Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| reactions involved in the lower pathway for degradation of 4-nitrotoluene by mycobacterium strain hl 4-nt-1. | in spite of the variety of initial reactions, the aerobic biodegradation of aromatic compounds generally yields dihydroxy intermediates for ring cleavage. recent investigation of the degradation of nitroaromatic compounds revealed that some nitroaromatic compounds are initially converted to 2-aminophenol rather than dihydroxy intermediates by a number of microorganisms. the complete pathway for the metabolism of 2-aminophenol during the degradation of nitrobenzene by pseudomonas pseudoalcaligene ... | 2000 | 10877799 |
| a new klebsiella planticola strain (cd-1) grows anaerobically at high cadmium concentrations and precipitates cadmium sulfide. | heavy metal resistance by bacteria is a topic of much importance to the bioremediation of contaminated soils and sediments. we report here the isolation of a highly cadmium-resistant klebsiella planticola strain, cd-1, from reducing salt marsh sediments. the strain grows in up to 15 mm cdcl(2) under a wide range of nacl concentrations and at acidic or neutral ph. in growth medium amended with thiosulfate, it precipitated significant amounts of cadmium sulfide (cds), as confirmed by x-absorption ... | 2000 | 10877810 |
| naphthalene and donor cell density influence field conjugation of naphthalene catabolism plasmids. | we examined transfer of naphthalene-catabolic genes from donor microorganisms native to a contaminated site to site-derived, rifampin-resistant recipient bacteria unable to grow on naphthalene. horizontal gene transfer (hgt) was demonstrated in filter matings using groundwater microorganisms as donors. two distinct but similar plasmid types, closely related to pdtg1, were retrieved. in laboratory-incubated sediment matings, the addition of naphthalene stimulated hgt. however, recipient bacteria ... | 2000 | 10877811 |
| the bacterial cell-division protein zipa and its interaction with an ftsz fragment revealed by x-ray crystallography. | in escherichia coli, ftsz, a homologue of eukaryotic tubulins, and zipa, a membrane-anchored protein that binds to ftsz, are two essential components of the septal ring structure that mediates cell division. recent data indicate that zipa is involved in the assembly of the ring by linking ftsz to the cytoplasmic membrane and that the zipa-ftsz interaction is mediated by their c-terminal domains. we present the x-ray crystal structures of the c-terminal ftsz-binding domain of zipa and a complex b ... | 2000 | 10880432 |
| models for estimating the non-specific toxicity of organic compounds in short-term bioassays. | the solvation parameter model is used to construct equations for the estimation of the non-specific toxicity of neutral organic compounds to five organisms used for short-term toxicity testing. for the bacteria vibrio fischeri (microtox test) and pseudomonas putida, the protozoan tetrahymena pyriformis (tetratox test), the green alga scendesmus quadricauda and the brine shrimp artemia salina, the main factors resulting in increased non-specific toxicity are size (dominantly) and lone-pair electr ... | 2000 | 10885071 |
| biosynthesis of pyridoxine: origin of the nitrogen atom of pyridoxine in microorganisms. | the amide nitrogen atom of glutamine was incorporated into pyridoxine in four eukaryotes, emericella nidulans, mucor racemosus, neurospora crassa and saccharomyces cerevisiae, and two prokaryotes, staphylococcus aureus and bacillus subtilis, but not in the following prokaryotes, pseudomonas putida, enterobacter aerogenes and escherichia coli. on the other hand, the nitrogen atom of glutamate was incorporated into pyridoxine in p. putida, e. aerogenes and e. coli, but not in s. aureus and b. subt ... | 2000 | 10885790 |
| indigo production by naphthalene-degrading bacteria. | a wild-type naphthalene-degrading strain pseudomonas putida rkj1 and two recombinant strains each of ps. putida and escherichia coli carrying the genes for naphthalene degradation on a recombinant plasmid prkj3, produced indigo and indirubin pigments from indole. naphthalene, salicylate and iptg induced cells of naphthalene-degrading recombinant bacteria produced up to two times higher indigo compared with the uninduced cells. the maximum rates of indigo formation by ps. putida rkj1, ps. putida ... | 2000 | 10886605 |
| structure-activity analysis of buforin ii, a histone h2a-derived antimicrobial peptide: the proline hinge is responsible for the cell-penetrating ability of buforin ii. | buforin ii is a 21-aa potent antimicrobial peptide that forms, in a hydrophobic medium, an amphipathic structure consisting of an n-terminal random coil region (residues 1-4), an extended helical region (residues 5-10), a hinge (residue 11), and a c-terminal regular alpha-helical region (residues 12-21). to elucidate the structural features of buforin ii that are required for its potent antimicrobial activity, we synthesized a series of n- and c-terminally truncated or amino acid-substituted syn ... | 2000 | 10890923 |
| structure of acinetobacter strain adp1 protocatechuate 3, 4-dioxygenase at 2.2 a resolution: implications for the mechanism of an intradiol dioxygenase. | the crystal structures of protocatechuate 3,4-dioxygenase from the soil bacteria acinetobacterstrain adp1 (ac 3,4-pcd) have been determined in space group i23 at ph 8.5 and 5.75. in addition, the structures of ac 3,4-pcd complexed with its substrate 3, 4-dihydroxybenzoic acid (pca), the inhibitor 4-nitrocatechol (4-nc), or cyanide (cn(-)) have been solved using native phases. the overall tertiary and quaternary structures of ac 3,4-pcd are similar to those of the same enzyme from pseudomonas put ... | 2000 | 10891075 |
| the bacterial enhancer-dependent sigma(54) (sigma(n)) transcription factor. | 2000 | 10894718 | |
| characterization of a second tfd gene cluster for chlorophenol and chlorocatechol metabolism on plasmid pjp4 in ralstonia eutropha jmp134(pjp4). | within the 5.9-kb dna region between the tfdr and tfdk genes on the 2,4-dichlorophenoxyacetic acid (2,4-d) catabolic plasmid pjp4 from ralstonia eutropha jmp134, we identified five open reading frames (orfs) with significant homology to the genes for chlorocatechol and chlorophenol metabolism (tfdcdef and tfdb) already present elsewhere on pjp4. the five orfs were organized and assigned as follows: tfdd(ii)c(ii)e(ii)f(ii) and tfdb(ii) (in short, the tfd(ii) cluster), by analogy to tfdcdef and tf ... | 2000 | 10894723 |
| biochemical-genetic characterization and distribution of oxa-22, a chromosomal and inducible class d beta-lactamase from ralstonia (pseudomonas) pickettii. | from genomic dna of ralstonia pickettii isolate pic-1, a beta-lactamase gene was cloned that encodes the oxacillinase oxa-22. it differs from known oxacillinases, being most closely related to oxa-9 (38% amino acid identity). the hydrolytic spectrum of oxa-22 is limited mostly to benzylpenicillin, cloxacillin, and restricted-spectrum cephalosporins. oxa-22-like genes were identified as single chromosomal copies in five other r. pickettii clinical isolates. the expression of oxa-22-like beta-lact ... | 2000 | 10898703 |
| ecotoxicological testing with new kinetic photorhabdus luminescens growth and luminescence inhibition assays in microtitration scale | miniaturized luminescence and growth inhibition assays in microtitration plates with the terrestric enthomopathogenic nematode symbiont photorhabdus luminescens (dsmz 3368t) are presented and compared with standardized tests with vibrio fischeri (dsmz 7151/nrrlb-11177) and pseudomonas putida (dsmz 50026). toxicological parameters (ec and g values) of selected reference toxicants (e.g. heavy metals and environmental samples) were obtained at different temperatures and without sodium chloride supp ... | 1999 | 10903092 |
