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. ...200312620840
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 ...200314600240
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 ...200212634123
mixed culture bioconversion of 16-dehydropregnenolone acetate to androsta-1,4-diene-3,17-dione: optimization of parameters.bioconversion of 16-dehydropregnenolone acetate (16-dpa) to androsta-1,4-diene-3,17-dione (add), an intermediate for the production of female sex hormones, by mixed culture of pseudomonas diminuta mtcc 3361 and comamonas acidovorans mtcc 3362 is reported. various physicochemical parameters for the bioconversion of 16-dpa to add have been optimized in shake flask cultures. nutrient broth inoculated with actively growing co-culture proved ideal for bacterial growth and bioconversion. a temperature ...200312675614
gene encoding the hydrolase for the product of the meta-cleavage reaction in testosterone degradation by comamonas 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 ...200312676694
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 ...200312686148
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 ...200312734184
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- ...200414741705
cometabolic biodegradation of quinoline's derivatives by a quinoline-degrading bacteria: comamonas sp. strain q10. 200314747977
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 ...200212433184
cloning and sequence analyses of a 2,3-dihydroxybiphenyl 1,2-dioxygenase gene ( bphc) from comamonas sp. smn4 for phylogenetic and structural analysis.a genomic library of biphenyl-degrading comamonas sp. smn4 for isolating fragments containing the 2,3-dihydroxybiphenyl 1,2-dioxygenase (23dbdo) gene was constructed. the smallest subclone (pnpx9) encoding 23dbdo activity was sequenced and analyzed. the c-terminal domain of 23dbdo from comamonas sp. smn4 had five catalytically essential residues and was more highly conserved than the n-terminal domain. phylogenetic and structural relationships of 23dbdo from comamonas sp. smn4 were analyzed.200312761654
bacteremia due to comamonas species possibly associated with exposure to tropical fish.comamonas species are environmental gram-negative rods that grow forming pink-pigmented colonies. despite their common occurrence in nature, they rarely cause human infection. we present a case of comamonas bacteremia that we think may have been related to tropical fish exposure. the patient was treated successfully with levofloxacin.200314515927
description of comamonas aquatica comb. nov. and comamonas kerstersii sp. nov. for two subgroups of comamonas terrigena and emended description of comamonas terrigena.three clusters of isolates have previously been defined within the species comamonas terrigena, on the basis of dna-rrna and dna-dna hybridization data, and of protein electrophoretic patterns and immunotyping. more detailed characterization in the current study shows that representatives of these three groups can also be differentiated phenotypically from each other. strains of c. terrigena sensu stricto (c. terrigena dna group 1) are pyrrolidone aminopeptidase-positive, do not grow at 40 degre ...200312807213
hydrodynamic characteristics of immobilized cell beads in a liquid-solid fluidized-bed bioreactor.this study examined the hydrodynamic characteristics of a liquid-solid fluidized-bed bioreactor using elastic particles (pva gel beads) of various diameters as carriers. the drag coefficient-reynolds number, velocity-voidage, and expansion index-reynolds number relationships observed during fluidization of pva gel beads in a fluidized bed in our experiments were compared with the published results. predictions made from previous correlations were examined with our new experimental findings, reve ...200312827700
biodegradation of quinoline by freely suspended and immobilized cells of comamonas sp strain q10. 200312833215
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- ...200414553993
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 ...200314608386
factors involved in the assembly of a functional molybdopyranopterin center in recombinant comamonas acidovorans xanthine dehydrogenase.previous work from this laboratory has shown that the spectral and functional properties of a prokaryotic xanthine dehydrogenase from comamonas acidovorans show some similarities to those of the well-characterized eukaryotic enzymes isolated from bovine milk and from chicken liver [xiang, q. & edmondson, d.e. (1996) biochemistry35, 5441-5450]. therefore, this system was chosen to study the factors involved in the expression of functional recombinant enzyme in escherichia coli to provide insights ...200314622263
conservation of the response regulator gene gaca in pseudomonas species.the response regulator gene gaca influences the production of several secondary metabolites in both pathogenic and beneficial pseudomonas spp. in this study, we developed primers and a probe for the gaca gene of pseudomonas species and sequenced a 425 bp fragment of gaca from ten pseudomonas strains isolated from different plant-associated environments. polymerase chain reaction analysis and southern hybridization showed that gaca is highly conserved within the genus pseudomonas: multiple strain ...200314641577
