| adaptation of a phenol-degrading denitrifying bacteria to high concentration of phenol in the medium. | the growth and uptake of phenol by 8 strains isolated from wastewater sediments in stationary cultures in medium with increasing concentrations of phenol (from 100 to 600 mg/l) under denitrifying conditions were studied. all the strains grew in media containing 250 mg phenol/l and only strains 101/1, 83/2 and 21/1/ in consecutive passages visibly increased both specific growth rate (mu day-1) as well as phenol-degrading activity (mg/l x day). consecutive passages of the culture in medium contain ... | 1998 | 9990712 |
| biotransformation of monoterpenes, bile acids, and other isoprenoids in anaerobic ecosystems. | isoprenoic compounds play a major part in the global carbon cycle. biosynthesis and mineralization by aerobic bacteria have been intensively studied. this review describes our knowledge on the anaerobic metabolism of isoprenoids, mainly by denitrifying and fermentative bacteria. nitrate-reducing beta-proteobacteria were isolated on monoterpenes as sole carbon source and electron donor. thauera spp. were obtained on the oxygen-containing monoterpenes linalool, menthol, and eucalyptol. several str ... | 1998 | 9990726 |
| dynamics and modeling on fermentative production of poly (beta-hydroxybutyric acid) from sugars via lactate by a mixed culture of lactobacillus delbrueckii and alcaligenes eutrophus. | the mixed culture system was considered in the present research where sugars such as glucose were converted to lactate by lactobacillus delbrueckii and the lactate was converted to poly beta-hydroxybutyrate (phb) by alcaligenes eutrophus in one fermentor. for the modeling of the effect of nh3 concentration on the cell growth of a. eutrophus and phb production rates, metabolic flux distributions were computed at two culture phases of cell growth and phb production periods. it was found that the n ... | 1999 | 9990731 |
| analysis of the nitrous oxide reduction genes, noszdfyl, of achromobacter cycloclastes. | the structural gene, nosz, for the monomeric n2o reductase has been cloned and sequenced from the denitrifying bacterium achromobacter cycloclastes. the nosz gene encodes a protein of 642 amino acid residues and the deduced amino acid sequence showed homology to the previously derived sequences for the dimeric n2o reductases. the relevant dna region of about 3.6 kbp was also sequenced and found to consist of four genes, nosdfyl based on the similarity with the n2o reduction genes of pseudomonas ... | 1998 | 10048486 |
| liberation of hydrogen sulfide during the catalytic action of desulfovibrio hydrogenase under the atmosphere of hydrogen. | the active site of [nife] hydrogenase from desulfovibrio species is composed of a binuclear ni-fe complex bearing three diatomic nonprotein ligands to fe and three bridges between the two metals, two of which are thiolate side chains of the protein moiety. the third bridging atom in the enzyme isolated from d. vulgaris miyazaki f was suggested to be sulfur species, but was suggested to be oxygen species in d. gigas enzyme. when the hydrogenase from d. vulgaris miyazaki f was incubated under the ... | 1999 | 10049702 |
| cloning, sequencing, and transcriptional studies of the gene encoding copper-containing nitrite reductase from alcaligenes xylosoxidans ncimb 11015. | gene encoding of the blue copper-containing nitrite reductase (nir) from alcaligenes xylosoxidans ncimb 11015 has been cloned and characterized. the nir is translated into a polypeptide of 360 amino acid residues as a precursor, and the n-terminal 24 residues are subsequently removed upon transport into the periplasm as a mature protein. a specific transcription product of nir was detected only in the presence of nitrate. the aeration level of the culture medium did not show a significant effect ... | 1999 | 10049725 |
| purification and characterization of gentisate 1,2-dioxygenases from pseudomonas alcaligenes ncib 9867 and pseudomonas putida ncib 9869. | two 3-hydroxybenzoate-inducible gentisate 1,2-dioxygenases were purified to homogeneity from pseudomonas alcaligenes ncib 9867 (p25x) and pseudomonas putida ncib 9869 (p35x), respectively. the estimated molecular mass of the purified p25x gentisate 1, 2-dioxygenase was 154 kda, with a subunit mass of 39 kda. its structure is deduced to be a tetramer. the pi of this enzyme was established to be 4.8 to 5.0. the subunit mass of p35x gentisate 1, 2-dioxygenase was 41 kda, and this enzyme was deduced ... | 1999 | 10049846 |
| metabolic engineering of poly(3-hydroxyalkanoates): from dna to plastic. | poly(3-hydroxyalkanoates) (phas) are a class of microbially produced polyesters that have potential applications as conventional plastics, specifically thermoplastic elastomers. a wealth of biological diversity in pha formation exists, with at least 100 different pha constituents and at least five different dedicated pha biosynthetic pathways. this diversity, in combination with classical microbial physiology and modern molecular biology, has now opened up this area for genetic and metabolic eng ... | 1999 | 10066830 |
| coenzyme-dependent oxidoreductions in organic media. | | 1998 | 10075633 |
| ochrobactrum anthropi bacteremia. | ochrobactrum anthropi (o. anthropi ), formerly known as achromobacter cdc group vd, is a gram-negative bacillus that is aerobic, oxidase producing, and nonlactose fermenting. this organism has been found in environmental and hospital water sources and has pathogenic potential in humans. most reports in the literature of o. anthropi bacteremia are associated with intravenous line infections. we describe a case of bacteremia with o. anthropi in a 33-month-old boy with acute osteomyelitis. o. anthr ... | 1999 | 10076115 |
| [neonatal meningitis due to alcaligenes xylosoxidans contaminating aqueous solution of eosin]. | | 1999 | 10079896 |
| alcaligenes xylosoxidans endophthalmitis 8 months after cataract extraction. | to report a case of alcaligenes xylosoxidans endophthalmitis and to increase awareness of its potential as an intraocular pathogen. | 1999 | 10088749 |
| crystallization and preliminary x-ray study of iso-2 azurin from the methylotrophic bacterium, methylomonas j. | the obligate methylotroph methylomonas j possesses two distinct azurins. the iso-2 azurin, which functions as an electron acceptor for methylamine dehydrogenase, has been crystallized using two kinds of precipitants: peg 4000 and ammonium sulfate. the crystals precipitated with peg belong to the monoclinic system, space group p21, with unit-cell parameters a = 32.96, b = 33.67, c = 47.34 a and beta = 101.35 degrees. the crystals precipitated with ammonium sulfate belong to the orthorhombic syste ... | 1999 | 10089434 |
| purification, crystallization and preliminary x-ray studies of two isoforms of rubisco from alcaligenes eutrophus. | two different isoforms of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) from alcaligenes eutrophus have been purified and crystallized. both isoforms crystallize in space group p43212. crystals of isoform i (unit-cell dimensions a = 112.0 and c = 402.7 a) diffract to 2.7 a, whereas isoform ii (unit-cell dimensions a = 111.8 and c = 400.0 a) presently diffract to 3.2 a, using synchrotron radiation in both cases. | 1999 | 10089435 |
| investigation into pcb biodegradation using uniformly 14c-labelled dichlorobiphenyl. | biodegradation of polychlorinated biphenyls (pcbs) in soil is considered to be very complex due to various physico-chemical factors involved. isotope labelling technique is the best to trace fate of the xenobiotic in the environment. in this work, the uniformly 14c-labelled pcb congener 11 (3,3'-chlorobiphenyl) was chosen as a low chlorinated coplanar biphenyl which was assumed to be readily degraded by microorganisms. pleurotus ostreatus and two pseudomonas species, representing white rot fungi ... | 1998 | 10089593 |