| agonistic and antagonistic toxic effects observed with miniaturized growth and luminescence inhibition assays. | kinetic data recordings with miniaturized growth and luminescence inhibition assays with prokaryotes (pseudomonas putida and vibrio fischeri) reveal typical sample and species specific growth and light emission patterns respectively. growth inhibiting influences, based on toxicokinetic and toxicodynamic sample specificities appeared in each growth phase. agonistic and antagonistic effects of combinations of heavy metals like cd2+, hg2+ and pb2+ and other compounds were easily recognized after ac ... | 1999 | 10903093 |
| binding of camphor to pseudomonas putida cytochrome p450(cam): steady-state and picosecond time-resolved fluorescence studies. | the binding of camphor to cytochrome p450(cam) has been investigated by steady-state and time-resolved tryptophan fluorescence spectroscopy to obtain information on the substrate access channel. the fluorescence quenching experiments show that some of the tryptophan residues undergo changes in their local environment on camphor binding. the time-resolved fluorescence decay profile gives four lifetime components in the range from 99 ps to 4.5 ns. the shortest lifetime component assigned to w42 li ... | 2000 | 10908713 |
| phenol biodegradation by pseudomonas putida dsm 548 in a batch reactor. | phenol biodegradation in a batch reactor using a pure culture of pseudomonas putida dsm 548 was studied. the purpose of the experiments was to determine the kinetics of biodegradation by measuring biomass growth rates and phenol concentration as a function of time in a batch reactor. the haldane equation µ=µ(m)s/((k(s)+s+s(2))/k(i)) adequately describes cell growth with kinetic constants µ(m)=0.436h(-1), k(s)=6.19mgl(-1), k(i)=54.1mgl(-1). these values are in the range of those published in lite ... | 2000 | 10908868 |
| trfa-dependent inner membrane-associated plasmid rk2 dna synthesis and association of trfa with membranes of different gram-negative hosts. | trfa, the replication initiator protein of broad-host-range plasmid rk2, was tested for its ability to bind to the membrane of four different gram-negative hosts in addition to escherichia coli: pseudomonas aeruginosa, pseudomonas putida, salmonella enterica serovar typhimurium, and rhodobacter sphaeroides. cells harboring trfa-encoding plasmids were fractionated into soluble, inner membrane, and outer membrane fractions. the fractions were subjected to western blotting, and the blots were probe ... | 2000 | 10913068 |
| characterization of lrpc dna-binding properties and regulation of bacillus subtilis lrpc gene expression. | the lrpc gene was identified during the bacillus subtilis genome sequencing project. previous experiments suggested that lrpc has a role in sporulation and in the regulation of amino acid metabolism and that it shares features with escherichia coli lrp, a transcription regulator (c. beloin, s. ayora, r. exley, l. hirschbein, n. ogasawara, y. kasahara, j. c. alonso, and f. le hégarat, mol. gen. genet. 256:63-71, 1997). to characterize the interactions of lrpc with dna, the protein was overproduce ... | 2000 | 10913073 |
| global gene expression profiles of bacillus subtilis grown under anaerobic conditions. | bacillus subtilis can grow under anaerobic conditions, either with nitrate or nitrite as the electron acceptor or by fermentation. a dna microarray containing 4,020 genes from this organism was constructed to explore anaerobic gene expression patterns on a genomic scale. when mrna levels of aerobic and anaerobic cultures during exponential growth were compared, several hundred genes were observed to be induced or repressed under anaerobic conditions. these genes are involved in a variety of cell ... | 2000 | 10913079 |
| ankb, a periplasmic ankyrin-like protein in pseudomonas aeruginosa, is required for optimal catalase b (katb) activity and resistance to hydrogen peroxide. | in this study, we have cloned the ankb gene, encoding an ankyrin-like protein in pseudomonas aeruginosa. the ankb gene is composed of 549 bp encoding a protein of 183 amino acids that possesses four 33-amino-acid ankyrin repeats that are a hallmark of erythrocyte and brain ankyrins. the location of ankb is 57 bp downstream of katb, encoding a hydrogen peroxide-inducible catalase, katb. monomeric ankb is a 19.4-kda protein with a pi of 5.5 that possesses 22 primarily hydrophobic amino acids at re ... | 2000 | 10913088 |
| an a-factor-dependent extracytoplasmic function sigma factor (sigma(adsa)) that is essential for morphological development in streptomyces griseus. | a-factor (2-isocapryloyl-3r-hydroxymethyl-gamma-butyrolactone) at an extremely low concentration triggers streptomycin production and aerial mycelium formation in streptomyces griseus. a-factor induces the expression of an a-factor-dependent transcriptional activator, adpa, essential for both morphological and physiological differentiation by binding to the a-factor receptor protein arpa, which has bound and repressed the adpa promoter, and dissociating it from the promoter. nine dna fragments t ... | 2000 | 10913094 |
| a carboxy-terminal 16-amino-acid region of sigma(38) of escherichia coli is important for transcription under high-salt conditions and sigma activities in vivo. | sigma(38) (or sigma(s), the rpos gene product) is a sigma subunit of rna polymerase in escherichia coli and directs transcription from a number of stationary-phase promoters as well as osmotically inducible promoters. in this study, we analyzed the function of the carboxy-terminal 16-amino-acid region of sigma(38) (residues 315 to 330), which is well conserved among the rpos gene products of enteric bacterial species. truncation of this region was shown to result in the loss of sigma activity in ... | 2000 | 10913098 |
| novel insertion sequence elements associated with genetic heterogeneity and phenotype conversion in ralstonia solanacearum. | three insertion sequences (is) elements were isolated from the phytopathogen ralstonia solanacearum. southern hybridization using these is elements as probes revealed hybridization profiles that varied greatly between different strains of the pathogen. during a spontaneous phenotype conversion event, the promoter of the phca gene was interrupted by one of these is elements. | 2000 | 10913109 |
| characterization of a sulfur-regulated oxygenative alkylsulfatase from pseudomonas putida s-313. | the atsk gene of pseudomonas putida s-313 was required for growth with alkyl sulfate esters as sulfur source. the atsk protein was overexpressed in escherichia coli and purified to homogeneity. sequence analysis revealed that atsk was closely related to e. coli taurine dioxygenase (38% amino acid identity). the atsk protein catalyzed the alpha-ketoglutarate-dependent cleavage of a range of alkyl sulfate esters, with chain lengths ranging from c(4) to c(12), required oxygen and fe(2+) for activit ... | 2000 | 10913158 |
| mutational analysis of the highly conserved c-terminal residues of the xyls protein, a member of the arac family of transcriptional regulators. | the xyls protein of the tol plasmid of pseudomonas putida belongs to the so-called arac/xyls family of regulators, that includes more than 100 different bacterial proteins. a conserved stretch of about 100 amino acids is present at the c-terminal end. this conserved region is believed to contain seven alpha-helices, including two helix-turn-helix (hth) dna binding motifs (alpha(2)-t-alpha(3) and alpha(5)-talpha-(6)), connected by a linker alpha-helix (alpha(4)), and two flanking alpha-helices (a ... | 2000 | 10913634 |
