Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| nickel-resistance-based minitransposons: new tools for genetic manipulation of environmental bacteria. | the ncc and nre nickel resistance determinants from ralstonia eutropha-like strain 31a were used to construct mini-tn5 transposons. broad host expression of nickel resistance was observed for the nre minitransposons in members of the alpha, beta, and gamma subclasses of the proteobacteria, while the ncc minitransposons expressed nickel resistance only in r. eutropha-like strains. | 2001 | 11157282 |
| cloning and characterization of the pnb genes, encoding enzymes for 4-nitrobenzoate catabolism in pseudomonas putida tw3. | pseudomonas putida strain tw3 is able to metabolize 4-nitrotoluene via 4-nitrobenzoate (4nben) and 3, 4-dihydroxybenzoic acid (protocatechuate [pca]) to central metabolites. we have cloned, sequenced, and characterized a 6-kbp fragment of tw3 dna which contains five genes, two of which encode the enzymes involved in the catabolism of 4nben to pca. in order, they encode a 4nben reductase (pnba) which is responsible for catalyzing the direct reduction of 4nben to 4-hydroxylaminobenzoate with the o ... | 2001 | 11157934 |
| drosophila as a model host for pseudomonas aeruginosa infection. | using the fruit fly drosophila melanogaster as model host, we have identified mutants of the bacterium pseudomonas aeruginosa with reduced virulence. strikingly, all strains strongly impaired in fly killing also lacked twitching motility; most such strains had a mutation in pilghijkl chpabcde, a gene cluster known to be required for twitching motility and potentially encoding a signal transduction system. the pil chp genes appear to control the expression of additional virulence factors, however ... | 2001 | 11157963 |
| a novel rolling-circle-replicating plasmid from pseudomonas putida p8: molecular characterization and use as vector. | in pseudomonas putida p8, three cryptic circular plasmids were detected, i.e. ppp8-1 (2.5 kbp), ppp8-2 (42 kbp) and ppp8-3 (approximately 100 kbp). cloning and complete sequencing of ppp8-1 revealed a 2534 bp element harbouring four open reading frames (orfs a, b, c and d). no function could be attributed to the latter three orfs, whereas the predicted orf a gene product is homologous to replication proteins known from small multicopy plasmids of gram-positive bacteria and single-stranded (ss) p ... | 2001 | 11158350 |
| comparative specificities of two evolutionarily divergent hydrolases involved in microbial degradation of polychlorinated biphenyls. | 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate (hopda) hydrolase (bphd) is a key determinant in the aerobic transformation of polychlorinated biphenyls (pcbs) by burkholderia sp. strain lb400 (s. y. k. seah, g. labbé, s. nerdinger, m. johnson, v. snieckus, and l. d. eltis, j. biol. chem. 275:15701-15708, 2000). to determine whether this is also true in divergent biphenyl degraders, the homologous hydrolase of rhodococcus globerulus p6, bphd(p6), was hyperexpressed, purified to apparent homogeneity, a ... | 2001 | 11160080 |
| nucleotide sequence and analysis of conjugative plasmid pvt745. | the complete nucleotide sequence and genetic map of pvt745 are presented. the 25-kb plasmid was isolated from actinobacillus actinomycetemcomitans, a periodontal pathogen. two-thirds of the plasmid encode functions related to conjugation, replication, and replicon stability. among potential gene products with a high degree of similarity to known proteins are those associated with plasmid conjugation. it was shown that pvt745 derivatives not only mobilized a coresident nontransmissible plasmid, p ... | 2001 | 11160089 |
| role of the tat ransport system in nitrous oxide reductase translocation and cytochrome cd1 biosynthesis in pseudomonas stutzeri. | by transforming n2o to n2, the multicopper enzyme nitrous oxide reductase provides a periplasmic electron sink for a respiratory chain that is part of denitrification. the signal sequence of the enzyme carries the heptameric twin-arginine consensus motif characteristic of the tat pathway. we have identified tat genes of pseudomonas stutzeri and functionally analyzed the unlinked tatc and tate loci. a tatc mutant retained n2o reductase in the cytoplasm in the unprocessed form and lacking the meta ... | 2001 | 11160097 |
| gene structures and regulation of the alkane hydroxylase complex in acinetobacter sp. strain m-1. | in the long-chain n-alkane degrader acinetobacter sp. strain m-1, two alkane hydroxylase complexes are switched by controlling the expression of two n-alkane hydroxylase-encoding genes in response to the chain length of n-alkanes, while rubredoxin and rubredoxin ruductase are encoded by a single gene and expressed constitutively. | 2001 | 11160120 |
| conserved gene cluster at replication origins of the alpha-proteobacteria caulobacter crescentus and rickettsia prowazekii. | a 30-kb region surrounding the replication origin in caulobacter crescentus was analyzed. comparison to the genome sequence of another alpha-proteobacterium, rickettsia prowazekii, revealed a conserved cluster of genes (rp001, heme, hemh, and rp883) that overlaps the established origin of replication in c. crescentus and the putative origin of replication in r. prowazekii. the genes flanking this cluster differ between these two organisms. we therefore propose that this conserved gene cluster ca ... | 2001 | 11160121 |
| pseudomonas putida ce2010 can degrade biphenyl by a mosaic pathway encoded by the tod operon and cmte, which are identical to those of p. putida f1 except for a single base difference in the operator-promoter region of the cmt operon. | psudomonas putida ce2010 can assimilate biphenyl despite its high similarity to p. putida f1. biphenyl degradation in strain ce2010 was achieved using a mosaic of pathways consisting of the cmt and tod operons. cmte hydrolysed 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid, the meta-cleavage product of 2,3-dihydroxybiphenyl. this enzyme was expressed differently in strains ce2010 and f1. a cmte disruption mutant, a tod operon disruption mutant and a cmt operon disruption mutant were unable to uti ... | 2001 | 11160798 |
| identification and molecular characterization of an efflux system involved in pseudomonas putida s12 multidrug resistance. | the authors previously described srpabc, an operon involved in proton-dependent solvent efflux in the solvent-tolerant pseudomonas putida s12. recently, it was shown that organic solvents and not antibiotics induce this operon. in the present study, the authors characterize a new efflux pump, designated arpabc, on the basis of two isolated chloramphenicol-sensitive transposon mutants. the arpabc operon is involved in the active efflux of multiple antibiotics, such as tetracycline, chloramphenico ... | 2001 | 11160799 |
| the chlorobenzoate dioxygenase genes of burkholderia sp. strain nk8 involved in the catabolism of chlorobenzoates. | burkholderia sp. nk8 grows abundantly on 3-chlorobenzoate (3cb),4-chlorobenzoate (4cb) and benzoate. the genes encoding the oxidation of (chloro)benzoates (cbeabcd) and catechol (cata, catbc), the lysr-type regulatory gene cber and the gene cbee with unknown function, all of which form a single cluster in nk8, were cloned and analysed. the protein sequence of chlorobenzoate 1,2-dioxygenase (cbeabc) is 50-65% identical to the benzoate dioxygenase (benabc) of acinetobacter sp. adp1, toluate dioxyg ... | 2001 | 11160806 |
| rational design of a bacterial transcriptional cascade for amplifying gene expression capacity. | cascade regulatory circuits have been described that control numerous cell processes, and may provide models for the design of artificial circuits with novel properties. here we describe the design of a transcriptional regulatory cascade to amplify the cell response to a given signal. we used the salicylate-responsive activators of pseudomonas putida nahr of the naphthalene degradation plasmid nah7 and xyls2, a mutant regulator of the tol plasmid for catabolism of m-xylene and their respective c ... | 2001 | 11160899 |
