| functional analyses of bph-tod hybrid dioxygenase, which exhibits high degradation activity toward trichloroethylene. | biphenyl dioxygenase (bphdox) in pseudomonas pseudoalcaligenes kf707 is a multicomponent enzyme consisting of an iron-sulfur protein (isp) that is composed of alpha (bpha1) and beta (bpha2) subunits, a ferredoxin (fd(bpha3)), and a ferredoxin reductase (fdr(bpha4)). a recombinant escherichia coli strain expressing hybrid dox that had replaced bpha1 with todc1 (alpha subunit of toluene dioxygenase (toldox) of pseudomonas putida) exhibited high activity toward trichloroethylene (tce) (furukawa, k. ... | 2001 | 11390387 |
| pcr cloning of type ii polyhydroxyalkanoate biosynthesis genes from two pseudomonas strains. | two polyhydroxyalkanoate synthase genes, phac1 from pseudomonas pseudoalcaligenes hbq06 and phac2 from pseudomonas nitroreducens 0802, were cloned using a pcr cloning strategy based on the type ii pha loci property of pseudomonas strains. the complete open reading frames (orfs) of phac1 (p. nitroreducens hbq06) and phac2 (p. nitroreducens 0802) were identified from the pcr products. using the sequence information, the complete pha synthase genes were pcr cloned directly from the genomic dna and ... | 2001 | 11430409 |
| diverse oxygenations catalyzed by carbazole 1,9a-dioxygenase from pseudomonas sp. strain ca10. | carbazole 1,9a-dioxygenase (cardo) from pseudomonas sp. strain ca10 is a multicomponent enzyme that catalyzes the angular dioxygenation of carbazole, dibenzofuran, and dibenzo-p-dioxin. it was revealed by gas chromatography-mass spectrometry and 1h and 13c nuclear magnetic resonance analyses that xanthene and phenoxathiin were converted to 2,2',3-trihydroxydiphenylmethane and 2,2',3-trihydroxydiphenyl sulfide, respectively. thus, for xanthene and phenoxathiin, angular dioxygenation by cardo occu ... | 1999 | 10322011 |
| polychlorinated biphenyl degradation activities and hybridization analyses of fifteen aerobic strains isolated from a pcb-contaminated site. | fifteen bacterial strains using biphenyl as sole carbon and energy source, obtained from different positions and depths of a polychlorinated biphenyl (pcb)-contaminated area, were analyzed for their basic metabolic phenotypes and subjected to genomic dna hybridization screening for the presence of well characterized bph operons such as those of pseudomonas pseudoalcaligenes kf707 and rhodococcus globerulus p6. most of the isolates belonged to the gamma-subdivision (pseudomonas stutzeri, p. pluti ... | 2001 | 11501677 |
| 3-hydroxylaminophenol mutase from ralstonia eutropha jmp134 catalyzes a bamberger rearrangement. | 3-hydroxylaminophenol mutase from ralstonia eutropha jmp134 is involved in the degradative pathway of 3-nitrophenol, in which it catalyzes the conversion of 3-hydroxylaminophenol to aminohydroquinone. to show that the reaction was really catalyzed by a single enzyme without the release of intermediates, the corresponding protein was purified to apparent homogeneity from an extract of cells grown on 3-nitrophenol as the nitrogen source and succinate as the carbon and energy source. 3-hydroxylamin ... | 1999 | 10049374 |
| biological degradation of 2,4,6-trinitrotoluene. | nitroaromatic compounds are xenobiotics that have found multiple applications in the synthesis of foams, pharmaceuticals, pesticides, and explosives. these compounds are toxic and recalcitrant and are degraded relatively slowly in the environment by microorganisms. 2,4,6-trinitrotoluene (tnt) is the most widely used nitroaromatic compound. certain strains of pseudomonas and fungi can use tnt as a nitrogen source through the removal of nitrogen as nitrite from tnt under aerobic conditions and the ... | 2001 | 11527999 |
| complete nucleotide sequence and organization of the atrazine catabolic plasmid padp-1 from pseudomonas sp. strain adp. | the complete 108,845-nucleotide sequence of catabolic plasmid padp-1 from pseudomonas sp. strain adp was determined. plasmid padp-1 was previously shown to encode atza, atzb, and atzc, which catalyze the sequential hydrolytic removal of s-triazine ring substituents from the herbicide atrazine to yield cyanuric acid. computational analyses indicated that padp-1 encodes 104 putative open reading frames (orfs), which are predicted to function in catabolism, transposition, and plasmid maintenance, t ... | 2001 | 11544232 |
| stable-isotope-based labeling of styrene-degrading microorganisms in biofilters. | deuterated styrene ([(2)h(8)]styrene) was used as a tracer in combination with phospholipid fatty acid (plfa) analysis for characterization of styrene-degrading microbial populations of biofilters used for treatment of waste gases. deuterated fatty acids were detected and quantified by gas chromatography-mass spectrometry. the method was evaluated with pure cultures of styrene-degrading bacteria and defined mixed cultures of styrene degraders and non-styrene-degrading organisms. incubation of st ... | 2001 | 11571187 |
| molecular analysis of antibiotic resistance gene clusters in vibrio cholerae o139 and o1 sxt constins. | many recent asian clinical vibrio cholerae e1 tor o1 and o139 isolates are resistant to the antibiotics sulfamethoxazole (su), trimethoprim (tm), chloramphenicol (cm), and streptomycin (sm). the corresponding resistance genes are located on large conjugative elements (sxt constins) that are integrated into prfc on the v. cholerae chromosome. we determined the dna sequences of the antibiotic resistance genes in the sxt constin in mo10, an o139 isolate. in sxt(mo10), these genes are clustered with ... | 2001 | 11600347 |
| direct ring fission of salicylate by a salicylate 1,2-dioxygenase activity from pseudaminobacter salicylatoxidans. | in cell extracts of pseudaminobacter salicylatoxidans strain bn12, an enzymatic activity was detected which converted salicylate in an oxygen-dependent but nad(p)h-independent reaction to a product with an absorbance maximum at 283 nm. this metabolite was isolated, purified, and identified by mass spectrometry and (1)h and (13)c nuclear magnetic resonance spectroscopy as 2-oxohepta-3,5-dienedioic acid. this metabolite could be formed only by direct ring fission of salicylate by a 1,2-dioxygenase ... | 2001 | 11698383 |
| purification, characterization, and sequence analysis of 2-aminomuconic 6-semialdehyde dehydrogenase from pseudomonas pseudoalcaligenes js45. | 2-aminonumconic 6-semialdehyde is an unstable intermediate in the biodegradation of nitrobenzene and 2-aminophenol by pseudomonas pseudoalcaligenes js45. previous work has shown that enzymes in cell extracts convert 2-aminophenol to 2-aminomuconate in the presence of nad+. in the present work, 2-aminomuconic semialdehyde dehydrogenase was purified and characterized. the purified enzyme migrates as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a molecular mass of ... | 1998 | 9721300 |
| 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 |
| molecular characterization and substrate specificity of nitrobenzene dioxygenase from comamonas sp. strain js765. | comamonas sp. strain js765 can grow with nitrobenzene as the sole source of carbon, nitrogen, and energy. we report here the sequence of the genes encoding nitrobenzene dioxygenase (nbdo), which catalyzes the first step in the degradation of nitrobenzene by strain js765. the components of nbdo were designated reductase(nbz), ferredoxin(nbz), oxygenase(nbzalpha), and oxygenase(nbzbeta), with the gene designations nbzaa, nbzab, nbzac, and nbzad, respectively. sequence analysis showed that the comp ... | 2002 | 11823201 |