| broad substrate specificity of naphthalene- and biphenyl-utilizing bacteria. | although aromatic compounds are most often present in the environment as components of complex mixtures, biodegradation studies commonly focus on the degradation of individual compounds. the present study was performed to investigate the range of aromatic substrates utilized by biphenyl- and naphthalene-degrading environmental isolates and to ascertain the effects of co-occurring substrates during the degradation of mono-aromatic compounds. bacterial strains were isolated on the basis of their a ... | 2000 | 10919338 |
| controlling instability in gacs-gaca regulatory genes during inoculant production of pseudomonas fluorescens biocontrol strains. | secondary metabolism in fluorescent pseudomonads is globally regulated by gacs, which encodes a membrane-bound sensor kinase, and gaca, which encodes a transcriptional response regulator. spontaneous mutation in either gene blocked biosynthesis of the antimicrobial compounds hydrogen cyanide, 2,4-diacetylphloroglucinol, pyoluteorin, and pyrrolnitrin by the model biocontrol strain pseudomonas fluorescens cha0. spontaneous mutants also had altered abilities to utilize several carbon sources and to ... | 2000 | 10919762 |
| identification of the dimerization domain of dehalogenase iva of burkholderia cepacia mba4. | haloacid dehalogenases are enzymes that catalyze the hydrolytic removal of halogens from haloalkanoic acids. dehalogenase iva (dehiva) from burkholderia cepacia mba4 and dehalogenase ci (dehci) from pseudomonas sp. strain cbs3 exhibit 68% identity. despite their similarity dehiva is a dimeric enzyme while dehci is a monomer. in this work, we describe the identification of the domain that confers the dimerization function of dehiva. recombinant dna molecules were constructed by fusion of the resp ... | 2000 | 10919767 |
| molecular cloning, sequencing, and expression in escherichia coli of the gene encoding a novel 5-oxoprolinase without atp-hydrolyzing activity from alcaligenes faecalis n-38a. | the gene encoding a novel 5-oxoprolinase without atp-hydrolyzing activity from alcaligenes faecalis n-38a was cloned and characterized. the coding region of this gene is 1,299 bp long. the predicted primary protein is composed of 433 amino acid residues, with a 31-amino-acid signal peptide. the mature protein is composed of 402 amino acid residues with a molecular mass of 46,163 da. the derived amino acid sequence of the enzyme showed no significant sequence similarity to any other proteins repo ... | 2000 | 10919770 |
| chromosomal integration of tcb chlorocatechol degradation pathway genes as a means of expanding the growth substrate range of bacteria to include haloaromatics. | the tcbr-tcbcdef gene cluster, coding for the chlorocatechol ortho-cleavage pathway in pseudomonas sp. strain p51, has been cloned into a tn5-based minitransposon. the minitransposon carrying the tcb gene cluster and a kanamycin resistance gene was transferred to pseudomonas putida kt2442, and chromosomal integration was monitored by selection either for growth on 3-chlorobenzoate or for kanamycin resistance. transconjugants able to utilize 3-chlorobenzoate as a sole carbon source were obtained, ... | 2000 | 10919778 |
| autocloning and amplification of lip2 in yarrowia lipolytica. | we synthesized a yarrowia lipolytica strain overproducing lipase for industrial applications by using long terminal repeat (zeta) of the y. lipolytica retrotransposon ylt1 and an allele of ura3 with a promoter deletion to construct jmp3. jmp3 is a derivative of plasmid phss6 carrying a noti-noti cassette which contains a defective ura3 allele, a polylinker sequence, and the zeta region for targeting to multiple sites in the genome of the recipient. we inserted the lip2 gene (encoding extracellul ... | 2000 | 10919782 |
| effect of dissemination of 2,4-dichlorophenoxyacetic acid (2,4-d) degradation plasmids on 2,4-d degradation and on bacterial community structure in two different soil horizons. | transfer of the 2,4-dichlorophenoxyacetic acid (2,4-d) degradation plasmids pemt1 and pjp4 from an introduced donor strain, pseudomonas putida uwc3, to the indigenous bacteria of two different horizons (a horizon, depth of 0 to 30 cm; b horizon, depth of 30 to 60 cm) of a 2,4-d-contaminated soil was investigated as a means of bioaugmentation. when the soil was amended with nutrients, plasmid transfer and enhanced degradation of 2,4-d were observed. these findings were most striking in the b hori ... | 2000 | 10919784 |
| a genomic sample sequence of the entomopathogenic bacterium photorhabdus luminescens w14: potential implications for virulence. | photorhabdus luminescens is a pathogenic bacterium that lives in the guts of insect-pathogenic nematodes. after invasion of an insect host by a nematode, bacteria are released from the nematode gut and help kill the insect, in which both the bacteria and the nematodes subsequently replicate. however, the bacterial virulence factors associated with this "symbiosis of pathogens" remain largely obscure. in order to identify genes encoding potential virulence factors, we performed approximately 2,00 ... | 2000 | 10919786 |
| decolorization and detoxification of textile dyes with a laccase from trametes hirsuta. | trametes hirsuta and a purified laccase from this organism were able to degrade triarylmethane, indigoid, azo, and anthraquinonic dyes. initial decolorization velocities depended on the substituents on the phenolic rings of the dyes. immobilization of the t. hirsuta laccase on alumina enhanced the thermal stabilities of the enzyme and its tolerance against some enzyme inhibitors, such as halides, copper chelators, and dyeing additives. the laccase lost 50% of its activity at 50 mm nacl while the ... | 2000 | 10919791 |
| knockout of the p-coumarate decarboxylase gene from lactobacillus plantarum reveals the existence of two other inducible enzymatic activities involved in phenolic acid metabolism. | lactobacillus plantarum nc8 contains a pdc gene coding for p-coumaric acid decarboxylase activity (pdc). a food grade mutant, designated lpd1, in which the chromosomal pdc gene was replaced with the deleted pdc gene copy, was obtained by a two-step homologous recombination process using an unstable replicative vector. the lpd1 mutant strain remained able to weakly metabolize p-coumaric and ferulic acids into vinyl derivatives or into substituted phenyl propionic acids. we have shown that l. plan ... | 2000 | 10919793 |
| degradation of triphenyltin by a fluorescent pseudomonad. | triphenyltin (tpt)-degrading bacteria were screened by a simple technique using a post-column high-performance liquid chromatography using 3,3',4',7-tetrahydroxyflavone as a post-column reagent for determination of tpt and its metabolite, diphenyltin (dpt). an isolated strain, strain cnr15, was identified as pseudomonas chlororaphis on the basis of its morphological and biochemical features. the incubation of strain cnr15 in a medium containing glycerol, succinate, and 130 microm tpt resulted in ... | 2000 | 10919812 |
| analysis of gyrb and toxr gene sequences of vibrio hollisae and development of gyrb- and toxr-targeted pcr methods for isolation of v. hollisae from the environment and its identification. | isolation of vibrio hollisae strains, particularly from the environment, is rare. this may be due, in part, to the difficulty encountered when using conventional biochemical tests to identify the microorganism. in this study, we evaluated whether two particular genes may be useful for the identification of v. hollisae. the two genes are presumed to be conserved among the bacterial species (gyrb) or among the species of the genus vibrio (toxr). a portion of the gyrb sequence of v. hollisae was cl ... | 2000 | 10919814 |
