| detection of bioluminescence from individual bacterial cells: a comparison of two different low-light imaging systems. | detection of very low light levels arising from individual cells of the naturally bioluminescent bacterium vibrio fischeri as well as from a luminescence-marked pseudomonas putida strain was achieved by the aid of two different camera systems. using a liquid nitrogen-cooled slow-scan ccd (charge-coupled device) camera were able to detect single-cell bioluminescence within 1 min, and the pictures obtained were of good resolution. in contrast, employing a photon-counting video camera we were able ... | 1997 | 9315952 |
| the cis-diol dehydrogenase cbac gene of tn5271 is required for growth on 3-chlorobenzoate but not 3,4-dichlorobenzoate. | the nucleotide sequence of cbac, the 1-carboxy-3-chloro-4,5-dihydroxycyclohexa-2,6-diene (cis-diol) dehydrogenase gene from the 3-chlorobenzoate (3-cba) catabolic transposon tn5271 was determined. the functional significance of the deduced open reading frame was evaluated by deletion of an internal bsteii restriction site in cbac and by the creation of nested deletions using exonuclease iii. expression studies were carried out with alcaligenes sp. strain br6024, a chloramphenicol-resistant, tryp ... | 1997 | 9322760 |
| chemotaxis of pseudomonas spp. to the polyaromatic hydrocarbon naphthalene. | two naphthalene-degrading bacteria, pseudomonas putida g7 and pseudomonas sp. strain ncib 9816-4, were chemotactically attracted to naphthalene in drop assays and modified capillary assays. growth on naphthalene or salicylate induced the chemotactic response. p. putida g7 was also chemotactic to biphenyl; other polyaromatic hydrocarbons that were tested did not appear to be chemoattractants for either pseudomonas strain. strains that were cured of the naphthalene degradation plasmid were not att ... | 1997 | 9327579 |
| biochemical and genetic characterization of 2-carboxybenzaldehyde dehydrogenase, an enzyme involved in phenanthrene degradation by nocardioides sp. strain kp7. | 2-carboxybenzaldehyde dehydrogenase from the phenanthrene-degrading bacterium nocardioides sp. strain kp7 was purified and characterized. the purified enzyme had a molecular mass of 53 kda by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 205 kda by gel filtration chromatography. thus, the homotetramer of the 53-kda subunit constituted an active enzyme. the apparent km and kcat values of this enzyme for 2-carboxybenzaldehyde were 100 microm and 39 s(-1), respectively, and those fo ... | 1997 | 9335300 |
| bacterial genetic loci implicated in the pseudomonas putida gr12-2r3--canola mutualism: identification of an exudate-inducible sugar transporter. | pseudomonas putida gr12-2r3 promotes the emergence and growth of diverse plant species. analyses of tnphoa insertion mutations are revealing bacterial characteristics pertinent to the plant-microbe interaction. pseudomonas putida pg269 is a tnphoa insertion derivative of gr12-2r3 that expresses canola seed exudate-inducible alkaline phosphatase (phoa) activity. it promoted the growth of canola roots, as well as strain gr12-2r3, and outgrew its parent when they were cocultured in the presence of ... | 1997 | 9336944 |
| transcriptional control of the pseudomonas tol plasmid catabolic operons is achieved through an interplay of host factors and plasmid-encoded regulators. | the xyl genes of pseudomonas putida tol plasmid that specify catabolism of toluene and xylenes are organized in four transcriptional units: the upper-operon xyluwcambn for conversion of toluene/xylenes into benzoate/alkylbenzoates; the meta-operon xylxyzltegfjqkih, which encodes the enzymes for further conversion of these compounds into krebs cycle intermediates; and xyls and xylr, which are involved in transcriptional control. the xyls and xylr proteins are members of the xyls/arac and ntrc fam ... | 1997 | 9343354 |
| rapid physiological characterization of microorganisms by biosensor technique. | eleven microorganisms, arxula adeninivorans ls3, candida boidinii dsm 70034, candida lactis-condensi dsm 70635, pichia jadinii dsm 2361, pichia minuta dsm 7018, kluyveromyces lactis dsm 4394, pseudomonas putida dsm 50026, alcaligenes sp. dsm 30002, arthrobacter nicotianae dsm 20123 as well as issatchenkia orientalis dsm 70077 and rhodococcus erythropolis dsm 311 were characterized by the sensor technique by injection of 30 different substrates and substrate mixtures. the obtained data which are ... | 1997 | 9352658 |
| a tricarboxylic acid cycle intermediate regulating transcription of a chloroaromatic biodegradative pathway: fumarate-mediated repression of the clcabd operon. | the ortho-cleavage pathways of catechol and 3-chlorocatechol are central catabolic pathways of pseudomonas putida that convert aromatic and chloroaromatic compounds to tricarboxylic acid (tca) cycle intermediates. they are encoded by the evolutionarily related catbca and clcabd operons, respectively. expression of the cat and clc operons requires the lysr-type transcriptional activators catr and clcr, respectively, and the inducer molecules cis,cis-muconate and 2-chloro-cis,cis-muconate, respect ... | 1997 | 9352923 |
| identification of adjacent genes encoding the major catalase and a bacterioferritin from the plant-beneficial bacterium pseudomonas putida. | the cata gene, encoding the major cata from a root-colonizing isolate pseudomonas putida (pp), was cloned by complementation into a catalase (cat)-deficient escherichia coli (ec) strain um2. the orf for cata consisted of 479 aa with a higher degree of identity with typical cat from eukaryotes than prokaryotes. chromosomal homologous exchange with a mutant gene bearing an insertion of a luxab-npt cassette into the sfii site of cata generated a cata-deficient pp isolate. this mutant and another mu ... | 1997 | 9358059 |
| biodegradation of the gasoline oxygenates methyl tert-butyl ether, ethyl tert-butyl ether, and tert-amyl methyl ether by propane-oxidizing bacteria. | several propane-oxidizing bacteria were tested for their ability to degrade gasoline oxygenates, including methyl tert-butyl ether (mtbe), ethyl tert-butyl ether (etbe), and tert-amyl methyl ether (tame). both a laboratory strain and natural isolates were able to degrade each compound after growth on propane. when propane-grown strain env425 was incubated with 20 mg of uniformly labeled [14c]mtbe per liter, the strain converted > 60% of the added mtbe to 14co2 in < 30 h. the initial oxidation of ... | 1997 | 9361407 |
| indigo formation by microorganisms expressing styrene monooxygenase activity. | the transformation of indole to indigo by microorganisms expressing styrene monooxygenase (smo) has been studied. styrene and indole are structurally very similar, and thus we looked at a variety of styrene-degrading strains for indole transformation to indigo. two strains, pseudomonas putida s12 and ca-3, gave a blue color on solid media when grown in the presence of indole. indole induces its own transformation on solid media but is a poor inducer in liquid media. styrene is the best inducer o ... | 1997 | 9361415 |
| cis-trans isomerization of unsaturated fatty acids: cloning and sequencing of the cti gene from pseudomonas putida p8. | transposon mutants of pseudomonas putida p8 were generated by applying a mini-tn5 mutagenesis system. the mutants obtained were checked for their ability to tolerate increased temperatures and elevated phenol concentrations. approximately 5,800 transposon mutants were used to generate a pool of 600 temperature-sensitive strains; one of these strains was identified as being damaged in its ability to perform cis-trans isomerization of fatty acids. a gene library of p. putida p8 was constructed and ... | 1997 | 9361416 |