| [biosorption of heavy metals by bacteria isolated from activated sludge]. | in this paper, biosorption efficiency of heavy metals by bacteria isolated from activated sludge was tested. it was shown that pseudomonas pseudoalcaligenes and micrococcus luteus gc subgroup b had high biosorption capacities for cu(ii) and pb(ii) ions. the adsorption of the two ions on pseudomonas pseudoalcaligenes and micrococcus luteus gc subgroup b exhibited langmuir adsorption behavior with regression coefficient of 0.99. the ph value was the most important effect factor on biosorption of m ... | 2001 | 11855186 |
| nad(p)h:flavin mononucleotide oxidoreductase inactivation during 2,4,6-trinitrotoluene reduction. | bacteria readily transform 2,4,6-trinitrotoluene (tnt), a contaminant frequently found at military bases and munitions production facilities, by reduction of the nitro group substituents. in this work, the kinetics of nitroreduction were investigated by using a model nitroreductase, nad(p)h:flavin mononucleotide (fmn) oxidoreductase. under mediation by nad(p)h:fmn oxidoreductase, tnt rapidly reacted with nadh to form 2-hydroxylamino-4,6-dinitrotoluene and 4-hydroxylamino-2,6-dinitrotoluene, wher ... | 2002 | 11916686 |
| characterization of the hca cluster encoding the dioxygenolytic pathway for initial catabolism of 3-phenylpropionic acid in escherichia coli k-12. | we have identified, cloned, and sequenced the hca cluster encoding the dioxygenolytic pathway for initial catabolism of 3-phenylpropionic acid (pp) in escherichia coli k-12. this cluster maps at min 57.5 of the chromosome and is composed of five catabolic genes arranged as a putative operon (hcaa1a2cbd) and two additional genes transcribed in the opposite direction that encode a potential permease (hcat) and a regulator (hcar). sequence comparisons revealed that while hcaa1a2cd genes encode the ... | 1998 | 9603882 |
| comparative evaluation of the bd phoenix and vitek 2 automated instruments for identification of isolates of the burkholderia cepacia complex. | we evaluated two new automated identification systems, the bd phoenix (becton dickinson) and the vitek 2 (biomérieux), for identification of isolates of the burkholderia cepacia complex (bcc). the test sample included 42 isolates of the highly virulent and epidemic genomovar iii, 45 isolates of b. multivorans, and 47 isolates of other members of the bcc. rates of correct identification by the bd phoenix and vitek 2 were similar when all bcc isolates were considered (50 and 53%, respectively) but ... | 2002 | 11980954 |
| the membrane-bound respiratory chain of pseudomonas pseudoalcaligenes kf707 cells grown in the presence or absence of potassium tellurite. | the respiratory chain of pseudomonas pseudoalcaligenes kf707 in membranes isolated from cells grown in the presence or absence of the toxic oxyanion tellurite (teo3(2-)) was examined. aerobic growth in the absence of tellurite shows an nadh-dependent respiration which is 80% catalysed by the cytochrome (cyt) bc1-containing pathway leading to two terminal membrane-bound cyt c oxidases inhibited by different concentrations of kcn (ic50 0.2 and 1 microm). a third oxidase, catalysing the remaining 2 ... | 2002 | 12055290 |
| alteration of regiospecificity in biphenyl dioxygenase by active-site engineering. | biphenyl dioxygenase (bph dox) is responsible for the initial dioxygenation step during the metabolism of biphenyl. the large subunit (bpha1) of bph dox plays a crucial role in the determination of the substrate specificity of biphenyl-related compounds, including polychlorinated biphenyls (pcbs). based on crystallographic analyses of naphthalene dioxygenase (b. kauppi, k. lee, e. carredano, r. e. parales, d. t. gibson, h. eklund, and s. ramaswamy, structure 6:571-586, 1998), we developed a thre ... | 2002 | 12057964 |
| polyhydroxyalkanoate biosynthesis in pseudomonas pseudoalcaligenes ys1. | pseudomonas pseudoalcaligenes strain ys1 isolated from oil contaminated soil was able to produce polyhydroxybutyrate blended with medium-chain-length polyhydroxyalkanoates (mcl pha). pha synthesis genes were cloned from this strain. a fadb (gene for fatty acid degradation) deleted mutant escherichia coli km32b (fadb::tet) was constructed to express the cloned pha synthesis gene phac1(pp) or phac2(pp). the fadb deleted mutant km32b harboring phac1(pp) or phac2(pp) showed mcl pha accumulation whil ... | 2002 | 12076790 |
| a novel 2-aminomuconate deaminase in the nitrobenzene degradation pathway of pseudomonas pseudoalcaligenes js45. | 2-aminomuconate, an intermediate in the metabolism of tryptophan in mammals, is also an intermediate in the biodegradation of nitrobenzene by pseudomonas pseudoalcaligenes js45. strain js45 hydrolyzes 2-aminomuconate to 4-oxalocrotonic acid, with the release of ammonia, which serves as the nitrogen source for growth of the microorganism. as an initial step in studying the novel deamination mechanism, we report here the purification and some properties of 2-aminomuconate deaminase. the purified e ... | 1998 | 9573204 |
| studies of the catabolic pathway of degradation of nitrobenzene by pseudomonas pseudoalcaligenes js45: removal of the amino group from 2-aminomuconic semialdehyde. | pseudomonas pseudoalcaligenes js45 utilizes nitrobenzene as the sole source of nitrogen, carbon, and energy. previous studies have shown that degradation of nitrobenzene involves the reduction of nitrobenzene to nitrosobenzene and hydroxylaminobenzene, followed by rearrangement to 2-aminophenol, which then undergoes meta ring cleavage to 2-aminomuconic semialdehyde. in the present paper, we report the enzymatic reactions responsible for the release of ammonia after ring cleavage. 2-aminomuconic ... | 1997 | 9471964 |
| use of potassium tellurite for testing the survival and viability of pseudomonas pseudoalcaligenes kf707 in soil microcosms contaminated with polychlorinated biphenyls. | this study shows that the oxyanion tellurite teo3(2-) can be used as a tool to detect and quantify the release in soil microcosms of pseudomonas pseudoalcaligenes kf707, a strain spontaneously resistant to tellurite with a minimal inhibitory concentration (mic) of 150 microg ml(-1). kf707 cells which carry the genes for degradation of a wide range of polychlorinated biphenyl congeners (pcbs) were used for inoculation of laboratory microcosms prepared with two different pcb-contaminated soils (ci ... | 2002 | 12234009 |
| use of 16s rrna gene sequencing for identification of nonfermenting gram-negative bacilli recovered from patients attending a single cystic fibrosis center. | during 1999, we used partial 16s rrna gene sequencing for the prospective identification of atypical nonfermenting gram-negative bacilli isolated from patients attending our cystic fibrosis center. of 1,093 isolates of nonfermenting gram-negative bacilli recovered from 148 patients, 46 (4.2%) gave problematic results with conventional phenotypic tests. these 46 isolates were genotypically identified as pseudomonas aeruginosa (19 isolates, 12 patients), achromobacter xylosoxidans (10 isolates, 8 ... | 2002 | 12354883 |