| effect of field inoculation with sinorhizobium meliloti l33 on the composition of bacterial communities in rhizospheres of a target plant (medicago sativa) and a non-target plant (chenopodium album)-linking of 16s rrna gene-based single-strand conformation polymorphism community profiles to the diversity of cultivated bacteria. | fourteen weeks after field release of luciferase gene-tagged sinorhizobium meliloti l33 in field plots seeded with medicago sativa, we found that the inoculant also occurred in bulk soil from noninoculated control plots. in rhizospheres of m. sativa plants, s. meliloti l33 could be detected in noninoculated plots 12 weeks after inoculation, indicating that growth in the rhizosphere preceded spread into bulk soil. to determine whether inoculation affected bacterial diversity, 1,119 bacteria were ... | 2000 | 10919821 |
| overexpression of salicylate hydroxylase and the crucial role of lys(163) as its nadh binding site. | expression systems for the sal gene encoding salicylate hydroxylase from pseudomonas putida s-1 were examined and some constructs were expressed in these systems. by cultivation of escherichia coli bl21 (de3)/psah8 in lb medium at 37 degrees c with isopropyl-b-d-thiogalactopyranoside as the inducer, salicylate hydroxylase was overexpressed mainly in the form of inclusion bodies. lower temperature cultivation at 20 degrees c after induction resulted in a large amount of the enzyme in the soluble ... | 2000 | 10920265 |
| isotopic composition of inorganic carbon as an indicator of benzoate degradation by pseudomonas putida: temperature, growth rate and ph effects. | degradation experiments of benzoate by pseudomonas putida resulted in enzymatic carbon isotope fractionations. however, isotopic temperature effects between experiments at 20 and 30 degrees c were minor. averages of the last three values of the co(2) isotopic composition (delta(13)c(co2(g))) were more negative than the initial benzoate delta(13)c value (-26.2 per thousand vienna pee dee belenite (vpdb)) by 3.8, 3.4 and 3.2 per thousand at 20, 25 and 30 degrees c, respectively. although the maxim ... | 2000 | 10920348 |
| establishment of introduced antagonistic bacteria in the rhizosphere of transgenic potatoes and their effect on the bacterial community. | in a field release experiment, rifampicin resistant mutants of two antagonistic plant-associated bacteria were used for seed tuber inoculation of transgenic t4 lysozyme expressing potatoes, transgenic control potatoes and non-transgenic parental potatoes. the t4 lysozyme tolerant pseudomonas putida qc14-3-8 was originally isolated from the tuber surface (geocaulosphere) of t4 lysozyme producing plants and showed in vitro antibacterial activity to the bacterial pathogen erwinia carotovora ssp. at ... | 2000 | 10922502 |
| cometabolic biotransformation of nitrobenzene by 3-nitrophenol degrading pseudomonas putida 2np8. | a strain of pseudomonas putida (2np8) capable of growing on both 2-nitrophenol and 3-nitrophenol, but not on nitrobenzene (nb), was isolated from municipal activated sludge. 2-nitrophenol was degraded by this strain with production of nitrite. degradation of 3-nitrophenol resulted in the formation of ammonia. cells grown on 2-nitrophenol did not degrade nitrobenzene. a specific nitrobenzene degradation activity was induced by 3-nitrophenol. ammonia, nitrosobenzene, and hydroxylaminobenzene have ... | 2000 | 10932358 |
| isolation of vibrio and pseudomonas from brown shrimp (penaeus californiensis holmes) intestine. | bacteria of the genera vibrio, pseudomonas and aeromonas were isolated from the intestine of apparently healthy brown shrimp (penaeus californiensis holmes) cultured in a tidal pond. species from these genera of bacteria have been reported as shrimp pathogens and have been involved in human gastrointestinal disorders related to seafood consumption. isolation was done first in marine broth, then in selective media (tcbs, cetrimide and macconkey). the oxidase negative strains were discarded as ins ... | 1997 | 10932719 |
| identification of bacteria in water for pharmaceutical use. | different systems for the obtention of water used in biopharmaceutical industry were characterized from the bacteriological point of view. determination of aerobic mesophilic microorganisms was performed; as well as the isolation of contaminant microorganisms for what the techniques of membrane filtration was used. for the identification of the more representative species there were made conventional biochemical tests and quick systems: api. the results show that water serving as tap water for p ... | 1998 | 10932743 |
| microbial conversion of indene to indandiol: a key intermediate in the synthesis of crixivan. | indene is oxidized to mixtures of cis- and trans-indandiols and related metabolites by pseudomonas putida and rhodococcus sp. isolates. indene metabolism is consistent with monooxygenase and dioxygenase activity. p. putida resolves enantiomeric mixtures of cis-1,2-indandiol by further selective oxidation of the 1r, 2s-enantiomer yielding high enantiomeric purity of cis-(1s, 2r)-indandiol, a potential intermediate in the synthesis of indinavir sulfate (crixivan), a protease inhibitor used in the ... | 1999 | 10935755 |
| metabolic pathways for cytotoxic end product formation from glutamate- and aspartate-containing peptides by porphyromonas gingivalis. | metabolic pathways involved in the formation of cytotoxic end products by porphyromonas gingivalis were studied. the washed cells of p. gingivalis atcc 33277 utilized peptides but not single amino acids. since glutamate and aspartate moieties in the peptides were consumed most intensively, a dipeptide of glutamate or aspartate was then tested as a metabolic substrate of p. gingivalis. p. gingivalis cells metabolized glutamylglutamate to butyrate, propionate, acetate, and ammonia, and they metabo ... | 2000 | 10940008 |
| in vivo and in vitro effects of (p)ppgpp on the sigma(54) promoter pu of the tol plasmid of pseudomonas putida. | the connection between the physiological control of the sigma(54)-dependent pu promoter of the tol plasmid pww0 of pseudomonas putida and the stringent response mediated by the alarmone (p)ppgpp has been examined in vivo an in vitro. to this end, the key regulatory elements of the system were faithfully reproduced in an escherichia coli strain and assayed as lacz fusions in various genetic backgrounds lacking (p)ppgpp or overexpressing rela. neither the responsiveness of pu to 3-methyl benzylalc ... | 2000 | 10940009 |
| genetic analysis of a gene cluster for cyclohexanol oxidation in acinetobacter sp. strain se19 by in vitro transposition. | biological oxidation of cyclic alcohols normally results in formation of the corresponding dicarboxylic acids, which are further metabolized and enter the central carbon metabolism in the cell. we isolated an acinetobacter sp. from an industrial wastewater bioreactor that utilized cyclohexanol as a sole carbon source. a cosmid library was constructed from acinetobacter sp. strain se19, and oxidation of cyclohexanol to adipic acid was demonstrated in recombinant escherichia coli carrying a se19 d ... | 2000 | 10940013 |
| mutations in each of the tol genes of pseudomonas putida reveal that they are critical for maintenance of outer membrane stability. | the outer membrane of gram-negative bacteria functions as a permeability barrier that protects cells against a large number of antibacterial agents. oprl protein of pseudomonas putida has been shown to be crucial to maintain the stability of this cell component (j. j. rodríguez-herva, m.-i. ramos-gonzález, and j. l. ramos. j. bacteriol. 178:1699-1706, 1996). in the present study we cloned and mutagenized the orf1, tolq, tolr, tola, and tolb genes from p. putida kt2440, which were located upstrea ... | 2000 | 10940016 |
