oxoadipyl-coa thiolase carry out the ultimate steps in the conversion of benzoate and 3-chlorobenzoate to tricarboxylic acid cycle intermediates in bacteria utilizing the 3-oxoadipate pathway. this report describes the characterization of dna fragments with the overall length of 5.9 kb from pseudomonas sp. strain b13 that encode these enzymes. dna sequence analysis revealed five open reading frames (orfs) plus an incomplete one. orf1, of u ... | 2002 | 11741863 |
| characterization of hybrid biphenyl dioxygenases obtained by recombining burkholderia sp. strain lb400 bpha with the homologous gene of comamonas testosteroni b-356. | the bacterial degradation of polychlorinated biphenyls depends on the ability of the enzyme biphenyl 2,3-dioxygenase (bpdo) to catalyze their oxygenation. analysis of hybrid bpdos obtained using common restriction sites to exchange large dna fragments between lb400 bpha and b-356 bpha showed that the c-terminal portion of lb400 alpha subunit can withstand extensive structural modifications, and that these modifications can change the catalytic properties of the enzyme. on the other hand, exchang ... | 2001 | 11766051 |
| coexistence of two distinct copies of naphthalene degradation genes in pseudomonas strains isolated from the western mediterranean region. | we analyzed the occurrence of the naphthalene degradation upper-pathway (nah) genes in the western mediterranean region. the amplification, restriction, and sequence analysis of internal fragments for several nah genes (nahac, nahb, nahc, and nahe) from naphthalene-degrading strains isolated from this geographical area proved the coexistence of two distinct sets of nah genes. | 2002 | 11823244 |
| two distinct alcohol dehydrogenases participate in butane metabolism by pseudomonas butanovora. | the involvement of two primary alcohol dehydrogenases, bdh and boh, in butane utilization in pseudomonas butanovora (atcc 43655) was demonstrated. the genes coding for boh and bdh were isolated and characterized. the deduced amino acid sequence of boh suggests a 67-kda alcohol dehydrogenase containing pyrroloquinoline quinone (pqq) as cofactor and in the periplasm (29-residue leader sequence). the deduced amino acid sequence of bdh is consistent with a 70.9-kda, soluble, periplasmic (37-residue ... | 2002 | 11889098 |
| ania regulates reserve polymer accumulation and global protein expression in rhizobium etli. | previously, it was reported that the oxidative capacity and ability to grow on carbon sources such as pyruvate and glucose were severely diminished in the rhizobium etli phac::omegasm(r)/sp(r) mutant car1, which is unable to synthesize poly-beta-hydroxybutyric acid (phb) (m. a. cevallos, s. encarnación, a. leija, y. mora, and j. mora, j. bacteriol. 178:1646-1654, 1996). by random tn5 mutagenesis of the phac strain, we isolated the mutants vem57 and vem58, both of which contained single tn5 inser ... | 2002 | 11914361 |
| genotyping cryptosporidium parvum with an hsp70 single-nucleotide polymorphism microarray. | we investigated the application of an oligonucleotide microarray to (i) specifically detect cryptosporidium spp., (ii) differentiate between closely related c. parvum isolates and cryptosporidium species, and (iii) differentiate between principle genotypes known to infect humans. a microarray of 68 capture probes targeting seven single-nucleotide polymorphisms (snps) within a 190-bp region of the hsp70 gene of cryptosporidium parvum was constructed. labeled hsp70 targets were generated by pcr wi ... | 2002 | 11916701 |
| rapid assessment of the physiological status of the polychlorinated biphenyl degrader comamonas testosteroni tk102 by flow cytometry. | the viability of the polychlorinated biphenyl-degrading bacterium comamonas testosteroni tk102 was assessed by flow cytometry (fcm) with the fluorogenic ester calcein-am (cam) and the nucleic acid dye propidium iodide (pi). cam stained live cells, whereas pi stained dead cells. when double staining with cam and pi was performed, three physiological states, i.e., live (calcein positive, pi negative), dead (calcein negative, pi positive), and permeabilized (calcein positive, pi positive), were det ... | 2002 | 11916727 |
| comamonas koreensis sp. nov., a non-motile species from wetland in woopo, korea. | a bacterial strain, designated yh12t, was isolated from a wetland sample collected from woopo, republic of korea, and characterized using a polyphasic approach. analysis of 16s rdna indicated that the isolate formed a monophyletic clade with the members of the genus comamonas. the closest phylogenetic relative among the valid species was comamonas testosteroni, with 96.6% 16s rdna similarity. the chemotaxonomic properties of the wetland isolate supported its membership of the genus comamonas, as ... | 2002 | 11931145 |
| requirement of two protein fractions for o-demethylase activity in pseudomonas testosteroni. | | 1971 | 11945566 |
| conformation of native pseudomonas testosteroni delta(5)-->(4) 3-oxosteroid isomerase. | | 1972 | 11946627 |
| trifluoroethanol increases the stability of delta(5)-3-ketosteroid isomerase. 15n nmr relaxation studies. | in the equilibrium unfolding process of delta(5)-3-ketosteroid isomerase from pseudomonas testosteroni by urea, it was observed that the enzyme stability increases by 2.5 kcal/mol in the presence of 5% trifluoroethanol (tfe). to elucidate the increased enzyme stability by tfe, the backbone dynamics of delta(5)-3-ketosteroid isomerase were studied in the presence and absence of 5% tfe by (15)n nmr relaxation measurements, and the motional parameters (s(2), tau(e), and r(ex)) were extracted from t ... | 2002 | 11973332 |
| characterization of a class ii defective transposon carrying two haloacetate dehalogenase genes from delftia acidovorans plasmid puo1. | the two haloacetate dehalogenase genes, dehh1 and dehh2, on the 65-kb plasmid puo1 from delftia acidovorans strain b were found to be located on transposable elements. the dehh2 gene was carried on an 8.9-kb class i composite transposon (tnhad1) that was flanked by two directly repeated copies of is1071, is1071l and is1071r. the dehh1 gene was also flanked by is1071l and a truncated version of is1071 (is1071n). tnhad1, dehh1, and is1071n were located on a 15.6-kb class ii transposon (tnhad2) who ... | 2002 | 11976102 |
| soil microbial population dynamics following bioaugmentation with a 3-chlorobenzoate-degrading bacterial culture. bioaugmentation effects on soil microorganisms. | changes in microbial populations were evaluated following inoculation of contaminated soil with a 3-chlorobenzoate degrader. madera sandy loam was amended with 0, 500, or 1,000 microg 3-chlorobenzoate g(-1) dry soil. selected microcosms were inoculated with the degrader comamonas testosteroni br60. culturable bacterial degraders were enumerated on minimal salts media containing 3-chlorobenzoate. culturable heterotrophic bacteria were enumerated on r2a. isolated degraders were grouped by enteroba ... | 2001 | 11998824 |