| characterization of plant beta-ureidopropionase and functional overexpression in escherichia coli. | pyrimidine bases are rapidly catabolized in growing plant tissues. the final enzyme of the catabolic pathway, beta-ureidopropionase (beta-up; ec 3.5.1.6), was partially purified from the shoots of etiolated maize (zea mays) seedlings. the enzyme had a k(m) for beta-ureidopropionate (the substrate derived from uracil) of 11 microm. only one enantiomer of racemic beta-ureidoisobutyrate (derived from thymine) was processed with a k(m) of 6 microm. the enzyme was inactivated by dialysis against 1,10 ... | 2001 | 11161056 |
| survival rate of microbes after freeze-drying and long-term storage. | the survival rates of 10 species of microorganisms were investigated after freeze-drying and preserving in a vacuum at 5 degrees c. the survival rates varied with species. the survival rates immediately after freeze-drying were different among yeast, gram-positive bacteria, and gram-negative bacteria, and the change in the 10-year survival rate was species-specific. the survival rate of yeast, saccharomyces cerevisiae, was about 10% immediately after drying, and the rate did not decrease signifi ... | 2000 | 11161557 |
| metabolic engineering of bacteria for environmental applications: construction of pseudomonas strains for biodegradation of 2-chlorotoluene. | in this article, we illustrate the challenges and bottlenecks in the metabolic engineering of bacteria destined for environmental bioremediation, by reporting current efforts to construct pseudomonas strains genetically designed for degradation of the recalcitrant compound 2-chlorotoluene. the assembled pathway includes one catabolic segment encoding the toluene dioxygenase of the tod system of pseudomonas putida f1 (todc1c2ba), which affords the bioconversion of 2-chlorotoluene into 2-chloroben ... | 2001 | 11165359 |
| the use of oxygen uptake rate measurements to control the supply of toxic substrate: toluene hydroxylation by pseudomonas putida uv4. | during toluene hydroxylation, catalyzed by pseudomonas putida uv4 one molecule of oxygen is added to the aromatic ring to produce the dihydroxylated (non-aromatic) ring structure, toluene cis-glycol. toluene, which is toxic to the cells at aqueous phase concentration above ( approximately 2.4 mmol), is fed to the reactor. a feed-back control system based on oxygen uptake rate measurements was used to control the feed rate, and thus maintain the aqueous phase toluene concentration in the desired ... | 2001 | 11166810 |
| new broad-host-range promoter probe vectors based on the plasmid rk2 replicon. | broad-host-range plasmid rk2-based promoter probe vectors with a known nucleotide sequence were constructed. in the absence of an upstream promoter, the expression of two tested reporter genes (luc and lacz) in escherichia coli was virtually zero, while insertion of the ptrc promoter resulted in strong inducer-dependent expression. the lacz-based vectors were mobilized into pseudomonas fluorescens st, pseudomonas putida kt2442, sphingomonas spp. and burkholderia spp. lb400, and expression analys ... | 2001 | 11167001 |
| identification and characterization of the dnaa upstream region of thermus thermophilus. | the gene order in the dnaa region of thermus thermophilus was determined. previously, we showed that the putative oric of t. thermophilus is located in the dnaa-dnan intergenic region. in the 4 kb region upstream of the dnaa gene four orfs were found, all orientated in the same direction which is opposite to that of dnaa. the orfs were identified as t. thermophilus homologs of gida, gidb, soj and spo0j of bacillus subtilis. the gene order spo0j-soj-gidb-gida-dnaa-dnan resembles that of b. subtil ... | 2000 | 11167017 |
| effectiveness of orbital shaking for the aeration of suspended bacterial cultures in square-deepwell microtiter plates. | growth of heterogeneous culture collections in microtiter plates is advantageous for logistic reasons and also in enabling significant savings in medium costs, labor input and use of equipment during large screening projects. the main hurdles to overcome for aerobic microbial strains are the prevention of cross-contamination and excessive evaporation while assuring sufficient aeration rates. for this purpose we developed a sandwich spongy silicone/cotton wool cover to close the wells of square-d ... | 2001 | 11173298 |
| can sequence determine function? | the functional annotation of proteins identified in genome sequencing projects is based on similarities to homologs in the databases. as a result of the possible strategies for divergent evolution, homologous enzymes frequently do not catalyze the same reaction, and we conclude that assignment of function from sequence information alone should be viewed with some skepticism. | 2000 | 11178260 |
| cytochromes p450: a success story. | cytochrome p450 proteins, named for the absorption band at 450 nm of their carbon-monoxide-bound form, are one of the largest superfamilies of enzyme proteins. the p450 genes (also called cyp) are found in the genomes of virtually all organisms, but their number has exploded in plants. their amino-acid sequences are extremely diverse, with levels of identity as low as 16% in some cases, but their structural fold has remained the same throughout evolution. p450s are heme-thiolate proteins; their ... | 2000 | 11178272 |
| bioremediation of sterile agricultural soils polluted with crude petroleum by application of the soil bacterium, pseudomonas putida, with inorganic nutrient supplementations. | the effects of bioremediation program of sterile agricultural soils contaminated with crude petroleum were determined with a view to developing a suitable technique for rehabilitation of similar environments upon pollution by oil spillage. sterile soils inoculated with the soil bacterium, pseudomonas putida (pp), with inorganic nutrients monitoring and supplementation constituted the experimental set-ups (esu). the control set-ups (csu) contained all the materials present in esu except that they ... | 2001 | 11178721 |
| an active role for a structured b-linker in effector control of the sigma54-dependent regulator dmpr. | the activities of many prokaryotic sigma54-dependent transcriptional activators are controlled by the n-terminal a-domain of the protein, which is linked to the central transcriptional activation domain via a short b-linker. it used to be thought that these b-linkers simply serve as flexible tethers. here we show that the b-linker of the aromatic-responsive regulator dmpr and many other regulators of the family contain signature heptad repeats with regularly spaced hydrophobic amino acids. mutan ... | 2001 | 11179226 |
| fine-mapping, mutation analyses, and structural mapping of cerebrotendinous xanthomatosis in u.s. pedigrees. | cerebrotendinous xanthomatosis (ctx) is a rare autosomal recessive disorder of bile acid biosynthesis. clinically, ctx patients present with tendon xanthomas, juvenile cataracts, and progressive neurological dysfunction and can be diagnosed by the detection of elevated plasma cholestanol levels. ctx is caused by mutations affecting the sterol 27-hydroxylase gene (cyp27 ). ctx has been identified in a number of populations, but seems to have a higher prevalence in the japanese, sephardic jewish, ... | 2001 | 11181744 |