| entry into and release of solvents by escherichia coli in an organic-aqueous two-liquid-phase system and substrate specificity of the acrab-tolc solvent-extruding pump. | growth of escherichia coli is inhibited upon exposure to a large volume of a harmful solvent, and there is an inverse correlation between the degree of inhibition and the log p(ow) of the solvent, where p(ow) is the partition coefficient measured for the partition equilibrium established between the n-octanol and water phases. the acrab-tolc efflux pump system is involved in maintaining intrinsic solvent resistance. we inspected the solvent resistance of delta acrab and/or delta tolc mutants in ... | 2000 | 10940021 |
| identification of the gene encoding sulfopyruvate decarboxylase, an enzyme involved in biosynthesis of coenzyme m. | the products of two adjacent genes in the chromosome of methanococcus jannaschii are similar to the amino and carboxyl halves of phosphonopyruvate decarboxylase, the enzyme that catalyzes the second step of fosfomycin biosynthesis in streptomyces wedmorensis. these two m. jannaschii genes were recombinantly expressed in escherichia coli, and their gene products were tested for the ability to catalyze the decarboxylation of a series of alpha-ketoacids. both subunits are required to form an alpha( ... | 2000 | 10940029 |
| genetic evidence that transcription activation by rhas involves specific amino acid contacts with sigma 70. | rhas activates transcription of the escherichia coli rhabad and rhat operons in response to l-rhamnose and is a member of the arac/xyls family of transcription activators. we wished to determine whether sigma(70) might be an activation target for rhas. we found that sigma(70) k593 and r599 appear to be important for rhas activation at both rhabad and rhat, but only at truncated promoters lacking the binding site for the second activator, crp. to determine whether these positively charged sigma(7 ... | 2000 | 10940041 |
| marine bacillus spores as catalysts for oxidative precipitation and sorption of metals. | the oxidation of soluble manganese(ii) to insoluble mn(iii,iv) oxide precipitates plays an important role in the environment. these mn oxides are known to oxidize numerous organic and inorganic compounds, scavenge a variety of other metals on their highly charged surfaces, and serve as electron acceptors for anaerobic respiration. although the oxidation of mn(ii) in most environments is believed to be bacterially-mediated, the underlying mechanisms of catalysis are not well understood. in recent ... | 1999 | 10941787 |
| factors influencing the ability of pseudomonas putida strains epi and ii to degrade the organophosphate ethoprophos. | two strains of pseudomonas putida (epi and epii), isolated previously from ethoprophos-treated soil, were able to degrade ethoprophos (10 mg 1(-1)) in a mineral salts medium plus nitrogen (msmn) in less than 50 h with a concurrent population growth. addition of glucose or succinate to msmn did not influence the degrading ability of ps. putida epi, but increased the lag phase before rapid degradation commenced with ps. putida epii. the degrading ability of the two isolates was lost when the pesti ... | 2000 | 10945777 |
| efflux-mediated resistance to fluoroquinolones in gram-negative bacteria. | 2000 | 10952561 | |
| role of arginine 277 in (s)-mandelate dehydrogenase from pseudomonas putida in substrate binding and transition state stabilization. | (s)-mandelate dehydrogenase from pseudomonas putida is an fmn-dependent alpha-hydroxy acid dehydrogenase. structural studies of two homologous enzymes, glycolate oxidase and flavocytochrome b(2), indicated that a conserved arginine residue (r277 in mdh) interacts with the product carboxylate group [lindqvist, y., branden, c.-i., mathews, f. s., and lederer, f. (1991) j. biol. chem. 266, 3198-3207]. the catalytic role of r277 was investigated by site-specific mutagenesis together with chemical re ... | 2000 | 10955993 |
| recovery of hydrogen peroxide-sensitive culturable cells of vibrio vulnificus gives the appearance of resuscitation from a viable but nonculturable state. | the viabilities of five strains of vibrio vulnificus were evaluated during the storage of the organisms in sterile seawater at 5 degrees c. the number of cfu was measured by plate count methods on rich media. the total cell numbers were determined by direct microscopic count methods. the titer of cfu declined logarithmically to undetectable levels over a period of 2 to 3 weeks, while the total cell numbers were unchanged. midway through each study, higher culturable cell counts began to be obser ... | 2000 | 10960089 |
| genetic analysis of an incomplete muts gene from pseudomonas putida. | we genetically characterized the pseudomonas putida muts gene and found that it encodes a smaller muts protein than do the genes of other bacteria. this gene is able to function in the muts mutants of escherichia coli and bacillus subtilis. a p. putida muts mutant has a mutation frequency 1,000-fold greater than that of the wild-type strain. | 2000 | 10960118 |
| genetic footprinting with mariner-based transposition in pseudomonas aeruginosa. | the complete dna sequence of pseudomonas aeruginosa provides an opportunity to apply functional genomics to a major human pathogen. a comparative genomics approach combined with genetic footprinting was used as a strategy to identify genes required for viability in p. aeruginosa. use of a highly efficient in vivo mariner transposition system in p. aeruginosa facilitated the analysis of candidate genes of this class. we have developed a rapid and efficient allelic exchange system by using the i-s ... | 2000 | 10963681 |
| crystal structure of the pyridoxal 5'-phosphate dependent l-methionine gamma-lyase from pseudomonas putida. | l-methionine gamma-lyase (mgl) catalyzes the pyridoxal 5'-phosphate (plp) dependent alpha,gamma-elimination of l-methionine. we have determined two crystal structures of mgl from pseudomonas putida using mad (multiwavelength anomalous diffraction) and molecular replacement methods. the structures have been refined to an r-factor of 21.1% at 2.0 and 1.7 a resolution using synchrotron radiation diffraction data. a homotetramer with 222 symmetry is built up by non-crystallographic symmetry. two mon ... | 2000 | 10965031 |
| role of phad in accumulation of medium-chain-length poly(3-hydroxyalkanoates) in pseudomonas oleovorans. | pseudomonas oleovorans is capable of producing poly(3-hydroxyalkanoates) (phas) as intracellular storage material. to analyze the possible involvement of phad in medium-chain-length (mcl) pha biosynthesis, we generated a phad knockout mutant by homologous recombination. upon disruption of the phad gene, mcl pha polymer accumulation was decreased. the pha granule size was reduced, and the number of granules inside the cell was increased. furthermore, mutant cells appeared to be smaller than wild- ... | 2000 | 10966380 |
| characterization of the minimal replicon of a cryptic deinococcus radiodurans sark plasmid and development of versatile escherichia coli-d. radiodurans shuttle vectors. | the nucleotide sequence of a 12-kb fragment of the cryptic deinococcus radiodurans sark plasmid pue10 was determined, in order to direct the development of small, versatile cloning systems for deinococcus. annotation of the sequence revealed 12 possible open reading frames. among these are the repu and resu genes, the predicted products of which share similarity with replication proteins and site-specific resolvases, respectively. the products of both genes were demonstrated using an overexpress ... | 2000 | 10966401 |