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 ...200314674583
determination of in situ bacterial growth rates in aquifers and aquifer sediments.laboratory and field-scale studies with stained cells were performed to monitor cell growth in groundwater systems. during cell division, the fluorescence intensity of the protein stain 5-(and 6-)-carboxyfluorescein diacetate succinimidyl ester (cfda/se) for each cell is halved, and the intensity can be tracked with a flow cytometer. two strains of bacteria, comamonas sp. strain da001 and acidovorax sp. strain oy-107, both isolated from a shallow aquifer, were utilized in this study. the change ...200312839747
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 ...200312686116
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 ...200415202565
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 ...200312686118
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 ...200414711640
detection of genes involved in biodegradation and biotransformation in microbial communities by using 50-mer oligonucleotide 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 ...200415240314
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 ...200312852789
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 ...200312729727
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 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 ...200312902225
characterization of microbial communities in gas industry pipelines.culture-independent techniques, denaturing gradient gel electrophoresis (dgge) analysis, and random cloning of 16s rrna gene sequences amplified from community dna were used to determine the diversity of microbial communities in gas industry pipelines. samples obtained from natural gas pipelines were used directly for dna extraction, inoculated into sulfate-reducing bacterium medium, or used to inoculate a reactor that simulated a natural gas pipeline environment. the variable v2-v3 (average siz ...200312957923
characterization of phenol biodegradation by comamonas testosteroni zd4-1 and pseudomonas aeruginosa investigate the characteristic and biochemical mechanism about the phenol biodegradation by bacterial strains zd 4-1 and zd 4-3.200312964790
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 ...200312975360
[comamonas testosteroni strain ti as a potential base for a microbial sensor detecting surfactants].strain comamonas testosteroni ti, capable of degrading the nonionic surfactant (nis) nonylphenolethoxylate (op-10), was used for constructing a pilot cellular biosensor. the lower nis detection limit for the biosensor was 0.25 mg/l. we studied the substrate specificity of the biosensor with respect to a wide range of organic compounds: surfactants, polyaromatic compounds (pac), carbohydrates, alcohols, etc. it was shown that the biosensor based on comamonas testosteroni ti did not respond to glu ...200415455722
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 ...200313680097
microbial ecology of activated sludge. i. dominant bacteria.over 300 bacterial strains were isolated from seven samples of activated sludge by plating on sewage agar. gram-negative bacteria of the genera zoogloea and comamonas predominated. many isolates (51%) showed sudanophilic inclusions of poly-beta-hydroxybutyric acid, whereas 34% accumulated iodophilic material on media containing starch. a large number required either vitamins or amino acids, or both, for growth. none of the isolates tested for their ability to bring about changes in autoclaved se ...196414215970
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 ...200314505323
application of a vital fluorescent staining method for simultaneous, near-real-time concentration monitoring of two bacterial strains in an atlantic coastal plain aquifer in oyster, virginia.two differentially labeled bacterial strains were monitored in near-real time during two field-scale bacterial transport experiments in a shallow aquifer in july 2000 and july 2001. comamonas sp. strain da001 and acidovorax sp. strain oy-107 were grown and labeled with the vital fluorescent stain tamra/se (5 [and -6]-carboxytetramethylrhodamine, succinimidyl ester) or cfda/se (5 [and -6]-carboxyfluorescein diacetate, succinimidyl ester). fluorescently labeled cells and a conservative bromide tra ...200415006793
n-acyl-l-homoserine lactones (ahls) affect microbial community composition and function in activated sludge.the role of intercellular signalling in the regulation of genes and phenotypes in a broad range of bacterial species is now firmly established. in contrast, the impact of intercellular signalling on microbial community parameters, such as species diversity and function, is less well understood. in this study the role of n-acyl-l-homoserine lactones (ahls) in microbial community dynamics in an industrial wastewater treatment system is addressed. seven proteobacterial strains producing compounds w ...200415008819
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 ...200415026087
[investigation of the bacteria in the seawater of xisha in the south china sea and their antibiotic sensitivity profile].to investigate the distribution and antibiotic sensitivity of the bacteria in the seawater of xisha in the south china sea.200415041561