| characterization of unusual bacteria isolated from respiratory secretions of cystic fibrosis patients and description of inquilinus limosus gen. nov., sp. nov. | using a polyphasic approach (including cellular protein and fatty acid analysis, biochemical characterization, 16s ribosomal dna sequencing, and dna-dna hybridizations), we characterized 51 bacterial isolates recovered from respiratory secretions of cystic fibrosis (cf) patients. our analyses showed that 24 isolates belong to taxa that have so far not (or only rarely) been reported from cf patients. these taxa include acinetobacter sp., bordetella hinzii, burkholderia fungorum, comamonas testost ... | 2002 | 12037065 |
| identification of a novel comamonas testosteroni gene encoding a steroid-inducible extradiol dioxygenase. | comamonas testosteroni is a gram-negative bacterium that can grow on steroids and polycyclic aromatic hydrocarbons (pah) as sole carbon and energy source. complete mineralisation of these compounds is achieved through complex metabolic pathways comprising a set of inducible enzymes. whereas the degradation pathways for pahs have been intensively studied, patterns of enzymes leading to ring fissions of the steroid nucleus are unclear. several intermediates of the steroid and pah degradation pathw ... | 2002 | 12056803 |
| family shuffling of a targeted bpha region to engineer biphenyl dioxygenase. | in this work we used a new strategy designed to reduce the size of the library that needs to be explored in family shuffling to evolve new biphenyl dioxygenases (bpdos). instead of shuffling the whole gene, we have targeted a fragment of bpha that is critical for enzyme specificity. we also describe a new protocol to screen for more potent bpdos that is based on the detection of catechol metabolites from chlorobiphenyls. several bpha variants with extended potency to degrade polychlorinated biph ... | 2002 | 12081948 |
| an arac/xyls family member at a high level in a hierarchy of regulators for phenol-metabolizing enzymes in comamonas testosteroni r5. | comamonas testosteroni strain r5 expresses a higher level of phenol-oxygenating activity than any other bacterial strain so far characterized. the expression of the operon encoding multicomponent phenol hydroxylase (mph), which is responsible for the phenol-oxygenating activity, is controlled by two transcriptional regulators, phcs and phcr, in strain r5. in this study, we identified a third transcriptional regulator for the mph operon (phct) that belongs to the arac/xyls family. while the disru ... | 2002 | 12081966 |
| roles for the two 1-butanol dehydrogenases of pseudomonas butanovora in butane and 1-butanol metabolism. | pseudomonas butanovora grown on butane or 1-butanol expresses two 1-butanol dehydrogenases, a quinoprotein (boh) and a quinohemoprotein (bdh). boh exhibited high affinity towards 1-butanol (k(m) = 1.7 +/- 0.2 microm). boh also oxidized butyraldehyde and 2-butanol (k(m) = 369 +/- 85 microm and k(m) = 662 +/- 98 microm, respectively). the mrna induction profiles of boh and bdh at three different levels of 1-butanol, a nontoxic level (0.1 mm), a growth-supporting level (2 mm), and a toxic level (40 ... | 2002 | 12142403 |
| transfer of microorganisms, including listeria monocytogenes, from various materials to beef. | the quantity of microorganisms that may be transferred to a food that comes into contact with a contaminated surface depends on the density of microorganisms on the surface and on the attachment strengths of the microorganisms on the materials. we made repeated contacts between pieces of meat and various surfaces (stainless steel and conveyor belt materials [polyvinyl chloride and polyurethane]), which were conditioned with meat exudate and then were contaminated with listeria monocytogenes, sta ... | 2002 | 12147503 |
| characterization of an acetate-degrading sludge without intracellular accumulation of polyphosphate and glycogen. | a sequencing batch reactor (sbr) was operated in the conventional anaerobic-aerobic mode for enhanced biological phosphate removal (ebpr) using acetate as the sole substrate. results showed that, however, the reactor was unable to remove phosphate from wastewater. the sludge containing 1.65% of phosphate did not exhibit the typical characteristics of polyphosphate-accumulating organisms (pao) or glycogen-accumulating organisms (gao). phylogenetic analysis, based on 16s rdna sequences of individu ... | 2002 | 12188117 |
| bars1, a gene for biosynthesis of a gamma-butyrolactone autoregulator, a microbial signaling molecule eliciting antibiotic production in streptomyces species. | from streptomyces virginiae, in which production of streptogramin antibiotic virginiamycin m(1) and s is tightly regulated by a low-molecular-weight streptomyces hormone called virginiae butanolide (vb), which is a member of the gamma-butyrolactone autoregulators, the hormone biosynthetic gene (bars1) was cloned and characterized by heterologous expression in escherichia coli and by gene disruption in s. virginiae. the bars1 gene (a 774-bp open reading frame encoding a 257-amino-acid protein [m( ... | 2002 | 12193632 |
| characterization of the 5-carboxyvanillate decarboxylase gene and its role in lignin-related biphenyl catabolism in sphingomonas paucimobilis syk-6. | sphingomonas paucimobilis syk-6 degrades a lignin-related biphenyl compound, 5,5'-dehydrodivanillate (ddva), to 5-carboxyvanillate (5cva) by the enzyme reactions catalyzed by the ddva o-demethylase (ligx), the ring cleavage oxygenase (ligz), and the meta-cleavage compound hydrolase (ligy). in this study we examined the degradation step of 5cva. 5cva was transformed to vanillate, o-demethylated, and further degraded via the protocatechuate 4,5-cleavage pathway by this strain. a cosmid clone which ... | 2002 | 12200294 |
| flow cytometry analysis of changes in the dna content of the polychlorinated biphenyl degrader comamonas testosteroni tk102: effect of metabolites on cell-cell separation. | flow cytometry was used to monitor changes in the dna content of the polychlorinated biphenyl (pcb)-degrading bacterium comamonas testosteroni tk102 during growth in the presence or absence of pcbs. in culture medium without pcbs, the majority of stationary-phase cells contained a single chromosome. in the presence of pcbs, the percentage of cells containing two chromosomes increased from 12% to approximately 50%. in contrast, addition of pcbs did not change the dna contents of three species tha ... | 2002 | 12324361 |
| inhibition of deoxyribonucleic acid-directed ribonucleic acid polymerase by extracts of steroid-induced and noninduced pseudomonas testosteroni. | | 1967 | 12325385 |
