| application of solid-phase microextraction-gas chromatography-mass spectrometry to characterize intermediates in a joint solar-microbial process for total mineralization of aroclor 1254. | a combined solid-phase microextraction-gc-ms analytical technique was used to monitor the formation of metabolites in the biodegradation of biphenyl, which were originally obtained from the solar photodechlorination of aroclor 1254 by pseudomonas pseudoalcaligenes kf707 and burkholderia sp lb400. in both cases, the following metabolites were detected: 2-hydroxybiphenyl (2-oh-bp), 2,3-dihydroxybiphenyl (2,3-di-oh-bp), and benzoic acid, which was detected as its benzoate derivative 1-methylethylbe ... | 2000 | 10757284 |
| coexistence of two different o demethylation systems in lignin metabolism by sphingomonas paucimobilis syk-6: cloning and sequencing of the lignin biphenyl-specific o-demethylase (ligx) gene. | sphingomonas paucimobilis syk-6 can grow on several dimeric model compounds of lignin as a carbon and energy source. it has o demethylation systems on three kinds of substrates: 5, 5'-dehydrodivanillic acid (ddva), syringate, and vanillate. we previously reported the cloning of a gene involved in the tetrahydrofolate-dependent o demethylation of syringate and vanillate. in the study reported here, we cloned the gene responsible for ddva o demethylation. using nitrosoguanidine mutagenesis, a muta ... | 2000 | 10788391 |
| d-malate production by permeabilized pseudomonas pseudoalcaligenes; optimization of conversion and biocatalyst productivity. | for the development of a continuous process for the production of solid d-malate from a ca-maleate suspension by permeabilized pseudomonas pseudoalcaligenes, it is important to understand the effect of appropriate process parameters on the stability and activity of the biocatalyst. previously, we quantified the effect of product (d-malate2 -) concentration on both the first-order biocatalyst inactivation rate and on the biocatalytic conversion rate. the effects of the remaining process parameter ... | 2000 | 10817338 |
| transformation of mono- and dichlorinated phenoxybenzoates by phenoxybenzoate-dioxygenase in pseudomonas pseudoalcaligenes pob310 and a modified diarylether-metabolizing bacterium. | pseudomonas pseudoalcaligenes pob310 contains genes that encode phenoxybenzoate dioxygenase. the enzyme transforms mono- and dichlorinated phenoxybenzoates to yield protocatechuate that is used as a growth substrate and chlorophenols that are nonmetabolizable. mass spectral analysis of (18)o metabolites obtained from the protocatechuate 3,4-dioxygenase-deficient mutant, pob310-b1, suggested that the reaction mechanism is a regioselective angular dioxygenation. a cloning vector containing reactio ... | 2000 | 10820337 |
| biotransformation of hydroxylaminobenzene and aminophenol by pseudomonas putida 2np8 cells grown in the presence of 3-nitrophenol. | biotransformation products of hydroxylaminobenzene and aminophenol produced by 3-nitrophenol-grown cells of pseudomonas putida 2np8, a strain grown on 2- and 3-nitrophenol, were characterized. ammonia, 2-aminophenol, 4-aminophenol, 4-benzoquinone, n-acetyl-4-aminophenol, n-acetyl-2-aminophenol, 2-aminophenoxazine-3-one, 4-hydroquinone, and catechol were produced from hydroxylaminobenzene. ammonia, n-acetyl-2-aminophenol, and 2-aminophenoxazine-3-one were produced from 2-aminophenol. all of these ... | 2000 | 10831408 |
| influence of chlorine substituents on rates of oxidation of chlorinated biphenyls by the biphenyl dioxygenase of burkholderia sp. strain lb400. | biphenyl dioxygenase from burkholderia (pseudomonas) sp. strain lb400 catalyzes the first reaction of a pathway for the degradation of biphenyl and a broad range of chlorinated biphenyls (cbs). the effect of chlorine substituents on catalysis was determined by measuring the specific activity of the enzyme with biphenyl and 18 congeners. the catalytic oxygenase component was purified and incubated with individual cbs in the presence of electron transport proteins and cofactors that were required ... | 2000 | 10877788 |
| sequence analysis and initial characterization of two isozymes of hydroxylaminobenzene mutase from pseudomonas pseudoalcaligenes js45. | pseudomonas pseudoalcaligenes js45 grows on nitrobenzene by a partially reductive pathway in which the intermediate hydroxylaminobenzene is enzymatically rearranged to 2-aminophenol by hydroxylaminobenzene mutase (hab mutase). the properties of the enzyme, the reaction mechanism, and the evolutionary origin of the gene(s) encoding the enzyme are unknown. in this study, two open reading frames (haba and habb), each encoding an hab mutase enzyme, were cloned from a p. pseudoalcaligenes js45 genomi ... | 2000 | 10877793 |
| 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 |
| growth of ca-d-malate crystals in a bioreactor. | to develop a bioreactor for solid-to-solid conversions, the conversion of solid ca-maleate to solid ca-d-malate by permeabilized pseudomonas pseudoalcaligenes was studied. in a bioreactor seeded with product (ca-d-malate) crystals, growth of ca-d-malate crystals is the last step in the solid-to-solid conversion and is described here. crystal growth is described as a transport process followed by surface processes. in contrast to the linear rate law obeyed by the transport process, the surface pr ... | 2000 | 10898864 |
| versatile transcription of biphenyl catabolic bph operon in pseudomonas pseudoalcaligenes kf707. | pseudomonas pseudoalcaligenes kf707 possesses a chromosomally encoded bph gene cluster responsible for the catabolism of biphenyl/polychlorinated biphenyls. the gene cluster consists of (orf0)bpha1a2(orf3)bpha3a4bcx0x1x2x3d. we studied the role of orf0 and transcription in the kf707 bph operon. primer extension analyses revealed that at least as many as six transcriptional initiation sites exist upstream of orf0, bpha1, bphx0, bphx1, and bphd, including two upstream of bphd. the orf0-disruptant ... | 2000 | 10900199 |
| modeling solid-to-solid biocatalysis: integration of six consecutive steps. | a quantitative model for the conversion of a solid-substrate salt to a solid-product salt in a batch bioreactor seeded with product crystals is presented. the overall process consists of six serial steps (with dissolution and crystallization each in themselves complex multistep processes): solid-salt dissolution, salt dissociation into an ionic substrate and a counter-ion, bioconversion accompanied by biocatalyst inactivation, complexation of the ionic product with the counter-ion, and salt crys ... | 2000 | 10918134 |
| transformation of 2,4,6-trinitrotoluene by purified xenobiotic reductase b from pseudomonas fluorescens i-c. | the enzymatic transformation of 2,4,6-trinitrotoluene (tnt) by purified xenb, an nadph-dependent flavoprotein oxidoreductase from pseudomonas fluorescens i-c, was evaluated by using natural abundance and [u-(14)c]tnt preparations. xenb catalyzed the reduction of tnt either by hydride addition to the aromatic ring or by nitro group reduction, with the accumulation of various tautomers of the protonated dihydride-meisenheimer complex of tnt, 2-hydroxylamino-4,6-dinitrotoluene, and 4-hydroxylamino- ... | 2000 | 11055918 |
| composition of soil microbial communities enriched on a mixture of aromatic hydrocarbons. | soil contaminated with c5+, which contained benzene (45%, wt/wt), dicyclopentadiene (dcpd) plus cyclopentadiene (together 20%), toluene (6%), styrene (3%), xylenes (2%), naphthalene (2%), and smaller quantities of other compounds, served as the source for isolation of 55 genomically distinct bacteria (standards). use of benzene as a substrate by these bacteria was most widespread (31 of 44 standards tested), followed by toluene (23 of 44), xylenes (14 of 44), styrene (10 of 44), and naphthalene ... | 2000 | 11097903 |