| high-resolution crystal structures of delta5-3-ketosteroid isomerase with and without a reaction intermediate analogue. | bacterial delta5-3-ketosteroid isomerase (ksi) catalyzes a stereospecific isomerization of steroid substrates at an extremely fast rate, overcoming a large disparity of pka values between a catalytic residue and its target. the crystal structures of ksi from pseudomonas putida and of the enzyme in complex with equilenin, an analogue of the reaction intermediate, have been determined at 1.9 and 2.5 a resolution, respectively. the structures reveal that the side chains of tyr14 and asp99 (a newly ... | 1997 | 9369474 |
| regioselectivity of nitroglycerin denitration by flavoprotein nitroester reductases purified from two pseudomonas species. | two species of pseudomonas capable of utilizing nitroglycerin (ng) as a sole nitrogen source were isolated from ng-contaminated soil and identified as pseudomonas putida ii-b and p. fluorescens i-c. while 9 of 13 laboratory bacterial strains that presumably had no previous exposure to ng could degrade low concentrations of ng (0.44 mm), the natural isolates tolerated concentrations of ng that were toxic to the lab strains (1.76 mm and higher). whole-cell studies revealed that the two natural iso ... | 1997 | 9371434 |
| identification of a thiamin-dependent synthase in escherichia coli required for the formation of the 1-deoxy-d-xylulose 5-phosphate precursor to isoprenoids, thiamin, and pyridoxol. | in escherichia coli, 1-deoxy-d-xylulose (or its 5-phosphate, dxp) is the biosynthetic precursor to isopentenyl diphosphate [broers, s. t. j. (1994) dissertation (eidgenössische technische hochschule, zürich)], thiamin, and pyridoxol [himmeldirk, k., kennedy, i. a., hill, r. e., sayer, b. g. & spenser, i. d. (1996) chem. commun. 1187-1188]. here we show that an open reading frame at 9 min on the chromosomal map of e. coli encodes an enzyme (deoxyxylulose-5-phosphate synthase, dxp synthase) that c ... | 1997 | 9371765 |
| competition of plasmid-bearing pseudomonas putida strains catabolizing naphthalene via various pathways in chemostat culture. | plasmid-carrying pseudomonas putida strains degrade naphthalene through different biochemical pathways. the influence of various combinations of host bacteria and plasmids on growth characteristics and competitiveness of p. putida strains was studied in chemostat culture at a low dilution rate (d = 0.05 h-1) with naphthalene as the sole source of carbon and energy. under naphthalene limitation, the plasmid-bearing strains degrading naphthalene that use catechol 1,2-dioxygenase for catechol oxida ... | 1997 | 9390458 |
| a direct electrode-driven p450 cycle for biocatalysis. | the large potential of redox enzymes to carry out formation of high value organic compounds motivates the search for innovative strategies to regenerate the cofactors needed by their biocatalytic cycles. here, we describe a bioreactor where the reducing power to the cycle is supplied directly to purified cytochrome cyp101 (p450cam; ec 1.14.15.1) through its natural redox partner (putidaredoxin) using an antimony-doped tin oxide working electrode. required oxygen was produced at a pt counter elec ... | 1997 | 9391064 |
| water stress effects on toluene biodegradation by pseudomonas putida. | we quantified the effects of matric and solute water potential on toluene biodegradation by pseudomonas putida mt-2, a bacterial strain originally isolated from soil. across the matric potential range of 0 to -1.5 mpa, growth rates were maximal for p. putida at -0.25 mpa and further reductions in the matric potential resulted in concomitant reductions in growth rates. growth rates were constant over the solute potential range 0 to -1.0 mpa and lower at -1.5 mpa. first order toluene depletion rat ... | 1997 | 9396169 |
| mutational analysis of the three cysteines and active-site aspartic acid 103 of ketosteroid isomerase from pseudomonas putida biotype b. | in order to clarify the roles of three cysteines in ketosteroid isomerase (ksi) from pseudomonas putida biotype b, each of the cysteine residues has been changed to a serine residue (c69s, c81s, and c97s) by site-directed mutagenesis. all cysteine mutations caused only a slight decrease in the k(cat) value, with no significant change of km for the substrate. even modification of the sulfhydryl group with 5,5'-dithiobis(2-nitrobenzoic acid) has almost no effect on enzyme activity. these results d ... | 1997 | 9401033 |
| purification, properties, and sequence of glycerol trinitrate reductase from agrobacterium radiobacter. | glycerol trinitrate (gtn) reductase, which enables agrobacterium radiobacter to utilize gtn and related explosives as sources of nitrogen for growth, was purified and characterized, and its gene was cloned and sequenced. the enzyme was a 39-kda monomeric protein which catalyzed the nadh-dependent reductive scission of gtn (km = 23 microm) to glycerol dinitrates (mainly the 1,3-isomer) with a ph optimum of 6.5, a temperature optimum of 35 degrees c, and no dependence on metal ions for activity. i ... | 1997 | 9401040 |
| acquisition of a deliberately introduced phenol degradation operon, pheba, by different indigenous pseudomonas species. | horizontal transfer of genes of selective value in an environment 6 years after their introduction into a watershed has been observed. expression of the gene phea, which encodes phenol monooxygenase and is linked to the pheba operon (a. nurk, l. kasak, and m. kivisaar, gene 102:13-18, 1991), allows pseudomonads to use phenol as a growth substrate. pseudomonas putida strains carrying this operon on a plasmid were used for bioremediation after an accidental fire in the estonia oil shale mine in es ... | 1997 | 9406411 |
| residence time calculation for chemotactic bacteria within porous media. | local chemical gradients can have a significant impact on bacterial population distributions within subsurface environments by evoking chemotactic responses. these local gradients may be created by consumption of a slowly diffusing nutrient, generation of a local food source from cell lysis, or dissolution of nonaqueous phase liquids trapped within the interstices of a soil matrix. we used a random walk simulation algorithm to study the effect of a local microscopic gradient on the swimming beha ... | 1997 | 9414207 |
| identification and molecular characterization of an efflux pump involved in pseudomonas putida s12 solvent tolerance. | bacteria able to grow in aqueous:organic two-phase systems have evolved resistance mechanisms to the toxic effects of solvents. one such mechanism is the active efflux of solvents from the cell, preserving the integrity of the cell interior. pseudomonas putida s12 is resistant to a wide variety of normally detrimental solvents due to the action of such an efflux pump. the genes for this solvent efflux pump were cloned from p. putida s12 and their nucleotide sequence determined. the deduced amino ... | 1998 | 9417051 |
| heterologous expression of heterotrophic nitrification genes. | paracoccus denitrificans is a heterotrophic organism capable of oxidizing ammonia to nitrite during growth on an organic carbon and energy source. this pathway, termed heterotrophic nitrification, requires the concerted action of an ammonia monooxygenase (amo) and hydroxylamine oxidase (hao). the genes required for heterotrophic nitrification have been isolated by introducing a pa. denitrificans genomic library into pseudomonas putida and screening for the accumulation of nitrite. in contrast to ... | 1997 | 9421902 |
| rpon of the fish pathogen vibrio (listonella) anguillarum is essential for flagellum production and virulence by the water-borne but not intraperitoneal route of inoculation. | to investigate the involvement of rpon in flagellum production and pathogenicity of vibrio (listonella) anguillarum, the rpon gene was cloned and sequenced. the deduced product of the rpon gene displayed strong homology to the alternative sigma 54 factor (rpon) of numerous species of bacteria. in addition, partial sequencing of rpon-linked orfs revealed a marked resemblance to similarly located orfs in other bacterial species. a polar insertion or an in-frame deletion in the coding region of rpo ... | 1997 | 9421909 |