| bioaugmenting bioreactors for the continuous removal of 3-chloroaniline by a slow release approach. | the survival and activity of microbial degradative inoculants in bioreactors is critical to obtain successful biodegradation of non- or slowly degradable pollutants. achieving this in industrial wastewater reactors is technically challenging. we evaluated a strategy to obtain complete and stable bioaugmentation of activated sludge, which is used to treat a 3-chloroaniline (3-ca) contaminated wastewater in a lab-scale semi-continuous activated sludge system. a 3-ca metabolizing bacterium, comamon ... | 2002 | 12433184 |
| use of bioconversion for the preparation of [4-14c]-labeled 7 alpha- and 7 beta-hydroxylated derivatives of dehydroepiandrosterone and epiandrosterone. | the 7 alpha- and 7 beta-hydroxylated derivatives of [4-14c]-dehydroepiandrosterone were prepared with use of the yeast-expressed human cytochrome p4507b1. epiandrosterone (epia), 5 alpha-androstane-3beta,17 beta-diol, and 5 alpha-androstane-3,17-dione were obtained after incubation of [4-14c]-5 alpha-dihydrotestosterone with escherichia coli-expressed (3beta,17 beta)-hydroxysteroid dehydrogenase from pseudomonas testosteroni. the 7 alpha- and 7 beta-hydroxylated derivatives of [4-14c]-epia produ ... | 2002 | 12441198 |
| structure of bacterial 3beta/17beta-hydroxysteroid dehydrogenase at 1.2 a resolution: a model for multiple steroid recognition. | the enzyme 3beta/17beta-hydroxysteroid dehydrogenase (3beta/17beta-hsd) is a steroid-inducible component of the gram-negative bacterium comamonas testosteroni. it catalyzes the reversible reduction/dehydrogenation of the oxo/beta-hydroxy groups at positions 3 and 17 of steroid compounds, including hormones and isobile acids. crystallographic analysis at 1.2 a resolution reveals the enzyme to have nearly identical subunits that form a tetramer with 222 symmetry. this is one of the largest oligome ... | 2002 | 12475215 |
| characterization of the 4-carboxy-4-hydroxy-2-oxoadipate aldolase gene and operon structure of the protocatechuate 4,5-cleavage pathway genes in sphingomonas paucimobilis syk-6. | the protocatechuate (pca) 4,5-cleavage pathway is the essential metabolic route for degradation of low-molecular-weight products derived from lignin by sphingomonas paucimobilis syk-6. in the 10.5-kb ecori fragment carrying the genes for pca 4,5-dioxygenase (ligab), 2-pyrone-4,6-dicarboxylate hydrolase (ligi), 4-oxalomesaconate hydratase (ligj), and a part of 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase (ligc), we found the ligk gene, which encodes 4-carboxy-4-hydroxy-2-oxoadipate (c ... | 2003 | 12486039 |
| novel approach to the improvement of biphenyl and polychlorinated biphenyl degradation activity: promoter implantation by homologous recombination. | to improve the capabilities of microorganisms relevant for biodegradation, we developed a new genetic approach and applied it to the bph operon (bphegf[orf4]a1a2a3cd[orf1]a4r) of pseudomonas sp. strain kks102 to enhance its biphenyl- and polychlorinated biphenyl (pcb)-degrading activity. a native promoter of the bph operon, which was under control, was replaced through homologous recombination by a series of promoters that had constitutive activity. by testing a series of promoters with various ... | 2003 | 12513989 |
| directed evolution approach to a structural genomics project: rv2002 from mycobacterium tuberculosis. | one of the serious bottlenecks in structural genomics projects is overexpression of the target proteins in soluble form. we have applied the directed evolution technique and prepared soluble mutants of the mycobacterium tuberculosis rv2002 gene product, the wild type of which had been expressed as inclusion bodies in escherichia coli. a triple mutant i6tv47mt69k (rv2002-m3) was chosen for structural and functional characterizations. enzymatic assays indicate that the rv2002-m3 protein has a high ... | 2003 | 12524453 |
| regulation of 3alpha-hydroxysteroid dehydrogenase/carbonyl reductase in comamonas testosteroni: function and relationship of two operators. | comamonas testosteroni 3alpha-hydroxysteroid dehydrogenase/carbonyl reductase (3alpha-hsd/cr) is a key enzyme in the degradation of steroid compounds in soil, and may therefore play a significant role in the bioremediation of hormonally active substances in the environment. we previously reported the isolation of the 3alpha-hsd/cr gene (hsda) from c. testosteroni and two repressor genes, repa and repb, for hsda transcriptional and translational regulation, respectively. in this work, we found th ... | 2003 | 12604228 |
| characterization and recombinant expression of the translational repressor repb of 3alpha-hydroxysteroid dehydrogenase/carbonyl reductase in comamonas testosteroni. | 3alpha-hydroxysteroid dehydrogenase/carbonyl reductase (3alpha-hsd/cr) from comamonas testosteroni is a key enzyme involved in the degradation of steroids and xenobiotic carbonyl compounds. the gene of 3alpha-hsd/cr (hsda) was cloned and characterized by our group. we have also reported that two repressor proteins (repa and repb) have been identified which regulate hsda expression. to further characterize repb, the protein was expressed in escherichia coli and purified in an active state. gel sh ... | 2003 | 12604229 |
| bioaugmentation as a tool to protect the structure and function of an activated-sludge microbial community against a 3-chloroaniline shock load. | bioaugmentation of bioreactors focuses on the removal of xenobiotics, with little attention typically paid to the recovery of disrupted reactor functions such as ammonium-nitrogen removal. chloroanilines are widely used in industry as a precursor to a variety of products and are occasionally released into wastewater streams. this work evaluated the effects on activated-sludge reactor functions of a 3-chloroaniline (3-ca) pulse and bioaugmentation by inoculation with the 3-ca-degrading strain com ... | 2003 | 12620837 |
| synergistic degradation of linuron by a bacterial consortium and isolation of a single linuron-degrading variovorax strain. | the bacterial community composition of a linuron-degrading enrichment culture and the role of the individual strains in linuron degradation have been determined by a combination of methods, such as denaturing gradient gel electrophoresis of the total 16s rrna gene pool, isolation and identification of strains, and biodegradation assays. three strains, variovorax sp. strain wdl1, delftia acidovorans wdl34, and pseudomonas sp. strain wdl5, were isolated directly from the linuron-degrading culture. ... | 2003 | 12620840 |
| prokaryotic homologs of the eukaryotic 3-hydroxyanthranilate 3,4-dioxygenase and 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase in the 2-nitrobenzoate degradation pathway of pseudomonas fluorescens strain ku-7. | the 2-nitrobenzoic acid degradation pathway of pseudomonas fluorescens strain ku-7 proceeds via a novel 3-hydroxyanthranilate intermediate. in this study, we cloned and sequenced a 19-kb dna locus of strain ku-7 that encompasses the 3-hydroxyanthranilate meta-cleavage pathway genes. the gene cluster, designated nbaexhjigfcdr, is organized tightly and in the same direction. the nbac and nbad gene products were found to be novel homologs of the eukaryotic 3-hydroxyanthranilate 3,4-dioxygenase and ... | 2003 | 12620844 |