| occurrence of tn4371-related mobile elements and sequences in (chloro)biphenyl-degrading bacteria. | tn4371, a 55-kb transposable element involved in the degradation and biphenyl or 4-chlorobiphenyl identified in ralstonia eutropha a5, displays a modular structure including a phage-like integrase gene (int), a pseudomonas-like (chloro)biphenyl catabolic gene cluster (bph), and rp4- and ti-plasmid-like transfer genes (trb) (c. merlin, d. springael, and a. toussaint, plasmid 41:40-54, 1999). southern blot hybridization was used to examine the presence of different regions of tn4371 in a collectio ... | 2001 | 11133426 |
| genetic and molecular organization of the alkylbenzene catabolism operon in the psychrotrophic strain pseudomonas putida 01g3. | the 11-kb sequence encompassing the alkylbenzene upper pathway in pseudomonas putida 01g3, a psychrotrophic strain able to degrade alkylbenzenes at low temperatures, was characterized. together with a potential regulator (ebdr), six putative enzymes (ebdaaabacadbc) were identified, and they exhibited highly significant similarities with enzymes implicated in the equivalent pathway in p. putida re204. ebd genes appeared to be preferentially induced by ethylbenzene. multiple-alignment data and gro ... | 2001 | 11133479 |
| role for dratg and rnf genes in reduction of 2,4-dinitrophenol by rhodobacter capsulatus. | the phototrophic bacterium rhodobacter capsulatus is able to reduce 2,4-dinitrophenol (dnp) to 2-amino-4-nitrophenol enzymatically and thus can grow in the presence of this uncoupler. dnp reduction was switched off by glutamine or ammonium, but this short-term regulation did not take place in a dratg deletion mutant. nevertheless, the target of dratg does not seem to be the nitrophenol reductase itself since the ammonium shock did not inactivate the enzyme. in addition to this short-term regulat ... | 2001 | 11160111 |
| ecological and physiological analyses of pseudomonad species within a phenol remediation system. | a diverse collection of 700 bacteria obtained from an operational phenolic remediating industrial treatment plant was made to select potential strains as microbial biosensors. pseudomonads were the most abundant group, of which 48 selected from the liquor or suspended solids were assessed for their physiological response to phenolic pollutant loading and niche specialisation. by fame-mis identification the pseudomonads were clustered into six major species groups. those isolates able to utilise ... | 2001 | 11166102 |
| [cloning and expression in escherichia coli of an alkaline and thermostable exolipase from pseudomonas pseudoalcaligenes]. | a gene coding for an alkaline and thermostable exolipase of pseudomonas pseudoalcaligenes was cloned into escherichia coli le392 by inserting sau3 ai-generated dna fragments into the bamhi site of pij285. four colonies with esterase and lipase activities on the tributyrin agar plate were isolated by screening the constructed pseudomonas pseudoalcaligenes genomic library. only one out of the four positive colonies showed lipase activity on the agar plate contatining olive oil and rhodamine-b. sub ... | 1997 | 11189374 |
| the evolutionary history of chromosomal super-integrons provides an ancestry for multiresistant integrons. | integrons are genetic elements that acquire and exchange exogenous dna, known as gene cassettes, by a site-specific recombination mechanism. characterized gene cassettes consist of a target recombination sequence (attc site) usually associated with a single open reading frame coding for an antibiotic resistance determinant. the affiliation of multiresistant integrons (mris), which contain various combinations of antibiotic resistance gene cassettes, with transferable elements underlies the rapid ... | 2001 | 11209061 |
| occurrence and diversity of tetracycline resistance genes in lagoons and groundwater underlying two swine production facilities. | in this study, we used pcr typing methods to assess the presence of tetracycline resistance determinants conferring ribosomal protection in waste lagoons and in groundwater underlying two swine farms. all eight classes of genes encoding this mechanism of resistance [tet(o), tet(q), tet(w), tet(m), tetb(p), tet(s), tet(t), and otra] were found in total dna extracted from water of two lagoons. these determinants were found to be seeping into the underlying groundwater and could be detected as far ... | 2001 | 11282596 |
| map of the incp1beta plasmid ptsa encoding the widespread genes (tsa) for p-toluenesulfonate degradation in comamonas testosteroni t-2. | the catabolic incp1beta plasmid ptsa from comamonas testosteroni t-2 was mapped by subtractive analysis of restriction digests, by sequencing outwards from the tsa operon (toluenesulfonate degradation), and by generating overlapping, long-distance-pcr amplification products. the plasmid was estimated to comprise 72 +/- 4 kb. the tsa region was found to be a composite transposon flanked by two is1071 elements. a cryptic tsa operon was also present in the tsa transposon. those backbone genes and r ... | 2001 | 11282598 |
| emergence of multifunctional oxygenase activities by random priming recombination. | biphenyl dioxygenase (bph dox) is responsible for the initial dioxygenation of biphenyl. the large subunit (bpha1) of bph dox plays a crucial role in determination of substrate specificity of biphenyl-related compounds including polychlorinated biphenyls (pcbs). functional evolution of bph dox of pseudomonas pseudoalcaligenes kf707 was accomplished by random priming recombination of the bpha1 gene, involving two rounds of in vitro recombination and mutation followed by selection for increased ac ... | 2001 | 11312272 |
| genetic characterization and evolutionary implications of a car gene cluster in the carbazole degrader pseudomonas sp. strain ca10. | the nucleotide sequences of the 27,939-bp-long upstream and 9,448-bp-long downstream regions of the caraaaababbcac(orf7)ad genes of carbazole-degrading pseudomonas sp. strain ca10 were determined. thirty-two open reading frames (orfs) were identified, and the car gene cluster was consequently revealed to consist of 10 genes (caraaaababbcacaddfe) encoding the enzymes for the three-step conversion of carbazole to anthranilate and the degradation of 2-hydroxypenta-2,4-dienoate. the high identities ... | 2001 | 11371531 |
| induction of bpha, encoding biphenyl dioxygenase, in two polychlorinated biphenyl-degrading bacteria, psychrotolerant pseudomonas strain cam-1 and mesophilic burkholderia strain lb400. | we investigated induction of biphenyl dioxygenase in the psychrotolerant polychlorinated biphenyl (pcb) degrader pseudomonas strain cam-1 and in the mesophilic pcb degrader burkholderia strain lb400. using a counterselectable gene replacement vector, we inserted a lacz-gm(r) fusion cassette between chromosomal genes encoding the large subunit (bpha) and small subunit (bphe) of biphenyl dioxygenase in cam-1 and lb400, generating cam-10 and lb400-1, respectively. potential inducers of bpha were ad ... | 2001 | 11375179 |
| functional analyses of bph-tod hybrid dioxygenase, which exhibits high degradation activity toward trichloroethylene. | biphenyl dioxygenase (bphdox) in pseudomonas pseudoalcaligenes kf707 is a multicomponent enzyme consisting of an iron-sulfur protein (isp) that is composed of alpha (bpha1) and beta (bpha2) subunits, a ferredoxin (fd(bpha3)), and a ferredoxin reductase (fdr(bpha4)). a recombinant escherichia coli strain expressing hybrid dox that had replaced bpha1 with todc1 (alpha subunit of toluene dioxygenase (toldox) of pseudomonas putida) exhibited high activity toward trichloroethylene (tce) (furukawa, k. ... | 2001 | 11390387 |