| hydroxylamine oxidation and subsequent nitrous oxide production by the heterotrophic ammonia oxidizer alcaligenes faecalis. | nitrous oxide (n2o), a greenhouse gas, is emitted during autotrophic and heterotrophic ammonia oxidation. this emission may result from either coupling to aerobic denitrification, or it may be formed in the oxidation of hydroxylamine (nh2oh) to nitrite (no2(-). therefore, the n2o production during nh2oh oxidation was studied with alcaligenes faecalis strain tud. continuous cultures of a. faecalis showed increased n2o production when supplemented with increasing nh2oh concentrations. 15n-labeling ... | 1999 | 10091333 |
| biochemical characterization and solution structure of nitrous oxide reductase from alcaligenes xylosoxidans (ncimb 11015). | nitrous oxide reductase (n2or) is the terminal enzyme involved in denitrification by microbes. no three-dimensional structural information has been published for this enzyme. we have isolated and characterised n2or from alcaligenes xylosoxidans (axn2or) as a homodimer of m(r) 134,000 containing seven to eight copper atoms per dimer. comparison of sequence and compositional data with other n2ors suggests that axn2or is typical and can be expected to have similar domain folding and subunit structu ... | 1999 | 10092849 |
| evaluation of alcaligenes eutrophus cells as an nadh regenerating catalyst in organic-aqueous two-phase system. | a soluble nad-dependent hydrogenase contained in alcaligenes eutrophus was evaluated as a coenzyme regenerating catalyst in an organic-aqueous two-phase (predominantly organic) system. the horse-liver alcohol-dehydrogenase (hladh) catalyzed reduction of cyclohexanone to cyclohexanol was used as a model reaction. the impact of different solvents (selected to span a large variety of principal properties) on the stability and activity of the hladh, using substrate-driven regeneration, was studied. ... | 1998 | 10099181 |
| metabolic modeling of polyhydroxybutyrate biosynthesis. | a mathematical model describing intracellular polyhydroxybutyrate (phb) synthesis in alcaligenes eutrophus has been constructed. the model allows investigation of issues such as the existence of rate-limiting enzymatic steps, possible regulatory mechanisms in phb synthesis, and the effects different types of rate expressions have on model behavior. simulations with the model indicate that activities of all phb pathway enzymes influence overall phb flux and that no single enzymatic step can easil ... | 1998 | 10099235 |
| a tunable switch to regulate the synthesis of low and high molecular weight microbial polyesters. | the addition of poly(ethylene glycol) (mn = 200 g/mol) (peg-200) to the fermentation media of alcaligenes eutrophus and alcaligenes latus at various stages of growth resulted in the synthesis of poly(3-hydroxybutyrate) (phb) with bimodal molecular weight distributions. the presence of 2% w/v-peg-200 did not have deleterious effects on phb volumetric yields and cell productivity. in general, the mn values of the high (h) and low (l) fractions showed little variability as a function of the time at ... | 1999 | 10099518 |
| maximum production strategy for biodegradable copolymer p(hb-co-hv) in fed-batch culture of alcaligenes eutrophus. | a novel strategy for the maximum production of a biodegradable copolymer, poly(3-hydroxybutyric-co-hydroxyvaleric) acid, p(hb-co-hv), was developed, based on the kinetic parameters obtained from fed-batch culture experiments of alcaligenes eutrophus. the effects of various culture conditions such as mole ratio of carbon:nitrogen in feed medium (c/n); total fatty acids concentrations; and addition ratio of fatty acids on cultivation properties such as the specific rates of cell formation, mu (h-1 ... | 1999 | 10099560 |
| control of acetic acid concentration by ph-stat continuous substrate feeding in heterotrophic culture phase of two-stage cultivation of alcaligenes eutrophus for production of p(3hb) from co2, h2, and o2 under non-explosive conditions. | a-two stage culture method of hydrogen-oxidizing bacterium, alcaligenes eutrophus, is used to produce poly-d-3-hydroxybutyrate, p(3hb) from co2, o2, and h2 without using a very high oxygen transfer rate while maintaining the o2 concentration in gas phase below 6.9 (v/v)% to prevent detonation of the gas mixture. the two-stage method consists of a heterotrophic culture using fructose as carbon source for exponential cell growth and an autotrophic culture for p(3hb) accumulation. we investigated t ... | 1999 | 10099572 |
| pcr detection of genes encoding nitrite reductase in denitrifying bacteria. | using consensus regions in gene sequences encoding the two forms of nitrite reductase (nir), a key enzyme in the denitrification pathway, we designed two sets of pcr primers to amplify cd1- and cu-nir. the primers were evaluated by screening defined denitrifying strains, denitrifying isolates from wastewater treatment plants, and extracts from activated sludge. sequence relationships of nir genes were also established. the cd1 primers were designed to amplify a 778 to 799-bp region of cd1-nir in ... | 1999 | 10103263 |
| treatment of osteomyelitis by antibiotic impregnated porous hydroxyapatite block. | a novel drug delivery system was developed for osteomyelitis using porous hydroxyapatite blocks (ha-b) that were impregnated with antibiotics by a centrifuge method. for the experimental study, a 10 mm3 ha-b was placed in a container, mixed with an antibiotic solution and centrifuged at 1500 rpm for 15 min for the purpose of impregnating antibiotics into the pores. the slow release activity of antibiotic (arbekacin sulfate [1-n-(s)-4 amino-2-hydroxybutyryl dibekacin]) from the ha-b was tested. a ... | 1994 | 10155678 |
| effect of chronic intermittent administration of inhaled tobramycin on respiratory microbial flora in patients with cystic fibrosis. | pseudomonas aeruginosa endobronchial infection causes significant morbidity and mortality among cystic fibrosis patients. microbiology results from two multicenter, double-blind, placebo-controlled trials of inhaled tobramycin in cystic fibrosis were monitored for longitudinal changes in sputum microbial flora, antibiotic susceptibility, and selection of p. aeruginosa isolates with decreased tobramycin susceptibility. clinical response was examined to determine whether current susceptibility sta ... | 1999 | 10191222 |
| high cell density culture of metabolically engineered escherichia coli for the production of poly(3-hydroxybutyrate) in a defined medium. | a recombinant escherichia coli strain xl1-blue harboring a stable high-copy-number plasmid psyl107 containing the alcaligenes eutrophus polyhydroxyalkanoate biosynthesis genes and the escherichia coli ftsz gene was employed for the production of poly(3-hydroxybutyrate) (phb) by fed-batch culture in a defined medium. suppression of filamentation by overexpressing the cell division protein ftsz allowed production of phb to a high concentration (77 g/l) with high productivity (2 g/l/h) in a defined ... | 1998 | 10191411 |
| the blue copper-containing nitrite reductase from alcaligenes xylosoxidans: cloning of the nira gene and characterization of the recombinant enzyme. | the nira gene encoding the blue dissimilatory nitrite reductase from alcaligenes xylosoxidans has been cloned and sequenced. to our knowledge, this is the first report of the characterization of a gene encoding a blue copper-containing nitrite reductase. the deduced amino acid sequence exhibits a high degree of similarity to other copper-containing nitrite reductases from various bacterial sources. the full-length protein included a 24-amino-acid leader peptide. the nira gene was overexpressed i ... | 1999 | 10197991 |
