Publications

biodegradation of 2,4-dinitrotoluene by a pseudomonas sp.	previous studies of the biodegradation of nonpolar nitroaromatic compounds have suggested that microorganisms can reduce the nitro groups but cannot cleave the aromatic ring. we report here the initial steps in a pathway for complete biodegradation of 2,4-dinitrotoluene (dnt) by a pseudomonas sp. isolated from a four-member consortium enriched with dnt. the pseudomonas sp. degraded dnt as the sole source of carbon and energy under aerobic conditions with stoichiometric release of nitrite. during ...	1991	1781682
biotransformation of nitrobenzene by bacteria containing toluene degradative pathways.	nonpolar nitroaromatic compounds have been considered resistant to attack by oxygenases because of the electron withdrawing properties of the nitro group. we have investigated the ability of seven bacterial strains containing toluene degradative pathways to oxidize nitrobenzene. cultures were induced with toluene vapor prior to incubation with nitrobenzene, and products were identified by high-performance liquid chromatography and gas chromatography-mass spectrometry. pseudomonas cepacia g4 and ...	1991	1781679
production and characterization of n-acyl-d-glutamate amidohydrolase from pseudomonas sp. strain 5f-1.	n-acyl-d-glutamate amidohydrolase from pseudomonas sp. strain 5f-1 was inducibly produced by d isomers of n-acetylglutamate, glutamate, aspartate, and asparagine. the enzyme has been purified to homogeneity by deae-cellulose, (nh4)2so4 fractionation, and chromatofocusing followed by gel filtration on a sephadex g-100 column. the enzyme was a monomer with molecular weight of 55,000. the enzyme activity was optimal at ph 6.5 to 7.5 and 45 degrees c. the isoelectric point and the ph stability were ...	1991	1768127
production of the siderophore aerobactin by a halophilic pseudomonad.	a bacterial strain, isolated from a cyanobacterial culture, was identified as pseudomonas sp. strain x40. under iron-limiting conditions, the pseudomonas sp. produced aerobactin, a dihydroxamate siderophore previously found only in the family enterobacteriaceae. aerobactin was identified by electrophoretic mobility, spectrophotometric titration, proton nuclear magnetic resonance spectroscopy, mass spectrometry, acid hydrolysis, and biological activity. aerobactin was used as a siderophore in the ...	1991	1768095
substrate interactions of benzene, toluene, and para-xylene during microbial degradation by pure cultures and mixed culture aquifer slurries.	benzene, toluene, and p-xylene (btx) were degraded by indigenous mixed cultures in sandy aquifer material and by two pure cultures isolated from the same site. although btx compounds have a similar chemical structure, the fate of individual btx compounds differed when the compounds were fed to each pure culture and mixed culture aquifer slurries. the identification of substrate interactions aided the understanding of this behavior. beneficial substrate interactions included enhanced degradation ...	1991	1746958
cloning and sequencing of the genes involved in the conversion of 5-substituted hydantoins to the corresponding l-amino acids from the native plasmid of pseudomonas sp. strain ns671.	pseudomonas sp. strain ns671, which produces l-amino acids asymmetrically from the corresponding racemic 5-substituted hydantoins, harbored a plasmid of 172 kb. curing experiments suggest that this plasmid, designated phn671, is responsible for the conversion of 5-substituted hydantoins to their corresponding l-amino acids by strain ns671. dna fragments containing the genes involved in this conversion were cloned from phn671 in escherichia coli by using puc18 as a cloning vector. the smallest re ...	1992	1732229
nucleotide sequence and functional analysis of the complete phenol/3,4-dimethylphenol catabolic pathway of pseudomonas sp. strain cf600.	the meta-cleavage pathway for catechol is one of the major routes for the microbial degradation of aromatic compounds. pseudomonas sp. strain cf600 grows efficiently on phenol, cresols, and 3,4-dimethylphenol via a plasmid-encoded multicomponent phenol hydroxylase and a subsequent meta-cleavage pathway. the genes for the entire pathway were previously found to be clustered, and the nucleotide sequences of dmpklmnopbc and d, which encode the first four biochemical steps of the pathway, were deter ...	1992	1732207