| pcr cloning of type ii polyhydroxyalkanoate biosynthesis genes from two pseudomonas strains. | two polyhydroxyalkanoate synthase genes, phac1 from pseudomonas pseudoalcaligenes hbq06 and phac2 from pseudomonas nitroreducens 0802, were cloned using a pcr cloning strategy based on the type ii pha loci property of pseudomonas strains. the complete open reading frames (orfs) of phac1 (p. nitroreducens hbq06) and phac2 (p. nitroreducens 0802) were identified from the pcr products. using the sequence information, the complete pha synthase genes were pcr cloned directly from the genomic dna and ... | 2001 | 11430409 |
| genetic and structural organization of the aminophenol catabolic operon and its implication for evolutionary process. | the aminophenol (ap) catabolic operon in pseudomonas putida hs12 mineralizing nitrobenzene was found to contain all the enzymes responsible for the conversion of ap to pyruvate and acetyl coenzyme a via extradiol meta cleavage of 2-aminophenol. the sequence and functional analyses of the corresponding genes of the operon revealed that the ap catabolic operon consists of one regulatory gene, nbzr, and the following nine structural genes, nbzjcacbdgfeih, which encode catabolic enzymes. the nbzr pr ... | 2001 | 11489860 |
| polychlorinated biphenyl degradation activities and hybridization analyses of fifteen aerobic strains isolated from a pcb-contaminated site. | fifteen bacterial strains using biphenyl as sole carbon and energy source, obtained from different positions and depths of a polychlorinated biphenyl (pcb)-contaminated area, were analyzed for their basic metabolic phenotypes and subjected to genomic dna hybridization screening for the presence of well characterized bph operons such as those of pseudomonas pseudoalcaligenes kf707 and rhodococcus globerulus p6. most of the isolates belonged to the gamma-subdivision (pseudomonas stutzeri, p. pluti ... | 2001 | 11501677 |
| directed evolution of biphenyl dioxygenase: emergence of enhanced degradation capacity for benzene, toluene, and alkylbenzenes. | biphenyl dioxygenase (bph dox) catalyzes the initial oxygenation of biphenyl and related compounds. bph dox is a multicomponent enzyme in which a large subunit (encoded by the bpha1 gene) is significantly responsible for substrate specificity. by using the process of dna shuffling of bpha1 of pseudomonas pseudoalcaligenes kf707 and burkholderia cepacia lb400, a number of evolved bph dox enzymes were created. among them, an escherichia coli clone expressing chimeric bph dox exhibited extremely en ... | 2001 | 11514531 |
| biological degradation of 2,4,6-trinitrotoluene. | nitroaromatic compounds are xenobiotics that have found multiple applications in the synthesis of foams, pharmaceuticals, pesticides, and explosives. these compounds are toxic and recalcitrant and are degraded relatively slowly in the environment by microorganisms. 2,4,6-trinitrotoluene (tnt) is the most widely used nitroaromatic compound. certain strains of pseudomonas and fungi can use tnt as a nitrogen source through the removal of nitrogen as nitrite from tnt under aerobic conditions and the ... | 2001 | 11527999 |
| complete nucleotide sequence and organization of the atrazine catabolic plasmid padp-1 from pseudomonas sp. strain adp. | the complete 108,845-nucleotide sequence of catabolic plasmid padp-1 from pseudomonas sp. strain adp was determined. plasmid padp-1 was previously shown to encode atza, atzb, and atzc, which catalyze the sequential hydrolytic removal of s-triazine ring substituents from the herbicide atrazine to yield cyanuric acid. computational analyses indicated that padp-1 encodes 104 putative open reading frames (orfs), which are predicted to function in catabolism, transposition, and plasmid maintenance, t ... | 2001 | 11544232 |
| stable-isotope-based labeling of styrene-degrading microorganisms in biofilters. | deuterated styrene ([(2)h(8)]styrene) was used as a tracer in combination with phospholipid fatty acid (plfa) analysis for characterization of styrene-degrading microbial populations of biofilters used for treatment of waste gases. deuterated fatty acids were detected and quantified by gas chromatography-mass spectrometry. the method was evaluated with pure cultures of styrene-degrading bacteria and defined mixed cultures of styrene degraders and non-styrene-degrading organisms. incubation of st ... | 2001 | 11571187 |
| molecular analysis of antibiotic resistance gene clusters in vibrio cholerae o139 and o1 sxt constins. | many recent asian clinical vibrio cholerae e1 tor o1 and o139 isolates are resistant to the antibiotics sulfamethoxazole (su), trimethoprim (tm), chloramphenicol (cm), and streptomycin (sm). the corresponding resistance genes are located on large conjugative elements (sxt constins) that are integrated into prfc on the v. cholerae chromosome. we determined the dna sequences of the antibiotic resistance genes in the sxt constin in mo10, an o139 isolate. in sxt(mo10), these genes are clustered with ... | 2001 | 11600347 |
| direct ring fission of salicylate by a salicylate 1,2-dioxygenase activity from pseudaminobacter salicylatoxidans. | in cell extracts of pseudaminobacter salicylatoxidans strain bn12, an enzymatic activity was detected which converted salicylate in an oxygen-dependent but nad(p)h-independent reaction to a product with an absorbance maximum at 283 nm. this metabolite was isolated, purified, and identified by mass spectrometry and (1)h and (13)c nuclear magnetic resonance spectroscopy as 2-oxohepta-3,5-dienedioic acid. this metabolite could be formed only by direct ring fission of salicylate by a 1,2-dioxygenase ... | 2001 | 11698383 |
| oxidative transformation of aminodinitrotoluene isomers by multicomponent dioxygenases. | the electron-withdrawing nitro substituents of 2,4,6-trinitrotoluene (tnt) make the aromatic ring highly resistant to oxidative transformation. the typical biological transformation of tnt involves reduction of one or more of the nitro groups of the ring to produce the corresponding amine. reduction of a single nitro substituent of tnt to an amino substituent increases the electron density of the aromatic nucleus considerably. the comparatively electron-dense nuclei of the aminodinitrotoluene (a ... | 2001 | 11722893 |
| case of catheter sepsis with ralstonia gilardii in a child with acute lymphoblastic leukemia. | acute lymphoblastic leukemia was diagnosed in a 7-year-old girl. two months after insertion of a central venous catheter, she developed fever and complained of headache and abdominal pain. physical examination revealed no focus of infection. a gram-negative nonfermenting bacillus was recurrently cultured from blood. extensive biochemical testing and 16s ribosomal dna sequencing led to the identification of ralstonia gilardii. | 2001 | 11724891 |
| molecular characterization and substrate specificity of nitrobenzene dioxygenase from comamonas sp. strain js765. | comamonas sp. strain js765 can grow with nitrobenzene as the sole source of carbon, nitrogen, and energy. we report here the sequence of the genes encoding nitrobenzene dioxygenase (nbdo), which catalyzes the first step in the degradation of nitrobenzene by strain js765. the components of nbdo were designated reductase(nbz), ferredoxin(nbz), oxygenase(nbzalpha), and oxygenase(nbzbeta), with the gene designations nbzaa, nbzab, nbzac, and nbzad, respectively. sequence analysis showed that the comp ... | 2002 | 11823201 |
| [biosorption of heavy metals by bacteria isolated from activated sludge]. | in this paper, biosorption efficiency of heavy metals by bacteria isolated from activated sludge was tested. it was shown that pseudomonas pseudoalcaligenes and micrococcus luteus gc subgroup b had high biosorption capacities for cu(ii) and pb(ii) ions. the adsorption of the two ions on pseudomonas pseudoalcaligenes and micrococcus luteus gc subgroup b exhibited langmuir adsorption behavior with regression coefficient of 0.99. the ph value was the most important effect factor on biosorption of m ... | 2001 | 11855186 |