| distribution of catabolic pathways in some hydrocarbon-degrading bacteria from a subsurface polluted soil. | enrichment cultures on naphtha solvent were used to select aromatic hydrocarbon-degrading bacteria from a btex (benzene, toluene, ethylbenzene, xylene)-contaminated subsoil obtained from beneath a paint factory located in milan, italy. fifteen isolated strains were studied for their different biodegradative capacities. among these, 13 were able to grow on naphtha solvent. ten were identified as pseudomonas putida and three as pseudomonas aureofaciens. two other degraders were identified as pseud ... | 2000 | 11191814 |
| role of tyrosine 114 of l-methionine gamma-lyase from pseudomonas putida. | l-methionine gamma-lyase from pseudomonas putida has a conserved tyrosine residue (tyr114) in the active site as in all known sequences of y-family pyridoxal 5'-phosphate dependent enzymes. a mutant form of l-methionine y-lyase in which tyr114 was replaced by phenylalanine (y114f) resulted in 910-fold decrease in kcat for alpha,gamma-elimination of l-methionine, while the km remained the same as the wild type enzyme. the y114f mutant had the reduced kcat by only 28- and 16-fold for substrates wi ... | 2000 | 11193400 |
| [degradation of phenanthrene by mutant strains--naphthalene degraders]. | five naphthalene- and salicylate-utilizing pseudomonas putida strains cultivated for a long time on phenanthrene produced mutants capable of growing on this substrate and 1-hydroxy-2-naphthoate as the sole sources of carbon and energy. the mutants catabolize phenanthrene with the formation of 1-hydroxy-2-naphthoate, 2-hydroxy-1-naphthoate, salicylate, and catechol. the latter products are further metabolized by the meta- and ortho-cleavage pathways. in all five mutants, naphthalene and phenanthr ... | 2000 | 11195577 |
| detection of small sequence differences using competitive pcr: molecular monitoring of genetically improved, mercury-reducing bacteria. | a quantitative pcr approach is presented to detect small genomic sequence differences for molecular quantification of recombinant dna. the only unique genetic feature of the mercury-reducing, genetically improved pseudomonas putida kt2442::mer73 available to distinguish it from its native mercury-resistant relatives is the dna sequence crossing the border of the insertion site of the introduced dna fragment. the quantification assay is a combination of specific pcr amplification and temperature ... | 2001 | 11196305 |
| biodegradation of phenol in a continuous process: comparative study of stirred tank and fluidized-bed bioreactors. | the paper presents the main results obtained from the study of the biodegradation process of phenol by a pure culture of pseudomonas putida atcc 17484. the experimental work was carried out in two different systems: a stirred tank where cells grew as a suspended culture and a fluidized bed where cells were immobilized within calcium alginate gel beads. the influence of the hydraulic residence time (hrt) and organic loading rate on the removal efficiency of phenol was determined for both bioreact ... | 2001 | 11198177 |
| molecular screening for alkane hydroxylase genes in gram-negative and gram-positive strains. | we have developed highly degenerate oligonucleotides for polymerase chain reaction (pcr) amplification of genes related to the pseudomonas oleovorans gpo1 and acinetobacter sp. adp1 alkane hydroxylases, based on a number of highly conserved sequence motifs. in all gram-negative and in two out of three gram-positive strains able to grow on medium- (c6-c11) or long-chain n-alkanes (c12-c16), pcr products of the expected size were obtained. the pcr fragments were cloned and sequenced and found to e ... | 1999 | 11207749 |
| 13c/12c isotope fractionation of aromatic hydrocarbons during microbial degradation. | the influence of microbial degradation on the 13c/12c isotope composition of aromatic hydrocarbons is presented using toluene as a model compound. four different toluene-degrading bacterial strains grown in batch culture with oxygen, nitrate, ferric iron or sulphate as electron acceptors were studied as representatives of different environmental redox conditions potentially prevailing in contaminated aquifers. the biological degradation induced isotope shifts in the residual, non-degraded toluen ... | 1999 | 11207760 |
| cell envelope mutants of pseudomonas putida: physiological characterization and analysis of their ability to survive in soil. | to generate mutants with altered lipopolysaccharides (lps) of the wild-type pseudomonas putida kt2442, we used the mini-tn5luxab-km transposon. a mutant was found among luminescent colonies and selected as a negative clone in enzyme-linked immunosorbent assay (elisa) with monoclonal antibody (mab) 7.3b, which recognizes the o-antigen of p. putida lps. the dna region of the lps mutant interrupted by the minitransposon insertion was cloned and sequenced. comparison of the deduced amino acid sequen ... | 1999 | 11207769 |
| identification of a genomic island present in the majority of pathogenic isolates of pseudomonas aeruginosa. | pseudomonas aeruginosa, a ubiquitous gram-negative bacterium, is capable of colonizing a wide range of environmental niches and can also cause serious infections in humans. in order to understand the genetic makeup of pathogenic p. aeruginosa strains, a method of differential hybridization of arrayed libraries of cloned dna fragments was developed. an m13 library of dna from strain x24509, isolated from a patient with a urinary tract infection, was screened using a dna probe from p. aeruginosa s ... | 2001 | 11208781 |
| effects exerted by transcriptional regulator pcau from acinetobacter sp. strain adp1. | protocatechuate degradation is accomplished in a multistep inducible catabolic pathway in acinetobacter sp. strain adp1. the induction is brought about by the transcriptional regulator pcau in concert with the inducer protocatechuate. pcau, a member of the new iclr family of transcriptional regulators, was shown to play a role in the activation of transcription at the promoter for the structural pca genes, leaving open the participation of additional activators. in this work we show that there i ... | 2001 | 11208784 |
| p-hydroxyphenylacetic acid metabolism in pseudomonas putida f6. | pseudomonas putida f6 was found to metabolize p-hydroxyphenylacetic acid through 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxymandelic acid, and 3,4-dihydroxybenzaldehyde. cell extracts of p. putida f6 catalyze the nad(p)h-independent hydroxylation of p-hydroxyphenylacetic acid to 3,4-dihydroxyphenylacetic acid which is further oxidized to 3,4-dihydroxymandelic acid. oxidation and decarboxylation of the latter yields 3,4-dihydroxybenzaldehyde. a red-brown color accompanies all of the above enzym ... | 2001 | 11208791 |
| exchange of xcp (gsp) secretion machineries between pseudomonas aeruginosa and pseudomonas alcaligenes: species specificity unrelated to substrate recognition. | pseudomonas aeruginosa and pseudomonas alcaligenes are gram-negative bacteria that secrete proteins using the type ii or general secretory pathway, which requires at least 12 xcp gene products (xcpa and xcpp to -z). despite strong conservation of this secretion pathway, gram-negative bacteria usually cannot secrete exoproteins from other species. based on results obtained with erwinia, it has been proposed that the xcpp and/or xcpq homologs determine this secretion specificity (m. linderberg, g. ... | 2001 | 11208795 |
| anaerobic metabolism of 3-hydroxybenzoate by the denitrifying bacterium thauera aromatica. | the anaerobic metabolism of 3-hydroxybenzoate was studied in the denitrifying bacterium thauera aromatica. cells grown with this substrate were adapted to grow with benzoate but not with 4-hydroxybenzoate. vice versa, 4-hydroxybenzoate-grown cells did not utilize 3-hydroxybenzoate. the first step in 3-hydroxybenzoate metabolism is a coenzyme a (coa) thioester formation, which is catalyzed by an inducible 3-hydroxybenzoate-coa ligase. the enzyme was purified and characterized. further metabolism ... | 2001 | 11208796 |