| transcriptional organization of the czc heavy-metal homeostasis determinant from alcaligenes eutrophus. | the czc system of alcaligenes eutrophus mediates resistance to cobalt, zinc, and cadmium through ion efflux catalyzed by the czccb2a cation-proton antiporter. dna sequencing of the region upstream of the czcnicbadrs determinant located on megaplasmid pmol30 revealed the 5' end of czcn and a gene for a mgtc-like protein which is transcribed in the orientation opposite that of czc. additional open reading frames upstream of czc had no homologs in the current databases. using oligonucleotide-probed ... | 1999 | 10198000 |
| selective transport of divalent cations by transition metal permeases: the alcaligenes eutrophus hoxn and the rhodococcus rhodochrous nhlf. | nhlf and hoxn, the genes encoding a cobalt transporter of rhodococcus rhodochrous j1 and a nickel permease of alcaligenes eutrophus h16, respectively, were expressed in escherichia coli. 57co2+ and 63ni2+ transport of the recombinants was examined by means of a previously described physiological assay. although the transporters are highly similar, different preferences for divalent transition metal cations were observed. hoxn was unable to transport 57co2+, but mediated 63ni2+ uptake. the latter ... | 1999 | 10201093 |
| re-evaluation of the primary structure of ralstonia eutropha phasin and implications for polyhydroxyalkanoic acid granule binding. | sequence analysis of several cdnas encoding the phasin protein of ralstonia eutropha indicated that the carboxyl terminus of the resulting derived protein sequence is different from that reported previously. this was confirmed by: (1) sequencing of the genomic dna; (2) sds-page and peptide analysis of wild-type and recombinant phasin; and (3) mass spectrometry of wild-type phasin protein. the results have implications for the model proposed for the binding of this protein to polyhydroxyalkanoic ... | 1999 | 10218591 |
| structural and kinetic evidence for an ordered mechanism of copper nitrite reductase. | the crystallographic structures of several copper-containing nitrite reductases are now available. despite this wealth of structural data, no definitive information is available as to whether the reaction proceeds by an ordered mechanism where nitrite binds to the oxidised type 2 site, followed by an internal electron transfer from the type 1 cu, or whether binding occurs to the reduced type 2 cu centre, or a random mechanism operates. we present here the first structural information on both typ ... | 1999 | 10222206 |
| chromosome-determined zinc-responsible operon czr in staphylococcus aureus strain 912. | a novel operon, czrab (zinc-responsible genes), was identified in the chromosome of staphylococcus aureus. the operon consists of two genes, czra and czrb. the czra gene, coding for an 11.5 kda protein, was homologous to cadc, arsr of s. aureus plasmid pi258 and smtb of synechococcus pcc7942. the czrb, coding for a 36 kda membrane spanning protein, was homologous to the czcd gene, cobalt, zinc and the cadmium-resistant factor of bacillus subtilis and alcaligenes eutrophus. in the presence of zin ... | 1999 | 10229265 |
| classification of alcaligenes faecalis-like isolates from the environment and human clinical samples as ralstonia gilardii sp. nov. | a polyphasic taxonomic study that included dna-dna hybridizations, dna base ratio determinations, 16s rdna sequence analysis, whole-cell protein and fatty acid analyses, aflp (amplified fragment length polymorphism) fingerprinting and an extensive biochemical characterization was performed on 10 strains provisionally identified as alcaligenes faecalis-like bacteria. the six environmental and four human isolates belonged to the genus ralstonia and were assigned to a new species for which the name ... | 1999 | 10319461 |
| the crystal structure of rubisco from alcaligenes eutrophus reveals a novel central eight-stranded beta-barrel formed by beta-strands from four subunits. | ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) is involved in photosynthesis where it catalyzes the initial step in the fixation of carbon dioxide. the enzyme also catalyzes a competing oxygenation reaction leading to loss of fixed carbon dioxide, thus reducing the net efficiency of photosynthesis significantly. rubisco has therefore been studied extensively, and a challenging goal is the engineering of a more photosynthetically efficient enzyme. hexadecameric rubiscos fall in two dis ... | 1999 | 10329167 |
| biodegradation of s-triazine compounds by a stable mixed bacterial community. | the potential for biodegradation of s-triazine pesticides was investigated in laboratory batch and sequence batch experiments using a stable mixed bacterial community enriched on atrazine. the experiments were performed aerobically in a mineral salt solution complemented with a mixture of s-triazines as sole carbon and energy sources. comparisons were made between the efficiency of the inoculum for atrazine degradation in mineral salt solution and in wastewater. in batch cultivation, atrazine, s ... | 1999 | 10330320 |
| phospholipid bound to the flavohemoprotein from alcaligenes eutrophus. | the structurally characterized flavohemoprotein from alcaligenes eutrophus (fhp) contains a phospholipid-binding site with 1-16 : 0-2-cyclo-17 : 0-diacyl-glycerophospho-ethanolamine and 1-16 : 0-2-cyclo-17 : 0-diacyl-glycerophospho-glycerol as the major occupying compounds. the structure of the phospholipid is characterized by its compact form, due to the -sc/beta/-sc conformation of the glycerol and the nonlinear arrangement of the sn-1- and sn-2-fatty acid chains. the phospholipid-binding site ... | 1999 | 10336624 |
| ochrobactrum anthropi meningitis in a pre-term neonate. | | 1999 | 10342661 |
| removal of endotoxin during purification of poly(3-hydroxybutyrate) from gram-negative bacteria. | poly(3-hydroxybutyrate) (phb) was produced by cultivating several gram-negative bacteria, including ralstonia eutropha, alcaligenes latus, and recombinant escherichia coli. phb was recovered from these bacteria by two different methods, and the endotoxin levels were determined. when phb was recovered by the chloroform extraction method, the endotoxin level was less than 10 endotoxin units (eu) per g of phb irrespective of the bacterial strains employed and the phb content in the cell. the naoh d ... | 1999 | 10347075 |
| crystal structure determinations of oxidized and reduced pseudoazurins from achromobacter cycloclastes. concerted movement of copper site in redox forms with the rearrangement of hydrogen bond at a remote histidine. | the crystal structures of oxidized and reduced pseudoazurins from a denitrifying bacterium, achromobacter cycloclastes iam1013, have been determined at 1.35- and 1.6-a resolutions, respectively. the copper site in the oxidized state exhibits a distorted tetrahedral structure like those of other pseudoazurins. however, not only a small change of the copper geometry, but concerted peptide bond flips are identified. the imidazole ring of remote his6 has a hydrogen bonding distance of 2.73 a between ... | 1999 | 10364229 |
| validation of genetically engineered bioluminescent surfactant resistant bacteria as toxicity assessment tools. | bacteria are useful organisms for measuring acute and chronic toxicity. the most popular toxicity tests utilize the inhibition of bioluminescence as an indication of toxicity. an extensive toxicity database on pure chemical compounds has been created using the bioluminescent microorganism, vibrio fischeri. however, the use of the microtox assay in applications for environmental samples is not always successful, due to the test organism. because the genes for bioluminescence have been cloned from ... | 1999 | 10375425 |