| the role of cell bioaugmentation and gene bioaugmentation in the remediation of co-contaminated soils. | soils co-contaminated with metals and organics present special problems for remediation. metal contamination can delay or inhibit microbial degradation of organic pollutants such that for effective in situ biodegradation, bioaugmentation is necessary. we monitored the degradation of 2,4-dichlorophenoxyacetic acid (2,4-d) or 3-chlorobenzoate (3-cb) in two different soils with and without cadmium (cd) contamination. additionally, we evaluated the ability of bioaugmentation to enhance organic degra ... | 2002 | 12634123 |
| gene encoding the hydrolase for the product of the meta-cleavage reaction in testosterone degradation by comamonas testosteroni. | in a previous study we isolated the meta-cleavage enzyme gene, tesb, that encodes an enzyme that carries out a meta-cleavage reaction in the breakdown of testosterone by comamonas testeroni ta441 (m. horinouchi et al., microbiology 147:3367-3375, 2001). here we report the isolation of a gene, tesd, that encodes a hydrolase which acts on the product of the meta-cleavage reaction. we isolated tesd by using a tn5 mutant of ta441 that showed limited growth on testosterone. tesd exhibited ca. 40% ide ... | 2003 | 12676694 |
| horizontal transfer of phnac dioxygenase genes within one of two phenotypically and genotypically distinctive naphthalene-degrading guilds from adjacent soil environments. | several distinct naphthalene dioxygenases have been characterized to date, which provides the opportunity to investigate the ecological significance, relative distribution, and transmission modes of the different analogs. in this study, we showed that a group of naphthalene-degrading isolates from a polycyclic aromatic hydrocarbon (pah)-contaminated hillside soil were phenotypically and genotypically distinct from naphthalene-degrading organisms isolated from adjacent, more highly contaminated s ... | 2003 | 12676698 |
| characterization of tsar, an oxygen-sensitive lysr-type regulator for the degradation of p-toluenesulfonate in comamonas testosteroni t-2. | tsar is the putative lysr-type regulator of the tsa operon (tsambcd) which encodes the first steps in the degradation of p-toluenesulfonate (tsa) in comamonas testosteroni t-2. transposon mutagenesis was used to knock out tsar. the resulting mutant lacked the ability to grow with tsa and p-toluenecarboxylate (tca). reintroduction of tsar in trans on an expression vector reconstituted growth with tsa and tca. the tsar gene was cloned into escherichia coli with a c-terminal his tag and overexpress ... | 2003 | 12676713 |
| the ethanol oxidation system and its regulation in pseudomonas aeruginosa. | pseudomonas aeruginosa atcc 17933, when growing on ethanol, uses a pyrroloquinoline quinone (pqq)-dependent ethanol oxidation system. the genes coding for the ethanol oxidizing enzyme, a quinoprotein ethanol dehydrogenase (qedh), cytochrome c(550), which is an essential component of the electron transport chain and accepts the electrons from qedh, and an nad-dependent acetaldehyde dehydrogenase form the exaabc gene cluster. downstream of the exabc genes the pqqabcde gene cluster is found, which ... | 2003 | 12686116 |
| the quinohaemoprotein lupanine hydroxylase from pseudomonas putida. | lupanine hydroxylase catalyses the first reaction in the catabolism of the alkaloid lupanine by pseudomonas putida. it dehydrogenates the substrate, which can then be hydrated. it is a monomeric protein of m(r) 72,000 and contains a covalently bound haem and a molecule of pqq. the gene for this enzyme has been cloned and sequenced and the derived protein sequence has a 26 amino acid signal sequence at the n-terminal for translocation of the protein to the periplasm. many of the features seen in ... | 2003 | 12686118 |
| deuterium isotope effect on enantioselectivity in the comamonas testosteroni quinohemoprotein alcohol dehydrogenase-catalyzed kinetic resolution of rac-2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane, solketal. | isotopic substitution provides an effective tool to probe the mechanism of enzyme-catalyzed reactions. to our knowledge, kinetic isotope effects on the enantioselectivity of enzymes have not been reported. we investigated the effect of deuterium substitution on the enantiomeric ratio, e, of pqq-containing quinohemoprotein alcohol dehydrogenase, qh-adh, from comamonas testosteroni in the ferricyanide-coupled kinetic resolution of rac-2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane, solketal. under oth ... | 2003 | 12686148 |
| substrate specificity and expression of three 2,3-dihydroxybiphenyl 1,2-dioxygenases from rhodococcus globerulus strain p6. | rhodococcus globerulus strain p6 contains at least three genes, bphc1, bphc2, and bphc3, coding for 2,3-dihydroxybiphenyl 1,2-dioxygenases; the latter two specify enzymes of the family of one-domain extradiol dioxygenases. in order to assess the importance of these different isoenzymes for the broad catabolic activity of this organism towards the degradation of polychlorinated biphenyls (pcbs), the capacities of recombinant enzymes expressed in escherichia coli to transform different chlorosubst ... | 2003 | 12700274 |
| chaperone-assisted expression, purification, and characterization of recombinant nitrile hydratase ni1 from comamonas testosteroni. | nitrile hydratases (nhases) are industrially important iron- and cobalt-containing enzymes that are used in the large-scale synthesis of acrylamide. heterologous expression of nhases has been complicated by the fact that other proteins (activators or metallochaperones) appear to be required to produce nhases in their catalytically active form. we report a novel heterologous system for the expression of catalytically active iron-containing ni1 nhase in escherichia coli, involving coexpression wit ... | 2003 | 12729727 |
| origin of the different ph activity profile in two homologous ketosteroid isomerases. | two homologous delta5-3-ketosteroid isomerases from comamonas testosteroni (ti-wt) and pseudomonas putida biotype b (pi-wt) exhibit different ph activity profiles. ti-wt loses activity below ph 5.0 due to the protonation of the conserved catalytic base, asp-38, while pi-wt does not. based on the structural analysis of pi-wt, the critical catalytic base, asp-38, was found to form a hydrogen bond with the indole ring nh of trp-116, which is homologously replaced with phe-116 in ti-wt. to investiga ... | 2003 | 12734184 |