| chlorocatechols substituted at positions 4 and 5 are substrates of the broad-spectrum chlorocatechol 1,2-dioxygenase of pseudomonas chlororaphis rw71. | the nucleotide sequence of a 10,528-bp region comprising the chlorocatechol pathway gene cluster tetrtetcdef of the 1,2,3,4-tetrachlorobenzene via the tetrachlorocatechol-mineralizing bacterium pseudomonas chlororaphis rw71 (t. potrawfke, k. n. timmis, and r.-m. wittich, appl. environ. microbiol. 64:3798-3806, 1998) was analyzed. the chlorocatechol 1,2-dioxygenase gene tetc was cloned and overexpressed in escherichia coli. the recombinant gene product was purified, and the alpha,alpha-homodimeri ... | 2001 | 11208799 |
| evidence of multiple regulatory functions for the ptsn (iia(ntr)) protein of pseudomonas putida. | the ptsn gene of pseudomonas putida encodes iia(ntr), a protein of the phosphoenol pyruvate:sugar phosphotransferase (pts) system which is required for the c source inhibition of the sigma(54)-dependent promoter pu of the tol (toluate degradation) plasmid pww0. using two-dimensional gel electrophoresis, we have examined the effect of ptsn disruption on the general expression pattern of p. putida. to this end, cells were grown in the presence or absence of glucose, and a 1,117-spot subset of the ... | 2001 | 11208802 |
| role of alginate and its o acetylation in formation of pseudomonas aeruginosa microcolonies and biofilms. | attenuated total reflection/fourier transform-infrared spectrometry (atr/ft-ir) and scanning confocal laser microscopy (sclm) were used to study the role of alginate and alginate structure in the attachment and growth of pseudomonas aeruginosa on surfaces. developing biofilms of the mucoid (alginate-producing) cystic fibrosis pulmonary isolate frd1, as well as mucoid and nonmucoid mutant strains, were monitored by atr/ft-ir for 44 and 88 h as ir absorbance bands in the region of 2,000 to 1,000 c ... | 2001 | 11208804 |
| transcript analysis of multiple copies of amo (encoding ammonia monooxygenase) and hao (encoding hydroxylamine oxidoreductase) in nitrosomonas europaea. | the genes encoding ammonia monooxygenase (amocab), hydroxylamine oxidoreductase (hao), and the c-type cytochrome c-554 (hcy) are present in multiple copies in the genome of nitrosomonas europaea. the upstream regions of the two copies of amoc, the three copies of hao, and one copy of hcy were cloned and sequenced. primer extension reactions were done to identify transcription start sites for these genes, as well as for amoa. putative sigma(70) promoter sequences were found associated with all bu ... | 2001 | 11208810 |
| a complex signaling module governs the activity of malt, the prototype of an emerging transactivator family. | malt, the specific activator of the maltose regulon, is the prototype of a family of high-molecular-mass atp-binding bacterial transcription activators. on binding of its two positive effectors, the inducer maltotriose and atp, malt oligomerizes to an active state competent for promoter binding and transcription activation. in addition to its previously known dna-binding domain, limited proteolysis showed that malt contains three other domains, the boundaries of which were accurately delimited b ... | 2001 | 11209048 |
| arthrobacter siderocapsulatus dubinina and zhdanov 1975al is a later subjective synonym of pseudomonas putida (trevisan 1889) migula 1895al. | the taxonomic position of arthrobacter siderocapsulatus dubinina and zhdanov 1975al was investigated using 16s rdna, fatty acid and phenotypic analyses. the type strain (ncimb 11286t) showed 99.85% 16s rdna similarity to the type strain of pseudomonas putida. phenotypic properties of the two strains were compared using api 20ne and biolog kits. identical reactions were recorded for all tests, except for assimilation of malonic acid. the two strains also showed almost identical cellular fatty aci ... | 2001 | 11211254 |
| reinvestigation of a new type of aerobic benzoate metabolism in the proteobacterium azoarcus evansii. | the aerobic metabolism of benzoate in the proteobacterium azoarcus evansii was reinvestigated. the known pathways leading to catechol or protocatechuate do not operate in this bacterium. the presumed degradation via 3-hydroxybenzoyl-coenzyme a (coa) and gentisate could not be confirmed. the first committed step is the activation of benzoate to benzoyl-coa by a specifically induced benzoate-coa ligase (amp forming). this enzyme was purified and shown to differ from an isoenzyme catalyzing the sam ... | 2001 | 11222587 |
| analysis of the pmsceab gene cluster involved in biosynthesis of salicylic acid and the siderophore pseudomonine in the biocontrol strain pseudomonas fluorescens wcs374. | mutants of pseudomonas fluorescens wcs374 defective in biosynthesis of the fluorescent siderophore pseudobactin still display siderophore activity, indicating the production of a second siderophore. a recombinant cosmid clone (pmb374-07) of a wcs374 gene library harboring loci necessary for the biosynthesis of salicylic acid (sa) and this second siderophore pseudomonine was isolated. the salicylate biosynthesis region of wcs374 was localized in a 5-kb ecori fragment of pmb374-07. the sa and pseu ... | 2001 | 11222588 |
| catalytic and molecular properties of the quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase from ralstonia eutropha strain bo. | the quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase (thfa-dh) from ralstonia eutropha strain bo was investigated for its catalytic properties. the apparent k(cat)/k(m) and k(i) values for several substrates were determined using ferricyanide as an artificial electron acceptor. the highest catalytic efficiency was obtained with n-pentanol exhibiting a k(cat)/k(m) value of 788 x 10(4) m(-1) s(-1). the enzyme showed substrate inhibition kinetics for most of the alcohols and aldehydes inve ... | 2001 | 11222593 |
| phylogenetic relationships among group ii intron orfs. | group ii introns are widely believed to have been ancestors of spliceosomal introns, yet little is known about their own evolutionary history. in order to address the evolution of mobile group ii introns, we have compiled 71 open reading frames (orfs) related to group ii intron reverse transcriptases and subjected their derived amino acid sequences to phylogenetic analysis. the phylogenetic tree was rooted with reverse transcriptases (rts) of non-long terminal repeat retroelements, and the infer ... | 2001 | 11222775 |
| effects of community composition and growth rate on aquifer biofilm bacteria and their susceptibility to betadine disinfection. | biofilm formation and function was studied in mixed culture using 20 bacterial strains isolated from a karst aquifer. when co-cultured in a glucose-limited chemostat, vogesella indigofera and pseudomonas putida were the dominant planktonic and biofilm organisms respectively. biofilm formation and resistance to the iodine disinfectant betadine were then studied with monoculture and binary cultures of v. indigofera and p. putida and a 20-strain community. biofilm population size [measured as colon ... | 2001 | 11225722 |
| the black cat/white cat principle of signal integration in bacterial promoters. | 2001 | 11226149 | |
| the nitrite reductase from pseudomonas aeruginosa: essential role of two active-site histidines in the catalytic and structural properties. | cd(1) nitrite reductase catalyzes the conversion of nitrite to no in denitrifying bacteria. reduction of the substrate occurs at the d(1)-heme site, which faces on the distal side some residues thought to be essential for substrate binding and catalysis. we report the results obtained by mutating to ala the two invariant active site histidines, his-327 and his-369, of the enzyme from pseudomonas aeruginosa. both mutants have lost nitrite reductase activity but maintain the ability to reduce o(2) ... | 2001 | 11226222 |