| atzc is a new member of the amidohydrolase protein superfamily and is homologous to other atrazine-metabolizing enzymes. | pseudomonas sp. strain adp metabolizes atrazine to cyanuric acid via three plasmid-encoded enzymes, atza, atzb, and atzc. the first enzyme, atza, catalyzes the hydrolytic dechlorination of atrazine, yielding hydroxyatrazine. the second enzyme, atzb, catalyzes hydroxyatrazine deamidation, yielding n-isopropylammelide. in this study, the third gene in the atrazine catabolic pathway, atzc, was cloned from a pseudomonas sp. strain adp cosmid library as a 25-kb ecori dna fragment in escherichia coli. ... | 1998 | 9422605 |
| expression and characterization of a heme oxygenase (hmu o) from corynebacterium diphtheriae. iron acquisition requires oxidative cleavage of the heme macrocycle. | a full-length heme oxygenase gene from the pathogenic bacterium corynebacterium diphtheriae has been subcloned and expressed in escherichia coli. the enzyme is expressed at high levels as a soluble catalytically active protein that results in the accumulation of biliverdin within the e. coli cells. the purified heme oxygenase forms a 1:1 complex with heme (kd = 2.5 +/- 1 microm) and has hemeprotein spectra similar to those previously reported for the purified eukaryotic heme oxygenases. in the p ... | 1998 | 9422739 |
| role of the haemophilus ducreyi ton system in internalization of heme from hemoglobin. | by cloning into escherichia coli and construction of isogenic mutants of haemophilus ducreyi, we showed that the hemoglobin receptor (hgba) is tonb dependent. an e. coli hema tonb mutant expressing h. ducreyi hgba grew on low levels of hemoglobin as a source of heme only when an intact h. ducreyi ton system plasmid was present. in contrast, growth on heme by the e. coli hema tonb mutant expressing hgba was observed only at high concentrations of heme, was tonb independent, and demonstrated that ... | 1998 | 9423852 |
| complementation analysis of the dichelobacter nodosus fimn, fimo, and fimp genes in pseudomonas aeruginosa and transcriptional analysis of the fimnop gene region. | the causative agent of ovine footrot, the gram-negative anaerobe dichelobacter nodosus, produces polar type iv fimbriae, which are the major protective antigens. the d. nodosus genes fimn, fimo, and fimp are homologs of the pseudomonas aeruginosa fimbrial assembly genes, pilb, pilc, and pild, respectively. both the pild and fimp genes encode prepilin peptidases that are responsible for cleavage of the leader sequence from the immature fimbrial subunit. to investigate the functional similarity of ... | 1998 | 9423871 |
| recombinant methioninase infusion reduces the biochemical endpoint of serum methionine with minimal toxicity in high-stage cancer patients. | the tumor-specific increased minimal requirement for methionine has been shown to be a highly promising therapeutic target. to attack this target we have previously cloned the methioninase gene from pseudomonas putida and produced recombinant methioninase (rmetase). a pilot phase i clinical trial has been carried out to determine rmetase toxicity, rmetase pharmacokinetics, and serum met-depletion in cancer patients. patients with advanced breast cancer, lung cancer, renal cancer and lymphoma wer ... | 1997 | 9427792 |
| in vitro activities of granule-bound poly[(r)-3-hydroxyalkanoate]polymerase c1 of pseudomonas oleovorans--development of an activity test for medium-chain-length-poly(3-hydroxyalkanoate) polymerases. | a newly developed in vitro activity assay for medium-chain-length (mcl)-poly(3-hydroxyalkanoate) polymerases is described. polymerase c1 of pseudomonas oleovorans gpo1 attached to isolated granules was used as model enzyme. a direct correlation was found between (r)-3-hydroxyoctanoylcoa depletion and poly(3-hydroxyalkanoate) synthesis due to polymerase c1 activity. highest activities of 1.13 u/mg granule bound protein and highest specific activities of 2.3 u/mg polymerase c1 were determined towa ... | 1997 | 9428695 |
| identification of the open reading frame for the pseudomonas putida d-hydantoinase gene and expression of the gene in escherichia coli. | a dna fragment containing the gene for d-hydantoinase was cloned from pseudomonas putida ccrc 12857 into escherichia coli. the cloned gene contained an open reading frame (orf) of 1485 nucleotides encoding a protein of 53.4 kda in which the carboxyl terminal end is longer than that previously deduced from strain dsm 84. this orf was verified by amino acid sequencing of amino and carboxyl termini, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and amino acid sequence comparison. delet ... | 1998 | 9434154 |
| principal transcription sigma factors of pseudomonas putida strains mt-2 and g1 are significantly different. | the rpod gene coding for the primary transcription sigma factor, sigma70, and its entire operon were cloned from strain mt-2 of the purple soil bacterium pseudomonas putida. comparison of the deduced amino acid sequence of ppmt-2 sigma70 with that of sigma70 from p. putida strain g1 shows that the two proteins differ in their primary structure, molecular weight, and isoelectric point. the significance of this difference is discussed in terms of bacterial taxonomy and transcription regulation. | 1997 | 9434175 |
| repression of phenol catabolism by organic acids in ralstonia eutropha. | during batch growth of ralstonia eutropha (previously named alcaligenes eutrophus) on phenol in the presence of acetate, acetate was found to be the preferred substrate; this organic acid was rapidly metabolized, and the specific rate of phenol consumption was considerably decreased, although phenol consumption was not abolished. this decrease corresponded to a drop in phenol hydroxylase and catechol-2,3-dioxygenase specific activities, and the synthesis of the latter was repressed at the transc ... | 1998 | 9435054 |
| survival in soil of different toluene-degrading pseudomonas strains after solvent shock. | we assayed the tolerance to solvents of three toluene-degrading pseudomonas putida strains and pseudomonas mendocina kr1 in liquid and soil systems. p. putida dot-t1 tolerated concentrations of heptane, propylbenzene, octanol, and toluene of at least 10% (vol/vol), while p. putida f1 and eez15 grew well in the presence of 1% (vol/vol) propylbenzene or 10% (vol/vol) heptane, but not in the presence of similar concentrations of octanol or toluene. p. mendocina kr1 grew only in the presence of hept ... | 1998 | 9435060 |
| rhizoremediation of trichloroethylene by a recombinant, root-colonizing pseudomonas fluorescens strain expressing toluene ortho-monooxygenase constitutively. | trichloroethylene (tce) was removed from soils by using a wheat rhizosphere established by coating seeds with a recombinant, tce-degrading pseudomonas fluorescens strain that expresses the toma+ (toluene o-monooxygenase) genes from burkholderia cepacia pr1(23)(tom23c). a transposon integration vector was used to insert toma+ into the chromosome of p. fluorescens 2-79, producing a stable strain that expressed constitutively the monooxygenase at a level of 1.1 nmol/min.mg of protein (initial tce c ... | 1998 | 9435067 |
| biodegradation of phosphonomycin by rhizobium huakuii pmy1. | the biodegradation by rhizobium huakuii pmy1 of up to 10 mm phosphonomycin as a carbon, energy, and phosphorus source with accompanying p(i) release is described. this biodegradation represents a further mechanism of resistance to this antibiotic and a novel, phosphate-deregulated route for organophosphonate metabolism by rhizobium spp. | 1998 | 9435089 |
| degradation of nonionic surfactants and polychlorinated biphenyls by recombinant field application vectors. | degradation of polychlorinated biphenyls (pcbs) in the environment is limited by their aqueous solubility and the degradative competence of indigenous populations. field application vectors (favs) have been developed in which surfactants are used to both increase the solubility of the pcbs and support the growth of surfactant-degrading strains engineered for pcb degradation. surfactant and pcb degradation by two recombinant strains were investigated. pseudomonas putida ipl5 utilizes both alkylet ... | 1997 | 9439001 |