| purification of 2,3-dihydroxybiphenyl 1,2-dioxygenase from pseudomonas putida ou83 and characterization of the gene (bphc). | the 2,3-dihydroxybiphenyl 1,2-dioxygenase (2,3-dbpd) of pseudomonas putida ou83 was constitutively expressed and purified to apparent homogeneity. the apparent molecular mass of the native enzyme was 256 kda, and the subunit molecular mass was 32 kda. the data suggested that 2,3-dbpd was an octamer of identical subunits. the nucleotide sequence of a dna fragment containing the bphc region was determined. the deduced protein sequence for 2,3-dbpd consisted of 292 amino acid residues, with a calcu ... | 1996 | 8633883 |
| pseudomonas fluorescens encodes the crohn's disease-associated i2 sequence and t-cell superantigen. | commensal bacteria have emerged as an important disease factor in human crohn's disease (cd) and murine inflammatory bowel disease (ibd) models. we recently isolated i2, a novel gene segment of microbial origin that is associated with human cd and that encodes a t-cell superantigen. to identify the i2 microorganism, blast analysis was used to identify a microbial homologue, pa2885, a novel open reading frame (orf) in the pseudomonas aeruginosa genome. pcr and southern analysis identified pseudom ... | 2002 | 12438326 |
| degradation of nitrobenzene by a pseudomonas pseudoalcaligenes. | a pseudomonas pseudoalcaligenes able to use nitrobenzene as the sole source of carbon, nitrogen, and energy was isolated from soil and groundwater contaminated with nitrobenzene. the range of aromatic substrates able to support growth was limited to nitrobenzene, hydroxylaminobenzene, and 2-aminophenol. washed suspensions of nitrobenzene-grown cells removed nitrobenzene from culture fluids with the concomitant release of ammonia. nitrobenzene, nitrosobenzene, hydroxylaminobenzene, and 2-aminophe ... | 1993 | 8368838 |
| methyl-beta-cyclodextrin-enhanced solubilization and aerobic biodegradation of polychlorinated biphenyls in two aged-contaminated soils. | the bioremediation of aged polychlorinated biphenyl (pcb)-contaminated soils is adversely affected by the low bioavailability of the pollutants. randomly methylated-beta-cyclodextrins (rameb) were tested as a potential pcb-bioavailability-enhancing agent in the aerobic treatment of two aged-contaminated soils. the soils, contaminated by about 890 and 8500 mg/kg of aroclor 1260 pcbs, were amended with biphenyl (4 g/kg), inorganic nutrients (to adjust their c:n ratio to 20:1), and variable amounts ... | 2003 | 12491523 |
| 2-hydroxypenta-2,4-dienoate metabolic pathway genes in a strong polychlorinated biphenyl degrader, rhodococcus sp. strain rha1. | a gram-positive polychlorinated biphenyl (pcb) degrader, rhodococcus sp. strain rha1, metabolizes biphenyl through the 2-hydroxypenta-2,4-dienoate (hpd) and benzoate metabolic pathways. the hpd metabolic pathway genes, the hpd hydratase (bphe1), 4-hydroxy-2-oxovalerate aldolase (bphf1), and acetaldehyde dehydrogenase (acylating) (bphg) genes, were cloned from rha1. the deduced amino acid sequences of bphgf1e1 have 30 to 58% identity with those of the hpd metabolic pathway genes of gram-negative ... | 2003 | 12514024 |
| morphological changes of pseudomonas pseudoalcaligenes in response to temperature selection. | adaptation to novel environments usually entails morphological changes. the cell morphology of six experimental populations of pseudomonas pseudoalcaligenes and their common ancestor were examined with scanning electron microscopy (sem). the six experimental populations were propagated under different temperatures for 10 months: three of them cultured at constant normal temperature (35 degrees c) forming the control group, and the other three cultured at incremental higher temperatures (from 41 ... | 2003 | 12520367 |
| [isolation and identification of a killing maggots bacterium]. | a notably killing maggots bacterium was isolated from natural dead maggots in the manure pits in the countryside of yancheng. its pathogenicity was confirmed by the law of kock. the results of preliminary bioassay show that the pathogen can infect the larvas of greenbottle flies and other larvas of flies in a certain extent, but can't infect animals and fowls. the g + c content of its dna is 62.46%. the hybridization ratio of its dna and the pseudomonas pseudoalcaligenes' (as1.1806) is 81.2%. ac ... | 2000 | 12548772 |
| [isolation and characterization of a insecticidal protein from pseudomonas pseudoalcaligenes]. | a insecticidal protein was purified by gel-filtration chromatography on sephadex g-100 and anion-exchange chromatography on deae-sephadex a-50 from the suspension of pseudomonas pseudoalcaligenes culture. certain biophysical and biochemical properties were also studied. the molecular weight of the subunit of the insecticidal protein is 25,100 and pi is 5.16. amino acid composition analysis showed that it is an acidic protein. | 1998 | 12549390 |
| gene components responsible for discrete substrate specificity in the metabolism of biphenyl (bph operon) and toluene (tod operon). | bph operons coding for biphenyl-polychlorinated biphenyl degradation in pseudomonas pseudoalcaligenes kf707 and pseudomonas putida kf715 and tod operons coding for toluene-benzene metabolism in p. putida f1 are very similar in gene organization as well as size and homology of the corresponding enzymes (g. j. zylstra and d. t. gibson, j. biol. chem. 264:14940-14946, 1989; k. taira, j. hirose, s. hayashida, and k. furukawa, j. biol. chem. 267:4844-4853, 1992), despite their discrete substrate rang ... | 1993 | 8349562 |
| [n-terminal analysis and antibody preparation of insecticidal protein form pseudomonas pseudoalcaligenes]. | the insecticidal protein from pseudomonas pseudoaligenes was and exotoxin which had toxicity on locusts. in order to elucidate its molecular properties an amino acid sequence, the insecticidal protein was purified from the culture supernatant by ultrafiltration, ion-exchange chromatography and gel filtration, and showed a single band on sds-page. analysis of the purified insecticidal protein dentified n-terminal sequence of ten amino acid residues. its polyclonal antibody was also obtained by im ... | 2001 | 12552816 |
| nucleotide sequence and functional analysis of the meta-cleavage pathway involved in biphenyl and polychlorinated biphenyl degradation in pseudomonas sp. strain kks102. | pseudomonas sp. strain kks102 is able to degrade biphenyl and polychlorinated biphenyls via the meta-cleavage pathway. we sequenced the upstream region of the bpha1a2a3bcd (open reading frame 1 [orf1]) a4 and found four orfs in this region. as the deduced amino acid sequences of the first, second, and third orfs are homologous to the meta-cleavage enzymes from pseudomonas sp. strain cf600 (v. shingler, j. powlowski, and u. marklund, j. bacteriol. 174:711-724, 1992), these orfs have been named bp ... | 1994 | 8021212 |
| [purification and properties of glutamate dehydrogenase from pseudomonas pseudoalcaligenes]. | glutamate dehydrogenase was purified from the crude extract of pseudomonas pseudoal-caligenes. the enzyme had a molecular weight of 290,000 and was composed of six subunits with identical molecular weight of 47,000. the enzyme was highly specific for nadp(h) and the substrates. the biochemical properties such as kinetic parameters and heat stability were also examined. the purified gdh showed considerable loss of activity upon freezing. | 1999 | 12555531 |