| distribution of oxytetracycline resistance plasmids between aeromonads in hospital and aquaculture environments: implication of tn1721 in dissemination of the tetracycline resistance determinant tet a. | oxytetracycline-resistant (ot(r)) mesophilic aeromonads were recovered from untreated hospital effluent (72 isolates) and from fish farm hatchery tanks (91 isolates) at sites within the english lake district, cumbria, england. the transfer of ot(r) plasmids from these isolates was investigated. using escherichia coli j53-1 as a recipient, 11 isolates from the hospital site and 6 isolates from the fish farm site transferred ot(r) plasmids (designated pfbaot1 to 17). original isolates were identif ... | 2000 | 10966404 |
| starvation improves survival of bacteria introduced into activated sludge. | a phenol-degrading bacterium, ralstonia eutropha e2, was grown in luria-bertani (lb) medium or in an inorganic medium (called mp) supplemented with phenol and harvested at the late-exponential-growth phase. phenol-acclimated activated sludge was inoculated with the e2 cells immediately after harvest or after starvation in mp for 2 or 7 days. the densities of the e2 populations in the activated sludge were then monitored by quantitative pcr. the e2 cells grown on phenol and starved for 2 days (p- ... | 2000 | 10966407 |
| role of respiratory nitrate reductase in ability of pseudomonas fluorescens yt101 to colonize the rhizosphere of maize. | selection of the denitrifying community by plant roots (i.e., increase in the denitrifier/total heterotroph ratio in the rhizosphere) has been reported by several authors. however, very few studies to evaluate the role of the denitrifying function itself in the selection of microorganisms in the rhizosphere have been performed. in the present study, we compared the rhizosphere survival of the denitrifying pseudomonas fluorescens yt101 strain with that of its isogenic mutant deficient in the abil ... | 2000 | 10966422 |
| effect of oxygen on formation and structure of azotobacter vinelandii alginate and its role in protecting nitrogenase. | the activity of nitrogenase in the nitrogen-fixing bacterium azotobacter vinelandii grown diazotrophically under aerobic conditions is generally considered to be protected against o(2) by a high respiration rate. in this work, we have shown that a high rate of respiration is not the prevailing mechanism for nitrogenase protection in a. vinelandii grown in phosphate-limited nitrogen-free chemostat culture. instead, the formation of alginate appeared to play a decisive role in protecting the nitro ... | 2000 | 10966426 |
| expression of green fluorescent protein in streptococcus gordonii dl1 and its use as a species-specific marker in coadhesion with streptococcus oralis 34 in saliva-conditioned biofilms in vitro. | streptococcus gordonii is one of the predominant streptococci in the biofilm ecology of the oral cavity. it interacts with other bacteria through receptor-adhesin complexes formed between cognate molecules on the surfaces of the partner cells. to study the spatial organization of s. gordonii dl1 in oral biofilms, we used green fluorescent protein (gfp) as a species-specific marker to identify s. gordonii in a two-species in vitro oral biofilm flowcell system. to drive expression of gfp, we isola ... | 2000 | 10966431 |
| toluene-degrading bacteria are chemotactic towards the environmental pollutants benzene, toluene, and trichloroethylene. | the bioremediation of polluted groundwater and toxic waste sites requires that bacteria come into close physical contact with pollutants. this can be accomplished by chemotaxis. five motile strains of bacteria that use five different pathways to degrade toluene were tested for their ability to detect and swim towards this pollutant. three of the five strains (pseudomonas putida f1, ralstonia pickettii pko1, and burkholderia cepacia g4) were attracted to toluene. in each case, the response was de ... | 2000 | 10966434 |
| hydrogen peroxide sensitivity of catechol-2,3-dioxygenase: a cautionary note on use of xyle reporter fusions under aerobic conditions. | catechol-2,3-dioxygenase (c23o) of pseudomonas putida, encoded by the xyle gene, was found to be sensitive to hydrogen peroxide (h(2)o(2)) when used as a reporter in gene fusion constructs. exposure of pseudomonas aeruginosa kata or kata katb mutants harboring kata- or katb-lacz (encoding beta-galactosidase) or -xyle fusion plasmids to h(2)o(2) stimulated beta-galactosidase activity, while there was little or no detectable c23o activity in these strains. more than 95% of c23o activity was lost a ... | 2000 | 10966438 |
| anhydrobiotic engineering of gram-negative bacteria. | anhydrobiotic engineering aims to improve desiccation tolerance in living organisms by adopting the strategies of anhydrobiosis. this was achieved for escherichia coli and pseudomonas putida by osmotic induction of intracellular trehalose synthesis and by drying from trehalose solutions, resulting in long-term viability in the dried state. | 2000 | 10966444 |
| [prevalence of microbiota in the digestive tract of wild females of lutzomyia longipalpis lutz & neiva, 1912) (diptera: psychodidae)]. | we dissected the digestive tract of 245 females in pools of 35 flies forming 7 groups. these flies were lutzomyia longipalpis originating from lapinha cave, lagoa santa, minas gerais. out of the 8 species of bacteria isolated there was a predominancy of gram negative bacterias (gnb) in the group of non-fermenters of sugar belonging to the following species: acinetobacter lwoffii, stenotrophomonas maltophilia, pseudomonas putida and flavimonas orizihabitans. the group of gnb fermenters were: ente ... | 2000 | 10967602 |
| a genetically modified solvent-tolerant bacterium for optimized production of a toxic fine chemical. | the aim of the study was to investigate whether toxic fine chemical production can be improved using the solvent-tolerant pseudomonas putida s12 in a two-liquid-phase system consisting of aqueous media and a water-immiscible octanol phase with production of 3-methylcatechol from toluene as the model conversion. for this purpose the genes involved in this conversion, todc1c2bad from p. putida f1, were introduced into p. putida s12 with high stable expression. production of 3-methylcatechol was mo ... | 2000 | 10968630 |
| analysis of the thiocapsa pfennigii polyhydroxyalkanoate synthase: subcloning, molecular characterization and generation of hybrid synthases with the corresponding chromatium vinosum enzyme. | the pha synthase structural gene of thiocapsa pfennigii was identified and subcloned on a 2.8-kbp bamhi restriction fragment, which was cloned recently from a genomic 15.6-kbp ecori restriction fragment. nucleotide sequence analysis of this fragment revealed three open reading frames (orfs), representing coding regions. two orfs encoded for the phae (mr 40,950) and phac (mr 40,190) subunits of the pha synthase from t. pfennigii and exhibited high homology with the corresponding proteins of the c ... | 2000 | 10968631 |
| cloning and expression of the nitrile hydratase and amidase genes from bacillus sp. br449 into escherichia coli. | a moderate thermophile, bacillus sp. br449 was previously shown to exhibit a high level of nitrile hydratase (nhase) activity when growing on high levels of acrylonitrile at 55 degrees c. in this report, we describe the cloning of a 6.1 kb sali dna fragment encoding the nhase gene cluster of br449 into escherichia coli. nucleotide sequencing revealed six orfs encoding (in order), two unidentified putative proteins, amidase, nhase beta- and alpha-subunits and a small putative protein of 101 amino ... | 2000 | 10978771 |