bacterial diversity of the inner mongolian baer soda lake as revealed by 16s rrna gene sequence analyses.bacterial diversity associated with baer soda lake in inner mongolia of china was investigated using a culture-independent method. bacterial 16s rrna gene libraries were generated using bacterial oligonucleotide primers, and 16s rrna gene sequences of 58 clones were analyzed phylogenetically. the library was dominated by 16s rdnas of gram-negative bacteria (24% alpha-proteobacteria, 31% beta-proteobacteria, 33% gamma-proteobacteria, and 2% delta-proteobacteria), with a lower percentage of clones ...200415064989
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, 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 ...200415113829
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.200415130151
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 ...200415143035
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 ...200415176949
expression, purification, and sequence analysis of catalase-1 from the soil bacterium comamonas terrigena n3h.catalases are essential components of the cellular equipment to cope with oxidative stress. we have purified and characterize herein the most abundant heme-containing catalase-1 from the soil bacterium comamonas terrigena n3h. this oxidative stress-induced enzyme was isolated from exponential phase cells grown in the presence of peroxyacetic acid. we have used consecutive steps of hydrophobic, molecular sieve, and ion exchange chromatography to achieve a high state of purity for this metalloenzy ...200415177292
culture-independent analysis of midgut microbiota in the arbovirus vector culicoides sonorensis (diptera: ceratopogonidae).differences in midgut microbial communities inhabiting culicoides spp., insect vectors of virus pathogens, may affect the variation observed in the ability of these biting midges to propagate arthropod-borne viruses. as a first step toward addressing this hypothesis, midgut bacterial communities were compared between culicoides species expected to be efficient and inefficient vectors of virus pathogens. we used 16s rdna sequence and restriction fragment information to provisionally identify 36 b ...200415185934
quinohemoprotein alcohol dehydrogenases: structure, function, and physiology.quino(hemo)protein alcohol dehydrogenases (adh) that have pyrroloquinoline quinone (pqq) as the prosthetic group are classified into 3 groups, types i, ii, and iii. type i adh is a simple quinoprotein having pqq as the only prosthetic group, while type ii and type iii adhs are quinohemoprotein having heme c as well as pqq in the catalytic polypeptide. type ii adh is a soluble periplasmic enzyme and is widely distributed in proteobacteria such as pseudomonas, ralstonia, comamonas, etc. in contras ...200415234265
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 ...200415240283
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 ...200415242125
identification of the phthalate-degrading bacteria isolated from phthalate-contaminated soil and characterization of their phthalate substrate specificity. 200415266685
high-level expression and characterization of a highly functional comamonas acidovorans xanthine dehydrogenase in pseudomonas improved procedure is described for the high-level expression of comamonas acidovorans xdh in pseudomonas aeruginosa pao1-lac. the level of functional expression (56 mg protein/l culture) is found to be 7-fold higher than that observed in escherichia coli and 30-fold higher than that induced in c. acidovorans. co-expression of the xdhc gene is required for maximal level of functional expression. comparison of purified preparations of xdh expressed in the absence of xdhc (xdh(ab)) with that ex ...200415294283
an extra large insertion in the polyhydroxyalkanoate synthase from delftia acidovorans ds-17: its deletion effects and relation to cellular proteolysis.the polyhydroxyalkanoate (pha) synthase (phac(da)) from delftia acidovorans ds-17 (formerly comamonas acidovorans) has a unique large insertion consisting of 40 amino acid residues in the alpha/beta hydrolase fold region. in order to examine whether this insertion is necessary for enzyme function, we generated a mutant gene where the nucleotides encoding the insertion sequence were deleted [phac(da)del(342-381)]. the ability of the mutant phac(da) lacking the insertion sequence to produce pha in ...200414769470
characterization of protocatechuate 4,5-dioxygenase induced from p-hydroxybenzoate-cultured pseudomonas sp. k82.pseudomonas sp. k82 has been reported to be an aniline-assimilating soil bacterium. however, this strain can use not only aniline as a sole carbon and energy source, but can also utilize benzoate, p-hydroxybenzoate, and aniline analogues. the strain accomplishes this metabolic diversity by using different aerobic pathways. pseudomonas sp. k82, when cultured in p-hydroxybenzoate, showed extradiol cleavage activity of protocatechuate. in accordance with those findings, our study attempted the puri ...200415357311
isolation and characterization of dibenzofuran-degrading comamonas sp. strains isolated from white clover roots.three dibenzofuran (df)-degrading strains were newly isolated from roots of white clover ( trifolium repens l.) and poplar trees grown in df-contaminated soil samples. these strains, designated kd2, kd7, and pd1, were characterized as comamonas sp. on the basis of their 16s rdna sequences and physiological characteristics. the metabolites produced when strain kd7 was incubated with df were identified by gas chromatography-mass spectrometry (gc-ms) analysis. interestingly, strain kd7 was found to ...200415386118