| diversity of tetracycline resistance genes in bacteria from chilean salmon farms. | twenty-five distinct tetracycline-resistant gram-negative bacteria recovered from four chilean fish farms with no history of recent antibiotic use were examined for the presence of tetracycline resistance (tet) genes. sixty percent of the isolates carried 1 of the 22 known tet genes examined. the distribution was as follows. the tet(a) gene was found in six isolates. the tet(b) gene was found in two isolates, including the first description in the genus brevundimonas: two isolates carried the te ... | 2003 | 12604516 |
| 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 |
| transposon-like organization of the plasmid-borne organophosphate degradation (opd) gene cluster found in flavobacterium sp. | several bacterial strains that can use organophosphate pesticides as a source of carbon have been isolated from soil samples collected from diverse geographical regions. all these organisms synthesize an enzyme called parathion hydrolase, and in each case the enzyme is encoded by a gene (opd) located on a large indigenous plasmid. these plasmids show considerable genetic diversity, but the region containing the opd gene is highly conserved. two opd plasmids, ppdl2 from flavobacterium sp. and pcm ... | 2003 | 12732518 |
| bacterial conversion of hydroxylamino aromatic compounds by both lyase and mutase enzymes involves intramolecular transfer of hydroxyl groups. | hydroxylamino aromatic compounds are converted to either the corresponding aminophenols or protocatechuate during the bacterial degradation of nitroaromatic compounds. the origin of the hydroxyl group of the products could be the substrate itself (intramolecular transfer mechanism) or the solvent water (intermolecular transfer mechanism). the conversion of hydroxylaminobenzene to 2-aminophenol catalyzed by a mutase from pseudomonas pseudoalcaligenes js45 proceeds by an intramolecular hydroxyl tr ... | 2003 | 12732549 |
| functional and structural relationship of various extradiol aromatic ring-cleavage dioxygenases of pseudomonas origin. | the extradiol ring-cleavage dioxygenases derived from seven different pseudomonas strains were expressed in escherichia coli and the substrate specificities were investigated for a variety of catecholic compounds. the substrate range of four 2,3-dihydroxybiphenyl dioxygenases from biphenyl-utilizing bacteria, 3-methylcatechol dioxygenase from toluene utilizing pseudomonas putida f1, 1,2-dihydroxynaphthalene dioxygenase from a nah7 plasmid, and catechol 2,3-dioxygenase from a tol plasmid pww0 wer ... | 1994 | 8020752 |
| control of the pyrimidine biosynthetic pathway in pseudomonas pseudoalcaligenes. | the five de novo enzyme activities unique to the pyrimidine biosynthetic pathway were found to be present in pseudomonas pseudoalcaligenes atcc 17440. a mutant strain with 31-fold reduced orotate phosphoribosyltransferase (encoded by pyre) activity was isolated that exhibited a pyrimidine requirement for uracil or cytosine. uptake of the nucleosides uridine or cytidine by wild-type or mutant cells was not detectable; explaining the inability of the mutant strain to utilize either nucleoside to s ... | 1994 | 7916185 |
| novel selective medium for isolation of burkholderia pseudomallei. | isolation of burkholderia pseudomallei currently relies on the use of ashdown's selective agar (asa). we designed a new selective agar (burkholderia pseudomallei selective agar [bpsa]) to improve recovery of the more easily inhibited strains of b. pseudomallei. b. pseudomallei, burkholderia cepacia, and pseudomonas aeruginosa were used to determine the selectivity and sensitivity of bpsa. bpsa was more inhibitory to p. aeruginosa and b. cepacia and should make recognition of burkholderia species ... | 2003 | 12843080 |
| effect of carbon source on pyrimidine biosynthesis in pseudomonas alcaligenes atcc 14909. | the effect of carbon source on the regulation of the de novo pyrimidine biosynthetic enzymes in pseudomonas alcaligenes atcc 14909 was investigated. the de novo pyrimidine biosynthetic enzymes were measured in extracts of p. alcaligenes atcc 14909 cells and of cells from an auxotroph deficient for orotate phosphoribosyltransferase activity. pyrimidine biosynthetic enzyme activities in atcc 14909 were influenced by pyrimidine supplementation to the culture medium but not by the carbon source pres ... | 2003 | 12906394 |
| flow-injection spectrophotometric determination of cyanate in bioremediation processes by use of immobilised inducible cyanase. | a new flow injection (fi) method for photometric monitoring of cyanate in bioremediation processes using immobilised native cyanase is described. the method is based on the catalytic reaction between cyanate and bicarbonate to produce ammonia and carbon dioxide in the presence of an inducible native cyanase, immobilised in a reactor packed with glass beads. two degrees of purification of the biocatalyst were used-heated cell-free extract and purified extract of cyanase from pseudomonas pseudoalc ... | 2003 | 13680069 |
| cis-2', 3'-dihydrodiol production on flavone b-ring by biphenyl dioxygenase from pseudomonas pseudoalcaligenes kf707 expressed in escherichia coli. | escherichia coli jm109 strains expressing either toluene dioxygenase from pseudomonas putida f1 or biphenyl dioxygenase from pseudomonas pseudoalcaligenes kf707 were examined for their ability to catalyze flavones. biphenyl dioxygenase produced metabolites from flavone and 5,7-dihydroxyflavone which were not found in the control experiments. the absorption maxima of uv-visible spectra for the metabolites from flavone and 5,7-dihydroxyflavone were found at 337 and 348 nm respectively by using a p ... | 2003 | 14574103 |
| cloning, nucleotide sequence, and expression of the gene encoding a novel dioxygenase involved in metabolism of carboxydiphenyl ethers in pseudomonas pseudoalcaligenes pob310. | pseudomonas pseudoalcaligenes strain pob310 degrades 3- and 4-carboxydiphenyl ether. the initial reaction involves an angular dioxygenation yielding an unstable hemiacetal that spontaneously decays to phenol and protocatechuate. we cloned a dna fragment containing the gene encoding the initial dioxygenase from an unstable, self-transmissible plasmid. sequence analysis revealed two open reading frames encoding proteins with putative molecular masses of 46.3 and 33.6 kda. the deduced amino acid se ... | 1995 | 7710319 |
| microbial growth and accumulation in industrial metal-working fluids. | the dynamics of microbial growth in metal-working fluids (mwf) and the effect of the addition of biocides were studied in large fluid systems, in this case, one central tank which holds 150 m3. in this system, populations of pseudomonas pseudoalcaligenes (greater than 10(8) cfu/ml) were sustained for a year, although large quantities of biocides were added. quantitation of 3-oh lauric acid, a marker for many pseudomonas spp., by gas chromatography indicated that the bacterial biomass exceeded th ... | 1989 | 2604406 |
| 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 |
| characterization of transcriptional regulatory genes for biphenyl degradation in rhodococcus sp. strain rha1. | transcription of the bpha1a2a3a4c1b genes, which are responsible for the conversion of biphenyl and polychlorinated biphenyl to the meta-cleavage products in rhodococcus sp. strain rha1, was examined. the bpha1 promoter (p(bpha1)) was identified and was shown to promote transcription induction by biphenyl and ethylbenzene. an 8.8-kb hindiii fragment that promotes transcription induction of p(bpha1) in rhodococcus erythropolis iam1399 was isolated from the region downstream of bphb by using a rep ... | 2004 | 15028699 |