| identification of a serine hydrolase which cleaves the alicyclic ring of tetralin. | a gene designated thnd, which is required for biodegradation of the organic solvent tetralin by sphingomonas macrogoltabidus strain tfa, has been identified. sequence comparison analysis indicated that thnd codes for a carbon-carbon bond serine hydrolase showing highest similarity to hydrolases involved in biodegradation of biphenyl. an insertion mutant defective in thnd accumulates the ring fission product which results from the extradiol cleavage of the aromatic ring of dihydroxytetralin. the ... | 2000 | 10986248 |
| regioselectivity and enantioselectivity of naphthalene dioxygenase during arene cis-dihydroxylation: control by phenylalanine 352 in the alpha subunit. | the naphthalene dioxygenase (ndo) system catalyzes the first step in the degradation of naphthalene by pseudomonas sp. strain ncib 9816-4. the enzyme has a broad substrate range and catalyzes several types of reactions including cis-dihydroxylation, monooxygenation, and desaturation. substitution of valine or leucine at phe-352 near the active site iron in the alpha subunit of ndo altered the stereochemistry of naphthalene cis-dihydrodiol formed from naphthalene and also changed the region of ox ... | 2000 | 10986254 |
| relation of capsular polysaccharide production and colonial cell organization to colony morphology in vibrio parahaemolyticus. | vibrio parahaemolyticus is a ubiquitous, gram-negative marine bacterium that undergoes phase variation between opaque and translucent colony morphologies. the purpose of this study was to determine the factor(s) responsible for the opaque and translucent phenotypes and to examine cell organization within both colony types. examination of thin sections of ruthenium red-stained bacterial cells by electron microscopy revealed a thick, electron-dense layer surrounding the opaque cells that was absen ... | 2000 | 10986256 |
| characterization of three xylt-like [2fe-2s] ferredoxins associated with catabolism of cresols or naphthalene: evidence for their involvement in catechol dioxygenase reactivation. | the xylt gene product, a component of the xylene catabolic pathway of pseudomonas putida mt2, has been recently characterized as a novel [2fe-2s] ferredoxin which specifically reactivates oxygen-inactivated catechol 2,3-dioxygenase (xyle). in this study, three xylt-like proteins potentially involved in the catabolism of naphthalene (naht) or cresols (phhq and dmpq) have been overexpressed in escherichia coli, purified, and compared with respect to their biochemical properties and interaction wit ... | 2000 | 10986264 |
| cloning and nucleotide sequence analysis of xyle gene responsible for meta-cleavage of 4-chlorocatechol from pseudomonas sp. s-47. | pseudomonas sp. s-47 expresses catechol 2,3-dioxygenase (c230) catalyzing the conversion of 4-chlorocatechol (4cc) as well as catechol to 5-chloro-2-hydroxymuconic semialdehyde and 2-hydroxymuconic semialdehyde, respectively, through meta-ring cleavage. the xyle gene encoding c230 for meta-cleavage was cloned from strain s-47 and its nucleotide sequence was analyzed. the pres101 containing the xyle gene exhibited high c230 activity toward catechol and 4cc without altering the substrate specifici ... | 2000 | 10987148 |
| purification of pseudomonas putida branched-chain keto acid dehydrogenase e1 component. | 2000 | 10989425 | |
| purification of branched-chain keto acid dehydrogenase regulator from pseudomonas putida. | bkdr can be isolated in nearly pure form as a tetramer by this procedure, which involves hyperexpressing bkdr from a plasmid, purification by chromatography on deae-sepharose cl-6b, heparin-sepharose cl-6b, and dialysis to precipitate bkdr. bkdr is relatively insoluble in aqueous buffers but can be kept in solution in buffer with 50% (v/v) glycerol and 0.2 m nacl. cultures of e. coli dh5 alpha (pjrs119) should be maintained at 30 degrees to promote plasmid stability. because bkdr is prone to for ... | 2000 | 10989441 |
| sequencing of the rpob gene in legionella pneumophila and characterization of mutations associated with rifampin resistance in the legionellaceae. | rifampin in combination with erythromycin is a recommended treatment for severe cases of legionellosis. mutations in the rpob gene are known to cause rifampin resistance in escherichia coli and mycobacterium tuberculosis, and the purpose of the present study was to investigate a possible similar resistance mechanism within the members of the family legionellaceae. since the rna polymerase genes of this genus have never been characterized, the dna sequence of the legionella pneumophila rpob gene ... | 2000 | 10991843 |
| effect of temperature on the inhibition kinetics of phenol biodegradation by pseudomonas putida q5. | the temperature-dependent performance of mixed-culture wastewater treatment processes may be strongly influenced by their content of psychrotrophic bacteria. in this work, the effect of temperature on cell growth and phenol biodegradation kinetics of the psychrotrophic bacterium pseudomonas putida q5 were determined using both batch and continuous cultures in the range of 10-25 degrees c. the haldane equation was found to be the most suitable substrate-inhibition model for the specific growth ra ... | 2000 | 10992233 |
| [isolation and comparative study of a group of temperate bacteriophages of rhizospheric pseudomonads pseudomonas putida]. | we have isolated several new temperate bacteriophages for rhizosphere pseudomonads pseudomonas putida. examination of these phages, along with two previously isolated temperate phages pp56 and pp71 of p. putida ppg1 (biovar a), allowed us to classify them into four species on the basis of dna cross-homology; relative genomic size; and, to a certain extent, the morphology of phage particles. two of these species are represented by nonidentical variants. no transposable phages were found among the ... | 2000 | 10994494 |
| substrate and solvent isotope effects on the fate of the active oxygen species in substrate-modulated reactions of putidamonooxin. | using 4-methoxybenzoate monooxygenase from pseudomonas putida, the substrate deuterium isotope effect on product formation and the solvent isotope effect on the stoichiometry of oxygen uptake, nadh oxidation, product and/or h2o2 (d2o2) formation for tight couplers, partial uncouplers, and uncouplers as substrates were measured. these studies revealed for the true, intrinsic substrate deuterium isotope effect on the oxygenation reaction a k1h/k2h ratio of < 2.0, derived from the inter- and intram ... | 2000 | 10998052 |
| leafy gall formation is controlled by fasr, an arac-type regulatory gene in rhodococcus fascians. | rhodococcus fascians can interact with many plant species and induce the formation of either leafy galls or fasciations. to provoke symptoms, r. fascians strain d188 requires pathogenicity genes that are located on a linear plasmid, pfid188. the fas genes are essential for virulence and constitute an operon that encodes, among other functions, a cytokinin synthase gene. expression of the fas genes is induced by extracts of infected plant tissue only. we have isolated an arac-type regulatory gene ... | 2000 | 11004184 |
| genes involved in anaerobic metabolism of phenol in the bacterium thauera aromatica. | genes involved in the anaerobic metabolism of phenol in the denitrifying bacterium thauera aromatica have been studied. the first two committed steps in this metabolism appear to be phosphorylation of phenol to phenylphosphate by an unknown phosphoryl donor ("phenylphosphate synthase") and subsequent carboxylation of phenylphosphate to 4-hydroxybenzoate under release of phosphate ("phenylphosphate carboxylase"). both enzyme activities are strictly phenol induced. two-dimensional gel electrophore ... | 2000 | 11004186 |