| nad(p)h:flavin mononucleotide oxidoreductase inactivation during 2,4,6-trinitrotoluene reduction. | bacteria readily transform 2,4,6-trinitrotoluene (tnt), a contaminant frequently found at military bases and munitions production facilities, by reduction of the nitro group substituents. in this work, the kinetics of nitroreduction were investigated by using a model nitroreductase, nad(p)h:flavin mononucleotide (fmn) oxidoreductase. under mediation by nad(p)h:fmn oxidoreductase, tnt rapidly reacted with nadh to form 2-hydroxylamino-4,6-dinitrotoluene and 4-hydroxylamino-2,6-dinitrotoluene, wher ... | 2002 | 11916686 |
| biosorption of heavy metals by bacteria isolated from activated sludge. | twelve aerobic bacteria from activated sludge were isolated and identified. these included both gram-positive (e.g., bacillus) and gram-negative (e.g., pseudomonas) bacteria. the biosorption capacity of these strains for three different heavy metals (copper, nickel, and lead) was determined at ph 5.0 and initial metal concentration of 100 mg/l. among these 12 isolates, pseudomonas pseudoalcaligenes was selected for further investigation owing to its high metal biosorption capacity. the lead and ... | 2001 | 11963846 |
| comparative evaluation of the bd phoenix and vitek 2 automated instruments for identification of isolates of the burkholderia cepacia complex. | we evaluated two new automated identification systems, the bd phoenix (becton dickinson) and the vitek 2 (biomérieux), for identification of isolates of the burkholderia cepacia complex (bcc). the test sample included 42 isolates of the highly virulent and epidemic genomovar iii, 45 isolates of b. multivorans, and 47 isolates of other members of the bcc. rates of correct identification by the bd phoenix and vitek 2 were similar when all bcc isolates were considered (50 and 53%, respectively) but ... | 2002 | 11980954 |
| the membrane-bound respiratory chain of pseudomonas pseudoalcaligenes kf707 cells grown in the presence or absence of potassium tellurite. | the respiratory chain of pseudomonas pseudoalcaligenes kf707 in membranes isolated from cells grown in the presence or absence of the toxic oxyanion tellurite (teo3(2-)) was examined. aerobic growth in the absence of tellurite shows an nadh-dependent respiration which is 80% catalysed by the cytochrome (cyt) bc1-containing pathway leading to two terminal membrane-bound cyt c oxidases inhibited by different concentrations of kcn (ic50 0.2 and 1 microm). a third oxidase, catalysing the remaining 2 ... | 2002 | 12055290 |
| alteration of regiospecificity in biphenyl dioxygenase by active-site engineering. | biphenyl dioxygenase (bph dox) is responsible for the initial dioxygenation step during the metabolism of biphenyl. the large subunit (bpha1) of bph dox plays a crucial role in the determination of the substrate specificity of biphenyl-related compounds, including polychlorinated biphenyls (pcbs). based on crystallographic analyses of naphthalene dioxygenase (b. kauppi, k. lee, e. carredano, r. e. parales, d. t. gibson, h. eklund, and s. ramaswamy, structure 6:571-586, 1998), we developed a thre ... | 2002 | 12057964 |
| polyhydroxyalkanoate biosynthesis in pseudomonas pseudoalcaligenes ys1. | pseudomonas pseudoalcaligenes strain ys1 isolated from oil contaminated soil was able to produce polyhydroxybutyrate blended with medium-chain-length polyhydroxyalkanoates (mcl pha). pha synthesis genes were cloned from this strain. a fadb (gene for fatty acid degradation) deleted mutant escherichia coli km32b (fadb::tet) was constructed to express the cloned pha synthesis gene phac1(pp) or phac2(pp). the fadb deleted mutant km32b harboring phac1(pp) or phac2(pp) showed mcl pha accumulation whil ... | 2002 | 12076790 |
| family shuffling of a targeted bpha region to engineer biphenyl dioxygenase. | in this work we used a new strategy designed to reduce the size of the library that needs to be explored in family shuffling to evolve new biphenyl dioxygenases (bpdos). instead of shuffling the whole gene, we have targeted a fragment of bpha that is critical for enzyme specificity. we also describe a new protocol to screen for more potent bpdos that is based on the detection of catechol metabolites from chlorobiphenyls. several bpha variants with extended potency to degrade polychlorinated biph ... | 2002 | 12081948 |
| identification of a new class of cytochrome p450 from a rhodococcus sp. | a degenerate set of pcr primers were used to clone a gene encoding a cytochrome p450 (the p450rhf gene) from rhodococcus sp. strain ncimb 9784 which is of unique primary structural organization. surprisingly, analysis of the translation product revealed that the p450 is fused to a reductase domain at the c terminus which displays sequence conservation for dioxygenase reductase proteins. the reductase partner comprises flavin mononucleotide- and nadh-binding motifs and a [2fe2s] ferredoxin-like c ... | 2002 | 12081961 |
| use of potassium tellurite for testing the survival and viability of pseudomonas pseudoalcaligenes kf707 in soil microcosms contaminated with polychlorinated biphenyls. | this study shows that the oxyanion tellurite teo3(2-) can be used as a tool to detect and quantify the release in soil microcosms of pseudomonas pseudoalcaligenes kf707, a strain spontaneously resistant to tellurite with a minimal inhibitory concentration (mic) of 150 microg ml(-1). kf707 cells which carry the genes for degradation of a wide range of polychlorinated biphenyl congeners (pcbs) were used for inoculation of laboratory microcosms prepared with two different pcb-contaminated soils (ci ... | 2002 | 12234009 |
| use of 16s rrna gene sequencing for identification of nonfermenting gram-negative bacilli recovered from patients attending a single cystic fibrosis center. | during 1999, we used partial 16s rrna gene sequencing for the prospective identification of atypical nonfermenting gram-negative bacilli isolated from patients attending our cystic fibrosis center. of 1,093 isolates of nonfermenting gram-negative bacilli recovered from 148 patients, 46 (4.2%) gave problematic results with conventional phenotypic tests. these 46 isolates were genotypically identified as pseudomonas aeruginosa (19 isolates, 12 patients), achromobacter xylosoxidans (10 isolates, 8 ... | 2002 | 12354883 |
| cloning and sequencing of a phenol hydroxylase gene of pseudomonas pseudoalcaligenes strain mh1: a bacterium able to mineralize various aromatic compounds. | the phenol-degrading strain pseudomonas pseudoalcaligenes mh1, identified by the rrna approach, was isolated from wastewater enrichment culture. it utilized phenol up to 1.5 g/l as the sole source of carbon and energy. in addition, cresols (o-, m-, p-), 4-hydroxybenzoic acid, syringic acid, and vanillic acid were metabolized as sole substrates by phenol-grown cells of strain mh1. using primers, designed on the basis of the sequence of the dmp operon of p. putida strain cf600, a gene encoding phe ... | 2002 | 12396129 |
| pseudomonas fluorescens encodes the crohn's disease-associated i2 sequence and t-cell superantigen. | commensal bacteria have emerged as an important disease factor in human crohn's disease (cd) and murine inflammatory bowel disease (ibd) models. we recently isolated i2, a novel gene segment of microbial origin that is associated with human cd and that encodes a t-cell superantigen. to identify the i2 microorganism, blast analysis was used to identify a microbial homologue, pa2885, a novel open reading frame (orf) in the pseudomonas aeruginosa genome. pcr and southern analysis identified pseudom ... | 2002 | 12438326 |