| use of whole cells of pseudomonas aeruginosa for synthesis of the antioxidant hydroxytyrosol via conversion of tyrosol. | for the first time, a soil bacterium, designated pseudomonas aeruginosa, was isolated based on its ability to grow on tyrosol as a sole source of carbon and energy. during growth on tyrosol, this strain was capable of promoting the formation of a significant amount of hydroxytyrosol and trace quantities of parahydroxyphenyl acetic acid and 3,4-dihydroxyphenyl acetic acid. the products were confirmed by high-performance liquid chromatography and gas chromatography-mass spectrometry analyses. usin ... | 2004 | 15066802 |
| 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 |
| genetic environments of the rmta gene in pseudomonas aeruginosa clinical isolates. | nine pseudomonas aeruginosa strains showing very high levels of resistance to various aminoglycosides have been isolated from clinical specimens in seven separate japanese hospitals in five prefectures since 1997. these strains harbor the newly identified 16s rrna methylase gene (rmta). when an rmta gene probe was hybridized with genomic dnas of the nine strains digested with ecori, two distinct patterns were observed. the 11.1- and 15.8-kb regions containing the rmta genes of strains ar-2 and a ... | 2004 | 15155201 |
| cloning and sequencing of two tandem genes involved in degradation of 2,3-dihydroxybiphenyl to benzoic acid in the polychlorinated biphenyl-degrading soil bacterium pseudomonas sp. strain kks102. | two genes involved in the degradation of biphenyl were isolated from a gene library of a polychlorinated biphenyl-degrading soil bacterium, pseudomonas sp. strain kks102, by using a broad-host-range cosmid vector, pks13. when a 3.2-kilobase (kb) psti fragment of a 29-kb cosmid dna insert was subcloned into puc18 at the psti site downstream of the lacz promoter, escherichia coli cells carrying this recombinant plasmid expressed 2,3-dihydroxybiphenyl dioxygenase activity. nucleotide sequencing of ... | 1989 | 2540155 |
| 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 |
| promoter sequences necessary for high-level expression of the plasmid-associated ampc beta-lactamase gene blamir-1. | little is known about mechanisms involved in high-level expression of plasmid-associated ampc genes. the sequence for bla(mir-1) has been elucidated, and the gene is not inducible. although the sequence for the promoter (pra) that drives expression of enterobacter cloacae chromosomal ampc is present upstream of bla(mir-1), high-level expression from bla(mir-1) is directed from a hybrid promoter (prb) located further upstream of pra. the purpose of this study was to determine the influence of eac ... | 2004 | 15504838 |
| effects of the metalloid oxyanion tellurite (teo32-) on growth characteristics of the phototrophic bacterium rhodobacter capsulatus. | this work examines the effects of potassium tellurite (k2teo3) on the cell viability of the facultative phototroph rhodobacter capsulatus. there was a growth mode-dependent response in which cultures anaerobically grown in the light tolerate the presence of up to 250 to 300 microg of tellurite (teo3(2-)) per ml, while dark-grown aerobic cells were inhibited at tellurite levels as low as 2 microg/ml. the tellurite sensitivity of aerobic cultures was evident only for growth on minimal salt medium, ... | 2004 | 15528523 |
| engineering of chimeric class ii polyhydroxyalkanoate synthases. | pha synthase is a key enzyme involved in the biosynthesis of polyhydroxyalkanoates (phas). using a combinatorial genetic strategy to create unique chimeric class ii pha synthases, we have obtained a number of novel chimeras which display improved catalytic properties. to engineer the chimeric pha synthases, we constructed a synthetic phac gene from pseudomonas oleovorans (phac1po) that was devoid of an internal 540-bp fragment. randomly amplified pcr products (created with primers based on conse ... | 2004 | 15528546 |
| gene-specific transposon mutagenesis of the biphenyl/polychlorinated biphenyl-degradation-controlling bph operon in soil bacteria. | a transposon, tn5-b21, was gene-specifically inserted into the chromosomal biphenyl/polychlorinated biphenyl-catabolic operon (bph operon) of soil bacteria. the cloned bpha, bphb and bphc genes of pseudomonas pseudoalcaligenes kf707, coding for conversion of biphenyl into a ring meta-cleavage product (2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid), carried random insertions of tn5-b21. the mutagenized bphabc dna, carried by a suicide plasmid, was introduced back into the parent strain kf707, res ... | 1991 | 1849495 |
| assimilation of nitrogen from nitrite and trinitrotoluene in pseudomonas putida jlr11. | pseudomonas putida jlr11 releases nitrogen from the 2,4,6-trinitrotoluene (tnt) ring as nitrite or ammonium. these processes can occur simultaneously, as shown by the observation that a nasb mutant impaired in the reduction of nitrite to ammonium grew at a slower rate than the parental strain. nitrogen from tnt is assimilated via the glutamine syntethase-glutamate synthase (gs-gogat) pathway, as evidenced by the inability of gogat mutants to use tnt. this pathway is also used to assimilate ammon ... | 2005 | 15601726 |
| interfamilial transfer of amber suppressor gene for the isolation of amber mutants of mycobacteriophage i3. | a suppressor-containing strain of mycobacterium smegmatis sn2 was isolated by transferring an amber suppressor carried on the plasmid of pseudomonas pseudoalcaligenes era through transformation. amber mutants of mycobacteriophage i3 were isolated. | 1979 | 443992 |
| bacterial degradation of cyanide and its metal complexes under alkaline conditions. | a bacterial strain able to use cyanide as the sole nitrogen source under alkaline conditions has been isolated. the bacterium was classified as pseudomonas pseudoalcaligenes by comparison of its 16s rna gene sequence to those of existing strains and deposited in the coleccion espanola de cultivos tipo (spanish type culture collection) as strain cect5344. cyanide consumption is an assimilative process, since (i) bacterial growth was concomitant and proportional to cyanide degradation and (ii) the ... | 2005 | 15691951 |
| crystal structure of the terminal oxygenase component of cumene dioxygenase from pseudomonas fluorescens ip01. | the crystal structure of the terminal component of the cumene dioxygenase multicomponent enzyme system of pseudomonas fluorescens ip01 (cumdo) was determined at a resolution of 2.2 a by means of molecular replacement by using the crystal structure of the terminal oxygenase component of naphthalene dioxygenase from pseudomonas sp. strain ncib 9816-4 (nphdo). the ligation of the two catalytic centers of cumdo (i.e., the nonheme iron and rieske [2fe-2s] centers) and the bridging between them in nei ... | 2005 | 15774891 |
| first isolation of blavim-2 in an environmental isolate of pseudomonas pseudoalcaligenes. | | 2005 | 15855549 |
| emergence of multifunctional oxygenase activities by random priming recombination. | biphenyl dioxygenase (bph dox) is responsible for the initial dioxygenation of biphenyl. the large subunit (bpha1) of bph dox plays a crucial role in determination of substrate specificity of biphenyl-related compounds including polychlorinated biphenyls (pcbs). functional evolution of bph dox of pseudomonas pseudoalcaligenes kf707 was accomplished by random priming recombination of the bpha1 gene, involving two rounds of in vitro recombination and mutation followed by selection for increased ac ... | 2001 | 11312272 |