effect of sodium chloride on transport of bacteria in a saturated aquifer material.	determinations were made of the influence of nacl concentration, cell density, and flow velocity on the transport of pseudomonas sp. strain kl2 through columns of aquifer sand under saturated conditions. a pulse-type boundary condition was used. the experiments were conducted by using 0.3-m-long plexiglas columns with an internal diameter of 0.05 m. when a 1-h pulse of a 0.01 m nacl solution containing 10(8) cells per ml was added at a flow rate of 10(-4) m s-1, the bacterial density in the effl ...	1991	1662934
identification of a novel composite transposable element, tn5280, carrying chlorobenzene dioxygenase genes of pseudomonas sp. strain p51.	analysis of one of the regions of catabolic plasmid pp51 which encode chlorobenzene metabolism of pseudomonas sp. strain p51 revealed that the tcba and tcbb genes for chlorobenzene dioxygenase and dehydrogenase are located on a transposable element, tn5280. tn5280 showed the features of a composite bacterial transposon with iso-insertion elements (is1066 and is1067) at each end of the transposon oriented in an inverted position. when a 12-kb hindiii fragment of pp51 containing tn5280 was cloned ...	1991	1657878
lupanine hydroxylase, a quinocytochrome c from an alkaloid-degrading pseudomonas sp.	lupanine 17-hydroxylase, the first enzyme in the pathway for bacterial degradation of the alkaloid, lupanine, was purified from a pseudomonas sp. the enzyme acts by initial dehydrogenation of the substrate, and cytochrome c was used as electron acceptor in assays. it had an mr of 66,000 by ultracentrifuge studies and 74,000 by gel filtration. the visible absorption spectrum was that of a cytochrome c, and a stoicheiometry of one haem group per molecule of enzyme was calculated. sds/page gave a s ...	1991	1656935
biodegradation of mixtures of substituted benzenes by pseudomonas sp. strain js150.	pseudomonas sp. strain js150 was isolated as a nonencapsulated variant of pseudomonas sp. strain js1 that contains the genes for the degradative pathways of a wide range of substituted aromatic compounds. pseudomonas sp. strain js150 grew on phenol, ethylbenzene, toluene, benzene, naphthalene, benzoate, p-hydroxybenzoate, salicylate, chlorobenzene, and several 1,4-dihalogenated benzenes. we designed experiments to determine the conditions required for induction of the individual pathways and to ...	1992	1637161
biosorption of dichlorodiphenyltrichloroethane and hexachlorobenzene in groundwater and its implications for facilitated transport.	the potential for enhanced mobility of hydrophobic pollutants by cotransport with bacteria in saturated soils was evaluated from measurements of biosorption of 14c-labeled hexachlorobenzene and dichlorodiphenyltrichloroethane (ddt) to five strains of soil and sewage bacteria. the sorption process could be described by a linear partition equation and appeared to be reversible, but desorption kinetics were slow and/or partly irreversible. the ddt partition coefficients varied with equilibration ti ...	1992	1637158
construction of a 3-chlorobiphenyl-utilizing recombinant from an intergeneric mating.	recombinant pseudomonas sp. strain cb15, which grows on 3-chlorobiphenyl (3cb), was constructed from pseudomonas sp. strain hf1, which grows on 3-chlorobenzoate, and from acinetobacter sp. strain p6, which grows on biphenyl, by using a continuous amalgamated culture apparatus. dna from strains cb15 and hf1 hybridized very strongly to each other, while hybridization between both parental strains, hf1 and p6, was negligible. however, dna from the recombinant cb15 hybridized moderately to strongly ...	1992	1610186
survival and function of a genetically engineered pseudomonad in aquatic sediment microcosms.	pseudomonas sp. strain b13 fr1(pfrc20p) is a genetically engineered microorganism (gem) which is able to degrade chloro- and methylaromatics through a constructed ortho cleavage pathway. the fate of the gem and its ability to degrade substituted aromatic compounds in two different aquatic sediments was investigated by using a microcosm system which consisted of intact layered sediment cores with an overlying water column. the gem survived in lake plussee and in rhine river sediments at densities ...	1992	1599245