| microbial population diversity in the urethras of healthy males and males suffering from nonchlamydial, nongonococcal urethritis. | nonchlamydial, nongonococcal urethritis (ncngu) is suggested to be a sexually transmitted disease in men. ncngu patients were compared to control subjects with regard to the presence of potentially infectious bacteria in the first void urine. patients' pre- and post-antibiotic-treatment urine samples and two samples obtained 2 weeks apart from healthy volunteers, who did not receive antibiotic therapy, were analyzed with broad-spectrum pcr tests aiming at eubacterial small subunit rrna genes. re ... | 2003 | 12734237 |
| comamonas testosteroni meningitis in a patient with recurrent cholesteatoma. | comamonas testosteroni, a lesser-known member of the genus, has shown little apparent capacity for causing infections in humans. we here present a case of purulent meningitis due to c. testosteroni, which occurred in a patient who had recurrent cholesteatoma. ceftriaxone treatment was not effective in this patient even though in vitro the bacteria were susceptible to the drug. the patient responded well to meropenem therapy. | 2003 | 12780521 |
| the conserved cis-pro39 residue plays a crucial role in the proper positioning of the catalytic base asp38 in ketosteroid isomerase from comamonas testosteroni. | ksi (ketosteroid isomerase) from comamonas testosteroni is a homodimeric enzyme that catalyses the allylic isomerization of delta5-3-ketosteroids to their conjugated delta4-isomers at a reaction rate equivalent to the diffusion-controlled limit. based on the structural analysis of ksi at a high resolution, the conserved cis-pro39 residue was proposed to be involved in the proper positioning of asp38, a critical catalytic residue, since the residue was found not only to be structurally associated ... | 2003 | 12852789 |
| evaluation of effective diffusion coefficient and intrinsic kinetic parameters on azo dye biodegradation using pva-immobilized cell beads. | an immobilized mixed culture (aeromonas hydrophila, comamonas testosteroni, and acinetobacter baumannii) was prepared by entrapment into phosphorylated polyvinyl alcohol (pva) gel beads. the unsteady-state diffusion mechanism in a gel bead was applied to estimate the effective diffusion coefficients (d(e)) and the partition coefficients (k(p)) of azo dye. in addition, a simple method was developed to determine the intrinsic kinetic parameters of immobilized cells from observed reaction rates and ... | 2003 | 12889022 |
| cloning of a nitrilase gene from the cyanobacterium synechocystis sp. strain pcc6803 and heterologous expression and characterization of the encoded protein. | the gene encoding a putative nitrilase was identified in the genome sequence of the photosynthetic cyanobacterium synechocystis sp. strain pcc6803. the gene was amplified by pcr and cloned into an expression vector. the encoded protein was heterologously expressed in the native form and as a his-tagged protein in escherichia coli, and the recombinant strains were shown to convert benzonitrile to benzoate. the active enzyme was purified to homogeneity and shown by gel filtration to consist probab ... | 2003 | 12902216 |
| a new bacterial steroid degradation gene cluster in comamonas testosteroni ta441 which consists of aromatic-compound degradation genes for seco-steroids and 3-ketosteroid dehydrogenase genes. | in comamonas testosteroni ta441, testosterone is degraded via aromatization of the a ring, which is cleaved by the meta-cleavage enzyme tesb, and further degraded by tesd, the hydrolase for the product of tesb. tesefg, encoded downstream of tesd, are probably hydratase, aldolase, and dehydrogenase for degradation of 2-oxohex-4-enoicacid, one of the products of tesd. here we present a new and unique steroid degradation gene cluster in ta441, which consists of orf18, orf17, tesi, tesh, orf11, orf1 ... | 2003 | 12902225 |
| cynd, the cyanide dihydratase from bacillus pumilus: gene cloning and structural studies. | the cyanide dihydratase in bacillus pumilus was shown to be an 18-subunit spiral structure by three-dimensional reconstruction of electron micrographs of negatively stained material at its optimum ph, 8.0. at ph 5.4, the subunits rearrange to form an extended left-handed helix. gel electrophoresis of glutaraldehyde cross-linked enzyme suggests that the fundamental component of the spiral is a dimer of the 37-kda subunit. the gene was cloned, and the recombinant enzyme was readily expressed at hi ... | 2003 | 12902273 |
| dual labeling of pseudomonas putida with fluorescent proteins for in situ monitoring of conjugal transfer of the tol plasmid. | we describe here a dual-labeling technique involving the green fluorescent protein (gfp) and the red fluorescent protein (dsred) for in situ monitoring of horizontal gene transfer via conjugation. a gfpmut3b-tagged derivative of narrow-host-range tol plasmid (pwwo) was delivered to pseudomonas putida kt2442, which was chromosomally labeled with dsred by transposon insertion via biparental mating. green and red fluorescent proteins were coexpressed in donor p. putida cells. cells expressing both ... | 2003 | 12902279 |
| hydroxycinnamate (hca) catabolic genes from acinetobacter sp. strain adp1 are repressed by hcar and are induced by hydroxycinnamoyl-coenzyme a thioesters. | hydroxycinnamates are plant products catabolized through the diphenol protocatechuate in the naturally transformable bacterium acinetobacter sp. strain adp1. genes for protocatechuate catabolism are central to the dca-pca-qui-pob-hca chromosomal island, for which gene designations corresponding to catabolic function are dca (dicarboxylic acid), pca (protocatechuate), qui (quinate), pob (p-hydroxybenzoate), and hca (hydroxycinnamate). acinetobacter hcac had been cloned and shown to encode a hydro ... | 2003 | 12957928 |
| growth of escherichia coli in model distribution system biofilms exposed to hypochlorous acid or monochloramine. | bacteria indigenous to water distribution systems were used to grow multispecies biofilms within continuous-flow slide chambers. six flow chambers were also inoculated with an escherichia coli isolate obtained from potable water. the effect of disinfectants on bacterial populations was determined after exposure of established biofilms to 1 ppm of hypochlorous acid (cloh) for 67 min or 4 ppm of monochloramine (nh(2)cl) for 155 min. to test the ability of bacterial populations to initiate biofilm ... | 2003 | 12957935 |
| characterization of phenol biodegradation by comamonas testosteroni zd4-1 and pseudomonas aeruginosa zd4-3. | to investigate the characteristic and biochemical mechanism about the phenol biodegradation by bacterial strains zd 4-1 and zd 4-3. | 2003 | 12964790 |
| identification and characterization of a novel translational repressor of the steroid-inducible 3 alpha-hydroxysteroid dehydrogenase/carbonyl reductase gene in comamonas testosteroni. | comamonas testosteroni 3 alpha-hydroxysteroid dehydrogenase/carbonyl reductase (3 alpha-hsd/cr) is a key enzyme in the degradation of steroid compounds in soil and may therefore play a significant role in the bioremediation of hormonally active compounds in the environment. the enzyme is also involved in the degradation of the steroid antibiotic fusidic acid. in addition, 3 alpha-hsd/cr mediates the carbonyl reduction of non-steroidal aldehydes and ketones. because the gene of 3 alpha-hsd/cr (hs ... | 2003 | 12975360 |