| a previously unrecognized step in pentachlorophenol degradation in sphingobium chlorophenolicum is catalyzed by tetrachlorobenzoquinone reductase (pcpd). | the first step in the pentachlorophenol (pcp) degradation pathway in sphingobium chlorophenolicum has been believed for more than a decade to be conversion of pcp to tetrachlorohydroquinone. we show here that pcp is actually converted to tetrachlorobenzoquinone, which is subsequently reduced to tetrachlorohydroquinone by pcpd, a protein that had previously been suggested to be a pcp hydroxylase reductase. pcpd is immediately downstream of pcpb, the gene encoding pcp hydroxylase (pcp monooxygenas ... | 2003 | 12486067 |
| methyl-beta-cyclodextrin-enhanced solubilization and aerobic biodegradation of polychlorinated biphenyls in two aged-contaminated soils. | the bioremediation of aged polychlorinated biphenyl (pcb)-contaminated soils is adversely affected by the low bioavailability of the pollutants. randomly methylated-beta-cyclodextrins (rameb) were tested as a potential pcb-bioavailability-enhancing agent in the aerobic treatment of two aged-contaminated soils. the soils, contaminated by about 890 and 8500 mg/kg of aroclor 1260 pcbs, were amended with biphenyl (4 g/kg), inorganic nutrients (to adjust their c:n ratio to 20:1), and variable amounts ... | 2003 | 12491523 |
| 2-hydroxypenta-2,4-dienoate metabolic pathway genes in a strong polychlorinated biphenyl degrader, rhodococcus sp. strain rha1. | a gram-positive polychlorinated biphenyl (pcb) degrader, rhodococcus sp. strain rha1, metabolizes biphenyl through the 2-hydroxypenta-2,4-dienoate (hpd) and benzoate metabolic pathways. the hpd metabolic pathway genes, the hpd hydratase (bphe1), 4-hydroxy-2-oxovalerate aldolase (bphf1), and acetaldehyde dehydrogenase (acylating) (bphg) genes, were cloned from rha1. the deduced amino acid sequences of bphgf1e1 have 30 to 58% identity with those of the hpd metabolic pathway genes of gram-negative ... | 2003 | 12514024 |
| morphological changes of pseudomonas pseudoalcaligenes in response to temperature selection. | adaptation to novel environments usually entails morphological changes. the cell morphology of six experimental populations of pseudomonas pseudoalcaligenes and their common ancestor were examined with scanning electron microscopy (sem). the six experimental populations were propagated under different temperatures for 10 months: three of them cultured at constant normal temperature (35 degrees c) forming the control group, and the other three cultured at incremental higher temperatures (from 41 ... | 2003 | 12520367 |
| [isolation and identification of a killing maggots bacterium]. | a notably killing maggots bacterium was isolated from natural dead maggots in the manure pits in the countryside of yancheng. its pathogenicity was confirmed by the law of kock. the results of preliminary bioassay show that the pathogen can infect the larvas of greenbottle flies and other larvas of flies in a certain extent, but can't infect animals and fowls. the g + c content of its dna is 62.46%. the hybridization ratio of its dna and the pseudomonas pseudoalcaligenes' (as1.1806) is 81.2%. ac ... | 2000 | 12548772 |
| [isolation and characterization of a insecticidal protein from pseudomonas pseudoalcaligenes]. | a insecticidal protein was purified by gel-filtration chromatography on sephadex g-100 and anion-exchange chromatography on deae-sephadex a-50 from the suspension of pseudomonas pseudoalcaligenes culture. certain biophysical and biochemical properties were also studied. the molecular weight of the subunit of the insecticidal protein is 25,100 and pi is 5.16. amino acid composition analysis showed that it is an acidic protein. | 1998 | 12549390 |
| [transfer and expression of tyrosinase gene of pseudomonas maltophilia in pseudomonas pseudoalcaligenes]. | pseudomonas pseudoalcaligenes is a notably killing maggots bacterium, which was isolated from natural dead maggots in the manure pits in the countryside of yancheng. it easily die from effect of ultra-violet ray when it is exposed in the sun. antiradiation effect of melanin is quite strong. mel gene of p. maltophilia at18 has been introduced into p. pseudoalcaligenes, and enabled it the ability of producing melanin steadily. southern hybridization studies confirmed that the small fragment cloned ... | 2001 | 12552802 |
| [n-terminal analysis and antibody preparation of insecticidal protein form pseudomonas pseudoalcaligenes]. | the insecticidal protein from pseudomonas pseudoaligenes was and exotoxin which had toxicity on locusts. in order to elucidate its molecular properties an amino acid sequence, the insecticidal protein was purified from the culture supernatant by ultrafiltration, ion-exchange chromatography and gel filtration, and showed a single band on sds-page. analysis of the purified insecticidal protein dentified n-terminal sequence of ten amino acid residues. its polyclonal antibody was also obtained by im ... | 2001 | 12552816 |
| [melanin properties studies of the recombinant of pseudomonas pseudoalcaligenes containing tyrosinase gene]. | pseudomonas pseudoalcaligenes is a notably killing maggots bacterium, which was isolated from natural dead maggots. tyrosinase gene of p. maltophilia at18 has been introduced into p. pseudoalcaligenes, and enabled it the ability of producing melanin steadily. antiradiation effect of the melanin is quite strong. the melanin of the recombinant is nonfixiform material. it's solubility is very little in many sorts of organic or inorganic solvent. it's solubility is big in alkaline solution, but litt ... | 2001 | 12552826 |
| [purification and properties of glutamate dehydrogenase from pseudomonas pseudoalcaligenes]. | glutamate dehydrogenase was purified from the crude extract of pseudomonas pseudoal-caligenes. the enzyme had a molecular weight of 290,000 and was composed of six subunits with identical molecular weight of 47,000. the enzyme was highly specific for nadp(h) and the substrates. the biochemical properties such as kinetic parameters and heat stability were also examined. the purified gdh showed considerable loss of activity upon freezing. | 1999 | 12555531 |
| diversity of tetracycline resistance genes in bacteria from chilean salmon farms. | twenty-five distinct tetracycline-resistant gram-negative bacteria recovered from four chilean fish farms with no history of recent antibiotic use were examined for the presence of tetracycline resistance (tet) genes. sixty percent of the isolates carried 1 of the 22 known tet genes examined. the distribution was as follows. the tet(a) gene was found in six isolates. the tet(b) gene was found in two isolates, including the first description in the genus brevundimonas: two isolates carried the te ... | 2003 | 12604516 |
| prokaryotic homologs of the eukaryotic 3-hydroxyanthranilate 3,4-dioxygenase and 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase in the 2-nitrobenzoate degradation pathway of pseudomonas fluorescens strain ku-7. | the 2-nitrobenzoic acid degradation pathway of pseudomonas fluorescens strain ku-7 proceeds via a novel 3-hydroxyanthranilate intermediate. in this study, we cloned and sequenced a 19-kb dna locus of strain ku-7 that encompasses the 3-hydroxyanthranilate meta-cleavage pathway genes. the gene cluster, designated nbaexhjigfcdr, is organized tightly and in the same direction. the nbac and nbad gene products were found to be novel homologs of the eukaryotic 3-hydroxyanthranilate 3,4-dioxygenase and ... | 2003 | 12620844 |