| functional analysis of the two-gene lysis system of the pneumococcal phage cp-1 in homologous and heterologous host cells. | the two lysis genes cph1 and cpl1 of the streptococcus pneumoniae bacteriophage cp-1 coding for holin and lysozyme, respectively, have been cloned and expressed in escherichia coli. synthesis of the cph1 holin resulted in bacterial cell death but not lysis. the cph1 gene was able to complement a lambda sam mutation in the nonsuppressing e. coli hb101 strain to produce phage progeny, suggesting that the holins encoded by both phage genes have analogous functions and that the pneumococcal holin in ... | 1998 | 9440507 |
| direct sulfhydrylation for methionine biosynthesis in leptospira meyeri. | a gene library of the leptospira meyeri serovar semaranga strain veldrat s.173 dna has been constructed in a mobilizable cosmid with inserts of up to 40 kb. it was demonstrated that a leptospira dna fragment carrying mety complemented escherichia coli strains carrying mutations in metb. the latter gene encodes cystathionine gamma-synthase, an enzyme which catalyzes the second step of the methionine biosynthetic pathway. the mety gene is 1,304 bp long and encodes a 443-amino-acid protein with a m ... | 1998 | 9440513 |
| degradation of chloroaromatics: purification and characterization of a novel type of chlorocatechol 2,3-dioxygenase of pseudomonas putida gj31. | a purification procedure for a new kind of extradiol dioxygenase, termed chlorocatechol 2,3-dioxygenase, that converts 3-chlorocatechol productively was developed. structural and kinetic properties of the enzyme, which is part of the degradative pathway used for growth of pseudomonas putida gj31 with chlorobenzene, were investigated. the enzyme has a subunit molecular mass of 33.4 kda by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. estimation of the native mr value under nondenatur ... | 1998 | 9440519 |
| detoxification of protoanemonin by dienelactone hydrolase. | protoanemonin is a toxic metabolite which may be formed during the degradation of some chloroaromatic compounds, such as polychlorinated biphenyls, by natural microbial consortia. we show here that protoanemonin can be transformed by dienelactone hydrolase of pseudomonas sp. strain b13 to cis-acetylacrylate. although similar km values were observed for cis-dienelactone and protoanemonin, the turnover rate of protoanemonin was only 1% that of cis-dienelactone. this indicates that at least this pe ... | 1998 | 9440530 |
| identification of major antigenic proteins of pasteurella piscicida. | two different antigenic protein-coding clones (ppa1 and ppa2) were isolated using anti-pasteurella piscicida rabbit serum from a genomic dna library of p. piscicida strain kp9038. the ppa1 and ppa2 expressed 7 kda and 45 kda proteins in escherichia coli, respectively, and the molecular sizes of these expressed proteins are the same as these of the major antigenic proteins of p. piscicida. ppa1 encodes a protein of 83 amino acids residues, which is similar to the bacterial lipoprotein. comparison ... | 1997 | 9441863 |
| cloning of the bacillus firmus of4 cls gene and characterization of its gene product. | the gene that codes for cardiolipin (cl) synthase and an adjacent gene that codes for a meca homolog in the alkaliphilic bacteria bacillus firmus of4 have been cloned and sequenced (genbank accession number u88888). the cls gene contains 1509 nucleotides, corresponding to a polypeptide of 57.9 kda. the predicted amino acid sequence has 129 identities and 100 similarities with the escherichia coli cl synthase. homologies were also noted with polypeptide sequences from putative cls genes from baci ... | 1998 | 9443601 |
| cloning and nucleotide sequence of the dna gyrase gyra gene from serratia marcescens and characterization of mutations in gyra of quinolone-resistant clinical isolates. | the sequence of the dna gyrase gyra gene of serratia marcescens atcc 14756 was determined. an open reading frame of 2,640 nucleotides coding for a polypeptide with a calculated molecular mass of 97,460 was found, and its sequence complemented the sequence of an escherichia coli gyra temperature-sensitive mutation. analysis of the pcr products of the quinolone resistance-determining regions of gyra genes from six quinolone-resistant clinical isolates revealed a single amino acid substitution, ser ... | 1998 | 9449286 |
| cloning and sequence analysis of a catechol 2,3-dioxygenase gene from the nitrobenzene-degrading strain comamonas sp js765. | comamonas sp strain js765 utilizes nitrobenzene as a carbon and nitrogen source. the initial attack on nitrobenzene is carried out by nitrobenzene 1,2-dioxygenase, which converts nitrobenzene to an unstable nitrohydrodiol that spontaneously decomposes to form catechol and nitrite. catechol is then degraded via a meta cleavage pathway. we now report the cloning of a dna fragment carrying a catechol 2,3-dioxygenase gene from js765. nucleotide sequence analysis revealed three open reading frames (o ... | 1997 | 9451836 |
| effect of long-term depletion of plasma methionine on the growth and survival of human brain tumor xenografts in athymic mice. | depletion of plasma methionine is expected to inhibit or reverse growth of methionine-dependent tumors; however, modulation of methionine and other sulfur amino acids is not a trivial task in experimental animals. l-methioninase from pseudomonas putida at 1,000 u/kg causes acute reduction of plasma methionine by 80% in mice, but recovery occurs within 14 hours. restriction of dietary choline and replacement of dietary methionine with homocystine results in 50% chronic reduction of plasma methion ... | 1997 | 9457739 |
| over-production of stereoselective nitrile hydratase from pseudomonas putida 5b in escherichia coli: activity requires a novel downstream protein. | the stereoselective nitrile hydratase (nhase) from pseudomonas putida 5b has been over-produced in escherichia coli. maximal enzyme activity requires the co-expression of a novel downstream gene encoding a protein (p14k) of 127 amino acids, which shows no significant homology to any sequences in the protein database. nitrile hydratase produced in transformed e. coli showed activity as high as 472 units/mg dry cell (sixfold higher than 5b), and retained the stereoselectivity observed in the nativ ... | 1997 | 9457799 |
| modulation of the function of the signal receptor domain of xylr, a member of a family of prokaryotic enhancer-like positive regulators. | the xylr protein controls expression from the pseudomonas putida tol plasmid upper pathway operon promoter (pu) in response to aromatic effectors. xylr-dependent stimulation of transcription from a pu::lacz fusion shows different induction kinetics with different effectors. with toluene, activation followed a hyperbolic curve with an apparent k of 0.95 mm and a maximum beta-galactosidase activity of 2,550 miller units. with o-nitrotoluene, in contrast, activation followed a sigmoidal curve with ... | 1998 | 9457863 |
| expression and characterization of (r)-specific enoyl coenzyme a hydratase involved in polyhydroxyalkanoate biosynthesis by aeromonas caviae. | complementation analysis of a polyhydroxyalkanoate (pha)-negative mutant of aeromonas caviae proved that orf3 in the pha locus (a 402-bp gene located downstream of the pha synthase gene) participates in pha biosynthesis on alkanoic acids, and the orf3 gene is here referred to as phaj(ac). escherichia coli bl21(de3) carrying phaj(ac). under the control of the t7 promoter overexpressed enoyl coenzyme a (enoyl-coa) hydratase, which was purified by one-step anion-exchange chromatography. the n-termi ... | 1998 | 9457873 |