evaluation of aquatic sediment microcosms and their use in assessing possible effects of introduced microorganisms on ecosystem parameters.	in this paper we describe a sediment microcosm system consisting of 20 undisturbed, layered sediment cores with overlying site water which are incubated under identical conditions of temperature, light, stirring rate of overlying water, and water exchange rate. ecosystem parameters (nutrient level, photosynthetic potential, community structure of heterotrophic bacteria, thymidine incorporation rate, and oxygen microgradients) of the laboratory microcosms and the source ecosystem were compared an ...	1992	1599244
anaerobic degradation of 2-aminobenzoic acid (anthranilic acid) via benzoyl-coenzyme a (coa) and cyclohex-1-enecarboxyl-coa in a denitrifying bacterium.	the enzymes catalyzing the initial reactions in the anaerobic degradation of 2-aminobenzoic acid (anthranilic acid) were studied with a denitrifying pseudomonas sp. anaerobically grown with 2-aminobenzoate and nitrate as the sole carbon and energy sources. cells grown on 2-aminobenzoate are simultaneously adapted to growth with benzoate, whereas cells grown on benzoate degrade 2-aminobenzoate several times less efficiently than benzoate. evidence for a new reductive pathway of aromatic metabolis ...	1992	1592816
cloning and partial sequencing of an operon encoding two pseudomonas putida haloalkanoate dehalogenases of opposite stereospecificity.	we have cloned fragments of dna (up to 13 kb), from pseudomonas putida aj1, that code for two stereospecific haloalkanoate dehalogenases. these enzymes are highly specific for d and l substrates. the two genes, designated hadd and hadl, have been isolated and independently expressed in escherichia coli and p. putida hosts by using broad-host-range vectors. they are closely adjacent and inducible in what appears to be an operon with an upstream open reading frame of unknown function. nucleotide s ...	1992	1556080
bacterial metabolism of 5-aminosalicylic acid. initial ring cleavage.	the metabolism of 5-aminosalicylate (5as) by a bacterial strain, pseudomonas sp. bn9, was studied. intact cells of pseudomonas sp. bn9 grown with 5as oxidized 5as and 2,5-dihydroxybenzoate (gentisate), whereas cells grown with gentisate oxidized only the growth substrate of all substituted salicylates tested. cell extracts from pseudomonas sp. bn9 catalysed the stoichiometric reaction of 1 mol of oxygen with 1 mol of 5as to a metabolite with an intense u.v.-absorption maximum at 352 nm (ph 8.0). ...	1992	1554350
structural and biochemical characterization of the escherichia coli arge gene product.	the dna sequence of a 2,100-bp region containing the arge gene from escherichia coli has been determined. the nucleotide sequence of the ppc-arge intergenic region was also solved and shown to contain six tandemly repeated rep sequences. moreover, the oxyr gene has been mapped on the e. coli chromosome and shown to flank the arg operon. the codon responsible for the translation start of arge was determined by using site-directed mutants. this gene spans 1,400 bp and encodes a 42,350-da polypepti ...	1992	1551850
oxidation of nitrotoluenes by toluene dioxygenase: evidence for a monooxygenase reaction.	pseudomonas putida f1 and pseudomonas sp. strain js150 initiate toluene degradation by incorporating molecular oxygen into the aromatic nucleus to form cis-1,2-dihydroxy-3-methylcyclohexa-3,5-diene. when toluene-grown cells were incubated with 2- and 3-nitrotoluene, the major products identified were 2- and 3-nitrobenzyl alcohol, respectively. the same cells oxidized 4-nitrotoluene to 2-methyl-5-nitrophenol and 3-methyl-6-nitrocatechol. escherichia coli jm109(pdtg601), which contains the toluene ...	1992	1514810
cloning and sequence analysis of genes for dehalogenation of 4-chlorobenzoate from arthrobacter sp. strain su.	strains of arthrobacter catalyze a hydrolytic dehalogenation of 4-chlorobenzoate (4-cba) to p-hydroxybenzoate. the reaction requires atp and coenzyme a (coa), indicating activation of the substrate via a thioester, like that reported for pseudomonas sp. strain cbs3 (j. d. scholten, k.-h. chang, p. c. babbit, h. charest, m. sylvestre, and d. dunaway-mariano, science 253:182-185, 1991). the dehalogenase genes of arthrobacter sp. strain su were cloned and expressed in escherichia coli. analyses of ...	1992	1476446