| characterization and regulation of the genes for a novel anthranilate 1,2-dioxygenase from burkholderia cepacia dbo1. | anthranilate (2-aminobenzoate) is an important intermediate in tryptophan metabolism. in order to investigate the degradation of tryptophan through anthranilate by burkholderia cepacia, several plasposon mutations were constructed of strain dbo1 and one mutant with the plasposon insertion in the anthranilate dioxygenase (antdo) genes was chosen for further study. the gene sequence obtained from flanking dna of the plasposon insertion site revealed unexpected information. b. cepacia dbo1 antdo (d ... | 2003 | 13129960 |
| an additional regulator, tsaq, is involved with tsar in regulation of transport during the degradation of p-toluenesulfonate in comamonas testosteroni t-2. | the degradation of p-toluenesulfonate (tsa) by comamonas testosteroni t-2 is initiated by a transport system (tsast) and enzymes (tsambcd) encoded on the tsa transposon, tn tsa, on the tsa plasmid (ptsa). tn tsa comprises an insert of 15 kb between two is 1071 elements. the left-hand 6 kb and the right-hand 6 kb are nearly mirror images. the regulator of the tsambcd1 genes (right-hand side) is the centrally located lysr-type tsar, which is encoded upstream of tsambcd1 on the reverse strand. the ... | 2003 | 13680097 |
| purification of steroid-induced enzymes from pseudomonas testosteroni. | | 1964 | 14209323 |
| physical and chemical characterization of hydroxysteroid dehydrogenases from pseudomonas testosteroni. | | 1964 | 14209324 |
| post-translational modification of rhodococcus r312 and comamonas ni1 nitrile hydratases. | nitrile hydratases (nhases) are industrially significant iron- and cobalt-containing enzymes used in the large-scale synthesis of acrylamide. previous reports have shown that the active site peptides of nhases are post-translationally modified by oxidation of cysteine residues, and that these modifications are essential for catalysis. we report mass spectrometric evidence of the oxidation states of the active site cysteines in the iron coordination spheres of two iron-containing nitrile hydratas ... | 2003 | 14505323 |
| identification of three new genes involved in morphogenesis and antibiotic production in streptomyces coelicolor. | we report the isolation and partial characterization of three new mutants of streptomyces coelicolor that are defective in morphogenesis and antibiotic production. the genes identified by the mutations were located and cloned by using a combination of tn5 in vitro mutagenesis, cotransformation, and genetic complementation. mutant se69 produces lower amounts of antibiotics than the wild type produces, produces spores only after prolonged incubation on rich media, and identifies a gene whose predi ... | 2003 | 14526027 |
| ability of bacterial biphenyl dioxygenases from burkholderia sp. lb400 and comamonas testosteroni b-356 to catalyse oxygenation of ortho-hydroxychlorobiphenyls formed from pcbs by plants. | capacity of enzymes of the biphenyl/chlorobiphenyl pathway, especially biphenyl dioxygenase (bpdo) of two polychlorinated biphenyls (pcb) degrading bacteria, burkholderia sp. lb400 and comamonas testosteroni b-356, to metabolize ortho-substituted hydroxybiphenyls was tested.,these compounds found among plant products of pcb metabolism, are carrying chlorine atoms on the hydroxyl-substituted ring. the abilities of his-tagged purified lb400 and b-356 bpdos to catalyze the oxygenation of 2-hydroxy- ... | 2004 | 14553993 |
| discovery of a bacterium, with distinctive dioxygenase, that is responsible for in situ biodegradation in contaminated sediment. | microorganisms maintain the biosphere by catalyzing biogeochemical processes, including biodegradation of organic chemical pollutants. yet seldom have the responsible agents and their respective genes been identified. here we used field-based stable isotopic probing (sip) to discover a group of bacteria responsible for in situ metabolism of an environmental pollutant, naphthalene. we released 13c-labeled naphthalene in a contaminated study site to trace the flow of pollutant carbon into the natu ... | 2003 | 14597712 |
| characterization of a soil-derived bacterial consortium degrading 4-chloroaniline. | a bacterial consortium comprising four different species was isolated from an indonesian agricultural soil using a mixture of aniline and 4-chloroaniline (4ca) as principal carbon sources. the four species were identified as chryseobacterium indologenes sb1, comamonas testosteroni sb2, pseudomonas corrugata sb4 and stenotrophomonas maltophilia sb5. growth studies on aniline and 4ca as single and mixed substrates demonstrated that the bacteria preferred to grow on and utilize aniline rather than ... | 2003 | 14600240 |
| molecular characterization and substrate preference of a polycyclic aromatic hydrocarbon dioxygenase from cycloclasticus sp. strain a5. | cycloclasticus sp. strain a5 is able to grow with petroleum polycyclic aromatic hydrocarbons (pahs), including unsubstituted and substituted naphthalenes, dibenzothiophenes, phenanthrenes, and fluorenes. a set of genes responsible for the degradation of petroleum pahs was isolated by using the ability of the organism to oxidize indole to indigo. this 10.5-kb dna fragment was sequenced and found to contain 10 open reading frames (orfs). seven orfs showed homology to previously characterized genes ... | 2003 | 14602629 |
| molecular determinants of the hpa regulatory system of escherichia coli: the hpar repressor. | the hpar-mediated regulation of the hpa-meta operon (pg promoter) of the 4-hydroxyphenylacetic acid catabolic pathway of escherichia coli has been studied. the hpar regulator was purified to homogeneity showing that it is able to bind selectively to 4-hydroxyphenylacetic, 3-hydroxyphenylacetic and 3,4-dihydroxyphenylacetic acids, which act as inducers of the system. the role of hpar as a repressor and the requirement for camp receptor protein for maximal activity have been confirmed by in vitro ... | 2003 | 14602920 |
| influence of peanut oil on microbial degradation of polycyclic aromatic hydrocarbons. | peanut oil amendment (0.1%-0.2% (v/v)) increased the biodegradation of various polycyclic aromatic hydrocarbons (pahs) by 15%-80% with a mixed bacterial culture and a pure culture of comamonas testosteroni in aqueous media and in pah-contaminated weathered soil slurry systems. the stimulatory effect on biodegradation was more pronounced with the high molecular weight pahs (e.g., >3 rings). the presence of peanut oil also accelerated the biodegradation of pahs sorbed onto activated carbon, indica ... | 2003 | 14608386 |