emended description of the species lampropedia hyalina.three lampropedia hyalina strains from different habitats were compared by phenotypic, chemotaxonomic and molecular characteristics. all strains form coccoid cells and have been reported to grow as square tablets of eight to 64 cells. however, two of these strains (atcc 11041t and atcc 43383) have apparently lost this ability, and the third strain may temporarily lose this capacity under certain cultivation conditions. the three strains showed only minor differences in metabolic characteristics: ...200415388733
microbial polyhydroxyalkanoates (phas): an emerging biomaterial for tissue engineering and therapeutic applications.among the various biomaterials available for tissue engineering and therapeutic applications, microbial polyhydroxyalkanoates (phas) offer the most diverse range of thermal and mechanical properties. of particular interest are the phas that contain 4-hydroxybutyrate such as poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [p(3hb-co-4hb) and poly(4-hydroxybutyrate) [p(4hb)]. these polyesters can only be synthesized by a few types of bacteria, among which comamonas acidovorans has the most efficient m ...200415468816
steroid degradation gene cluster of comamonas testosteroni consisting of 18 putative genes from meta-cleavage enzyme gene tesb to regulator gene tesr.steroid degradation genes of comamonas testosteroni ta441 are encoded in at least two gene clusters: one containing the meta-cleavage enzyme gene tesb and orf1, 2, 3; and another consisting of orf18, 17, tesi, h, a2, and tesa1, d, e, f, g (tesa2 to orf18 and tesa1 to tesg are encoded in opposite directions). analysis of transposon mutants with low steroid degradation revealed 13 orfs and a gene (orf4, 5, 21, 22, 23, 25, 26, 27, 28, 30, 31, 32, 33, and tesr) involved in steroid degradation in the ...200415474469
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 ...200414973025
the genes encoding the hydroxylase of 3-hydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione in steroid degradation in comamonas testosteroni ta441.steroid degradation genes of comamonas testosteroni ta441 are encoded in at least two gene clusters: one containing the meta-cleavage enzyme gene tesb; and another consisting of orf18, 17, tesi, h, orf11, 12, and tesdefg. tesh and i are, respectively, the delta(1)- and delta(4)(5alpha)-dehydrogenase of the 3-ketosteroid, tesd is the hydrolase for the product of meta-cleavage reaction, and tesefg degrade one of the product of tesd. in this report, we describe the identification of the function of ...200415555908
an enzymatic cycling method for the determination of serum total bile acids with recombinant 3alpha-hydroxysteroid dehydrogenase.a highly sensitive enzymatic cycling method was developed for the serum total bile acids assay. we constructed a prokaryotic expression system to prepare the recombinant 3alpha-hydroxysteroid dehydrogenase in place of the natural enzyme and for the first time used it in the total bile acids assay. the production rate of thio-nadh correlated with the bile acids concentration and was measured by the change of absorbance at 405/660 nm. the enzymatic cycling method could detect 0.22 micromol/l total ...200515567156
rhizoremediation of a 3,4-dichloroaniline contaminated soil. 200115954271
mechanistic roles of ser-114, tyr-155, and lys-159 in 3alpha-hydroxysteroid dehydrogenase/carbonyl reductase from comamonas testosteroni.3alpha-hydroxysteroid dehydrogenase/carbonyl reductase (3alpha-hsd/cr) from comamonas testosteroni, a short chain dehydrogenase/reductase, catalyzes the oxidation of androsterone with nad+ to form androstanedione and nadh. a catalytic triad of ser-114, tyr-155, and lys-159 in 3alpha-hsd/cr has been proposed based on structural analysis and sequence alignment of the short chain dehydrogenase/reductase family. the 3alpha-hsd/cr-catalyzed reaction has not been kinetically analyzed in detail, howeve ...200415572373
a novel 2-aminophenol 1,6-dioxygenase involved in the degradation of p-chloronitrobenzene by comamonas strain cnb-1: purification, properties, genetic cloning and expression in escherichia coli.comamonas strain cnb-1 was isolated from a biological reactor treating wastewater from a p-chloronitrobenzene production factory. strain cnb-1 used p-chloronitrobenzene as sole source of carbon, nitrogen, and energy. a 2-aminophenol 1,6-dioxygenase was purified from cells of strain cnb-1. the purified 2-aminophenol 1,6-dioxygenase had a native molecular mass of 130 kda and was composed of alpha- and beta-subunits of 33 and 38 kda, respectively. this enzyme is different from currently known 2-ami ...200415580337
investigation of product quality between extemporaneously compounded progesterone vaginal suppositories and an approved progesterone vaginal gel.the purpose of this investigation was to compare quality parameters, including product appearance, content uniformity, ph, weight uniformity, microbial limit testing and preservative effectiveness testing on extemporaneously compounded progesterone vaginal suppositories obtained from 10 randomly chosen compounding pharmacies (90 suppositories each) across the united states, to the food and drug administration (fda) approved prescription progesterone gel product (prochieve/crinone) which is manuf ...200415595573