| transposon-like organization of the plasmid-borne organophosphate degradation (opd) gene cluster found in flavobacterium sp. | several bacterial strains that can use organophosphate pesticides as a source of carbon have been isolated from soil samples collected from diverse geographical regions. all these organisms synthesize an enzyme called parathion hydrolase, and in each case the enzyme is encoded by a gene (opd) located on a large indigenous plasmid. these plasmids show considerable genetic diversity, but the region containing the opd gene is highly conserved. two opd plasmids, ppdl2 from flavobacterium sp. and pcm ... | 2003 | 12732518 |
| bacterial conversion of hydroxylamino aromatic compounds by both lyase and mutase enzymes involves intramolecular transfer of hydroxyl groups. | hydroxylamino aromatic compounds are converted to either the corresponding aminophenols or protocatechuate during the bacterial degradation of nitroaromatic compounds. the origin of the hydroxyl group of the products could be the substrate itself (intramolecular transfer mechanism) or the solvent water (intermolecular transfer mechanism). the conversion of hydroxylaminobenzene to 2-aminophenol catalyzed by a mutase from pseudomonas pseudoalcaligenes js45 proceeds by an intramolecular hydroxyl tr ... | 2003 | 12732549 |
| characterization of the second lysr-type regulator in the biphenyl-catabolic gene cluster of pseudomonas pseudoalcaligenes kf707. | pseudomonas pseudoalcaligenes kf707 possesses a biphenyl-catabolic (bph) gene cluster consisting of bphr1a1a2-(orf3)-bpha3a4bcx0x1x2x3d. the bphr1 (formerly orf0) gene product, which belongs to the gntr family, is a positive regulator for itself and bphx0x1x2x3d. further analysis in this study revealed that a second regulator belonging to the lysr family (designated bphr2) is involved in the regulation of the bph genes in kf707. the bphr2 gene was not located near the bph gene cluster, and its p ... | 2003 | 12775695 |
| production of 6-phenylacetylene picolinic acid from diphenylacetylene by a toluene-degrading acinetobacter strain. | several strategies for using enzymes to catalyze reactions leading to the synthesis of relatively simple substituted picolinic acids have been described. the goal of the work described here was to synthesize a more complex molecule, 6-phenylacetylene picolinic acid [6-(2-phenylethynyl)pyridine-2-carboxylic acid], for use as a potential endcapping agent for aerospace polymers. we screened 139 toluene-degrading strains that use a variety of catabolic pathways for the ability to catalyze oxidative ... | 2003 | 12839779 |
| novel selective medium for isolation of burkholderia pseudomallei. | isolation of burkholderia pseudomallei currently relies on the use of ashdown's selective agar (asa). we designed a new selective agar (burkholderia pseudomallei selective agar [bpsa]) to improve recovery of the more easily inhibited strains of b. pseudomallei. b. pseudomallei, burkholderia cepacia, and pseudomonas aeruginosa were used to determine the selectivity and sensitivity of bpsa. bpsa was more inhibitory to p. aeruginosa and b. cepacia and should make recognition of burkholderia species ... | 2003 | 12843080 |
| effect of carbon source on pyrimidine biosynthesis in pseudomonas alcaligenes atcc 14909. | the effect of carbon source on the regulation of the de novo pyrimidine biosynthetic enzymes in pseudomonas alcaligenes atcc 14909 was investigated. the de novo pyrimidine biosynthetic enzymes were measured in extracts of p. alcaligenes atcc 14909 cells and of cells from an auxotroph deficient for orotate phosphoribosyltransferase activity. pyrimidine biosynthetic enzyme activities in atcc 14909 were influenced by pyrimidine supplementation to the culture medium but not by the carbon source pres ... | 2003 | 12906394 |
| flow-injection spectrophotometric determination of cyanate in bioremediation processes by use of immobilised inducible cyanase. | a new flow injection (fi) method for photometric monitoring of cyanate in bioremediation processes using immobilised native cyanase is described. the method is based on the catalytic reaction between cyanate and bicarbonate to produce ammonia and carbon dioxide in the presence of an inducible native cyanase, immobilised in a reactor packed with glass beads. two degrees of purification of the biocatalyst were used-heated cell-free extract and purified extract of cyanase from pseudomonas pseudoalc ... | 2003 | 13680069 |
| cis-2', 3'-dihydrodiol production on flavone b-ring by biphenyl dioxygenase from pseudomonas pseudoalcaligenes kf707 expressed in escherichia coli. | escherichia coli jm109 strains expressing either toluene dioxygenase from pseudomonas putida f1 or biphenyl dioxygenase from pseudomonas pseudoalcaligenes kf707 were examined for their ability to catalyze flavones. biphenyl dioxygenase produced metabolites from flavone and 5,7-dihydroxyflavone which were not found in the control experiments. the absorption maxima of uv-visible spectra for the metabolites from flavone and 5,7-dihydroxyflavone were found at 337 and 348 nm respectively by using a p ... | 2003 | 14574103 |
| construction of escherichia coli strains for conversion of nitroacetophenones to ortho-aminophenols. | the predominant bacterial pathway for nitrobenzene (nb) degradation uses an nb nitroreductase and hydroxylaminobenzene (hab) mutase to form the ring-fission substrate ortho-aminophenol. we tested the hypothesis that constructed strains might accumulate the aminophenols from nitroacetophenones and other nitroaromatic compounds. we constructed a recombinant plasmid carrying nb nitroreductase (nbza) and hab mutase a (haba) genes, both from pseudomonas pseudoalcaligenes js45, and expressed the enzym ... | 2003 | 14602609 |
| population structure of alexandrium (dinophyceae) cyst formation-promoting bacteria in hiroshima bay, japan. | a total of 31 bacterial isolates that have potential alexandrium cyst formation-promoting activity (alex-cfpb) were isolated from hiroshima bay (japan), which is characterized by seasonal blooms of the toxic dinoflagellate alexandrium tamarense. the population structure of alex-cfpb was analyzed by means of restriction fragment length polymorphism analysis of the 16s rrna genes (16s rdna). fourteen ribotypes, a to n, were observed among the 31 isolates of alex-cfpb by using four restriction enzy ... | 2003 | 14602614 |
| molecular characterization and substrate preference of a polycyclic aromatic hydrocarbon dioxygenase from cycloclasticus sp. strain a5. | cycloclasticus sp. strain a5 is able to grow with petroleum polycyclic aromatic hydrocarbons (pahs), including unsubstituted and substituted naphthalenes, dibenzothiophenes, phenanthrenes, and fluorenes. a set of genes responsible for the degradation of petroleum pahs was isolated by using the ability of the organism to oxidize indole to indigo. this 10.5-kb dna fragment was sequenced and found to contain 10 open reading frames (orfs). seven orfs showed homology to previously characterized genes ... | 2003 | 14602629 |
| characterization of transcriptional regulatory genes for biphenyl degradation in rhodococcus sp. strain rha1. | transcription of the bpha1a2a3a4c1b genes, which are responsible for the conversion of biphenyl and polychlorinated biphenyl to the meta-cleavage products in rhodococcus sp. strain rha1, was examined. the bpha1 promoter (p(bpha1)) was identified and was shown to promote transcription induction by biphenyl and ethylbenzene. an 8.8-kb hindiii fragment that promotes transcription induction of p(bpha1) in rhodococcus erythropolis iam1399 was isolated from the region downstream of bphb by using a rep ... | 2004 | 15028699 |
| use of whole cells of pseudomonas aeruginosa for synthesis of the antioxidant hydroxytyrosol via conversion of tyrosol. | for the first time, a soil bacterium, designated pseudomonas aeruginosa, was isolated based on its ability to grow on tyrosol as a sole source of carbon and energy. during growth on tyrosol, this strain was capable of promoting the formation of a significant amount of hydroxytyrosol and trace quantities of parahydroxyphenyl acetic acid and 3,4-dihydroxyphenyl acetic acid. the products were confirmed by high-performance liquid chromatography and gas chromatography-mass spectrometry analyses. usin ... | 2004 | 15066802 |