| haloalkanoate dehalogenase ii (dehe) of a rhizobium sp.--molecular analysis of the gene and formation of carbon monoxide from trihaloacetate by the enzyme. | a 3-kb ecori fragment of genomic dna from a rhizobium sp. cloned into puc19 endowed escherichia coli k-12 with the ability to grow, albeit slowly, with 2-chloropropionic acid as substrate. the construct expressed weakly a gene that encoded a non-stereospecific 2-chloropropionic acid dehalogenase (dehalogenase ii; dehe). the dehe gene was not closely linked to the organism's other two dehalogenase genes, dehd and dehl. the derived amino acid sequence of dehe showed little identity with dehd or de ... | 1997 | 9461303 |
| characterization of a gene cluster from ralstonia eutropha jmp134 encoding metabolism of 4-methylmuconolactone. | a 2,585 bp chromosomal dna segment of ralstonia eutropha jmp134 (formerly: alcaligenes eutrophus jmp134) which contains a gene cluster encoding part of the modified ortho-cleavage pathway encodes a putative transport protein for 4-methylmuconolactone, a novel 4-methylmuconolactone methylisomerase and methylmuconolactone isomerase. the putative 4-methylmuconolactone transporter, a protein with a calculated molecular mass of 45.8 kda, exhibits sequence homology to other members of the major superf ... | 1998 | 9461415 |
| nonstereospecific transamination catalyzed by pyridoxal phosphate-dependent amino acid racemases of broad substrate specificity. | pyridoxal 5'-phosphate-dependent amino acid racemases of broad substrate specificity catalyze transamination as a side reaction. we studied the stereospecificities for hydrogen abstraction from c-4' of the bound pyridoxamine 5'-phosphate during transamination from pyridoxamine 5'-phosphate to pyruvate catalyzed by three amino acid racemases of broad substrate specificity. when the enzymes were incubated with (4's)- or (4'r)-[4'-3h]pyridoxamine 5'-phosphate in the presence of pyruvate, tritium wa ... | 1998 | 9461589 |
| a new 4-nitrotoluene degradation pathway in a mycobacterium strain. | mycobacterium sp. strain hl 4-nt-1, isolated from a mixed soil sample from the stuttgart area, utilized 4-nitrotoluene as the sole source of nitrogen, carbon, and energy. under aerobic conditions, resting cells of the mycobacterium strain metabolized 4-nitrotoluene with concomitant release of small amounts of ammonia; under anaerobic conditions, 4-nitrotoluene was completely converted to 6-amino-m-cresol. 4-hydroxylaminotoluene was converted to 6-amino-m-cresol by cell extracts and thus could be ... | 1998 | 9464378 |
| alcaligenes eutrophus as a bacterial chromate sensor. | in alcaligenes eutrophus ch34, determinants encoding inducible resistance to chromate (chr) and to cobalt and nickel (cnr) are located adjacent to each other on plasmid pmol28. to develop metal-sensing bacterial strains, a cloned part of plasmid pmol28, which contains both determinants, was mutated with tn5-lacz. the chr::lacz fusions were specifically induced by chromium; cnr was induced best by ni2+ but was also induced by co2+, mn2+, chromate, cu2+, cd2+, and zn2+. the broad-host-range incp1 ... | 1998 | 9464379 |
| a cold-adapted lipase of an alaskan psychrotroph, pseudomonas sp. strain b11-1: gene cloning and enzyme purification and characterization. | a psychrotrophic bacterium producing a cold-adapted lipase upon growth at low temperatures was isolated from alaskan soil and identified as a pseudomonas strain. the lipase gene (lipp) was cloned from the strain and sequenced. the amino acid sequence deduced from the nucleotide sequence of the gene (924 bp) corresponded to a protein of 308 amino acid residues with a molecular weight of 33,714. lipp also has consensus motifs conserved in other cold-adapted lipases, i.e., lipase 2 from antarctic m ... | 1998 | 9464382 |
| effect of low temperatures on growth, structure, and metabolism of campylobacter coli sp10. | the effect of low temperatures on the survival, structure, and metabolism of campylobacter coli sp10, a virulent strain, was investigated. c. coli became nonculturable rapidly at 20 and 10 degree c and slightly later at 4 degrees c. incubation in a microaerobic atmosphere improved survival, but after day 8, campylobacters were detectable by direct-count procedures only. the increase in the number of coccoid cells was most pronounced at 37 degrees c but also was noticeable at 20 and 10 degrees c. ... | 1998 | 9464397 |
| identification of bacterial isolates obtained from intestinal contents associated with 12,000-year-old mastodon remains. | mastodon (mammut americanum) remains unearthed during excavation of ancient sediments usually consist only of skeletal material, due to postmortem decomposition of soft tissues by microorganisms. two recent excavations of skeletal remains in anoxic sediments in ohio and michigan, however, have uncovered organic masses which appear to be remnants of the small and large intestines, respectively. macrobotanical examinations of the composition of these masses revealed assemblages of plant material r ... | 1998 | 9464403 |
| cloning and nucleotide sequence of the gyrb gene of vibrio parahaemolyticus and its application in detection of this pathogen in shrimp. | because biochemical testing and 16s rrna sequence analysis have proven inadequate for the differentiation of vibrio parahaemolyticus from closely related species, we employed the gyrase b gene (gyrb) as a molecular diagnostic probe. the gyrb genes of v. parahaemolyticus and closely related vibrio alginolyticus were cloned and sequenced. oligonucleotide pcr primers were designed for the amplification of a 285-bp fragment from within gyrb specific for v. parahaemolyticus. these primers recognized ... | 1998 | 9464408 |
| protein method for investigating mercuric reductase gene expression in aquatic environments. | a colorimetric assay for nadph-dependent, mercuric ion-specific oxidoreductase activity was developed to facilitate the investigation of mercuric reductase gene expression in polluted aquatic ecosystems. protein molecules extracted directly from unseeded freshwater and samples seeded with pseudomonas aeruginosa pu21 (rip64) were quantitatively assayed for mercuric reductase activity in microtiter plates by stoichiometric coupling of mercuric ion reduction to a colorimetric redox chain through na ... | 1998 | 9464410 |
| in situ gene expression in mixed-culture biofilms: evidence of metabolic interactions between community members. | microbial communities growing in laboratory-based flow chambers were investigated in order to study compartmentalization of specific gene expression. among the community members studied, the focus was in particular on pseudomonas putida and a strain of an acinetobacter sp., and the genes studied are involved in the biodegradation of toluene and related aromatic compounds. the upper-pathway promoter (pu) and the meta-pathway promoter (pm) from the tol plasmid were fused independently to the gene ... | 1998 | 9464414 |
| engineering of quasi-natural pseudomonas putida strains for toluene metabolism through an ortho-cleavage degradation pathway. | to construct a bacterial catalyst for bioconversion of toluene and several alkyl and chloro- and nitro-substituted derivatives into the corresponding benzoates, the upper tol operon of plasmid pww0 of pseudomonas putida was fully reassembled as a single gene cassette along with its cognate regulatory gene, xylr. the corresponding dna segment was then targeted to the chromosome of a p. putida strain by using a genetic technique that allows deletion of all recombinant tags inherited from previous ... | 1998 | 9464417 |
| localization of f plasmid sopb protein to positions near the poles of escherichia coli cells. | the subcellular localization of the sopb protein, which is encoded by the escherichia coli f plasmid and is involved in the partition of the single-copy plasmid, was directly visualized through the expression of the protein fused to the jellyfish green fluorescent protein (gfp). the fusion protein, but not gfp itself, was found to localize to positions close but not at the poles of exponentially growing cells. neither the presence of other f-encoded proteins nor the binding of sopb to its recogn ... | 1998 | 9465048 |