lag period of 14co2 evolution from dioctyl sulpho[2,3-14c]succinate in relation to adaptation of bacterium, comamonas terrigena, to dialkyl esters of sulphosuccinate.comamonas terrigena, strain n3h, which was isolated from soil polluted with crude oil products, degraded dioctyl sulphosuccinate, a synthetic commercial surfactant. the primary degradation of this compound, the cleavage of ester bonds between octyl groups and sulphosuccinate, lasted significantly shorter time than the subsequent breakdown of the sulphosuccinate moiety of dioctyl sulpho[2,3-(14)c]succinate. (14)co(2) evolution had a significant shorter lag period with cells in tris/phosphate medi ...200415604786
the atomic resolution structure of methanol dehydrogenase from methylobacterium extorquens.the crystal structure of methanol dehydrogenase (mdh) from methylobacterium extorquens has been refined without stereochemical restraints at a resolution of 1.2 a. the high-resolution data have defined the conformation of the tricyclic pyrroloquinoline quinone (pqq) cofactor ring as entirely planar. the detailed definition of the active-site geometry has shown many features that are similar to the quinohaemo-protein alcohol dehydrogenases from comamonas testosteroni and pseudomonas putida, both ...200415608378
bacterial diversity in spent mushroom compost assessed by amplified rdna restriction analysis and sequencing of cultivated isolates.spent mushroom compost (smc) is the residual by-product of commercial agaricus spp. cultivation, and it is mainly composed of a thermally treated cereal straw/animal manure mixture colonized by the fungal biomass. research on the valorization of this material is mainly focusing on its use as soil conditioner and plant fertilizer. an investigation of the bacterial diversity in smc was performed using molecular techniques in order to reveal the origin of smc microflora and its potential effect on ...200415612633
genes involved in aniline degradation by delftia acidovorans strain 7n and its distribution in the natural environment.aniline-degraders were isolated from activated sludge and environmental samples and classified into eight phylogenetic groups. seven groups were classified into gram-negative bacteria, such as acidovorax sp., acinetobacter sp., delftia sp., comamonas sp., and pseudomonas sp., suggesting the possible dominance of gram-negative aniline-degraders in the environment. aniline degradative genes were cloned from d. acidovorans strain 7n, and the nucleotide sequence of the 8,039-bp fragment containing e ...200415618615
effects of ph amendment on metal working fluid wastewater biological treatment using a defined bacterial consortium.the aim of this study was to determine whether ph amendment of a highly alkaline metal working fluid (mwf) wastewater would improve biological treatment in a bioreactor system following introduction of a bacterial inoculum (comprised of the following strains: agrobacterium radiobacter, comamonas testosteroni, methylobacterium mesophilicum, microbacterium esteraromaticum, and microbacterium saperdae). the ph values tested were 6, 7, 8, and 9. three replicate batch mode bioreactors inoculated with ...200515625673
continuous acetonitrile degradation in a packed-bed bioreactor.a 20-l packed-bed reactor filled with foamed glass beads was tested for the treatment of acetonitrile hplc wastes. aeration was provided by recirculating a portion of the reactor liquid phase through an aeration tank, where the dissolved oxygen concentration was kept at 6 mg/l. at a feeding rate of 0.77 g acetonitrile l(-1) reactor day(-1), 99% of the acetonitrile was removed; and 86% of the nitrogen present in acetonitrile was released as nh3, confirming that acetonitrile volatilization was not ...200415630519
protocatechuate 4,5-dioxygenase from comamonas testosteroni t-2: biochemical and molecular properties of a new subgroup within class iii of extradiol dioxygenases.comamonas testosteroni t-2 degraded at least eight aromatic compounds via protocatechuate (pca), whose extradiol ring cleavage to 2-hydroxy-4-carboxymuconate semialdehyde (hcms) was catalysed by pca 4,5-dioxygenase (pmdab). this inducible, heteromultimeric enzyme was purified. it contained two subunits, alpha (pmda) and beta (pmdb), and the molecular masses of the denatured proteins were 18 kda and 31 kda, respectively. pca was converted stoichiometrically to hcms with an apparent k(m) of 55 mum ...200515650824
over-expression in escherichia coli of a thermally stable and regio-selective nitrile hydratase from comamonas testosteroni 5-mgam-4d.the genes encoding a thermally stable and regio-selective nitrile hydratase (nhase) and an amidase from comamonas testosteroni 5-mgam-4d have been cloned and sequenced, and active nhase has been over-produced in escherichia coli. maximal activity requires co-expression of a small open reading frame immediately downstream from the nhase beta subunit gene. compared to the native organism, the e. coli biocatalyst has nearly threefold more nhase activity on a dry cell weight basis, and this activity ...200515668757