| fungal metabolism of toluene: monitoring of fluorinated analogs by (19)f nuclear magnetic resonance spectroscopy. | we used isomeric fluorotoluenes as model substrates to study the catabolism of toluene by five deuteromycete fungi and one ascomycete fungus capable of growth on toluene as the sole carbon and energy source, as well as by two fungi (cunninghamella echinulata and aspergillus niger) that cometabolize toluene. whole cells were incubated with 2-, 3-, and 4-fluorotoluene, and metabolites were characterized by (19)f nuclear magnetic resonance. oxidation of fluorotoluene by c. echinulata was initiated ... | 2001 | 11229888 |
| analysis of bacterial community structure in sulfurous-oil-containing soils and detection of species carrying dibenzothiophene desulfurization (dsz) genes. | the selective effects of sulfur-containing hydrocarbons, with respect to changes in bacterial community structure and selection of desulfurizing organisms and genes, were studied in soil. samples taken from a polluted field soil (a) along a concentration gradient of sulfurous oil and from soil microcosms treated with dibenzothiophene (dbt)-containing petroleum (fsl soil) were analyzed. analyses included plate counts of total bacteria and of dbt utilizers, molecular community profiling via soil d ... | 2001 | 11229891 |
| chromate reduction by a pseudomonad isolated from a site contaminated with chromated copper arsenate. | a pseudomonad (crb5) isolated from a decommissioned wood preservation site reduced toxic chromate [cr(vi)] to an insoluble cr(iii) precipitate under aerobic and anaerobic conditions. crb5 tolerated up to 520 mg of cr(vi) liter(-1) and reduced chromate in the presence of copper and arsenate. under anaerobic conditions it also reduced co(iii) and u(vi), partially internalizing each metal. metal precipitates were also found on the surface of the outer membrane and (sometimes) on a capsule. the resu ... | 2001 | 11229894 |
| genetic diversity among 3-chloroaniline- and aniline-degrading strains of the comamonadaceae. | we examined the diversity of the plasmids and of the gene tdnq, involved in the oxidative deamination of aniline, in five bacterial strains that are able to metabolize both aniline and 3-chloroaniline (3-ca). three strains have been described and identified previously, i.e., comamonas testosteroni i2 and delftia acidovorans ca28 and bn3.1. strains lme1 and b8c were isolated in this study from linuron-treated soil and from a wastewater treatment plant, respectively, and were both identified as d. ... | 2001 | 11229899 |
| succession of indigenous pseudomonas spp. and actinomycetes on barley roots affected by the antagonistic strain pseudomonas fluorescens dr54 and the fungicide imazalil. | in recent years, the interest in the use of bacteria for biological control of plant-pathogenic fungi has increased. we studied the possible side effects of coating barley seeds with the antagonistic strain pseudomonas fluorescens dr54 or a commercial fungicide, imazalil. this was done by monitoring the number of indigenous pseudomonas organisms and actinomycetes on barley roots during growth in soil, harvest after 50 days, and subsequent decomposition. bacteria were enumerated by traditional pl ... | 2001 | 11229904 |
| phylogenetic analysis of culturable dimethyl sulfide-producing bacteria from a spartina-dominated salt marsh and estuarine water. | dimethylsulfoniopropionate (dmsp), an abundant osmoprotectant found in marine algae and salt marsh cordgrass, can be metabolized to dimethyl sulfide (dms) and acrylate by microbes having the enzyme dmsp lyase. a suite of dms-producing bacteria isolated from a salt marsh and adjacent estuarine water on dmsp agar plates differed markedly from the pelagic strains currently in culture. while many of the salt marsh and estuarine isolates produced dms and methanethiol from methionine and dimethyl sulf ... | 2001 | 11229912 |
| specific growth rate plays a critical role in hydrogen peroxide resistance of the marine oligotrophic ultramicrobacterium sphingomonas alaskensis strain rb2256. | the marine oligotrophic ultramicrobacterium sphingomonas alaskensis rb2256 has a physiology that is distinctly different from that of typical copiotrophic marine bacteria, such as vibrio angustum s14. this includes a high level of inherent stress resistance and the absence of starvation-induced stress resistance to hydrogen peroxide. in addition to periods of starvation in the ocean, slow, nutrient-limited growth is likely to be encountered by oligotrophic bacteria for substantial periods of tim ... | 2001 | 11229924 |
| spatial arrangements and associative behavior of species in an in vitro oral biofilm model. | the spatial arrangements and associative behavior of actinomyces naeslundii, veillonella dispar, fusobacterium nucleatum, streptococcus sobrinus, and streptococcus oralis strains in an in vitro model of supragingival plaque were determined. using species-specific fluorescence-labeled antibodies in conjunction with confocal laser scanning microscopy, the volumes and distribution of the five strains were assessed during biofilm formation. the volume-derived cell numbers of each strain correlated w ... | 2001 | 11229930 |
| substrate selectivity of a 3-nitrophenol-induced metabolic system in pseudomonas putida 2np8 transforming nitroaromatic compounds into ammonia under aerobic conditions. | the 3-nitrophenol-induced enzyme system in cells of pseudomonas putida 2np8 manifested a wide substrate range in transforming nitroaromatic compounds through to ammonia production. all of the 30 mono- or dinitroaromatic substrates except 4-nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol, 3-nitroaniline, 2-nitrobenzoic acid, and 2-nitrofuran were quickly transformed. ammonia production from most nitroaromatic substrates appeared to be stoichiometric. | 2001 | 11229938 |
| phenotypic methods for determining genomovar status of the burkholderia cepacia complex. | recent taxonomic advances have demonstrated that burkholderia cepacia is a cluster of at least seven closely related genomic species (or genomovars) collectively referred to as the b. cepacia complex, all of which may cause infections among cystic fibrosis patients and other vulnerable individuals. thus, it is important for clinical microbiologists to be able to differentiate genomovars. prior to this study, 361 b. cepacia complex isolates and 51 isolates easily confused with b. cepacia complex ... | 2001 | 11230429 |
| oxidation of polychlorinated benzenes by genetically engineered cyp101 (cytochrome p450(cam)). | polychlorinated benzenes are recalcitrant environmental pollutants primarily because they are resistant to attack by dioxygenases commonly used by micro-organisms for the biodegradation of aromatic compounds. we have investigated the oxidation of polychlorinated benzenes by mutants of the haem mono-oxygenase cyp101 (cytochrome p450(cam)) from pseudomonas putida with the aim of generating novel systems for their biodegradation. wild-type cyp101 had low activity for the oxidation of dichlorobenzen ... | 2001 | 11231299 |
| biosynthesis of polyketides in heterologous hosts. | polyketide natural products show great promise as medicinal agents. typically the products of microbial secondary biosynthesis, polyketides are synthesized by an evolutionarily related but architecturally diverse family of multifunctional enzymes called polyketide synthases. a principal limitation for fundamental biochemical studies of these modular megasynthases, as well as for their applications in biotechnology, is the challenge associated with manipulating the natural microorganism that prod ... | 2001 | 11238987 |