| luxi- and luxr-homologous genes of rhizobium etli cnpaf512 contribute to synthesis of autoinducer molecules and nodulation of phaseolus vulgaris. | autoinduction plays an important role in intercellular communication among symbiotic and pathogenic gram-negative bacteria. we report here that a nitrogen-fixing symbiont of phaseolus vulgaris, rhizobium etli cnpaf512, produces at least seven different autoinducer molecules. one of them exhibits a growth-inhibitory effect like that of the bacteriocin small [n-(3r-hydroxy-7-cis-tetradecanoyl)-l-homoserine lactone]. at least two of the other autoinducers are synthesized by a luxi-homologous autoin ... | 1998 | 9473034 |
| identification and characterization of alcr, a gene encoding an arac-like regulator of alcaligin siderophore biosynthesis and transport in bordetella pertussis and bordetella bronchiseptica. | a bordetella bronchiseptica iron transport mutant was isolated following an enrichment procedure based on streptonigrin resistance. the mutant displayed a growth defect on iron-restricted medium containing ferric alcaligin as the sole iron source. in addition to the apparent inability to acquire iron from the siderophore, the mutant failed to produce alcaligin as well as two known iron-regulated proteins, one of which is the alcc alcaligin biosynthesis protein. a 1.6-kb kpni-psti bordetella pert ... | 1998 | 9473040 |
| identification of alcr, an arac-type regulator of alcaligin siderophore synthesis in bordetella bronchiseptica and bordetella pertussis. | a fur titration assay was used to isolate dna fragments bearing putative fur binding sites (fbs) from a partial bordetella bronchiseptica genomic dna library. a recombinant plasmid bearing a 3.5-kb dna insert was further studied. successive deletions in the cloned fragment enabled us to map a putative fbs at about 2 kb from one end. sequence analysis revealed the presence of an fbs upstream from a new gene encoding an arac-type transcriptional regulator. the deduced protein displays similarity t ... | 1998 | 9473041 |
| involvement of outer membrane protein tolc, a possible member of the mar-sox regulon, in maintenance and improvement of organic solvent tolerance of escherichia coli k-12. | escherichia coli mutants with improved organic solvent tolerance levels showed high levels of outer membrane protein tolc and inner membrane protein acra. the tolc level was regulated positively by mara, rob, or soxs. a possible mar-rob-sox box sequence was found upstream of the tolc gene. these findings suggest that tolc is a member of the mar-sox regulon responsive to stress conditions. when a defective tolc gene was transferred to n-hexane- or cyclohexane-tolerant strains by p1 transduction, ... | 1998 | 9473050 |
| biochemical and genetic characterization of trans-2'-carboxybenzalpyruvate hydratase-aldolase from a phenanthrene-degrading nocardioides strain. | trans-2'-carboxybenzalpyruvate hydratase-aldolase was purified from a phenanthrene-degrading bacterium, nocardioides sp. strain kp7, and characterized. the purified enzyme was found to have molecular masses of 38 kda by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 113 kda by gel filtration chromatography. thus, the homotrimer of the 38-kda subunit constituted an active enzyme. the km and kcat values of this enzyme for trans-2'-carboxybenzalpyruvate were 50 microm and 13 s(-1), r ... | 1998 | 9473051 |
| polyethylene glycol conjugation of recombinant methioninase for cancer therapy. | recombinant methioninase (rmetase) is a homotetrameric pyridoxal 5'-phosphate enzyme of 172-kda molecular mass derived from pseudomonas putida and cloned in escherichia coli. rmetase has been found previously to be an effective, anti-tumor agent in vitro and in vivo. the enzyme targets the elevated minimal methionine requirement seen in all tumor types. in order to prevent immunological reactions which might be produced by multiple dosing of rmetase and to prolong the serum half-life of rmetase, ... | 1998 | 9473456 |
| organization and transcriptional characterization of the cat1 gene cluster in acinetobacter lwoffi k24. | previously, we have reported that two clustered cat genes from acenitobacter lwoffi k24 had different arrangements, catb1c1a1 and catb2a2c2 (kim, s.i., s.-h. leem, j.-s. choi, y.h. chung, s. kim, y.-m. park, y.k. park, y.n. lee, and k.-s. ha. 1997, j. bacteriol. 179, 5226-5231). by further analysis of the organization of the cat1 gene cluster, we obtained a complete sequence of the catb1 gene, which encoded 40.8-kda polypeptide containing 379 amino acids, and found a open reading frame (orf) cod ... | 1998 | 9473520 |
| the pseudomonas aeruginosa flagellar cap protein, flid, is responsible for mucin adhesion. | mucin-specific adhesion of pseudomonas aeruginosa plays an important role in the initial colonization of this organism in the airways of cystic fibrosis patients. we report here that the flagellar cap protein, flid, participates in this adhesion process. a polar chromosomal insertional mutation in the p. aeruginosa flid gene made this organism nonadhesive to mucin in an in vitro mucin adhesion assay. the adhesive phenotype was restored by providing the flid gene alone on a multicopy plasmid, sug ... | 1998 | 9488388 |
| the primitive protozoon trichomonas vaginalis contains two methionine gamma-lyase genes that encode members of the gamma-family of pyridoxal 5'-phosphate-dependent enzymes. | methionine gamma-lyase, the enzyme that catalyzes the breakdown of methionine by an alpha,gamma-elimination reaction and is a member of the gamma-family of pyridoxal 5'-phosphate-dependent enzymes, is present in high activity in the primitive protozoan parasite trichomonas vaginalis but is absent from mammals. two genes, mgl1 and mgl2, encoding methionine gamma-lyase, have now been isolated from t. vaginalis. they are both single copy, encode predicted proteins (mgl1 and mgl2) of 43 kda, have 69 ... | 1998 | 9488680 |
| molecular characterization of benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase ii of acinetobacter calcoaceticus. | the nucleotide sequences of xylb and xylc from acinetobacter calcoaceticus, the genes encoding benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase ii, were determined. the complete nucleotide sequence indicates that these two genes form part of an operon and this was supported by heterologous expression and physiological studies. benzaldehyde dehydrogenase ii is a 51654 da protein with 484 amino acids per subunit and it is typical of other prokaryotic and eukaryotic aldehyde dehydrogenas ... | 1998 | 9494109 |
| genetic and functional analysis of the styrene catabolic cluster of pseudomonas sp. strain y2. | the chromosomal region of pseudomonas sp. strain y2 involved in the conversion of styrene to phenylacetate (upper catabolic pathway) has been cloned and sequenced. four catabolic genes, styabcd, and two regulatory genes, stysr, were identified. this gene cluster when transferred to escherichia coli w confers to this phenylacetate-degrading host the ability to grow on styrene as the sole carbon and energy source. genes styabcd are homologous to those encoding the styrene upper catabolic pathway i ... | 1998 | 9495743 |
| characterization of a protocatechuate catabolic gene cluster from rhodococcus opacus 1cp: evidence for a merged enzyme with 4-carboxymuconolactone-decarboxylating and 3-oxoadipate enol-lactone-hydrolyzing activity. | the catechol and protocatechuate branches of the 3-oxoadipate pathway, which are important for the bacterial degradation of aromatic compounds, converge at the common intermediate 3-oxoadipate enol-lactone. a 3-oxoadipate enol-lactone-hydrolyzing enzyme, purified from benzoate-grown cells of rhodococcus opacus (erythropolis) 1cp, was found to have a larger molecular mass under denaturing conditions than the corresponding enzymes previously purified from gamma-proteobacteria. sequencing of the n ... | 1998 | 9495744 |