exploitation of gene(s) involved in 2,4-diacetylphloroglucinol biosynthesis to confer a new biocontrol capability to a pseudomonas strain.	tn5 mutagenesis and complementation analysis were used to clone a 6-kb genomic fragment required for biosynthesis of 2,4-diacetylphloroglucinol (phl) from fluorescent pseudomonas sp. strain f113. a recombinant plasmid, pcu203, containing this region partially complemented a phl production-negative mutant (f113g22) derived from strain f113. when sugar beet seeds were sown into an unsterilized soil, in which sugar beet was subject to damping-off by pythium ultimum, the emergence of sugar beet seed ...	1992	1476431
purification and characterization of the hydantoin racemase of pseudomonas sp. strain ns671 expressed in escherichia coli.	the hydantoin racemase gene of pseudomonas sp. strain ns671 had been cloned and expressed in escherichia coli. hydantoin racemase was purified from the cell extract of the e. coli strain by phenyl-sepharose, deae-sephacel, and sephadex g-200 chromatographies. the purified enzyme had an apparent molecular mass of 32 kda as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. by gel filtration, a molecular mass of about 190 kda was found, suggesting that the native enzyme is a ...	1992	1459947
metabolism of hexadecyltrimethylammonium chloride in pseudomonas strain b1.	a bacterium (strain b1) utilizing hexadecyltrimethylammonium chloride as a carbon and energy source was isolated from activated sludge and tentatively identified as a pseudomonas sp. this bacterium only grew on alkyltrimethylammonium salts (c12 to c22) and possible intermediates of hexadecyltrimethylammonium chloride breakdown such as hexadecanoate and acetate. pseudomonas strain b1 did not grow on amines. simultaneous adaptation studies suggested that the bacterium oxidized only the alkyl chain ...	1992	1444422
characterization of a novel pseudomonas sp. that mineralizes high concentrations of pentachlorophenol.	a pentachlorophenol (pcp)-mineralizing bacterium was isolated from polluted soil and identified as pseudomonas sp. strain ra2. in batch cultures, pseudomonas sp. strain ra2 used pcp as its sole source of carbon and energy and was capable of completely degrading this compound as indicated by radiotracer studies, stoichiometric release of chloride, and biomass formation. pseudomonas sp. strain ra2 was able to mineralize a higher concentration of pcp (160 mg liter-1) than any previously reported pc ...	1992	1444401
expression and transfer of engineered catabolic pathways harbored by pseudomonas spp. introduced into activated sludge microcosms.	two genetically engineered microorganisms (gems), pseudomonas sp. strain b13 fr1(pfrc20p) (fr120) and pseudomonas putida kt2440(pwwo-eb62) (eb62), were introduced into activated sludge microcosms that had the level of aeration, nutrient makeup, and microbial community structure of activated sludge reactors. fr120 contains an experimentally assembled ortho cleavage route for simultaneous degradation of 3-chlorobenzoate (3cb) and 4-methyl benzoate (4mb); eb62 contains a derivative tol plasmid-enco ...	1992	1444370
identification and sequencing of a gene encoding a hydantoin racemase from the native plasmid of pseudomonas sp. strain ns671.	dna fragments containing the genes involved in the conversion of 5-substituted hydantoins to their corresponding l-amino acids have been cloned from the 172-kb native plasmid (phn671) of pseudomonas sp. strain ns671. the largest recombinant plasmid, designated phpb14, encoded the ability to convert d-5-substituted hydantoins to the corresponding l-amino acids, whereas the smallest one, designated phpb12, encoded the ability to convert them to their corresponding n-carbamyl-d-amino acids. restric ...	1992	1339422
characterization of tn5 mutants deficient in dissimilatory nitrite reduction in pseudomonas sp. strain g-179, which contains a copper nitrite reductase.	tn5 was used to generate mutants that were deficient in the dissimilatory reduction of nitrite for pseudomonas sp. strain g-179, which contains a copper nitrite reductase. three types of mutants were isolated. the first type showed a lack of growth on nitrate, nitrite, and nitrous oxide. the second type grew on nitrate and nitrous oxide but not on nitrite (nir-). the two mutants of this type accumulated nitrite, showed no nitrite reductase activity, and had no detectable nitrite reductase protei ...	1992	1328160