| interactions of the xyls regulators with the c-terminal domain of the rna polymerase alpha subunit influence the expression level from the cognate pm promoter. | the pseudomonas putida meta-cleavage operon encodes the enzymes for the catabolism of alkylbenzoates. activation of meta-operon transcription is mediated by the xyls protein which, upon activation by effectors, binds two sites between -70 and -35 with respect to the main transcription initiation point at the pm promoter. two naturally occurring regulators, xyls and xyls1, that differ by only five amino acids, have been analyzed with regard to potential interactions of these positive regulators w ... | 2001 | 11240128 |
| altering catalytic properties of 3-chlorocatechol-oxidizing extradiol dioxygenase from sphingomonas xenophaga bn6 by random mutagenesis. | the 2,3-dihydroxybiphenyl 1,2-dioxygenase from sphingomonas xenophaga strain bn6 (bphc1) oxidizes 3-chlorocatechol by a rather unique distal ring cleavage mechanism. in an effort to improve the efficiency of this reaction, bphc1 was randomly mutated by error-prone pcr. mutants which showed increased activities for 3-chlorocatechol were obtained, and the mutant forms of the enzyme were shown to contain two or three amino acid substitutions. variant enzymes containing single substitutions were con ... | 2001 | 11244073 |
| heterogeneous transcription of an indoleacetic acid biosynthetic gene in erwinia herbicola on plant surfaces. | we investigated the spatial pattern of expression of ipdc, a plant inducible gene involved in indoleacetic acid biosynthesis in erwinia herbicola, among individual cells on plants to gain a better understanding of the role of this phenotype in the epiphytic ecology of bacteria and the factors involved in the regulation of ipdc. nonpathogenic e. herbicola strain 299r harboring a transcriptional fusion of ipdc to gfp was inoculated onto bean plants, recovered from individual leaves 48 h after inoc ... | 2001 | 11248099 |
| the role of motility in the in vitro attachment of pseudomonas putida paw8 to wheat roots. | the attachment of motile and non-motile strains of pseudomonas putida paw8 to sterile wheat roots was assessed in both non-competitive and intra-specific competitive assays. the motile strain showed significantly greater attachment to wheat roots than non-motile strains in phosphate buffer. overall, the motile strain attached better than the non-motile strain at 10(6), 10(7) and 10(8) cfu ml(-1) in competitive assays and at 10(6) and 10(7) cfu ml(-1) in non-competitive assays. when attachment wa ... | 2001 | 11248390 |
| two different pathways are involved in the beta-oxidation of n-alkanoic and n-phenylalkanoic acids in pseudomonas putida u: genetic studies and biotechnological applications. | in pseudomonas putida u, the degradation of n-alkanoic and n-phenylalkanoic acids is carried out by two sets of beta-oxidation enzymes (betai and betaii). whereas the first one (called betai) is constitutive and catalyses the degradation of n-alkanoic and n-phenylalkanoic acids very efficiently, the other one (betaii), which is only expressed when some of the genes encoding betai enzymes are mutated, catabolizes n-phenylalkanoates (n > 4) much more slowly. genetic studies revealed that disruptio ... | 2001 | 11251808 |
| global and cognate regulators control the expression of the organic solvent efflux pumps ttgabc and ttgdef of pseudomonas putida. | pseudomonas putida dot-t1e grows on a water-toluene double liquid phase. toluene tolerance in this microorganism is mainly achieved by at least two efflux pumps that belong to the rnd family. the ttgdef efflux pump is induced by toluene, whereas the other efflux pump, called ttgabc, is expressed at a high level in cells not exposed to toluene and at a lower level in cells grown with toluene. the ttgr gene is adjacent to the ttgabc operon and is transcribed divergently from ttga. the expression l ... | 2001 | 11251828 |
| determination of the toxicity of several aromatic carbonylic compounds and their reduced derivatives on phanerochaete chrysosporium using a pseudomonas putida test system. | we tested four aromatic carbonylic compounds and their corresponding reduced derivatives, possible substrates, and products of a biotransformation for toxicity against the white-rot fungus phanerochaete chrysosporium. the bacterium pseudomonas putida, which has been proven to be a good test organism for investigating toxic effects, was used as a primary screen. for both p. chrysosporium and p. putida, all ketones showed a higher toxicity than their corresponding alcohol derivatives. within one c ... | 2001 | 11255153 |
| biotreatment of hydrogen sulfide- and ammonia-containing waste gases by fluidized bed bioreactor. | gas mixtures of h2s and nh3 are the focus of this study of research concerning gases generated from animal husbandry and treatments of anaerobic wastewater lagoons. a heterotrophic microflora (a mixture of pseudomonas putida for h2s and arthrobacter oxydans for nh3) was immobilized with ca-alginate and packed into a fluidized bed reactor to simultaneously decompose h2s and nh3. this bioreactor was continuously supplied with h2s and nh3 separately or together at various ratios. the removal effici ... | 2001 | 11256495 |
| structural characterization of n-butyl-isocyanide complexes of cytochromes p450nor and p450cam. | alkyl-isocyanides are able to bind to both ferric and ferrous iron of the heme in cytochrome p450, and the resulting complexes exhibit characteristic optical absorption spectra. while the ferric complex gives a single soret band at 430 nm, the ferrous complex shows double soret bands at 430 and 450 nm. the ratio of intensities of the double soret bands in the ferrous isocyanide complex of p450 varies, as a function of ph, ionic strength, and the origin of the enzyme. to understand the structural ... | 2001 | 11258878 |
| complete genome sequence of caulobacter crescentus. | the complete genome sequence of caulobacter crescentus was determined to be 4,016,942 base pairs in a single circular chromosome encoding 3,767 genes. this organism, which grows in a dilute aquatic environment, coordinates the cell division cycle and multiple cell differentiation events. with the annotated genome sequence, a full description of the genetic network that controls bacterial differentiation, cell growth, and cell cycle progression is within reach. two-component signal transduction p ... | 2001 | 11259647 |
| rapid ribosequencing--an effective diagnostic tool for detecting microbial infection. | rapid and reliable identification of microorganisms is a prerequisite for the diagnosis and subsequent treatment of infectious diseases. the identification of pathogenic bacteria is traditionally based on their isolation from clinical samples and propagation on culture medium in the routine laboratory. however, despite clinical signs of infection, culture of the pathogenic agent often fails. this may be due to a low number of microorganisms, prior antibiotic treatment, nonculturable microorganis ... | 2001 | 11261751 |
| detection of catabolic genes in indigenous microbial consortia isolated from a diesel-contaminated soil. | bioremediation is often used for in situ remediation of petroleum-contaminated sites. the primary focus of this study was on understanding the indigenous microbial community which can survive in contaminated environment and is responsible for the degradation. diesel. toluene and naphthalene-degrading microbial consortia were isolated from diesel-contaminated soil by growing on selective hydrocarbon substrates. the presence and frequency of the catabolic genes responsible for aromatic hydrocarbon ... | 2001 | 11265787 |
| stability analysis of the biodegradation of mixed wastes in a continuous bioreactor with cell recycle. | the stability characteristics of a continuous bioreactor with cell recycle for biodegradation of mixed wastes are investigated. the system involves a pure culture of pseudomonas putida and media containing phenol and glucose as carbon and energy sources. the model growth kinetics for the two substitutable substrates were experimentally validated in a previous study. the stability analysis carried out using elementary principles of bifurcation theory shows rich dynamics characteristics of the rea ... | 2001 | 11268840 |