| evolutionary relationship between chlorocatechol catabolic enzymes from rhodococcus opacus 1cp and their counterparts in proteobacteria: sequence divergence and functional convergence. | biochemical investigations of the muconate and chloromuconate cycloisomerases from the chlorophenol-utilizing strain rhodococcus opacus (erythropolis) 1cp had previously indicated that the chlorocatechol catabolic pathway of this strain may have developed independently from the corresponding pathways of proteobacteria. to test this hypothesis, we cloned the chlorocatechol catabolic gene cluster of strain 1cp by using pcr with primers derived from sequences of n termini and peptides of purified c ... | 1998 | 9495745 |
| variation in flagellin genes and proteins of burkholderia cepacia. | the majority of isolates of burkholderia cepacia, an important opportunistic pathogen associated with cystic fibrosis, can be classified into two types on the basis of flagellin protein size. electron microscopic analysis indicates that the flagella of strains with the larger flagellin type (type i) are wider in diameter. flagellin genes representative of both types were cloned and sequenced to design oligonucleotide primers for pcr amplification of the central variable domain of b. cepacia flag ... | 1998 | 9495748 |
| enzyme specificity of 2-nitrotoluene 2,3-dioxygenase from pseudomonas sp. strain js42 is determined by the c-terminal region of the alpha subunit of the oxygenase component. | biotransformations with recombinant escherichia coli expressing the genes encoding 2-nitrotoluene 2,3-dioxygenase (2ntdo) from pseudomonas sp. strain js42 demonstrated that 2ntdo catalyzes the dihydroxylation and/or monohydroxylation of a wide range of aromatic compounds. extremely high nucleotide and deduced amino acid sequence identity exists between the components from 2ntdo and the corresponding components from 2,4-dinitrotoluene dioxygenase (2,4-dntdo) from burkholderia sp. strain dnt (form ... | 1998 | 9495758 |
| cloning and sequencing of the sphingomonas (pseudomonas) paucimobilis gene essential for the o demethylation of vanillate and syringate. | sphingomonas (pseudomonas) paucimobilis syk-6 is able to grow on 5,5'-dehydrodivanillic acid (ddva), syringate, vanillate, and other dimeric model compounds of lignin as a sole carbon source. nitrosoguanidine mutagenesis of s. paucimobilis syk-6 was performed, and two mutants with altered ddva degradation pathways were isolated. the mutant strain nt-1 could not degrade ddva, but could degrade syringate, vanillate, and 2,2',3'-trihydroxy-3-methoxy-5,5'-dicarboxybiphenyl (oh-ddva). strain dc-49 co ... | 1998 | 9501423 |
| biochemical and genetic characterization of an extracellular protease from pseudomonas fluorescens cy091. | pseudomonas fluorescens cy091 cultures produce an extracellular protease with an estimated molecular mass of 50 kda. production of this enzyme (designated aprx) was observed in media containing cacl2 or srcl2 but not in media containing zncl2, mgcl2, or mncl2. the requirement of ca2+ (or sr2+) for enzyme production was concentration dependent, and the optimal concentration for production was determined to be 0.35 mm. following ammonium sulfate precipitation and ion-exchange chromatography, the a ... | 1998 | 9501431 |
| bacterial community dynamics during start-up of a trickle-bed bioreactor degrading aromatic compounds. | this study was performed with a laboratory-scale fixed-bed bioreactor degrading a mixture of aromatic compounds (solvesso100). the starter culture for the bioreactor was prepared in a fermentor with a wastewater sample of a care painting facility as the inoculum and solvesso100 as the sole carbon source. the bacterial community dynamics in the fermentor and the bioreactor were examined by a conventional isolation procedure and in situ hybridization with fluorescently labeled rrna-targeted oligon ... | 1998 | 9501433 |
| development and testing of a bacterial biosensor for toluene-based environmental contaminants. | a bacterial biosensor for benzene, toluene, and similar compounds has been constructed, characterized, and field tested on contaminated water and soil. the biosensor is based on a plasmid incorporating the transcriptional activator xylr from the tol plasmid of pseudomonas putida mt-2. the xylr protein binds a subset of toluene-like compounds and activates transcription at its promoter, pu. a reporter plasmid was constructed by placing the luc gene for firefly luciferase under the control of xylr ... | 1998 | 9501440 |
| identification of a chemotaxis gene region from pseudomonas putida. | pseudomonas putida is chemotactic to a range of organic compounds, including several aromatic compounds. genes involved in this behavioral response were identified by tn5 mutagenesis of p. putida prs2000, resulting in a strain that was nonchemotactic to all chemoattractants tested. cloning and sequencing of the dna at the dna at the tn5 insertion site revealed a 13-kb region that contained 12 open reading frames, 9 of which are homologous to chemotaxis, flagellar and motility genes in other bact ... | 1998 | 9503621 |
| species-specific and ubiquitous-dna-based assays for rapid identification of staphylococcus aureus. | staphylococcus aureus is the cause of serious infections in humans, including endocarditis, deep-seated abscesses, and bacteremia, which lead to toxic and septic shock syndromes. rapid and direct identification of this bacterium specifically and ubiquitously directly from clinical specimens would be useful in improving the diagnosis of s. aureus infections in the clinical microbiology laboratory. a wide variety of kits based on biochemical characteristics efficiently identify s. aureus, but the ... | 1998 | 9508283 |
| evaluation of pcr for diagnosis of bordetella pertussis and bordetella parapertussis infections. | pcr, using primers plp1 and plp2, was evaluated for the detection of dna from bordetella pertussis in bacterial strains and in nasopharyngeal samples from patients with a cough lasting at least 7 days. the assay could detect dna from 6 cfu of b. pertussis/10 microl of sample. results of the pcr assay were compared with those of cultures, a determination of serum antibodies against pertussis toxin and filamentous hemagglutinin, and a clinical evaluation of 2,442 coughing episodes. the overall sen ... | 1998 | 9508295 |
| a protein-induced dna bend increases the specificity of a prokaryotic enhancer-binding protein. | control of transcription in prokaryotes often involves direct contact of regulatory proteins with rna polymerase from binding sites located adjacent to the target promoter. alternatively, in the case of genes transcribed by escherichia coli rna polymerase holoenzyme containing the alternate sigma factor sigma54, regulatory proteins bound at more distally located enhancer sites can activate transcription via dna looping by taking advantage of the increasing flexibility of dna over longer distance ... | 1998 | 9512522 |
| cloning and sequencing of a 2,5-dichlorohydroquinone reductive dehalogenase gene whose product is involved in degradation of gamma-hexachlorocyclohexane by sphingomonas paucimobilis. | sphingomonas (formerly pseudomonas) paucimobilis ut26 utilizes gamma-hexachlorocyclohexane (gamma-hch), a halogenated organic insecticide, as a sole carbon and energy source. in a previous study, we showed that gamma-hch is degraded to 2,5-dichlorohydroquinone (2,5-dchq) (y. nagata, r. ohtomo, k. miyauchi, m. fukuda, k. yano, and m. takagi, j. bacteriol. 176:3117-3125, 1994). in the present study, we cloned and characterized a gene, designated lind, directly involved in the degradation of 2,5-dc ... | 1998 | 9515900 |
| pcau, a transcriptional activator of genes for protocatechuate utilization in acinetobacter. | the acinetobacter pcaijfbdkchg operon encodes the six enzymes that convert protocatechuate to citric acid cycle intermediates. directly downstream from the operon are qui and pob genes encoding sets of enzymes that convert quinate and p-hydroxybenzoate, respectively, to protocatechuate. prior to this investigation, the only known regulatory gene in the pca-qui-pob cluster was pobr, which encodes a transcriptional activator that responds to p-hydroxybenzoate and activates transcription of poba. t ... | 1998 | 9515921 |