| the rice inoculant strain alcaligenes faecalis a15 is a nitrogen-fixing pseudomonas stutzeri. | the taxonomic position of the nitrogen-fixing rice isolate a15, previously classified as alcaligenes faecalis, was reinvestigated. on the basis of its small subunit ribosomal rna (16s rrna) sequence this strain identifies as pseudomonas stutzeri. phenotyping and fatty acid profiling confirm this result. dna:dna hybridisations, using the optical renaturation rate method, between strain a15 and pseudomonas stutzeri lmg 11199t revealed a mean dna-binding of 77%. the identification was further corro ... | 1999 | 10390872 |
| amplified rdna restriction analysis and further genotypic characterisation of metal-resistant soil bacteria and related facultative hydrogenotrophs. | the level of genotypic relationship between czc+ soil bacteria mainly resistant to zinc (but also to various other metals), and related facultative hydrogenotrophs previously assigned to the genera alcaligenes, ralstonia, and burkholderia was evaluated using ardra (amplified ribosomal dna restriction analysis). the analysis included 44 strains isolated from harsh industrial environments in sediments, soils and wastes with high content of heavy metals. these strains were selected by their ability ... | 1999 | 10390877 |
| specificity of the lipase-specific foldases of gram-negative bacteria and the role of the membrane anchor. | folding of lipases that are secreted by pseudomonads and other gram-negative bacteria via the type ii secretion pathway is facilitated by dedicated chaperones, called lipase-specific foldases (lifs). lifs are membrane-anchored proteins with a large periplasmic domain. the functional interaction between the lif and its cognate lipase is specific, since the pseudomonas aeruginosa lif was found not to substitute for lifs from burkholderia glumae or acinetobacter calcoaceticus. however, the p. aerug ... | 1999 | 10394914 |
| factors influencing capacitance-based monitoring of microbial growth. | microbiological impedance devices are routinely used by food and manufacturing industries, and public health agencies to measure microbiological growth. factors contributing to increases and decreases in capacitance at the culture medium-electrode interface are poorly understood. to objectively evaluate the effects of temperature, cell density and medium conductivity on capacitance, admittance values from an impedance device were standardized; capacitance was converted to susceptance to allow un ... | 1999 | 10395464 |
| use of exogenous specialised bacteria in the biological detoxification of a dump site-polychlorobiphenyl-contaminated soil in slurry phase conditions | the possibility of biologically detoxifying a contaminated soil from an italian dump site containing about 1500 mg/kg (in dry soil) of polychlorinated biphenyls was studied in the laboratory in this work. the soil, which contained indigenous aerobic bacteria capable of growing on biphenyl or on monochlorobenzoic acids at concentration of about 300 cfu per g of air-dried soil, was amended with inorganic nutrients, saturated with water and treated in aerobic 3-l batch slurry reactors (soil suspens ... | 1999 | 10397860 |
| characterization of alpha-pinene-degrading microorganisms and application to a bench-scale biofiltration system for voc degradation | a study was conducted to isolate and characterize monoterpene-degrading microorganisms and apply them to a biofiltration unit for use in degrading high levels of alpha-pinene. soil from a monoterpene-contaminated site was used with enrichment culture techniques to recover a consortium of bacteria able to utilize alpha-pinene as the sole source of carbon and energy. the biolog system was utilized to identify the bacteria as pseudomonas fluorescens and alcaligenes xylosoxidans. aerobic growth and ... | 1999 | 10398764 |
| water and air in two poultry processing plants' chilling facilities--a bacteriological survey. | 1. water, aerosols and air in chilling facilities in 2 poultry abattoirs were bacteriologically examined. the different types of samples displayed a variety of bacterial loads and genera. 2. the aerobic plate count in water from spray nozzles was about log10 2 to 3 in both plants. flavobacterium, alcaligenes, acinetobacter and pseudomonadaceae were predominant in these samples. 3. the microbial load in air of the 2 plants was quite different, consisting mainly of micrococcaceae and gram-positive ... | 1999 | 10405036 |
| substrate and binding specificities of bacterial polyhydroxybutyrate depolymerases. | the substrate specificities of three extracellular polyhydroxybutyrate (phb) depolymerases from alcaligenes faecalis (phaz afa), pseudomonas stutzeri (phaz pst), and comamonas acidovorans (phaz cac), which are grouped into types a and b based on the position of a lipase box sequence in the catalytic domain, were examined for films of 12 different aliphatic polyesters. each of these phb depolymerases used was capable of hydrolyzing poly(3-hydroxybutyrate) (p(3hb)), poly(3-hydroxypropionate) (p(3h ... | 1999 | 10408639 |
| dynamics of multigene expression during catabolic adaptation of ralstonia eutropha jmp134 (pjp4) to the herbicide 2, 4-dichlorophenoxyacetate. | ralstonia eutropha jmp134 carries a 22 kb dna region on plasmid pjp4 necessary for the degradation of 2,4-d (2,4-dichlorophenoxyacetate). in this study, expression of the 2,4-d pathway genes (designated tfd ) upon exposure to different concentrations of 2,4-d was measured at a detailed timescale in chemostat-grown r. eutropha cultures. a sharp increase in mrna levels for tfda, tfdcdef-b, tfddiiciieiifii-bii and tfdk was detected between 2 and 13 min after exposure to 2,4-d. this response time wa ... | 1999 | 10411755 |
| chain termination in polyhydroxyalkanoate synthesis: involvement of exogenous hydroxy-compounds as chain transfer agents. | we have identified a range of compounds which, when present during poly(3-hydroxybutyrate) [p(3hb)] accumulation by ralstonia eutropha (reclassified from alcaligenes eutrophus), can act as chain transfer agents in the chain termination step of polymerization. end-group analysis by 31p nmr of polymer derivatized with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane revealed that all these compounds were covalently linked to p(3hb) at the carboxyl terminus. all chain transfer agents possessed o ... | 1999 | 10416649 |
| extracellular polymerization of 3-hydroxyalkanoate monomers with the polymerase of alcaligenes eutrophus. | previous investigations on the role of the polymerase in the synthesis of poly-3-hydroxybutyrate (phb) are reviewed, and the results from earlier in vitro studies on the activity and selectivity of the polymerase of alcaligenes eutrophus are discussed. in the present study the effect of glycerol on stabilizing the polymerase after purification and on eliminating the lag phase in in vitro polymerization reactions of 3-hydroxybutyl coa (hbcoa), and 3-hydroxyvaleryl coa (hvcoa) are described. k(m) ... | 1999 | 10416650 |
| production of two phase polyhydroxyalkanoic acid granules in ralstonia eutropha. | to synthesize layered granules consisting of selected phases of polyhydroxybutyrate (phb) homopolymer and ph(b-co-v) copolymer, ralstonia eutropha was grown on fructose and limited quantities (1 g/l) of valeric acid. exhaustion of the valerate resulted in a carbon source shift and a shift in the composition of polyhydroxyalkanoate (pha) being synthesized within the cell. the synthesis rates were 0.030 g ph(b-co-v)/l per h and 0.033 g phb/l per h, giving a copolymer composition of 48% hv. the val ... | 1999 | 10416651 |