| transporter-mediated uptake of 2-chloro- and 2-hydroxybenzoate by pseudomonas huttiensis strain d1. | we investigated the mechanisms of uptake of 2-chlorobenzoate (2-cba) and 2-hydroxybenzoate (2-hba) by pseudomonas huttiensis strain d1. uptake was monitored by assaying intracellular accumulation of 2-[ul-ring-14c]cba and 2-[ul-ring-14c]hba. uptake of 2-cba showed substrate saturation kinetics with an apparent km of 12.7 +/- 2.6 micromoles and a maximum velocity (vmax) of 9.76 +/- 0.78 nmol min-1 mg of protein-1. enhanced rates of uptake were induced by growth on 2-cba and 2-hba, but not by grow ... | 2003 | 14660391 |
| energization of comamonas testosteroni atcc 17454 for indicating toxic effects of chlorophenoxy herbicides. | the toxicity of chlorophenoxy herbicides to a bacterium, strongly related to the well-known species delftia (formerly comamonas) acidovorans that are able to detoxify these xenobiotics, was investigated. the oxidation of n-hexanol via alcohol dehydrogenases, coupled with the generation of atp by electron transport phosphorylation (etp), was used as an indicator for energy-toxic effects on the growth of comamonas testosteroni atcc 17454. uncoupling--reductions in atp synthesis accompanied by incr ... | 2003 | 14674583 |
| metabolism of 2,2'- and 3,3'-dihydroxybiphenyl by the biphenyl catabolic pathway of comamonas testosteroni b-356. | the purpose of this investigation was to examine the capacity of the biphenyl catabolic enzymes of comamonas testosteroni b-356 to metabolize dihydroxybiphenyls symmetrically substituted on both rings. data show that 3,3'-dihydroxybiphenyl is by far the preferred substrate for strain b-356. however, the dihydrodiol metabolite is very unstable and readily tautomerizes to a dead-end metabolite or is dehydroxylated by elimination of water. the tautomerization route is the most prominent. thus, a ve ... | 2004 | 14711640 |
| pqq glucose dehydrogenase with novel electron transfer ability. | pqq glucose dehydrogenase from acinetobacter calcoaceticus (gdh-b) is one of the most industrially attractive enzymes, as a sensor constituent for glucose sensing, because of its high catalytic activity and insensitivity to oxygen. we attempted to engineer gdh-b to enable electron transfer to the electrode in the absence of artificial electron mediator by mimicking the domain structure of the quinohemoprotein ethanol dehydrogenase (qh-edh) from comamonas testosteroni, which is composed of a pqq- ... | 2004 | 14741705 |
| teir, a luxr-type transcription factor required for testosterone degradation in comamonas testosteroni. | we have identified a new steroid-inducible gene (designated teir [testosterone-inducible regulator]) in comamonas testosteroni that is required for testosterone degradation. nucleotide sequence analysis of teir predicts a 391-amino-acid protein which shows homology between residues 327 and 380 (c-terminal domain) to the luxr helix-turn-helix dna binding domain and between residues 192 and 227 to the pas sensor domain. this domain distribution resembles that described for trar, a specific transcr ... | 2004 | 14973025 |
| identification of a novel steroid inducible gene associated with the beta hsd locus of comamonas testosteroni. | comamonas testosteroni is a soil bacterium, which can use a variety of steroids as carbon and energy source. even if it can be estimated that the complete degradation of the steroid nucleus requires more than 20 enzymatic reactions, the complete molecular characterization of the genes encoding these steroid degradative enzymes as well as the genetic organization of them remain to be elucidated. we have previously reported the cloning and nucleotide sequence of two steroid-inducible genes, beta h ... | 2004 | 15026087 |
| molecular breeding of 2,3-dihydroxybiphenyl 1,2-dioxygenase for enhanced resistance to 3-chlorocatechol. | 3-chlorobiphenyl is known to be mineralized by biphenyl-utilizing bacteria to 3-chlorobenzoate, which is further metabolized to 3-chlorocatechol. an extradiol dioxygenase, 2,3-dihydroxybiphenyl 1,2-dioxygenase (dhb12o; ec 1.13.11.39), which is encoded by the bphc gene, catalyzes the third step of the upper pathway of 3-chlorobiphenyl degradation. in this study, two full-length bphcs and nine partial fragments of bphcs fused to the 3' end of bphc in pseudomonas pseudoalcaligenes kf707 were cloned ... | 2004 | 15113829 |
| conjugal transfer of plasmid pnb2 to activated sludge bacteria leads to 3-chloroaniline degradation in enrichment cultures. | the involvement of the aniline-degradative plasmid pnb2 in degradation of 3-chloroaniline (3-ca) was investigated. | 2004 | 15130151 |
| herbaspirillum chlorophenolicum sp. nov., a 4-chlorophenol-degrading bacterium. | a 4-chlorophenol-degrading bacterial strain, formerly designated as a strain of comamonas testosteroni, was reclassified as a member of the genus herbaspirillum based on its phenotypic and chemotaxonomic characteristics, as well as phylogenetic analysis using 16s rdna sequences. phylogenetic inference based on 16s rdna sequences showed that strain cpw301(t) clusters in a phylogenetic branch that contains herbaspirillum species. 16s rdna sequence similarity of strain cpw301(t) to species of the g ... | 2004 | 15143035 |
| a novel outer-membrane anion channel (porin) as part of a putatively two-component transport system for 4-toluenesulphonate in comamonas testosteroni t-2. | inducible mineralization of tsa (4-toluenesulphonate) by comamonas testosteroni t-2 is initiated by a secondary transport system, followed by oxygenation and oxidation by tsambcd to 4-sulphobenzoate under the regulation of tsar and tsaq. evidence is presented for a novel, presumably two-component transport system (tsast). it is proposed that tsat, an outer-membrane porin, formed an anion-selective channel that works in co-operation with the putative secondary transporter, tsas, located in the in ... | 2004 | 15176949 |
| kinetic property and phylogenic relationship of 2-hydroxymuconic semialdehyde dehydrogenase encoded in tomc gene of burkholderia cepacia g4. | 2-hydroxymuconic semialdehyde (2-hms) dehydrogenase catalyzes the conversion of 2-hms to 4-oxalocrotonate, which is a step in the meta cleavage pathway of aromatic hydrocarbons in bacteria. a tomc gene that encodes 2-hms dehydrogenase of burkholderia cepacia g4, a soil bacterium that can grow on toluene, cresol, phenol, or benzene, was overexpressed into e. coli hb101, and its gene product was characterized in this study. 2-hms dehydrogenase from b. cepacia g4 has a high catalytic efficiency in ... | 2004 | 15202565 |
| structural double-mutant cycle analysis of a hydrogen bond network in ketosteroid isomerase from pseudomonas putida biotype b. | ksi (ketosteroid isomerase) catalyses an allylic isomerization reaction at a diffusion-controlled rate. a hydrogen bond network, asp(99).water(504).tyr(14).tyr(55).tyr(30), connects two critical catalytic residues, tyr(14) and asp(99), with tyr(30), tyr(55) and a water molecule in the highly apolar active site of the pseudomonas putida ksi. in order to characterize the interactions among these amino acids in the hydrogen bond network of ksi, double-mutant cycle analysis was performed, and the cr ... | 2004 | 15228388 |