| characterization of the gene cassette required for biosynthesis of the (alpha1-->6)-linked n-acetyl-d-mannosamine-1-phosphate capsule of serogroup a neisseria meningitidis. | the (alpha1-->6)-linked n-acetyl-d-mannosamine-1-phosphate meningococcal capsule of serogroup a neisseria meningitidis is biochemically distinct from the sialic acid-containing capsules produced by other disease-associated meningococcal serogroups (e.g., b, c, y, and w-135). we defined the genetic cassette responsible for expression of the serogroup a capsule. the cassette comprised a 4,701-bp nucleotide sequence located between the outer membrane capsule transporter gene, ctra, and gale, encodi ... | 1998 | 9515923 |
| biodegradation of cyanides, cyanates and thiocyanates to ammonia and carbon dioxide by immobilized cells of pseudomonas putida. | pseudomonas putida utilizes cyanide as the sole source of carbon and nitrogen. agar, alginate, and carrageenan were screened as the encapsulating matrices for p. putida. alginate-immobilized cells of p. putida degraded sodium cyanide (nacn) more efficiently than non-immobilized cells or cells immobilized in agar or carrageenan. the end products of biodegradation of cyanide were identified as ammonia (nh3) and carbon dioxide (co2). these products changed the medium ph. in bioreactors, the rate of ... | 1998 | 9523454 |
| characterization of the cvaa and cvi promoters of the colicin v export system: iron-dependent transcription of cvaa is modulated by downstream sequences. | secretion of the escherichia coli toxin colicin v was previously determined to be iron regulated via the fur (ferric uptake regulator) protein, based on studies in fur mutants. the iron dependence of transcription and expression of cvaa, which encodes a transporter accessory protein, and cvi, encoding the colicin v immunity protein, was assessed under conditions of iron excess or depletion. immunoblots showed that production of both cvi and cvaa is iron dependent. the iron-dependent transcriptio ... | 1998 | 9537361 |
| the rhizobium etli rpon locus: dna sequence analysis and phenotypical characterization of rpon, ptsn, and ptsa mutants. | the rpon region of rhizobium etli was isolated by using the bradyrhizobium japonicum rpon1 gene as a probe. nucleotide sequence analysis of a 5,600-bp dna fragment of this region revealed the presence of four complete open reading frames (orfs), orf258, rpon, orf191, and ptsn, coding for proteins of 258, 520, 191, and 154 amino acids, respectively. the gene product of orf258 is homologous to members of the atp-binding cassette-type permeases. orf191 and ptsn are homologous to conserved orfs foun ... | 1998 | 9537369 |
| cloning and characterization of the pseudomonas aeruginosa zwf gene encoding glucose-6-phosphate dehydrogenase, an enzyme important in resistance to methyl viologen (paraquat). | in this study, we cloned the pseudomonas aeruginosa zwf gene, encoding glucose-6-phosphate dehydrogenase (g6pdh), an enzyme that catalyzes the nad+- or nadp+-dependent conversion of glucose-6-phosphate to 6-phosphogluconate. the predicted zwf gene product is 490 residues, which could form a tetramer with a molecular mass of approximately 220 kda. g6pdh activity and zwf transcription were maximal in early logarithmic phase when inducing substrates such as glycerol, glucose, or gluconate were abun ... | 1998 | 9537370 |
| the atrazine catabolism genes atzabc are widespread and highly conserved. | pseudomonas strain adp metabolizes the herbicide atrazine via three enzymatic steps, encoded by the genes atzabc, to yield cyanuric acid, a nitrogen source for many bacteria. here, we show that five geographically distinct atrazine-degrading bacteria contain genes homologous to atza, -b, and -c. the sequence identities of the atz genes from different atrazine-degrading bacteria were greater than 99% in all pairwise comparisons. this differs from bacterial genes involved in the catabolism of othe ... | 1998 | 9537398 |
| occurrence of homologs of the escherichia coli lytb gene in gram-negative bacterial species. | the escherichia coli lytb protein regulates the activity of guanosine 3',5'-bispyrophosphate synthetase i (rela). a southern blot analysis of chromosomal dna with the e. coli lytb gene as a probe revealed the presence of lytb homologs in all of the gram-negative bacterial species examined but not in gram-positive species. the lytb homologs from enterobacter aerogenes and pseudomonas fluorescens complemented the e. coli lytb44 mutant allele. | 1998 | 9537400 |
| the dimerization of pseudomonas putida cytochrome p450cam: practical consequences and engineering of a monomeric enzyme. | cytochrome p450cam dimerizes via the formation of an intermolecular disulfide bond, complicating the storage and handling of the enzyme, particularly at higher concentrations. the dimeric enzyme is 14% less active than the monomer and forms at a slow but significant rate even at 4 degrees c [k = 1.09 x 10(-3) mm(-1) h(-1)]. to eliminate any ambiguity introduced by dimer formation and to simplify handling and storage of the enzyme, site-directed mutagenesis was used to identify c334 as the single ... | 1997 | 9542996 |
| a novel -2fe-2s- ferredoxin from pseudomonas putida mt2 promotes the reductive reactivation of catechol 2,3-dioxygenase. | catechol 2,3-dioxygenase (xyle) is a component of the tol plasmid-encoded pathway for the degradation of toluene and xylenes and catalyzes the dioxygenolytic cleavage of the aromatic ring. purified xyle is oxygen-sensitive and unstable in vitro, particularly in the presence of substituted catechol substrates, but it is stabilized in vivo by another protein, xylt, encoded by the xylt gene located just upstream of xyle. in this study, we have purified to homogeneity the xylt product from a recombi ... | 1998 | 9545294 |
| alkane hydroxylase from acinetobacter sp. strain adp1 is encoded by alkm and belongs to a new family of bacterial integral-membrane hydrocarbon hydroxylases. | degradation of long-chain alkanes by acinetobacter sp. strain adp1 involves rubredoxin and rubredoxin reductase. we complemented a mutant deficient in alkane utilization and sequenced four open reading frames (orfs) on the complementing dna. each of these orfs was disrupted by insertional mutagenesis on the chromosome. as determined from sequence comparisons, orf1 and orf4 seem to encode a rotamase of the ppic type and an acyl coenzyme a dehydrogenase, respectively. disruption of these orfs does ... | 1998 | 9546151 |
| effects of bacterial host and dichloromethane dehalogenase on the competitiveness of methylotrophic bacteria growing with dichloromethane. | methylobacterium sp. strain dm4 and methylophilus sp. strain dm11 can grow with dichloromethane (dcm) as the sole source of carbon and energy by virtue of homologous glutathione-dependent dcm dehalogenases with markedly different kinetic properties (the kcat values of the enzymes of these strains are 0.6 and 3.3 s-1, respectively, and the km values are 9 and 59 microm, respectively). these strains, as well as transconjugant bacteria expressing the dcm dehalogenase gene (dcma) from dm11 or dm4 on ... | 1998 | 9546153 |
| population dynamics of phenol-degrading bacteria in activated sludge determined by gyrb-targeted quantitative pcr. | a method for quantifying bacterial populations introduced into an activated-sludge microbial community is described. the method involves extraction of dna from activated sludge, appropriate dilution of the extracted dna with dna extracted from nonintroduced activated sludge, pcr amplification of a gyrb gene fragment from the introduced strain with a set of strain-specific primers, and quantification of the electrophoresed pcr product by densitometry. the adequacy of the method was examined by an ... | 1998 | 9546154 |