| modeling solid-to-solid biocatalysis: integration of six consecutive steps. | a quantitative model for the conversion of a solid-substrate salt to a solid-product salt in a batch bioreactor seeded with product crystals is presented. the overall process consists of six serial steps (with dissolution and crystallization each in themselves complex multistep processes): solid-salt dissolution, salt dissociation into an ionic substrate and a counter-ion, bioconversion accompanied by biocatalyst inactivation, complexation of the ionic product with the counter-ion, and salt crys ... | 2000 | 10918134 |
| genetic variation in clones of pseudomonas pseudoalcaligenes after ten months of selection in different thermal environments in the laboratory. | the random amplification of polymorphic dna (rapd) method was used to examine genetic variation in experimental clones of pseudomonas pseudoalcaligenes in two experimental groups, as well as their common ancestor. six clones derived from a single colony of p. pseudoalcaligenes were cultured in two different thermal regimes for 10 months. three clones in the control group were cultured at constant temperature of 35 degrees c and another three clones in the high temperature (ht) group were propaga ... | 2005 | 15886916 |
| hydrocarbon biodegradation in oxygen-limited sequential batch reactors by consortium from weathered, oil-contaminated soil. | we studied the use of sequential batch reactors under oxygen limitation to improve and maintain consortium ability to biodegrade hydrocarbons. air-agitated tubular reactors (2.5 l) were operated for 20 sequential 21-day cycles. maya crude oil-paraffin mixture (13,000 mg/l) was used as the sole carbon source. the reactors were inoculated with a consortium from the rhizosphere of cyperus laxus, a native plant that grows naturally in weathered, contaminated soil. oxygen limitation was induced in th ... | 2005 | 15920621 |
| microbial diversity in ultra-high-pressure rocks and fluids from the chinese continental scientific drilling project in china. | microbial communities in ultra-high-pressure (uhp) rocks and drilling fluids from the chinese continental scientific drilling project were characterized. the rocks had a porosity of 1 to 3.5% and a permeability of approximately 0.5 mdarcy. abundant fluid and gas inclusions were present in the minerals. the rocks contained significant amounts of fe2o3, feo, p2o5, and nitrate (3 to 16 ppm). acridine orange direct counting and phospholipid fatty acid analysis indicated that the total counts in the ... | 2005 | 15933024 |
| identification of bacteria isolated from an oligotrophic lake with pesticide removal capacities. | we studied the growth and capacities for pesticides removal of bacterial strains isolated from the laguna grande, an oligotrophic lake at the south of spain (archidona, málaga). strains were isolated from water samples amended with 10 and 50 microg/ml of nine pesticides: organochlorinated insecticides (aldrin and lindane), organophosphorous insecticides (dimetoate, methyl-parathion and methidation), s-triazine herbicides (simazine and atrazine), fungicide (captan) and diflubenzuron (1-(-4-chloro ... | 2005 | 15943106 |
| biodegradation of pyridine in a completely mixed activated sludge process. | a potential bacterial culture (p1), isolated from garden soil and identified as pseudomonas pseudoalcaligenes-kpn, was used as a starter seed to develop the biomass in a completely mixed activated sludge (cmas) reactor and the system was evaluated for treatment of wastewater containing pyridine. the results of this study indicate that pyridine could be degraded efficiently at a loading of 0.251 kg pyridine kg mlss(-1) d(-1) (0.156 kg toc kg mlss(-1) d(-1)) and at an optimal hydraulic retention t ... | 2006 | 16084081 |
| alcaligenes faecalis subsp. phenolicus subsp. nov. a phenol-degrading, denitrifying bacterium isolated from a graywater bioprocessor. | a gram (-) coccobacillary bacterium, j(t), was isolated from a graywater bioprocessor. 16s rrna and biochemical analysis has revealed strain j(t) closely resembles alcaligenes faecalis atcc 8750t and a. faecalis subsp. parafaecalis dsm 13975t, but is a distinct, previously uncharacterized isolate. strain j(t), along with the type strain of a. faecalis and its previously described subspecies share the ability to aerobically degrade phenol. the degradation rates of phenol for strain j(t) and refer ... | 2005 | 16094869 |
| diversity of alkaliphilic and alkalitolerant bacteria cultivated from decomposing reed rhizomes in a hungarian soda lake. | bacterial communities associated with decomposing rhizomes of phragmites australis were investigated in lake ferto (neusiedlersee, hungary). alkaliphilic and alkalitolerant strains were isolated on cellulose-containing alkaline medium spread with dilutions of scrapings taken from the surface of the decaying plant material. fifty-one strains were grouped by numerical analysis based on physiological tests and biolog sole carbon source utilization data. the strains identified by 16s rdna sequence c ... | 2005 | 16132425 |
| growth of ca-d-malate crystals in a bioreactor. | to develop a bioreactor for solid-to-solid conversions, the conversion of solid ca-maleate to solid ca-d-malate by permeabilized pseudomonas pseudoalcaligenes was studied. in a bioreactor seeded with product (ca-d-malate) crystals, growth of ca-d-malate crystals is the last step in the solid-to-solid conversion and is described here. crystal growth is described as a transport process followed by surface processes. in contrast to the linear rate law obeyed by the transport process, the surface pr ... | 2000 | 10898864 |
| influence of chlorine substituents on rates of oxidation of chlorinated biphenyls by the biphenyl dioxygenase of burkholderia sp. strain lb400. | biphenyl dioxygenase from burkholderia (pseudomonas) sp. strain lb400 catalyzes the first reaction of a pathway for the degradation of biphenyl and a broad range of chlorinated biphenyls (cbs). the effect of chlorine substituents on catalysis was determined by measuring the specific activity of the enzyme with biphenyl and 18 congeners. the catalytic oxygenase component was purified and incubated with individual cbs in the presence of electron transport proteins and cofactors that were required ... | 2000 | 10877788 |
| increased mesquite gum formation in nodal explants cultures after treatment with a microbial biomass preparation. | prosopis laevigata nodal explants cultures were established in murashige and skoog medium. simultaneously these cultures were subjected to stress with biotic elicitors and an environmental factor (temperature increase to promote heat stress) in order to promote and increase exuded mesquite gum production. the biotic elicitors were: aspergillus nidulans and pseudomonas pseudoalcaligenes both used in concentrations of 10, 20 and 30 mg, whereas the environmental condition was different incubation t ... | 2005 | 16198591 |