| abundance of dioxygenase genes similar to ralstonia sp. strain u2 nagac is correlated with naphthalene concentrations in coal tar-contaminated freshwater sediments. | we designed a real-time pcr assay able to recognize dioxygenase large-subunit gene sequences with more than 90% similarity to the ralstonia sp. strain u2 nagac gene (nagac-like gene sequences) in order to study the importance of organisms carrying these genes in the biodegradation of naphthalene. sequencing of pcr products indicated that this real-time pcr assay was specific and able to detect a variety of nagac-like gene sequences. one to 100 ng of contaminated-sediment total dna in 25-microl r ... | 2004 | 15240274 |
| mineralization of individual congeners of linear alkylbenzenesulfonate by defined pairs of heterotrophic bacteria. | parvibaculum lavamentivorans ds-1(t) utilized the commercial surfactant linear alkylbenzenesulfonate (las) (20 congeners with c(10) to c(13) side chains) as a carbon and energy source by shortening the side chain, and sulfophenylcarboxylates (spcs) and similar compounds (e.g., alpha,beta-unsaturated spcs [spc-2hs]) were excreted with quantitative recovery of the sulfophenyl moiety. 2-(4-sulfophenyl)decane (2-c10-las) was converted largely to 3-(4-sulfophenyl)butyrate (3-c4-spc), as were 2-c12-la ... | 2004 | 15240283 |
| detection of genes involved in biodegradation and biotransformation in microbial communities by using 50-mer oligonucleotide microarrays. | to effectively monitor biodegrading populations, a comprehensive 50-mer-based oligonucleotide microarray was developed based on most of the 2,402 known genes and pathways involved in biodegradation and metal resistance. this array contained 1,662 unique and group-specific probes with <85% similarity to their nontarget sequences. based on artificial probes, our results showed that under hybridization conditions of 50 degrees c and 50% formamide, the 50-mer microarray hybridization can differentia ... | 2004 | 15240314 |
| removal of nitriles from synthetic wastewater by acrylonitrile utilizing bacteria. | this study describes the ability of two bacteria strains, isolated from an abs resin manufacturing wastewater treatment system, to remove high acrylonitrile concentrations. straight chain aliphatic nitrile compound (propionitrile, allyl cyanide); branch chain aliphatic nitrile compound (isobutyronitrilc) and aromatic nitrile compound (benzonitrile) removal by comamonas testosteroni and acidovorax sp. was also investigated. the results are: comamonas testosteroni and acidovorax sp. can remove acr ... | 2004 | 15242125 |
| first comprehensively documented case of paracoccus yeei infection in a human. | paracoccus yeei was isolated in pure culture from an aerobic blood culture and bulla fluid from a 67-year-old male. the biochemical identification scheme for this recently described species is outlined. because of its reaction pattern it is not unlikely that p. yeei is underdiagnosed. | 2004 | 15243119 |
| characterization of the 3-o-methylgallate dioxygenase gene and evidence of multiple 3-o-methylgallate catabolic pathways in sphingomonas paucimobilis syk-6. | sphingomonas paucimobilis syk-6 is able to grow on various lignin-derived biaryls as the sole source of carbon and energy. these compounds are degraded to vanillate and syringate by the unique and specific enzymes in this strain. vanillate and syringate are converted to protocatechuate (pca) and 3-o-methylgallate (3mga), respectively, by the tetrahydrofolate-dependent o-demethylases. previous studies have suggested that these compounds are further degraded via the pca 4,5-cleavage pathway. howev ... | 2004 | 15262932 |
| measurement of bile acid in serum and bile with arylamine-glass-bound 3alpha-hydroxysteroid dehydrogenase and diaphorase. | 3alpha-hydroxysteroid dehydrogenase (3-hsd) from pseudomonas testosteroni and diaphorase (lipoyl dehydrogenase) from clostridium spp. have been immobilized individually onto arylamine glass beads through diazotization. a cost-effective enzymic colorimetric method for determination of bile acid in serum and bile employing a mixture of these immobilized enzymes was developed. the method is based on measurement of reduced nicotinamide adenine dinucleotide generated from bile acid in serum/bile by i ... | 2004 | 15301946 |
| crystal structure of a baeyer-villiger monooxygenase. | flavin-containing baeyer-villiger monooxygenases employ nadph and molecular oxygen to catalyze the insertion of an oxygen atom into a carbon-carbon bond of a carbonylic substrate. these enzymes can potentially be exploited in a variety of biocatalytic applications given the wide use of baeyer-villiger reactions in synthetic organic chemistry. the catalytic activity of these enzymes involves the formation of two crucial intermediates: a flavin peroxide generated by the reaction of the reduced fla ... | 2004 | 15328411 |
| rational proteomics ii: electrostatic nature of cofactor preference in the short-chain oxidoreductase (scor) enzyme family. | the dominant role of long-range electrostatic interatomic interactions in nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (nad/nadp) cofactor recognition has been shown for enzymes of the short-chain oxidoreductase (scor) family. an estimation of cofactor preference based only on the contribution of the electrostatic energy term to the total energy of enzyme-cofactor interaction has been tested for approximately 40 known three-dimensional (3d) crystal complexes and ... | 2004 | 15340916 |
| regulation of tetralin biodegradation and identification of genes essential for expression of thn operons. | the tetralin biodegradation genes of sphingomonas macrogolitabida strain tfa are clustered in two closely linked and divergent operons. to analyze expression of both operons under different growth conditions, transcriptional and translational gene fusions of the first genes of each operon to lacz have been constructed in plasmids unable to replicate in sphingomonas and integrated by recombination into the genome of strain tfa. expression analysis indicated that the transcription of both genes is ... | 2004 | 15342579 |
| bacterial transcriptional regulators for degradation pathways of aromatic compounds. | human activities have resulted in the release and introduction into the environment of a plethora of aromatic chemicals. the interest in discovering how bacteria are dealing with hazardous environmental pollutants has driven a large research community and has resulted in important biochemical, genetic, and physiological knowledge about the degradation capacities of microorganisms and their application in bioremediation, green chemistry, or production of pharmacy synthons. in addition, regulation ... | 2004 | 15353566 |