| biosynthesis of polyhydroxyalkanoates (pha) by recombinant ralstonia eutropha and effects of pha synthase activity on in vivo pha biosynthesis. | recombinant strains of ralstonia eutropha phb 4, which harbored aeromonas caviae polyhydroxyalkanoates (pha) biosynthesis genes under the control of a promoter for r. eutropha phb operon, were examined for pha production from various alkanoic acids. the recombinants produced poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [p(3hb-co-3hhx)] from hexanoate and octanoate, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxypentano ate) [p(3hb-co-3hv-co-3hhp)] from pentanoate and nonanoate. one ... | 1999 | 10416652 |
| properties and biodegradability of ultra-high-molecular-weight poly[(r)-hydroxybutyrate] produced by a recombinant escherichia coli. | ultra-high-molecular-weight poly[(r)-3-hydroxybutyrate] (p(3hb)) (mw = 3-11 x 10(6)) was produced from glucose by a recombinant escherichia coli xl1-blue (psyl105) harboring ralstonia eutropha h16 polyhydroxyalkanoate (pha) biosynthesis genes. morphology of ultra-high-molecular-weight p(3hb) granules in the recombinant cells was studied by transmission electron microscopy. the recombinant e. coli contained several p(3hb) granules within a cell. freeze-fracture morphology of ultra-high-molecular- ... | 1999 | 10416654 |
| structure and enzymatic degradation of poly(3-hydroxybutyrate) copolymer single crystals with an extracellular phb depolymerase from alcaligenes faecalis t1. | lamellar single crystals of four random copolymers of (r)-3-hydroxybutyrate with different hydroxyalkanoates: poly(3-hydroxybutyrate-co-8 mol%-3-hydroxyvalerate) (p(3hb-co-8%-3hv)), poly(3-hydroxybutyrate-co-10 mol%-4-hydroxybutyrate) (p(3hb-co-10%-4hb)), poly(3-hydroxybutyrate-co-8 mol%-3-hydroxyhexanoate) (p(3hb-co-8%-3hh)) and poly(3-hydroxybutyrate-co-10 mol%-6-hydroxyhexanoate) (p(3hb-co-10%-6hh)), were grown from dilute solutions of chloroform and ethanol. all single crystals have lath-sha ... | 1999 | 10416664 |
| structural effects on enzymatic degradabilities for poly[(r)-3-hydroxybutyric acid] and its copolymers. | poly[(r)-3-hydroxybutyric acid] and its copolymers were prepared by biosynthetic and chemosynthetic methods. the films of polyesters were prepared by both the solution-cast and melt-crystallized techniques. the enzymatic degradation of polyester films was carried out at 37 degrees c in an aqueous solution (ph 7.4) of phb depolymerase from alcaligenes faecalis. the rate of enzymatic erosion on the solution-cast films increased markedly with an increase in the fraction of second monomer units up t ... | 1999 | 10416666 |
| characterization of the bacterial community of a zinc-polluted soil. | the bacterial community of a zinc-contaminated soil (maatheide soil in lommel, belgium) was studied using cultivation as well as cultivation-independent techniques. colony-forming units (cfu) were determined by plating on media with or without metals. dominant isolates were characterized by fatty acid methyl ester analysis (fame analysis) and pcr fingerprinting using repetitive extragenic palindromic sequences as primers. dna was directly extracted from soil samples and used as a template for th ... | 1999 | 10420584 |
| towards a reduction in excess sludge production in activated sludge processes: biomass physicochemical treatment and biodegradation. | to decrease activated sludge production, microbial cell lysis can be amplified to enhance cryptic growth (biomass growth on lysates). cell breakage techniques (thermal, alkaline, acid) were studied to generate alcaligenes eutrophus and sludge lysates and to evaluate their biodegradability. gentle treatment conditions produced the best results. complete cell deactivation was obtained for temperatures higher than 55 degrees c. the release kinetics were similar for temperatures varying from 60 degr ... | 1999 | 10422234 |
| the ph-dependent changes of intramolecular electron transfer on copper-containing nitrite reductase. | electron transfer over 12.6 a from the type 1 copper (t1cu) to the type 2 copper (t2cu) was investigated in the copper-containing nitrite reductases from two denitrifying bacteria (alcaligenes xylosoxidans gifu 1051 and achromobacter cycloclastes ian 1013), following pulse radiolytical reduction of t1cu. in the presence of nitrite, the rate constant for the intramolecular electron transfer of the enzyme from a. xylosoxidans decreased 1/2 fold to 9 x 10(2) s-1 (20 degrees c, ph 7.0) as compared t ... | 1999 | 10423537 |
| cloning, molecular analysis, and expression of the polyhydroxyalkanoic acid synthase (phac) gene from chromobacterium violaceum. | the polyhydroxyalkanoic acid synthase gene from chromobacterium violaceum (phac(cv)) was cloned and characterized. a 6.3-kb bamhi fragment was found to contain both phac(cv) and the polyhydroxyalkanoic acid (pha)-specific 3-ketothiolase (phaa(cv)). escherichia coli strains harboring this fragment produced significant levels of pha synthase and 3-ketothiolase, as judged by their activities. while c. violaceum accumulated poly(3-hydroxybutyrate) or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) when ... | 1999 | 10427049 |
| a megaplasmid-borne anaerobic ribonucleotide reductase in alcaligenes eutrophus h16. | the conjugative 450-kb megaplasmid phg1 is essential for the anaerobic growth of alcaligenes eutrophus h16 in the presence of nitrate as the terminal electron acceptor. we identified two megaplasmid-borne genes (nrdd and nrdg) which are indispensable under these conditions. sequence alignment identified significant similarity of the 76.2-kda gene product nrdd and the 30.9-kda gene product nrdg with anaerobic class iii ribonucleotide reductases and their corresponding activases. deletion of nrdd ... | 1999 | 10438763 |
| processing and functional display of the 86 kda heterodimeric penicillin g acylase on the surface of phage fd. | the large heterodimeric penicillin g acylase from alcaligenes faecalis was displayed on the surface of phage fd. we fused the coding sequence (alpha subunit-internal peptide-beta subunit) to the gene of a phage coat protein. a modified g3p signal sequence was used to direct the polypeptide to the periplasm. here we show that a heterodimeric enzyme can be expressed as a fusion protein that matures to an active biocatalyst connected to the coat protein of phage fd, resulting in a phage to which th ... | 1999 | 10455029 |
| batch culture biodegradation of methylhydrazine contaminated nasa wastewater. | the batch culture degradation of nasa wastewater containing mixtures of citric acid, methylhydrazine, and their reaction product was studied. the organic contaminants present in the nasa wastewater were degraded by achromobacter sp., rhodococcus b30 and rhodococcus j10. while the achromobacter sp. showed a preference for the degradation of the citric acid, the rhodococcus species were most effective in reducing the methylhydrazine and the reaction product. removals of more than 50% were observed ... | 1999 | 10466199 |
| positive transcriptional feedback controls hydrogenase expression in alcaligenes eutrophus h16. | the protein hoxa is the central regulator of the alcaligenes eutrophus h16 hox regulon, which encodes two hydrogenases, a nickel permease and several accessory proteins required for hydrogenase biosynthesis. expression of the regulatory gene hoxa was analyzed. screening of an 8-kb region upstream of hoxa with a promoter probe vector localized four promoter activities. one of these was found in the region immediately 5' of hoxa; the others were correlated with the nickel metabolism genes hypa1, h ... | 1999 | 10482509 |