| biodegradation of the antineoplastics vindesine, vincristine, and vinblastine and their toxicity against bacteria in the aquatic environment. | antineoplastics are excreted into sewage, because patients often poorly metabolize them after administration or they are metabolized into more biologically reactive metabolites. there is little information on their biodegradation and toxicity in aquatic environments. therefore, the biodegradability of the vinca alkaloids, and their toxicity towards wastewater bacteria were investigated in this study. the biodegradability of vindesine, vincristine, and vinblastine was examined in the closed bottl ... | 2001 | 11270417 |
| isolation of the rpod gene encoding the principal sigma factor of the deep-sea piezophilic bacterium shewanella violacea strain dss12 and its overexpression in escherichia coli. | the gene encoding the principal a factor (rpod) of the piezophilic bacterium shewanella violacea was cloned and sequenced. the rpod gene was found to encode a polypeptide consisting of 614 amino acid residues, showing 75.6 and 64.3% identity to those of escherichia coli and pseudomonas putida, respectively. comparison with e. coli sigma70 and p. putida sigma70 showed that significant similarity exists in four conserved regions known to be required for promoter recognition and core binding. using ... | 2001 | 11272828 |
| nitric oxide signaling and transcriptional control of denitrification genes in pseudomonas stutzeri. | the expression of denitrification by a facultatively anaerobic bacterium requires as exogenous signals a low oxygen tension concomitant with an n oxide. we have studied the role of nitric oxide (no), nitrous oxide (n2o), and nitrite as signal molecules for the expression of the denitrification apparatus of pseudomonas stutzeri. transcriptional kinetics of structural genes were monitored by northern blot analysis in a 60-min time frame after cells were exposed to an n oxide signal. to differentia ... | 2001 | 11274111 |
| mutually exclusive distribution of is1548 and gbsi1, an active group ii intron identified in human isolates of group b streptococci. | the present study shows that active, self-splicing group ii intron gbsi1 is located downstream of the c5a-peptidase gene, scpb, in some group b streptococcus (gbs) isolates that lack insertion sequence is1548. is1548 was previously reported to be often present at the scpb locus in gbs isolated in association with endocarditis. since none of 67 gbs isolates examined, 40 of which were of serotype iii, harbored both is1548 and gbsi1, these two elements are suggested to be markers for different gene ... | 2001 | 11274116 |
| genetic organization of the region encoding regulation, biosynthesis, and transport of rhizobactin 1021, a siderophore produced by sinorhizobium meliloti. | eight genes have been identified that function in the regulation, biosynthesis, and transport of rhizobactin 1021, a hydroxamate siderophore produced under iron stress by sinorhizobium meliloti. the genes were sequenced, and transposon insertion mutants were constructed for phenotypic analysis. six of the genes, named rhbabcdef, function in the biosynthesis of the siderophore and were shown to constitute an operon that is repressed under iron-replete conditions. another gene in the cluster, name ... | 2001 | 11274118 |
| covalent intermediate trapped in 2-keto-3-deoxy-6- phosphogluconate (kdpg) aldolase structure at 1.95-a resolution. | 2-keto-3-deoxy-6-phosphogluconate (kdpg) aldolase catalyzes the reversible cleavage of kdpg to pyruvate and glyceraldehyde-3-phosphate. the enzyme is a class i aldolase whose reaction mechanism involves formation of schiff base intermediates between lys-133 and a keto substrate. a covalent adduct was trapped by flash freezing kdpg aldolase crystals soaked with 10 mm pyruvate in acidic conditions at ph 4.6. structure determination to 1.95-a resolution showed that pyruvate had undergone nucleophil ... | 2001 | 11274385 |
| microbial phyllosphere populations are more complex than previously realized. | phyllosphere microbial communities were evaluated on leaves of field-grown plant species by culture-dependent and -independent methods. denaturing gradient gel electrophoresis (dgge) with 16s rdna primers generally indicated that microbial community structures were similar on different individuals of the same plant species, but unique on different plant species. phyllosphere bacteria were identified from citrus sinesis (cv. valencia) by using dgge analysis followed by cloning and sequencing of t ... | 2001 | 11274410 |
| roles of dimerization in folding and stability of ketosteroid isomerase from pseudomonas putida biotype b. | equilibrium and kinetic analyses have been performed to elucidate the roles of dimerization in folding and stability of ksi from pseudomonas putida biotype b. folding was reversible in secondary and tertiary structures as well as in activity. equilibrium unfolding transition, as monitored by fluorescence and ellipticity measurements, could be modeled by a two-state mechanism without thermodynamically stable intermediates. consistent with the two-state model, one dimensional (1d) nmr spectra and ... | 2001 | 11274465 |
| sequencing of the ddl gene and modeling of the mutated d-alanine:d-alanine ligase in glycopeptide-dependent strains of enterococcus faecium. | glycopeptide dependence for growth in enterococci results from mutations in the ddl gene that inactivate the host d-ala:d-ala ligase. the strains require glycopeptides as inducers for synthesis of resistance proteins, which allows for the production of peptidoglycan precursors ending in d-ala-d-lac instead of d-ala-d-ala. the sequences of the ddl gene from nine glycopeptide-dependent enterococcus faecium clinical isolates were determined. each one had a mutation consisting either in a 5-bp inser ... | 2001 | 11274474 |
| an aerobic fixed-phase biofilm reactor system for the degradation of the low-molecular weight aromatic compounds occurring in the effluents of anaerobic digestors treating olive mill wastewaters. | an aerobic co-culture, prepared by combining ralstonia sp. ld35 and pseudomonas putida dsm1868, was recently found to be capable of extensively degrading many of the hydroxylated and/or methoxylated benzoic, phenylacetic and 3-phenyl-2-propenoic acids occurring in the olive mill wastewaters (omws). in the perspective of developing a biotechnological process for the degradation of low-molecular weight (mw) aromatic compounds occurring in the effluents of anaerobic digestors treating omws, the cap ... | 2001 | 11278039 |
| the essential hupb and hupn proteins of pseudomonas putida provide redundant and nonspecific dna-bending functions. | a protein mixture containing two major components able to catalyze a beta-recombination reaction requiring nonspecific dna bending was obtained by fractionation of a pseudomonas putida extract. n-terminal sequence analysis and genomic data base searches identified the major component as an analogue of hupb of pseudomonas aeruginosa and escherichia coli, encoding one hu protein variant. the minor component of the fraction, termed hupn, was divergent enough from hupb to predict a separate dna-bend ... | 2001 | 11278879 |
| biodegradation of hydroxylated and methoxylated benzoic, phenylacetic and phenylpropenoic acids present in olive mill wastewaters by two bacterial strains. | two aerobic bacterial strains, a chlorophenol-degrading bacterium characterized in this work as a ralstonia sp. ld35 on the basis of the sequence of the gene encoding for 16s ribosomal rna, and pseudomonas putida dsm 1868, capable of metabolizing 4-methoxybenzoic acid, were tested for their capacity to degrade monocyclic aromatic acids responsible for the toxicity of olive mill wastewaters (omws). both strains possess interesting and complementary degradation capabilities in resting cell conditi ... | 2001 | 11281329 |