| active-site engineering of biphenyl dioxygenase: effect of substituted amino acids on substrate specificity and regiospecificity. | biphenyl dioxygenase (bph dox) catalyzes the initial dioxygenation step in the metabolism of biphenyl. the large subunit (bpha1) of bph dox plays a crucial role in the determination of the substrate specificity of biphenyl-related compounds including polychlorinated biphenyls (pcbs). previously, the substitution of asn at thr-376 near the active-site iron in the bpha1 of pseudomonas pseudoalcaligenes kf707 expanded the oxidation range and altered the regiospecificity of bph dox for pcbs. in this ... | 2006 | 16217654 |
| engineering a hybrid pseudomonad to acquire 3,4-dioxygenase activity for polychlorinated biphenyls. | we constructed a hybrid strain that acquired 3,4-dioxygenase activity for polychlorinated biphenyls (pcbs). this strain, kf707-d34, possessed a chimeric biphenyl dioxygenase gene, of which a portion of bpha1 (coding for a large subunit of biphenyl dioxygenase) of pseudomonas pseudoalcaligenes kf707 was replaced with that of a pcb-degrader, burkholderia cepacia lb400 by homologous recombination. kf707-d34 retained the ability to degrade 4,4'-dichlorobiphenyl via 2,3-dioxygenation in a fashion ide ... | 1999 | 16232495 |
| characterization of hydroxylaminobenzene mutase from pnbz139 cloned from pseudomonas pseudoalcaligenes js45. a highly associated sds-stable enzyme catalyzing an intramolecular transfer of hydroxy groups. | hydroxylaminobenzene mutase is the enzyme that converts intermediates formed during initial steps in the degradation of nitrobenzene to a novel ring-fission lower pathway in pseudomonas pseudoalcaligenes js45. the mutase catalyzes a rearrangement of hydroxylaminobenzene to 2-aminophenol. the mechanism of the reactions and the properties of the enzymes are unknown. in crude extracts, the hydroxylaminobenzene mutase was stable at sds concentrations as high as 2%. a procedure including hitrap-sp, h ... | 2000 | 10672020 |
| influence of inorganic nitrogen management regime on the diversity of nitrite-oxidizing bacteria in agricultural grassland soils. | to assess links between the diversity of nitrite-oxidizing bacteria (nob) in agricultural grassland soils and inorganic n fertilizer management, nob communities in fertilized and unfertilized soils were characterized by analysis of clone libraries and denaturing gradient gel electrophoresis (dgge) of 16s rrna gene fragments. previously uncharacterized nitrospira-like sequences were isolated from both long-term-fertilized and unfertilized soils, but dgge migration patterns indicated the presence ... | 2005 | 16332819 |
| regiospecificity of dioxygenation of di- to pentachlorobiphenyls and their degradation to chlorobenzoates by the bph-encoded catabolic pathway of burkholderia sp. strain lb400. | burkholderia sp. strain lb400 is one of the most potent aerobic polychlorobiphenyl (pcb)-degrading microorganisms that have been characterized. its pcb-dioxygenating activity originates predominantly or exclusively from the biphenyl dioxygenase encoded by its bph gene cluster. analysis of the dioxygenation products of several di- to pentachlorinated biphenyls formed by this enzyme revealed a complex dependence of the regiospecificity and the yield of dioxygenation on the substitution patterns of ... | 1999 | 10427057 |
| effects of chemical speciation on the mineralization of organic compounds by microorganisms. | the mineralization of 1.0 to 100 ng each of four complexing compounds-oxalate, citrate, nitrilotriacetate (nta), and edta-per ml was tested in media prepared in accordance with equilibrium calculations by a computer program so that the h, ca, mg, fe, or al complex (chemical species) was predominant. sewage microorganisms mineralized calcium citrate more rapidly than iron, aluminum, or hydrogen citrate, and magnesium citrate was degraded slowest. aluminum, hydrogen, and iron oxalates were mineral ... | 1985 | 16346854 |
| induction of bpha, encoding biphenyl dioxygenase, in two polychlorinated biphenyl-degrading bacteria, psychrotolerant pseudomonas strain cam-1 and mesophilic burkholderia strain lb400. | we investigated induction of biphenyl dioxygenase in the psychrotolerant polychlorinated biphenyl (pcb) degrader pseudomonas strain cam-1 and in the mesophilic pcb degrader burkholderia strain lb400. using a counterselectable gene replacement vector, we inserted a lacz-gm(r) fusion cassette between chromosomal genes encoding the large subunit (bpha) and small subunit (bphe) of biphenyl dioxygenase in cam-1 and lb400, generating cam-10 and lb400-1, respectively. potential inducers of bpha were ad ... | 2001 | 11375179 |
| initial reductive reactions in aerobic microbial metabolism of 2,4,6-trinitrotoluene. | because of its high electron deficiency, initial microbial transformations of 2,4,6-trinitrotoluene (tnt) are characterized by reductive rather than oxidation reactions. the reduction of the nitro groups seems to be the dominating mechanism, whereas hydrogenation of the aromatic ring, as described for picric acid, appears to be of minor importance. thus, two bacterial strains enriched with tnt as a sole source of nitrogen under aerobic conditions, a gram-negative strain called tnt-8 and a gram-p ... | 1998 | 16349484 |
| studies of the catabolic pathway of degradation of nitrobenzene by pseudomonas pseudoalcaligenes js45: removal of the amino group from 2-aminomuconic semialdehyde. | [this corrects the article on p. 4841 in vol. 63.]. | 1998 | 16349521 |
| cyanide metabolism of pseudomonas pseudoalcaligenes cect5344: role of siderophores. | cyanide is one of the most potent and toxic chemicals produced by industry. the jewelry industry of córdoba (spain) generates a wastewater (residue) that contains free cyanide, as well as large amounts of cyano-metal complexes. cyanide is highly toxic to living systems because it forms very stable complexes with transition metals that are essential for protein function. in spite of its extreme toxicity, some organisms have acquired mechanisms to avoid cyanide poisoning. the biological assimilati ... | 2006 | 16417508 |
| identification of nif genes in n2-fixing bacterial strains isolated from rice fields along the yangtze river plain. | the aim of this research was to identify nifh and nifhdkye ' genes in twenty strains of n2-fixing heterotrophic bacteria isolated from rice fields in the yangtze river plain. southern hybridization of the total dna from each strain was performed with the klebsiella pneumoniae nifhdkye ' gene probe (6.2 kb eco ri fragment from psa30) and the azospirillum brasilense nifh gene probe (0.6 kb eco ri-hin diii fragment from phu8). we found that eco ri fragments of total dna from aeromonas hydrophila hy ... | 2006 | 16463319 |
| genetic and structural organization of the aminophenol catabolic operon and its implication for evolutionary process. | the aminophenol (ap) catabolic operon in pseudomonas putida hs12 mineralizing nitrobenzene was found to contain all the enzymes responsible for the conversion of ap to pyruvate and acetyl coenzyme a via extradiol meta cleavage of 2-aminophenol. the sequence and functional analyses of the corresponding genes of the operon revealed that the ap catabolic operon consists of one regulatory gene, nbzr, and the following nine structural genes, nbzjcacbdgfeih, which encode catabolic enzymes. the nbzr pr ... | 2001 | 11489860 |
| directed evolution of biphenyl dioxygenase: emergence of enhanced degradation capacity for benzene, toluene, and alkylbenzenes. | biphenyl dioxygenase (bph dox) catalyzes the initial oxygenation of biphenyl and related compounds. bph dox is a multicomponent enzyme in which a large subunit (encoded by the bpha1 gene) is significantly responsible for substrate specificity. by using the process of dna shuffling of bpha1 of pseudomonas pseudoalcaligenes kf707 and burkholderia cepacia lb400, a number of evolved bph dox enzymes were created. among them, an escherichia coli clone expressing chimeric bph dox exhibited extremely en ... | 2001 | 11514531 |