| chiral compounds from bacterial polyesters: sugars to plastics to fine chemicals. | a novel and efficient method for the production of enantiomerically pure (r)-(-)-hydroxycarboxylic acids by in vivo depolymerization of microbial polyester polyhydroxyalkanoates (phas) was developed. using this method, several model compounds, (r)-(-)-3-hydroxyalkanoic acids, consisting of 4 to 12 carbon atoms, and (r)-(-)-3-hydroxy-5-phenylvaleric acid, could be prepared. in particular, (r)-(-)-3-hydroxybutyric acid could be efficiently prepared by this method. by providing the environmental co ... | 1999 | 10486136 |
| characterization of partially transesterified poly(beta-hydroxyalkanoate)s using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. | matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tofms) was used for the characterization of a partially transesterified poly(beta-hydroxyalkanoate), pha, polymer produced by the bacterial strain alcaligenes eutrophus using saponified vegetable oils as the sole carbon sources. the transesterification was carried out separately under acidic and basic conditions to obtain pha oligomers weighing less than 10 kda. the intact oligomers were detected in their cationi ... | 1999 | 10487942 |
| capillary electrophoresis-single-strand conformation polymorphism analysis for rapid identification of pseudomonas aeruginosa and other gram-negative nonfermenting bacilli recovered from patients with cystic fibrosis. | we used capillary electrophoresis-single-strand conformation polymorphism (ce-sscp) analysis of pcr-amplified 16s rrna gene fragments for rapid identification of pseudomonas aeruginosa and other gram-negative nonfermenting bacilli isolated from patients with cystic fibrosis (cf). target sequences were amplified by using forward and reverse primers labeled with various fluorescent dyes. the labeled pcr products were denatured by heating and separated by capillary gel electrophoresis with an autom ... | 1999 | 10488211 |
| beta-lactamase-free penicillin amidase from alcaligenes sp.: isolation strategy, strain characteristics, and enzyme immobilization. | isolation and characterization of a beta-lactamase (ec 3.5.2.6)-free, penicillin amidase (penicillin amidohydrolase, ec 3.5.1. 11)-producing organism is reported. the test strain was isolated by an enrichment technique with a substrate other than penicillins. the isolated strain belongs to the genus alcaligenes. phenylacetic acid was found to be the inducer of penicillin amidase. the amidase has a broad substrate spectrum. it is very active against penicillin g and semisynthetic cephalosporins, ... | 1999 | 10489431 |
| a data analysis of the irradiation parameter d10 for bacteria and spores under various conditions. | this paper provides approximate estimates for the irradiation parameter d10 to globally predict the effectiveness of any irradiation process. d10 is often reported to depend on many specific factors, implying that d10 cannot be estimated without exact knowledge of all factors involved. for specific questions these data can of course be useful but only if the conditions reported exactly match the specific question. alternatively, this study determined the most relevant factors influencing d10, by ... | 1999 | 10492477 |
| gated and ungated electron transfer reactions from aromatic amine dehydrogenase to azurin. | interprotein electron transfer (et) occurs between the tryptophan tryptophylquinone (ttq) prosthetic group of aromatic amine dehydrogenase (aadh) and copper of azurin. the et reactions from two chemically distinct reduced forms of ttq were studied: an o-quinol form that was generated by reduction by dithionite, and an n-quinol form that was generated by reduction by substrate. it was previously shown that on reduction by substrate, an amino group displaces a carbonyl oxygen on ttq, and that this ... | 1999 | 10506161 |
| phenol degradation by ralstonia eutropha: colorimetric determination of 2-hydroxymuconate semialdehyde accumulation to control feed strategy in fed-batch fermentations. | phenol biodegradation by ralstonia eutropha was modeled in different culture modes to assess phenol feeding in biotechnological depollution processes. the substrate-inhibited growth of r. eutropha was described by the haldane equation with a ks of 2 mg/l, a ki of 350 mg/l and a mumax of 0.41 h(-1). furthermore, growth in several culture modes was characterized by the appearance of a yellow color, due to production of a metabolic intermediate of the phenol catabolic pathway, 2-hydroxymuconic semi ... | 1999 | 10506416 |
| reactivity of lys(nh2)-containing peptides toward endopeptidases. | lys(nh2)-containing peptides were subjected to various proteolytic enzymes which were selected for their well-documented specificity for arginyl and/or lysyl peptide bonds. lys(nh2)-containing peptides were cleaved more rapidly by clostripain than the corresponding lysyl peptides. on the other hand, they proved to be resistant to achromobacter protease i hydrolysis. the modified peptides synthesized in this study were more stable than the arginyl and lysyl analogues when incubated with trypsin o ... | 1999 | 10507684 |
| high-level production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by fed-batch culture of recombinant escherichia coli. | fermentation strategies for production of high concentrations of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [p(3hb-co-3hv)] with different 3-hydroxyvalerate (3hv) fractions by recombinant escherichia coli harboring the alcaligenes latus polyhydroxyalkanoate biosynthesis genes were developed. fed-batch cultures of recombinant e. coli with the ph-stat feeding strategy facilitated production of high concentrations and high contents of p(3hb-co-3hv) in a chemically defined medium. when a feeding s ... | 1999 | 10508061 |
| quorum-sensing cross talk: isolation and chemical characterization of cyclic dipeptides from pseudomonas aeruginosa and other gram-negative bacteria. | in cell-free pseudomonas aeruginosa culture supernatants, we identified two compounds capable of activating an n-acylhomoserine lactone (ahl) biosensor. mass spectrometry and nmr spectroscopy revealed that these compounds were not ahls but the diketopiperazines (dkps), cyclo(deltaala-l-val) and cyclo(l-pro-l-tyr) respectively. these compounds were also found in cell-free supernatants from proteus mirabilis, citrobacter freundii and enterobacter agglomerans [cyclo(deltaala-l-val) only]. although ... | 1999 | 10510239 |
| localization of periplasmic redox proteins of alcaligenes faecalis by a modified general method for fractionating gram-negative bacteria. | a lysozyme-osmotic shock method is described for fractionation of alcaligenes faecalis which uses glucose to adjust osmotic strength and multiple osmotic shocks. during phenylethylamine-dependent growth, aromatic amine dehydrogenase, azurin, and a single cytochrome c were localized in the periplasm. their induction patterns are different from those for the related quinoprotein methylamine dehydrogenase and its associated redox proteins. | 1999 | 10515948 |
| [elastase activity of gram-negative non-fermenting bacteria and two variations of a simple method for their detection]. | the ability to produce elastase was examined in 1,168 strains of 11 representative genera of gram-negative non-fermenting bacteria isolated from weakened patients in the course of eight years. detection of the elastase activity was performed parallelly using the conventional method and its pulverisation variant. the difference between the results accomplished by the classical method and its pulverisation variant (53.9% versus 60.5% detected elastase-positive strains) was highly significant (p < ... | 1999 | 10528445 |