purification and properties of culture-broth-secreted esterase from the polyurethane degrader comamonas acidovorans tb-35.the polyester-polyurethane (pur)-degrading bacterium comamonas acidovorans tb-35 produces two kinds of esterases, one cell-bound esterase (pur esterase) and the other secreted in the culture broth (cbs esterase). in this study, the cbs esterase and the two recombinant esterases were purified. identification of the physical and biochemical properties of the cbs and pur esterases revealed that they have the same polypeptide from one gene. this finding was supported by the observation that escheric ...199916232649
physical versus chemical effects on bacterial and bromide transport as determined from on site sediment column pulse experiments.twenty-eight bacterial and br transport experiments were performed in the field to determine the effects of physical and chemical heterogeneity of the aquifer sediment. the experiments were performed using groundwater from two field locations to examine the effects of groundwater chemistry on transport. groundwater was extracted from multilevel samplers and pumped through 7-cm-long columns of intact sediment or repacked sieved and coated or uncoated sediment from the underlying aquifer. two bact ...200515683885
metabolism of dibenzofuran and dibenzo-p-dioxin by the biphenyl dioxygenase of burkholderia xenovorans lb400 and comamonas testosteroni b-356.we examined the metabolism of dibenzofuran (df) and dibenzo-p-dioxin (dd) by the biphenyl dioxygenase (bpdo) of comamonas testosteroni b-356 and compared it with that of burkholderia xenovorans lb400. data showed that both enzymes oxygenated df at a low rate, but escherichia coli cells expressing lb400 bpdo degraded df at higher rate (30 nmol in 18 h) compared with cells expressing b-356 bpdo (2 nmol in 18 h). furthermore, both bpdos produced dihydro-dihydroxy-dibenzofuran as a major metabolite, ...200515700128
comamonas badia sp. nov., a floc-forming bacterium isolated from activated sludge.strain iam 14839, isolated from activated sludge in japan, forms a visible floc and grows in the flocculated state. this bacterium is gram-negative, rod-shaped, strictly aerobic and highly motile with a single polar flagellum. both oxidase and catalase activities are positive. no growth was observed on sugars. the strain can grow at 20 degrees c, but does not grow at 37 degrees c. the g+c content of dna is 66.3 mol% and q-8 is the major quinone. the major cellular fatty acids are 16:1omega7c, 16 ...200415747228
medium composition affects the degree and pattern of cadmium inhibition of naphthalene biodegradation.metals have been reported to inhibit organic pollutant biodegradation; however, widely varying degrees and patterns of inhibition have been reported. to investigate the roles of medium composition and metal bioavailability on these different degrees and patterns of inhibition, we assessed the impact of cadmium on naphthalene biodegradation by a newly isolated strain of comamonas testosteroni in three chemically-defined minimal salts media (msm): tris-buffered msm, pipes-buffered msm, and bushnel ...200515823325
[isolation and identification of comamonas testosteroni: cloning and overexpression of 3alpha-hydroxysteroid dehydrogenase in e.coli].to isolate and identify 3alpha-hydroxysteroid dehydrogenase (3alpha-hsd) producing comamonas testosteroni from soil, and to clone and overexpress 3alpha-hsd in e.coli.200515841157
structural insight into the dioxygenation of nitroarene compounds: the crystal structure of nitrobenzene dioxygenase.nitroaromatic compounds are used extensively in many industrial processes and have been released into the environment where they are considered environmental pollutants. nitroaromatic compounds, in general, are resistant to oxidative attack due to the electron-withdrawing nature of the nitro groups and the stability of the benzene ring. however, the bacterium comamonas sp. strain js765 can grow with nitrobenzene as a sole source of carbon, nitrogen and energy. biodegradation is initiated by the ...200515854650
biodegradation of naphthalene-2-sulfonic acid present in tannery wastewater by bacterial isolates arthrobacter sp. 2ac and comamonas sp. 4bc.two bacterial strains, 2ac and 4bc, both capable of utilizing naphthalene-2-sulfonic acid (2-nsa) as a sole source of carbon, were isolated from activated sludges previously exposed to tannery wastewater. enrichments were carried out in mineral salt medium (msm) with 2-nsa as the sole carbon source. 16s rdna sequencing analysis indicated that 2ac is an arthrobacter sp. and 4bc is a comamonas sp. within 33 h, both isolates degraded 100% of 2-nsa in msm and also 2-nsa in non-sterile tannery wastew ...200515865148
depolymerisation and biodegradation of a synthetic tanning agent by activated sludges, the bacteria arthrobacter globiformis and comamonas testosteroni, and the fungus cunninghamella polymorpha.degradation of a synthetic tanning agent cnsf (a condensation product of 2-naphthalenesulfonic acid (2-nsa) and formaldehyde) by four activated sludges, two previously characterised bacterial strains, arthrobacter sp. 2ac and comamonas sp. 4bc, and the fungus cunninghamella polymorpha, was studied in batch culture at 25 degrees c by determining the changes in the concentrations of cnsf and its component monomers and oligomers (n2-n11). the loss of individual oligomers was correlated with the len ...200515865336