| use of 16s-rrna to investigate microbial population dynamics during biodegradation of toluene and phenol by a binary culture. | interspecies interactions and changes in the rate and extent of biodegradation in mixed culture-mixed substrate studies were investigated. a binary mixed culture of pseudomonas putida f1 and burkholderia sp. js150 degraded toluene, phenol, and their mixture. both toluene and phenol can serve as sole sources of carbon and energy for both p. putida f1 and strain js150. to investigate the population dynamics of this system, a fluorescent in-situ hybridization method was chosen because of its abilit ... | 2000 | 11005926 |
| development of formulations of biological agents for management of root rot of lettuce and cucumber. | the effect of various carrier formulations of bacillus subtilis and pseudomonas putida were tested on germination, growth, and yield of lettuce and cucumber crops in the presence of pythium aphanidermatum and fusarium oxysporum f.sp. cucurbitacearum, respectively. survival of b. subtilis and p. putida in various carriers under refrigeration (about 0 degree c) and at room temperature (about 22 degrees c) was also studied. in all carrier formulations, b. subtilis strain bact-0 survived up to 45 da ... | 2000 | 11006841 |
| bacterial phosphating of mild (unalloyed) steel. | mild (unalloyed) steel electrodes were incubated in phosphate-buffered cultures of aerobic, biofilm-forming rhodococcus sp. strain c125 and pseudomonas putida mt2. a resulting surface reaction leading to the formation of a corrosion-inhibiting vivianite layer was accompanied by a characteristic electrochemical potential (e) curve. first, e increased slightly due to the interaction of phosphate with the iron oxides covering the steel surface. subsequently, e decreased rapidly and after 1 day reac ... | 2000 | 11010888 |
| microbial degradation of the multiply branched alkane 2,6,10,15,19, 23-hexamethyltetracosane (squalane) by mycobacterium fortuitum and mycobacterium ratisbonense. | among several bacterial species belonging to the general gordonia, mycobacterium, micromonospora, pseudomonas, and rhodococcus, only two mycobacterial isolates, mycobacterium fortuitum strain nf4 and the new isolate mycobacterium ratisbonense strain sd4, which was isolated from a sewage treatment plant, were capable of utilizing the multiply branched hydrocarbon squalane (2,6,10,15,19, 23-hexamethyltetracosane) and its analogous unsaturated hydrocarbon squalene as the sole carbon source for grow ... | 2000 | 11010899 |
| pcr assays that identify the grapevine dieback fungus eutypa lata. | eutypa lata is the causal fungal agent of eutypa dieback, a serious grapevine necrotic disease. the erratic and delayed (1 to 2 months) appearance of characteristic conidia on culture media and the presence of numerous microorganisms in decaying wood make it difficult either to identify or to detect e. lata in grapevine wood samples. we designed six pairs of pcr primers for diagnosis of e. lata. three primer pairs were derived from ribosomal dna internal transcribed spacer sequences, and three p ... | 2000 | 11010901 |
| commensal interactions in a dual-species biofilm exposed to mixed organic compounds. | there is limited knowledge of interspecies interactions in biofilm communities. in this study, pseudomonas sp. strain gj1, a 2-chloroethanol (2-ce)-degrading organism, and pseudomonas putida dmp1, a p-cresol-degrading organism, produced distinct biofilms in response to model mixed waste streams composed of 2-ce and various p-cresol concentrations. the two organisms maintained a commensal relationship, with dmp1 mitigating the inhibitory effects of p-cresol on gj1. a triple-labeling technique com ... | 2000 | 11010902 |
| development of a vital fluorescent staining method for monitoring bacterial transport in subsurface environments. | previous bacterial transport studies have utilized fluorophores which have been shown to adversely affect the physiology of stained cells. this research was undertaken to identify alternative fluorescent stains that do not adversely affect the transport or viability of bacteria. initial work was performed with a groundwater isolate, comamonas sp. strain da001. potential compounds were first screened to determine staining efficiencies and adverse side effects. 5-(and 6-)-carboxyfluorescein diacet ... | 2000 | 11010903 |
| structure and species composition of mercury-reducing biofilms. | mercury-reducing biofilms from packed-bed bioreactors treating nonsterile industrial effluents were shown to consist of a monolayer of bacteria by scanning electron microscopy. droplets of several micrometers in diameter which accumulated outside of the bacterial cells were identified as elemental mercury by electron-dispersive x-ray analysis. the monospecies biofilms of pseudomonas putida spi3 initially present were invaded by additional strains, which were identified to the species level by th ... | 2000 | 11010917 |
| phenylacetyl-coenzyme a is the true inducer of the phenylacetic acid catabolism pathway in pseudomonas putida u. | aerobic degradation of phenylacetic acid in pseudomonas putida u is carried out by a central catabolism pathway (phenylacetyl-coenzyme a [coa] catabolon core). induction of this route was analyzed by using different mutants specifically designed for this objective. our results revealed that the true inducer molecule is phenylacetyl-coa and not other structurally or catabolically related aromatic compounds. | 2000 | 11010921 |
| a rhamnolipid biosurfactant reduces cadmium toxicity during naphthalene biodegradation. | a model cocontaminated system was developed to determine whether a metal-complexing biosurfactant, rhamnolipid, could reduce metal toxicity to allow enhanced organic biodegradation by a burkholderia sp. isolated from soil. rhamnolipid eliminated cadmium toxicity when added at a 10-fold greater concentration than cadmium (890 microm), reduced toxicity when added at an equimolar concentration (89 microm), and had no effect at a 10-fold smaller concentration (8.9 microm). the mechanism by which rha ... | 2000 | 11010924 |
| a bioluminescent whole-cell reporter for detection of 2, 4-dichlorophenoxyacetic acid and 2,4-dichlorophenol in soil. | a bioreporter was made containing a tfdrp(dii)-luxcdabe fusion in a modified mini-tn5 construct. when it was introduced into the chromosome of ralstonia eutropha jmp134, the resulting strain, jmp134-32, produced a sensitive bioluminescent response to 2, 4-dichlorophenoxyacetic acid (2,4-d) at concentrations of 2.0 microm to 5.0 mm. this response was linear (r(2) = 0.9825) in the range of 2.0 microm to 1.1 x 10(2) microm. saturation occurred at higher concentrations, with maximal bioluminescence ... | 2000 | 11010925 |
| a pyoverdine from pseudomonas putida cfml 90-51 with a lys epsilon-amino link in the peptide chain. | from pseudomonas putida cfml 90-51--a hospital isolate--a pyoverdine was obtained which is characterized by the unusual linkage by the epsilon--rather than the alpha-amino group of lys in the peptide chain. the structure elucidation by spectroscopic methods and degradation reactions is reported. | 2000 | 11016402 |
| quantification of biofilm structures by the novel computer program comstat. | the structural organization of four microbial communities was analysed by a novel computer program, comstat, which comprises ten features for quantifying three-dimensional biofilm image stacks. monospecies biofilms of each of the four bacteria, pseudomonas: putida, p. aureofaciens, p. fluorescens and p. aeruginosa, tagged with the green fluorescent protein (gfp) were grown in flow chambers with a defined minimal medium as substrate. analysis by the comstat program of four variables describing bi ... | 2000 | 11021916 |