| the effect of motility and cell-surface polymers on bacterial attachment. | recently it was shown that motility of vibrio alginolyticus facilitated cell attachment to glass surfaces. in the present study the same relationship between motility and cell attachment was confirmed for alcaligenes and alteromonas spp. these findings clearly answer a long-standing question: does motility facilitate attachment? however, they are contradictory to a general view on cell attachment that the energy barrier due to electrostatic repulsion between negatively charged bacterial cells an ... | 1999 | 10537201 |
| the use of chromogenic reference substrates for the kinetic analysis of penicillin acylases. | determination of kinetic parameters of penicillin acylases for phenylacetylated compounds is complicated due to the low k(m) values for these substrates, the lack of a spectroscopic signal, and the strong product inhibition by phenylacetic acid. to overcome these difficulties, a spectrophotometric method was developed, with which kinetic parameters could be determined by measuring the effects on the hydrolysis of the chromogenic reference substrate 2-nitro-5-[(phenylacetyl)amino]benzoic acid (ni ... | 1999 | 10542108 |
| acetate metabolism in a pta mutant of escherichia coli w3110: importance of maintaining acetyl coenzyme a flux for growth and survival. | in order to study the physiological role of acetate metabolism in escherichia coli, the growth characteristics of an e. coli w3100 pta mutant defective in phosphotransacetylase, the first enzyme of the acetate pathway, were investigated. the pta mutant grown on glucose minimal medium excreted unusual by-products such as pyruvate, d-lactate, and l-glutamate instead of acetate. in an analysis of the sequential consumption of amino acids by the pta mutant growing in tryptone broth (tb), a brief lag ... | 1999 | 10542166 |
| transcriptional activation of the chlorocatechol degradative genes of ralstonia eutropha nh9. | ralstonia eutropha (formerly alcaligenes eutrophus) nh9 degrades 3-chlorobenzoate via the modified ortho-cleavage pathway. a ca. 5.7-kb six-gene cluster is responsible for chlorocatechol degradation: the cbnabcd operon encoding the degradative enzymes (including orfx of unknown function) and the divergently transcribed cbnr gene encoding the lysr-type transcriptional regulator of the cbn operon. the cbnrab orfxcd gene cluster is nearly identical to the chlorocatechol genes (tcbrcd orfxef) of the ... | 1999 | 10542171 |
| metabolism of acrylate to beta-hydroxypropionate and its role in dimethylsulfoniopropionate lyase induction by a salt marsh sediment bacterium, alcaligenes faecalis m3a. | dimethylsulfoniopropionate (dmsp) is degraded to dimethylsulfide (dms) and acrylate by the enzyme dmsp lyase. dms or acrylate can serve as a carbon source for both free-living and endophytic bacteria in the marine environment. in this study, we report on the mechanism of dmsp-acrylate metabolism by alcaligenes faecalis m3a. suspensions of citrate-grown cells expressed a low level of dmsp lyase activity that could be induced to much higher levels in the presence of dmsp, acrylate, and its metabol ... | 1999 | 10543825 |
| genetic and biochemical comparison of 2-aminophenol 1,6-dioxygenase of pseudomonas pseudoalcaligenes js45 to meta-cleavage dioxygenases: divergent evolution of 2-aminophenol meta-cleavage pathway. | nitrobenzene is degraded to pyruvate and acetaldehyde by pseudomonas pseudoalcaligenes js45 via a reductive pathway, and by comamonas sp. js765 via an oxidative pathway. although the initial reactions in the degradation of nitrobenzene by the two bacteria are totally different, the lower pathways are similar and converge at the level of 4-oxalocrotonate. in order to further investigate the biochemical properties and reveal the evolutionary relationships between the two lower pathways, the genes ... | 1999 | 10550475 |
| organization and sequences of p-hydroxybenzaldehyde dehydrogenase and other plasmid-encoded genes for early enzymes of the p-cresol degradative pathway in pseudomonas putida ncimb 9866 and 9869. | the gene (designated pcha) encoding the aldehyde dehydrogenase that is required to metabolise the p-hydroxybenzaldehyde produced by the degradation of p-cresol in pseudomonas putida ncimb 9866 and 9869 has been identified on plasmids pra4000 and pra500, respectively. the gene lies immediately upstream of the pchc and pchf genes encoding the subunits of p-cresol methylhydroxylase (pcmh), the preceeding enzyme in the p-cresol degradative pathway. in pra500 the latter genes are followed by the gene ... | 1999 | 10565539 |
| 2,4'-dihydroxyacetophenone dioxygenase (ec 1.13.11.41) from alcaligenes sp. 4hap: a novel enzyme with an atypical dioxygenase sequence. | 2,4'-dihydroxyacetophenone dioxygenase (ec 1.13.11.41) was purified to homogeneity from alcaligenes sp. 4hap grown on 4-hydroxyacetophenone. measurements of the m(r) of the native enzyme ranged from 81600 to 87000, whereas values of 21000 and 20379 were given by sds/page and electrospray ms respectively. the enzyme is a homotetramer and contains one atom of iron per molecule of enzyme. from c- and n-terminal analyses, primers for pcr were designed and the dad gene cloned and sequenced. the predi ... | 1999 | 10567221 |
| purification and characterization of the single-component nitric oxide reductase from ralstonia eutropha h16. | nitric oxide (no) reductase was purified from ralstonia eutropha (formerly alcaligenes eutrophus) using a two step chromatographic procedure. unlike the common no reductases, the enzyme consists of a single subunit of 75 kda which contains both high-spin and low-spin heme b, but lacks heme c. one additional iron atom, probably a ferric non-heme iron, was identified per enzyme molecule. whereas reduced cytochrome c was ineffective as electron donor, no was reduced at a specific activity of 2.3 mi ... | 1999 | 10571051 |
| amino acid replacements at the h2-activating site of the nad-reducing hydrogenase from alcaligenes eutrophus. | the role of amino acid residues in the h(2)-activating subunit (hoxh) of the nad-reducing hydrogenase (sh) from alcaligenes eutrophus has been investigated by site-directed mutagenesis. conserved residues in the n-terminal l1 (rgxe) and l2 (rxcgxcx(3)h) and the c-terminal l5 (dpcx(2)cx(2)h/r) motifs of the active site-harboring subunit were chosen as targets. crystal structure analysis of the [nife] hydrogenase from desulfovibrio gigas uncovered two pairs of cysteines (motifs l2 and l5) as coord ... | 1999 | 10572008 |
| enzymatic synthesis of alpha-l-fucosyl-n-acetyllactosamines and 3'-o-alpha-l-fucosyllactose utilizing alpha-l-fucosidases. | an alpha-l-fucosidase from porcine liver produced alpha-l-fuc-(1-->2)-beta-d-gal-(1-->4)-d-glcnac (2'-o-alpha-l-fucosyl-n-acetyllactosamine, 1) together with its isomers alpha-l-fuc-(1-->3)-beta-d-gal-(1-->4)-d-glcnac (2) and alpha-l-fuc-(1-->6)-beta-d-gal-(1-->4)-d-glcnac (3) through a transglycosylation reaction from p-nitrophenyl alpha-l-fucopyranoside and beta-d-gal-(1-->4)-d-glcnac. the enzyme formed the trisaccharides 1-3 in 13% overall yield based on the donor, and in the ratio of 40:37:2 ... | 1999 | 10573857 |
| antibacterial activities of anthozoan corals on some marine microfoulers. | the antibacterial activities of twelve species of anthozoans (4 gorgonians, 5 soft corals and 3 antipatharians) collected off the east coast of india were assayed against four dominant marine fouling bacterial strains isolated from the biofilm of fouled aluminium panels. of the 48 combinations (12 corals x 4 bacteria) eighteen interactions showed antibacterial activity (37.5%). such activity was most apparent in gorgonians, which inhibited bacterial growth in ten out of sixteen interactions (62. ... | 1999 | 10581726 |