| oxidative transformation of aminodinitrotoluene isomers by multicomponent dioxygenases. | the electron-withdrawing nitro substituents of 2,4,6-trinitrotoluene (tnt) make the aromatic ring highly resistant to oxidative transformation. the typical biological transformation of tnt involves reduction of one or more of the nitro groups of the ring to produce the corresponding amine. reduction of a single nitro substituent of tnt to an amino substituent increases the electron density of the aromatic nucleus considerably. the comparatively electron-dense nuclei of the aminodinitrotoluene (a ... | 2001 | 11722893 |
| transformation of 2,4,6-trinitrotoluene by pseudomonas pseudoalcaligenes js52. | pseudomonas pseudoalcaligenes js52 grows on nitrobenzene via partial reduction of the nitro group and enzymatic rearrangement of the resultant hydroxylamine. cells and cell extracts of nitrobenzene-grown js52 catalyzed the transient formation of 4-hydroxylamino-2,6-dinitrotoluene (4hadnt), 4-amino-2,6-dinitrotoluene (4adnt), and four previously unidentified metabolites from 2,4,6-trinitrotoluene (tnt). two of the novel metabolites were identified by liquid chromatography/mass spectrometry and (s ... | 1997 | 16535610 |
| 16s rrna gene sequencing versus the api 20 ne system and the vitek 2 id-gnb card for identification of nonfermenting gram-negative bacteria in the clinical laboratory. | over a period of 26 months, we have evaluated in a prospective fashion the use of 16s rrna gene sequencing as a means of identifying clinically relevant isolates of nonfermenting gram-negative bacilli (non-pseudomonas aeruginosa) in the microbiology laboratory. the study was designed to compare phenotypic with molecular identification. results of molecular analyses were compared with two commercially available identification systems (api 20 ne, vitek 2 fluorescent card; biomérieux, marcy l'etoil ... | 2006 | 16597863 |
| the locus coding for the 3-nitrobenzoate dioxygenase of comamonas sp. strain js46 is flanked by is1071 elements and is subject to deletion and inversion events. | in comamonas sp. strain js46, 3-nitrobenzoate (3nba) is initially oxidized at the 3,4 position by a dioxygenase, which results in release of nitrite and production of protocatechuate. the locus coding for the 3nba dioxygenase (designated mnb, for m-nitrobenzoate) was mobilized from strain js46 using a plasmid capture method, cloned, and sequenced. the 3nba dioxygenase (mnba) is a member of the phthalate family of aromatic oxygenases. an open reading frame designated mnbb that codes for an nad(p) ... | 2006 | 16597970 |
| pseudomonad cyclopentadecanone monooxygenase displaying an uncommon spectrum of baeyer-villiger oxidations of cyclic ketones. | baeyer-villiger monooxygenases (bvmos) are biocatalysts that offer the prospect of high chemo-, regio-, and enantioselectivity in the organic synthesis of lactones or esters from a variety of ketones. in this study, we have cloned, sequenced, and overexpressed in escherichia coli a new bvmo, cyclopentadecanone monooxygenase (cpdb or cpdmo), originally derived from pseudomonas sp. strain hi-70. the 601-residue primary structure of cpdb revealed only 29% to 50% sequence identity to those of known ... | 2006 | 16597975 |
| steady-state kinetic characterization of evolved biphenyl dioxygenase, which acquired novel degradation ability for benzene and toluene. | biphenyl dioxygenase (bph dox) catalyzes initial oxygenation in the bacterial biphenyl degradation pathway. bph dox in pseudomonas pseudoalcaligenes kf707 is a rieske type three-component enzyme in which a large subunit (encoded by the bpha1 gene) plays an important role in the substrate specificity of bph dox. steady-state kinetic assays using purified enzyme components demonstrated that kf707 bph dox had a kcat/km of 33.1 x 10(3) (m(-1) s(-1)) for biphenyl. evolved 1072 bph dox generated by th ... | 2006 | 16636475 |
| characterization of genes involved in the initial reactions of 4-chloronitrobenzene degradation in pseudomonas putida zwl73. | the genes encoding enzymes involved in the initial reactions during degradation of 4-chloronitrobenzene (4cnb) were characterized from the 4cnb utilizer pseudomonas putida zwl73, in which a partial reductive pathway was adopted. a dna fragment containing genes coding for chloronitrobenzene nitroreductase (cnba) and hydroxylaminobenzene mutase (cnbb) were pcr-amplified and subsequently sequenced. these two genes were actively expressed in escherichia coli, and recombinant e. coli cells catalyzed ... | 2006 | 16642329 |
| assessment of toluene/biphenyl dioxygenase gene diversity in benzene-polluted soils: links between benzene biodegradation and genes similar to those encoding isopropylbenzene dioxygenases. | the pcr-single-strand conformation polymorphism (sscp) technique was used to assess the diversity and distribution of rieske nonheme iron oxygenases of the toluene/biphenyl subfamily in soil dna and bacterial isolates recovered from sites contaminated with benzene, toluene, ethylbenzene, and xylenes (btex). the central cores of genes encoding the catalytic alpha subunits were targeted, since they are responsible for the substrate specificities of these enzymes. sscp functional genotype fingerpri ... | 2006 | 16672497 |
| multiniche screening reveals the clinically relevant metallo-beta-lactamase vim-2 in pseudomonas aeruginosa far from the hospital setting: an ongoing dispersion process? | a screening study of the presence of metallo-beta-lactamases (imp and vim types and spm-1) in isolates from different nonhospital sources was conducted, and it revealed the presence of bla(vim-2), associated with the in58 class 1 integron, in two unrelated pseudomonas aeruginosa strains from aquatic habitats. the results suggest that the hospital setting was the possible origin of these bla(vim-2)-carrying strains. | 2006 | 16672526 |
| a glutathione s-transferase catalyzes the dehalogenation of inhibitory metabolites of polychlorinated biphenyls. | bphk is a glutathione s-transferase of unclear physiological function that occurs in some bacterial biphenyl catabolic (bph) pathways. we demonstrated that bphk of burkholderia xenovorans strain lb400 catalyzes the dehalogenation of 3-chloro 2-hydroxy-6-oxo-6-phenyl-2,4-dienoates (hopdas), compounds that are produced by the cometabolism of polychlorinated biphenyls (pcbs) by the bph pathway and that inhibit the pathway's hydrolase. a one-column protocol was developed to purify heterologously pro ... | 2006 | 16740949 |
| protein engineering of the 4-methyl-5-nitrocatechol monooxygenase from burkholderia sp. strain dnt for enhanced degradation of nitroaromatics. | 4-methyl-5-nitrocatechol (4m5nc) monooxygenase (dntb) from burkholderia sp. strain dnt catalyzes the second step of 2,4-dinitrotoluene degradation by converting 4m5nc to 2-hydroxy-5-methylquinone with the concomitant removal of the nitro group. dntb is a flavoprotein that has a very narrow substrate range. here, error-prone pcr was used to create variant dntb m22l/l380i, which accepts the two new substrates 4-nitrophenol (4np) and 3-methyl-4-nitrophenol (3m4np). at 300 microm of 4np, the initial ... | 2006 | 16751499 |