| molecular breeding of 2,3-dihydroxybiphenyl 1,2-dioxygenase for enhanced resistance to 3-chlorocatechol. | 3-chlorobiphenyl is known to be mineralized by biphenyl-utilizing bacteria to 3-chlorobenzoate, which is further metabolized to 3-chlorocatechol. an extradiol dioxygenase, 2,3-dihydroxybiphenyl 1,2-dioxygenase (dhb12o; ec 1.13.11.39), which is encoded by the bphc gene, catalyzes the third step of the upper pathway of 3-chlorobiphenyl degradation. in this study, two full-length bphcs and nine partial fragments of bphcs fused to the 3' end of bphc in pseudomonas pseudoalcaligenes kf707 were cloned ... | 2004 | 15113829 |
| genetic environments of the rmta gene in pseudomonas aeruginosa clinical isolates. | nine pseudomonas aeruginosa strains showing very high levels of resistance to various aminoglycosides have been isolated from clinical specimens in seven separate japanese hospitals in five prefectures since 1997. these strains harbor the newly identified 16s rrna methylase gene (rmta). when an rmta gene probe was hybridized with genomic dnas of the nine strains digested with ecori, two distinct patterns were observed. the 11.1- and 15.8-kb regions containing the rmta genes of strains ar-2 and a ... | 2004 | 15155201 |
| biphenyl and benzoate metabolism in a genomic context: outlining genome-wide metabolic networks in burkholderia xenovorans lb400. | we designed and successfully implemented the use of in situ-synthesized 45-mer oligonucleotide dna microarrays (xeochips) for genome-wide expression profiling of burkholderia xenovorans lb400, which is among the best aerobic polychlorinated biphenyl degraders known so far. we conducted differential gene expression profiling during exponential growth on succinate, benzoate, and biphenyl as sole carbon sources and investigated the transcriptome of early-stationary-phase cells grown on biphenyl. ba ... | 2004 | 15294836 |
| bacterial transcriptional regulators for degradation pathways of aromatic compounds. | human activities have resulted in the release and introduction into the environment of a plethora of aromatic chemicals. the interest in discovering how bacteria are dealing with hazardous environmental pollutants has driven a large research community and has resulted in important biochemical, genetic, and physiological knowledge about the degradation capacities of microorganisms and their application in bioremediation, green chemistry, or production of pharmacy synthons. in addition, regulation ... | 2004 | 15353566 |
| promoter sequences necessary for high-level expression of the plasmid-associated ampc beta-lactamase gene blamir-1. | little is known about mechanisms involved in high-level expression of plasmid-associated ampc genes. the sequence for bla(mir-1) has been elucidated, and the gene is not inducible. although the sequence for the promoter (pra) that drives expression of enterobacter cloacae chromosomal ampc is present upstream of bla(mir-1), high-level expression from bla(mir-1) is directed from a hybrid promoter (prb) located further upstream of pra. the purpose of this study was to determine the influence of eac ... | 2004 | 15504838 |
| effects of the metalloid oxyanion tellurite (teo32-) on growth characteristics of the phototrophic bacterium rhodobacter capsulatus. | this work examines the effects of potassium tellurite (k2teo3) on the cell viability of the facultative phototroph rhodobacter capsulatus. there was a growth mode-dependent response in which cultures anaerobically grown in the light tolerate the presence of up to 250 to 300 microg of tellurite (teo3(2-)) per ml, while dark-grown aerobic cells were inhibited at tellurite levels as low as 2 microg/ml. the tellurite sensitivity of aerobic cultures was evident only for growth on minimal salt medium, ... | 2004 | 15528523 |
| engineering of chimeric class ii polyhydroxyalkanoate synthases. | pha synthase is a key enzyme involved in the biosynthesis of polyhydroxyalkanoates (phas). using a combinatorial genetic strategy to create unique chimeric class ii pha synthases, we have obtained a number of novel chimeras which display improved catalytic properties. to engineer the chimeric pha synthases, we constructed a synthetic phac gene from pseudomonas oleovorans (phac1po) that was devoid of an internal 540-bp fragment. randomly amplified pcr products (created with primers based on conse ... | 2004 | 15528546 |
| in vivo 31p nuclear magnetic resonance investigation of tellurite toxicity in escherichia coli. | here we compare the physiological state of escherichia coli exposed to tellurite or selenite by using the noninvasive technique of phosphorus-31 nuclear magnetic resonance (nmr) spectroscopy. we studied glucose-fed escherichia coli hb101 cells containing either a normal puc8 plasmid with no tellurite resistance determinants present or the ptwt100 plasmid which contains the resistance determinants tehab. no differences could be observed in intracellular atp levels, the presence or absence of a tr ... | 2004 | 15574934 |
| assimilation of nitrogen from nitrite and trinitrotoluene in pseudomonas putida jlr11. | pseudomonas putida jlr11 releases nitrogen from the 2,4,6-trinitrotoluene (tnt) ring as nitrite or ammonium. these processes can occur simultaneously, as shown by the observation that a nasb mutant impaired in the reduction of nitrite to ammonium grew at a slower rate than the parental strain. nitrogen from tnt is assimilated via the glutamine syntethase-glutamate synthase (gs-gogat) pathway, as evidenced by the inability of gogat mutants to use tnt. this pathway is also used to assimilate ammon ... | 2005 | 15601726 |
| alkaline cyanide biodegradation by pseudomonas pseudoalcaligenes cect5344. | pseudomonas pseudoalcaligenes cect5344 uses cyanide, cyanate, beta-cyanoalanine, and other cyanoderivatives as nitrogen sources under alkaline conditions, which prevents volatile hcn (pk(a) 9.2) formation. the cyanide consumed by this strain is stoichiometrically converted into ammonium. in addition, this bacterium grows with the heavy metal, cyanide-containing waste water generated by the jewellery industry, and is also a cyanide-resistant strain which induces an alternative oxidase and a sider ... | 2005 | 15667296 |
| bacterial degradation of cyanide and its metal complexes under alkaline conditions. | a bacterial strain able to use cyanide as the sole nitrogen source under alkaline conditions has been isolated. the bacterium was classified as pseudomonas pseudoalcaligenes by comparison of its 16s rna gene sequence to those of existing strains and deposited in the coleccion espanola de cultivos tipo (spanish type culture collection) as strain cect5344. cyanide consumption is an assimilative process, since (i) bacterial growth was concomitant and proportional to cyanide degradation and (ii) the ... | 2005 | 15691951 |
| crystal structure of the terminal oxygenase component of cumene dioxygenase from pseudomonas fluorescens ip01. | the crystal structure of the terminal component of the cumene dioxygenase multicomponent enzyme system of pseudomonas fluorescens ip01 (cumdo) was determined at a resolution of 2.2 a by means of molecular replacement by using the crystal structure of the terminal oxygenase component of naphthalene dioxygenase from pseudomonas sp. strain ncib 9816-4 (nphdo). the ligation of the two catalytic centers of cumdo (i.e., the nonheme iron and rieske [2fe-2s] centers) and the bridging between them in nei ... | 2005 | 15774891 |