analysis of c-3 epimerization in (24r)-24,25-dihydroxyvitamin d3 catalyzed by hydroxysteroid dehydrogenase.studies on the c-3 epimerization in (24r)-24,25-dihydroxyvitamin d(3) [24r,25(oh)(2)d(3)] were performed using hydroxysteroid dehydrogenases (hsds). 3-epi-24r,25(oh)(2)d(3) was formed from 24r,25(oh)(2)d(3) by the catalysis of 3alpha- or beta-hsd. these hsds also catalyzed the c-3 epimerization in 3-epi-24r,25(oh)(2)d(3) to form 24r,25(oh)(2)d(3). 24r,25(oh)(2)d(3) and its c-3 epimer were separated by inclusion high-performance liquid chromatography using gamma-cyclodextrin (gamma-cd) as the mob ...200415522514
interactions in biofilms between listeria monocytogenes and resident microorganisms from food industry premises.twenty nine bacterial strains were grown as binary culture biofilms with listeria monocytogenes to assess their influence on the settlement of the latter on stainless steel coupons. most of the strains had been isolated from food processing plants after cleaning and disinfection and were tentatively identified by the apilab plus 3.3.3 database (biomerieux). sixteen of them decreased l. monocytogenes biofilm colony forming units (cfu) counts. three strains, bacillus sp. ccl 9 an unidentified gram ...200415541798
control of substrate specificity by active-site residues in nitrobenzene dioxygenase.nitrobenzene 1,2-dioxygenase from comamonas sp. strain js765 catalyzes the initial reaction in nitrobenzene degradation, forming catechol and nitrite. the enzyme also oxidizes the aromatic rings of mono- and dinitrotoluenes at the nitro-substituted carbon, but the basis for this specificity is not understood. in this study, site-directed mutagenesis was used to modify the active site of nitrobenzene dioxygenase, and the contribution of specific residues in controlling substrate specificity and e ...200616517627
aniline and 3-chloroaniline degrading bacteria: genetics and possible applications. 200115954269
purification, characterization, and crystallization of the components of the nitrobenzene and 2-nitrotoluene dioxygenase enzyme systems.the protein components of the 2-nitrotoluene (2nt) and nitrobenzene dioxygenase enzyme systems from acidovorax sp. strain js42 and comamonas sp. strain js765, respectively, were purified and characterized. these enzymes catalyze the initial step in the degradation of 2-nitrotoluene and nitrobenzene. the identical shared reductase and ferredoxin components were monomers of 35 and 11.5 kda, respectively. the reductase component contained 1.86 g-atoms iron, 2.01 g-atoms sulfur, and one molecule of ...200516000792
comamonas (pseudomonas) testosteroni endocarditis.comamonas testosteroni has rarely been implicated as a human pathogen. we report a case of infectious endocarditis due to this organism, occurring in a 49-year-old man. the posterior leaflet of the mitral valve contained a 1 x 1 cm vegetation and showed myxoid degeneration and acute inflammation. the patient had no evidence of reinfection after 32 months. the infection was almost certainly community acquired, as is usually true for this organism.200515914299
spatial variation in deposition rate coefficients of an adhesion-deficient bacterial strain in quartz sand.the transport of bacterial strain da001 was examined in packed quartz sand under a variety of environmentally relevant ionic strength and flow conditions. under all conditions, the retained bacterial concentrations decreased with distance from the column inlet at a rate that was faster than loglinear, indicating that the deposition rate coefficient decreased with increasing transport distance. the hyperexponential retained profile contrasted againstthe nonmonotonic retained profiles that had bee ...200515952372
molecular cloning and structural analysis of quinohemoprotein alcohol dehydrogenase adh-iig from pseudomonas putida hk5.depending on the alcohols used as growth substrates, pseudomonas putida hk5 produces two distinct quinohemoprotein alcohol dehydrogenases, adh-iib and adh-iig, both of which contain pyrroloquinoline quinone (pqq) and heme c as the prosthetic groups but show different substrate specificities, especially for diol substrates. molecular cloning of the gene of adh-iib and its crystal structure are already reported. here, molecular cloning of the gene, qgda, and solution of the three-dimensional struc ...200516061256
biosynthesis of medium chain length poly(3-hydroxyalkanoates) (mcl-phas) by comamonas testosteroni during cultivation on vegetable oils.comamonas testosteroni has been studied for its ability to synthesize and accumulate medium chain length poly(3-hydroxyalkanoates) (mcl-phas) during cultivation on vegetable oils available in the local market. castor seed oil, coconut oil, mustard oil, cotton seed oil, groundnut oil, olive oil and sesame oil were supplemented in the mineral medium as a sole source of carbon for growth and phas accumulation. the composition of phas was analysed by a coupled gas chromatography/mass spectroscopy (g ...200516084364