| chromosomal locus for cadmium resistance in pseudomonas putida consisting of a cadmium-transporting atpase and a merr family response regulator. | pseudomonads from environmental sources vary widely in their sensitivity to cadmium, but the basis for this resistance is largely uncharacterized. a chromosomal fragment encoding cadmium resistance was cloned from pseudomonas putida 06909, a rhizosphere bacterium, and sequence analysis revealed two divergently transcribed genes, cada and cadr. cada was similar to cadmium-transporting atpases known mostly from gram-positive bacteria, and to znta, a lead-, zinc-, and cadmium-transporting atpase fr ... | 2001 | 11282588 |
| degradation of phenanthrene and anthracene by cell suspensions of mycobacterium sp. strain pyr-1. | cultures of mycobacterium sp. strain pyr-1 were dosed with anthracene or phenanthrene and after 14 days of incubation had degraded 92 and 90% of the added anthracene and phenanthrene, respectively. the metabolites were extracted and identified by uv-visible light absorption, high-pressure liquid chromatography retention times, mass spectrometry, (1)h and (13)c nuclear magnetic resonance spectrometry, and comparison to authentic compounds and literature data. neutral-ph ethyl acetate extracts fro ... | 2001 | 11282593 |
| succession of phenotypic, genotypic, and metabolic community characteristics during in vitro bioslurry treatment of polycyclic aromatic hydrocarbon-contaminated sediments. | dredged harbor sediment contaminated with polycyclic aromatic hydrocarbons (pahs) was removed from the milwaukee confined disposal facility and examined for in situ biodegradative capacity. molecular techniques were used to determine the successional characteristics of the indigenous microbiota during a 4-month bioslurry evaluation. ester-linked phospholipid fatty acids (plfa), multiplex pcr of targeted genes, and radiorespirometry techniques were used to define in situ microbial phenotypic, gen ... | 2001 | 11282603 |
| development and application of a most-probable-number-pcr assay to quantify flagellate populations in soil samples. | this paper reports on the first successful molecular detection and quantification of soil protozoa. quantification of heterotrophic flagellates and naked amoebae in soil has traditionally relied on dilution culturing techniques, followed by most-probable-number (mpn) calculations. such methods are biased by differences in the culturability of soil protozoa and are unable to quantify specific taxonomic groups, and the results are highly dependent on the choice of media and the skills of the micro ... | 2001 | 11282613 |
| evaluation of inoculum addition to stimulate in situ bioremediation of oily-sludge-contaminated soil. | a full-scale study evaluating an inoculum addition to stimulate in situ bioremediation of oily-sludge-contaminated soil was conducted at an oil refinery where the indigenous population of hydrocarbon-degrading bacteria in the soil was very low (10(3) to 10(4) cfu/g of soil). a feasibility study was conducted prior to the full-scale bioremediation study. in this feasibility study, out of six treatments, the application of a bacterial consortium and nutrients resulted in maximum biodegradation of ... | 2001 | 11282620 |
| characterization of fluorescent and nonfluorescent peptide siderophores produced by pseudomonas syringae strains and their potential use in strain identification. | nonfluorescent highly virulent strains of pseudomonas syringae pv. aptata isolated in different european countries and in uruguay produce a nonfluorescent peptide siderophore, the production of which is iron repressed and specific to these strains. the amino acid composition of this siderophore is identical to that of the dominant fluorescent peptide siderophore produced by fluorescent p. syringae strains, and the molecular masses of the respective fe(iii) chelates are 1,177 and 1,175 atomic mas ... | 2001 | 11282626 |
| quorum-sensing genes in pseudomonas aeruginosa biofilms: their role and expression patterns. | acylated homoserine lactone molecules are used by a number of gram-negative bacteria to regulate cell density-dependent gene expression by a mechanism known as quorum sensing (qs). in pseudomonas aeruginosa, qs or cell-to-cell signaling controls expression of a number of virulence factors, as well as biofilm differentiation. in this study, we investigated the role played by the las and rhl qs systems during the early stages of static biofilm formation when cells are adhering to a surface and for ... | 2001 | 11282644 |
| genotypic analysis of escherichia coli strains from poultry carcasses and their susceptibilities to antimicrobial agents. | plasmid profiling and amplified fragment length polymorphism (aflp) analysis were used to genotype 50 escherichia coli strains from poultry carcasses. thirty different plasmid profiles were evident, and clustering of the aflp data showed that they were a distinctly heterogeneous group of strains. susceptibility testing against five antimicrobial agents used in the south african poultry industry showed all strains to be susceptible to danofloxacin and colistin, while the majority (96%) were resis ... | 2001 | 11282652 |
| growth interactions during bacterial colonization of seedling rootlets. | rootlet elongation and bacterial growth on rootlets were determined after inoculation of cucumber and spinach seedlings with pseudomonas strains differing in production of siderophores and hcn. siderophore producers grew more profusely than nonproducers on both species and promoted rootlet elongation on cucumber. coinoculation of siderophore producers and nonproducers resulted in restricted growth of the latter. the total populations of nonproducers of hcn in the presence of hcn producers were n ... | 2001 | 11282653 |
| cloning and expression of a ralstonia eutropha hf39 gene mediating indigo formation in escherichia coli. | on complex medium escherichia coli strains carrying hybrid plasmid pbec/ee:11.0, pskbec/be:9.0, pskbec/pp:3.3, or pskbec/pp:2.4 harboring genomic dna of ralstonia eutropha hf39 produced a blue pigment characterized as indigo by several chemical and spectroscopic methods. a 1,251-bp open reading frame (bec) was cloned and sequenced. the deduced amino acid sequence of bec showed only weak similarities to short-chain acyl-coenzyme a dehydrogenases, and the gene product catalyzed formation of indoxy ... | 2001 | 11282658 |
| biodegradation of n-alkylcycloalkanes and n-alkylbenzenes via new pathways in alcanivorax sp. strain mbic 4326. | the degradation of long-chain n-alkylbenzenes and n-alkylcyclohexanes by alcanivorax sp. strain mbic 4326 was investigated. the alkyl side chain of these compounds was mainly processed by beta-oxidation. in the degradation of n-alkylcyclohexanes, cyclohexanecarboxylic acid was formed as an intermediate. this compound was further transformed to benzoic acid via 1-cyclohexene-1-carboxylic acid. | 2001 | 11282659 |
| transcriptional regulation of styrene degradation in pseudomonas putida ca-3. | the styrene degradative pathway in pseudmonas putida ca-3 has previously been shown to be divided into an upper pathway involving the conversion of styrene to phenylacetic acid and a lower pathway for the subsequent degradation of phenylacetic acid. it is reported here that expression of the regulatory genes stys and styr is essential for transcription of the upper pathway, but not for degradation of the lower pathway inducer, phenylacetic acid. the presence of phenylacetic acid in the growth me ... | 2001 | 11283293 |