| first isolation of blavim-2 in an environmental isolate of pseudomonas pseudoalcaligenes. | | 2005 | 15855549 |
| effect of temperature and additional carbon sources on phenol degradation by an indigenous soil pseudomonad. | a new indigenous soil bacterium pseudomonas sp. growing on phenol and on a mixture of phenol, toluene, o-cresol, naphthalene and 1,2,3-trimethylbenzene (1,2,3-tmb) was isolated and characterized. phylogenetic analysis suggested its classification to pseudomonadaceae family and showed 99.8% dna sequence identity to pseudomonas pseudoalcaligenes species. the isolate was psychrotroph, with growth temperatures ranging from ca. 0 to 40 degrees c. the gc-ms structural analysis of metabolic products of ... | 2005 | 15865154 |
| protein engineering of the archetypal nitroarene dioxygenase of ralstonia sp. strain u2 for activity on aminonitrotoluenes and dinitrotoluenes through alpha-subunit residues leucine 225, phenylalanine 350, and glycine 407. | naphthalene dioxygenase (ndo) from ralstonia sp. strain u2 has not been reported to oxidize nitroaromatic compounds. here, saturation mutagenesis of ndo at position f350 of the alpha-subunit (nagac) created variant f350t that produced 3-methyl-4-nitrocatechol from 2,6-dinitrotoluene (26dnt), that released nitrite from 23dnt sixfold faster than wild-type ndo, and that produced 3-amino-4-methyl-5-nitrocatechol and 2-amino-4,6-dinitrobenzyl alcohol from 2-amino-4,6-dinitrotoluene (2a46dnt) (wild-ty ... | 2005 | 15866914 |
| genetic variation in clones of pseudomonas pseudoalcaligenes after ten months of selection in different thermal environments in the laboratory. | the random amplification of polymorphic dna (rapd) method was used to examine genetic variation in experimental clones of pseudomonas pseudoalcaligenes in two experimental groups, as well as their common ancestor. six clones derived from a single colony of p. pseudoalcaligenes were cultured in two different thermal regimes for 10 months. three clones in the control group were cultured at constant temperature of 35 degrees c and another three clones in the high temperature (ht) group were propaga ... | 2005 | 15886916 |
| hydrocarbon biodegradation in oxygen-limited sequential batch reactors by consortium from weathered, oil-contaminated soil. | we studied the use of sequential batch reactors under oxygen limitation to improve and maintain consortium ability to biodegrade hydrocarbons. air-agitated tubular reactors (2.5 l) were operated for 20 sequential 21-day cycles. maya crude oil-paraffin mixture (13,000 mg/l) was used as the sole carbon source. the reactors were inoculated with a consortium from the rhizosphere of cyperus laxus, a native plant that grows naturally in weathered, contaminated soil. oxygen limitation was induced in th ... | 2005 | 15920621 |
| microbial diversity in ultra-high-pressure rocks and fluids from the chinese continental scientific drilling project in china. | microbial communities in ultra-high-pressure (uhp) rocks and drilling fluids from the chinese continental scientific drilling project were characterized. the rocks had a porosity of 1 to 3.5% and a permeability of approximately 0.5 mdarcy. abundant fluid and gas inclusions were present in the minerals. the rocks contained significant amounts of fe2o3, feo, p2o5, and nitrate (3 to 16 ppm). acridine orange direct counting and phospholipid fatty acid analysis indicated that the total counts in the ... | 2005 | 15933024 |
| identification of bacteria isolated from an oligotrophic lake with pesticide removal capacities. | we studied the growth and capacities for pesticides removal of bacterial strains isolated from the laguna grande, an oligotrophic lake at the south of spain (archidona, málaga). strains were isolated from water samples amended with 10 and 50 microg/ml of nine pesticides: organochlorinated insecticides (aldrin and lindane), organophosphorous insecticides (dimetoate, methyl-parathion and methidation), s-triazine herbicides (simazine and atrazine), fungicide (captan) and diflubenzuron (1-(-4-chloro ... | 2005 | 15943106 |
| biodegradation of pyridine in a completely mixed activated sludge process. | a potential bacterial culture (p1), isolated from garden soil and identified as pseudomonas pseudoalcaligenes-kpn, was used as a starter seed to develop the biomass in a completely mixed activated sludge (cmas) reactor and the system was evaluated for treatment of wastewater containing pyridine. the results of this study indicate that pyridine could be degraded efficiently at a loading of 0.251 kg pyridine kg mlss(-1) d(-1) (0.156 kg toc kg mlss(-1) d(-1)) and at an optimal hydraulic retention t ... | 2006 | 16084081 |
| alcaligenes faecalis subsp. phenolicus subsp. nov. a phenol-degrading, denitrifying bacterium isolated from a graywater bioprocessor. | a gram (-) coccobacillary bacterium, j(t), was isolated from a graywater bioprocessor. 16s rrna and biochemical analysis has revealed strain j(t) closely resembles alcaligenes faecalis atcc 8750t and a. faecalis subsp. parafaecalis dsm 13975t, but is a distinct, previously uncharacterized isolate. strain j(t), along with the type strain of a. faecalis and its previously described subspecies share the ability to aerobically degrade phenol. the degradation rates of phenol for strain j(t) and refer ... | 2005 | 16094869 |
| diversity of alkaliphilic and alkalitolerant bacteria cultivated from decomposing reed rhizomes in a hungarian soda lake. | bacterial communities associated with decomposing rhizomes of phragmites australis were investigated in lake ferto (neusiedlersee, hungary). alkaliphilic and alkalitolerant strains were isolated on cellulose-containing alkaline medium spread with dilutions of scrapings taken from the surface of the decaying plant material. fifty-one strains were grouped by numerical analysis based on physiological tests and biolog sole carbon source utilization data. the strains identified by 16s rdna sequence c ... | 2005 | 16132425 |
| resistance of marine bacterioneuston to solar radiation. | a total of 90 bacterial strains were isolated from the sea surface microlayer (i.e., bacterioneuston) and underlying waters (i.e., bacterioplankton) from two sites of the northwestern mediterranean sea. the strains were identified by sequence analysis, and growth recovery was investigated after exposure to simulated solar radiation. bacterioneuston and bacterioplankton isolates were subjected to six different exposure times, ranging from 0.5 to 7 h of simulated noontime solar radiation. followin ... | 2005 | 16151115 |
| epoxide formation on the aromatic b ring of flavanone by biphenyl dioxygenase of pseudomonas pseudoalcaligenes kf707. | prokaryotic dioxygenase is known to catalyze aromatic compounds into their corresponding cis-dihydrodiols without the formation of an epoxide intermediate. biphenyl dioxygenase from pseudomonas pseudoalcaligenes kf707 showed novel monooxygenase activity by converting 2(r)- and 2(s)-flavanone to their corresponding epoxides (2-(7-oxabicyclo[4.1.0]hepta-2,4-dien-2-yl)-2, 3-dihydro-4h-chromen-4-one), whereby the epoxide bond was formed between c2' and c3' on the b ring of the flavanone. the enzyme ... | 2005 | 16151125 |
| increased mesquite gum formation in nodal explants cultures after treatment with a microbial biomass preparation. | prosopis laevigata nodal explants cultures were established in murashige and skoog medium. simultaneously these cultures were subjected to stress with biotic elicitors and an environmental factor (temperature increase to promote heat stress) in order to promote and increase exuded mesquite gum production. the biotic elicitors were: aspergillus nidulans and pseudomonas pseudoalcaligenes both used in concentrations of 10, 20 and 30 mg, whereas the environmental condition was different incubation t ... | 2005 | 16198591 |