plasmid-mediated bioaugmentation of activated sludge bacteria in a sequencing batch moving bed reactor using pnb2.the applicability of plasmid pnb2 for bioaugmentation of bacteria in model wastewater treatment reactors receiving 3-chloroaniline (3-ca) was investigated.200516108914
production of catalases by comamonas spp. and resistance to oxidative stress.bacterial isolates comamonas terrigena n3h (from soil contaminated with crude oil) and c. testosteroni (isolated from the sludge of a wastewater treatment plant), exhibit much higher total catalase activity than the same species from laboratory collection cultures. electrophoretic resolution of catalases revealed only one corresponding band in cell-free extracts of both c. testosteroni cultures. isolates of c. terrigena n3h exhibited catalase-1 and catalase-2 activity, whereas in the collection ...200516110914
photosynthetically oxygenated acetonitrile biodegradation by an algal-bacterial microcosm: a pilot-scale study.a 43-l column photobioreactor was tested for the treatment of acetonitrile using a symbiotic consortium consisting of a chlorella sorokiniana strain and a comamonas strain. complete biodegradation of 1 g acetonitrile/l was achieved in 79 hours under continuous illumination at 500 microe/m(2)s and 26 degrees c. when the photobioreactor was operated at 26 degrees c under a 14/10 hours light/dark illumination regime at 500 microe/m(2)s, complete mineralization of 1 g acetonitrile/l was achieved in ...200516114693
impact of membrane fatty acid composition on the uncoupling sensitivity of the energy conservation of comamonas testosteroni atcc 17454.the fatty acid composition of pyruvate-grown comamonas testosteroni atcc 17454 was analyzed after growth at 30 and 20 degrees c and after half-maximum growth inhibition caused by different membrane-active chemicals at 30 degrees c. palmitic acid (16:0), palmitoleic acid (16:1 omega7c) and vaccenic acid (18:1 omega7c) were the dominant fatty acids. at 20 degrees c, the proportion of palmitic acid decreased and those of palmitoleic and vaccenic acid increased. saturation degree was also lowered wh ...200616133339
identification of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid, 4-hydroxy-2-oxohexanoic acid, and 2-hydroxyhexa-2,4-dienoic acid and related enzymes involved in testosterone degradation in comamonas testosteroni ta441.comamonas testosteroni ta441 utilizes testosterone via aromatization of the a ring followed by meta-cleavage of the ring. the product of the meta-cleavage reaction, 4,5-9,10-diseco-3-hydroxy-5,9,17-trioxoandrosta-1(10),2-dien-4-oic acid, is degraded by a hydrolase, tesd. we directly isolated and identified two products of tesd as 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid and (2z,4z)-2-hydroxyhexa-2,4-dienoic acid. the latter was a pure 4z isomer. 2-hydroxyhexa-2,4-dienoic acid was con ...200516151114
active site residues controlling substrate specificity in 2-nitrotoluene dioxygenase from acidovorax sp. strain js42.acidovorax (formerly pseudomonas) sp. strain js42 utilizes 2-nitrotoluene as sole carbon, nitrogen, and energy source. 2-nitrotoluene 2,3-dioxygenase (2ntdo) catalyzes the initial step in 2-nitrotoluene degradation by converting 2-nitrotoluene to 3-methylcatechol. in this study, we identified specific amino acids at the active site that control specificity. the residue at position 350 was found to be critical in determining both the enantiospecificity of 2ntdo with naphthalene and the ability to ...200516175409
the copy-number of plasmids and other genetic elements can be determined by sybr-green-based quantitative real-time this study, we explored whether sybr green-based quantitative real-time pcr (qpcr) could be used to determine the copy number of a plasmid and whether the method was broadly applicable to chromosomally encoded genetic elements often occurring in multiple copies, such as rrna genes and insertion sequences (is). three different template sources (whole cells, total dna, and restriction-enzyme digested total dna) derived from the bacterium comamonas sp. strain js46 were analyzed by qpcr using pri ...200616216354
effect of the applied organic load rate on biodegradable polymer production by mixed microbial cultures in a sequencing batch reactor.this article studies the operation of a new process for the production of biopolymers (polyhydroxyalkanoates, phas) at different applied organic load rates (olrs). the process is based on the aerobic enrichment of activated sludge to obtain mixed cultures able to store phas at high rates and yields. a mixture of acetic, lactic, and propionic acids at different concentrations (in the range 8.5-31.25 gcod/l) was fed every 2 h in a sequencing batch reactor (sbr). the resulting applied olr was in th ...200616224790
characterization of floating activity of indigenous diesel-assimilating bacterial isolates.six diesel-degrading bacterial strains were isolated from oil-polluted sites located in central taiwan. the floating activity of the isolates in an oil-supplemented liquid medium was monitored. cell-surface hydrophobicity as well as cell-free and cell-residue emulsification activities were also investigated. three isolates, identified as gordonia alkanivorans cc-jg 39, rhodococcus erythropolis cc-bc 04, and r. erythropolis cc-bc 11, were found to float and grow near the diesel layer on the surfa ...200516233818
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