| the oxygenase component of the 2-aminobenzenesulfonate dioxygenase system from alcaligenes sp. strain o-1. | growth of alcaligenes sp. strain o-1 with 2-aminobenzenesulfonate (abs; orthanilate) as sole source of carbon and energy requires expression of the soluble, multicomponent 2-aminobenzenesulfonate 2,3-dioxygenase system (deaminating) (absdos) which is plasmid-encoded. absdos was separated by anion-exchange chromatography to yield a flavin-dependent reductase component and an iron-dependent oxygenase component. the oxygenase component was purified to about 98% homogeneity and an alpha2beta2 subuni ... | 1999 | 10589735 |
| [isolation of bacteria which could perform nitrification and denitrification simultaneously by gene probe]. | the bacteria which could perform nitrification and denitrification simultaneously from nitrogen containing wastes in taiwan were isolated by using the probes made from random dna fragments of thiosphaera pantotropha. two isolates were identified and named alcaligenes faecalis subsp. faecalis strain 1 and strain 2 respectively. the effects on nitrification and denitrification by different medium ph, oxygen content, addition of different electron donors or inhibitors were studied. the isolates not ... | 1997 | 10592830 |
| feasibility study on the utilization of rubber latex effluent for producing bacterial biopolymers. | rubber latex effluent is a polluting source that has a high biochemical oxygen demand (bod). it is estimated that about 100 million liters of effluent are discharged daily from rubber processing factories. utilization of this effluent such as the use of a coupled system not only can reduce the cost of treatment but also yield a fermentation feedstock for the production of bioplastic. this study initially was carried out to increase the production of organic acids by anaerobic treatment of rubber ... | 1999 | 10595441 |
| heavy metals bioremediation of soil. | historical emissions of old nonferrous factories lead to large geographical areas of metals-contaminated sites. at least 50 sites in europe are contaminated with metals like zn, cd, cu, and pb. several methods, based on granular differentiation, were developed to reduce the metals content. however, the obtained cleaned soil is just sand. methods based on chemical leaching or extraction or on electrochemistry do release a soil without any salts and with an increased bioavailability of the remaini ... | 1999 | 10596372 |
| herbicide-degrading alpha-keto acid-dependent enzyme tfda: metal coordination environment and mechanistic insights. | tfda is a non-heme iron enzyme which catalyzes the first step in the oxidative degradation of the widely used herbicide (2, 4-dichlorophenoxy)acetate (2,4-d). like other alpha-keto acid-dependent enzymes, tfda utilizes a mononuclear fe(ii) center to activate o(2) and oxidize substrate concomitant with the oxidative decarboxylation of alpha-ketoglutarate (alpha-kg). spectroscopic analyses of various cu(ii)-substituted and fe(ii)-reconstituted tfda complexes via electron paramagnetic resonance (ep ... | 1999 | 10600135 |
| the c-terminal domain of the pseudomonas secretin xcpq forms oligomeric rings with pore activity. | the pseudomonas secretin xcpq forms an oligomeric complex, which is involved in the translocation of proteins across the outer membrane via the type ii secretion pathway. pseudomonas aeruginosa produces only small amounts of this complex, 50 to 100 copies per bacterium, and overexpression is lethal to these cells. however, overexpression of pseudomonas alcaligenes xcpq could be achieved in the p. alcaligenes mutant strain 537. protease protection experiments with p. alcaligenes xcpq showed that ... | 1999 | 10600375 |
| characterization of the endogenous plasmid from pseudomonas alcaligenes ncib 9867: dna sequence and mechanism of transfer. | the endogenous plasmid pra2 from pseudomonas alcaligenes ncib 9867 was determined to have 32,743 bp with a g+c content of 59.8%. sequence analysis predicted a total of 29 open reading frames, with approximately half of them contributing towards the functions of plasmid replication, mobilization, and stability. the pac25i restriction-modification system and two mobile elements, tn5563 and is1633, were physically localized. an additional eight open reading frames with unknown functions were also d ... | 2000 | 10613866 |
| endotoxic activity of lipopolysaccharides isolated from emergent potential cystic fibrosis pathogens. | improved antimicrobial therapies against the classical spectrum of pathogenic bacteria which colonise the lungs of cystic fibrosis (cf) patients has resulted in improved life expectancy and quality of life. bacterial species that are resistant to a broad range of antibiotics including stenotrophomonas maltophilia and alcaligenes xylosoxidans have now emerged as potential new pathogens to fill the niche. at present, it is unclear from clinical data whether these microbes are commensal or pathogen ... | 2000 | 10617793 |
| convenient test for screening metallo-beta-lactamase-producing gram-negative bacteria by using thiol compounds. | a simple disk diffusion test was constructed for detection of imp-1-type metallo-beta-lactamase-producing gram-negative bacteria. two kirby-bauer disks containing ceftazidime (caz) and a filter disk containing a metallo-beta-lactamase inhibitor were used in this test. several imp-1 inhibitors such as thiol compounds including 2-mercaptopropionic acid, heavy metal salts, and edta were evaluated for this test. two caz disks were placed on a mueller-hinton agar plate on which a bacterial suspension ... | 2000 | 10618060 |
| expression of alcaligenes eutrophus flavohemoprotein and engineered vitreoscilla hemoglobin-reductase fusion protein for improved hypoxic growth of escherichia coli. | expression of the vhb gene encoding hemoglobin from vitreoscilla sp. (vhb) in several organisms has been shown to improve microaerobic cell growth and enhance oxygen-dependent product formation. the amino-terminal hemoglobin domain of the flavohemoprotein (fhp) of the gram-negative hydrogen-oxidizing bacterium alcaligenes eutrophus has 51% sequence homology with vhb. however, like other flavohemoglobins and unlike vhb, fhp possesses a second (carboxy-terminal) domain with nad(p)h and flavin aden ... | 2000 | 10618209 |
| spectroscopic and electrochemical properties of two azurins (az-iso1 and az-iso2) from the obligate methylotroph methylomonas sp. strain j and the structure of novel az-iso2. | two azurin-type blue copper proteins, which are related to the electron-transfer processes involving methylamine/methanol oxidation, have been spectroscopically and electrochemically characterized. the obligate methylotroph methylomonas sp. strain j gives rise to two azurins (az-isol and az-iso2) with methylamine dehydrogenase (madh-mj). the intense blue bands characteristic of az-iso1 and az-iso2 are observed at 621 and 616 nm in the visible absorption spectra respectively, being revealed at 62 ... | 1999 | 10631606 |
| ralstonia eutropha tf93 is blocked in tat-mediated protein export. | ralstonia eutropha (formerly alcaligenes eutrophus) tf93 is pleiotropically affected in the translocation of redox enzymes synthesized with an n-terminal signal peptide bearing a twin arginine (s/t-r-r-x-f-l-k) motif. immunoblot analyses showed that the catalytic subunits of the membrane-bound [nife] hydrogenase (mbh) and the molybdenum cofactor-binding periplasmic nitrate reductase (nap) are mislocalized to the cytoplasm and to the inner membrane, respectively. moreover, physiological studies s ... | 2000 | 10633089 |