| mimicking biological electron transfer and oxygen activation involving iron and copper proteins: a bio(in)organic supramolecular approach. | | 2001 | 11219019 |
| sequence variation in dichloromethane dehalogenases/glutathione s-transferases. | dichloromethane dehalogenase/glutathione s-transferase allows methylotrophic bacteria to grow with dichloromethane (dcm), a predominantly man-made compound. bacteria growing with dcm by virtue of this enzyme have been readily isolated in the past. so far, the sequence of the dcma gene encoding dcm dehalogenase has been determined for methylobacterium dichloromethanicum dm4 and methylophilus sp. dm11. dcm dehalogenase genes closely related to that of strain dm4 were amplified by pcr and cloned fr ... | 2001 | 11238968 |
| identification of methyl halide-utilizing genes in the methyl bromide-utilizing bacterial strain imb-1 suggests a high degree of conservation of methyl halide-specific genes in gram-negative bacteria. | strain imb-1, an aerobic methylotrophic member of the alpha subgroup of the proteobacteria, can grow with methyl bromide as a sole carbon and energy source. a single cmu gene cluster was identified in imb-1 that contained six open reading frames: cmuc, cmua, orf146, paae, huti, and partial metf. cmua from imb-1 has high sequence homology to the methyltransferase cmua from methylobacterium chloromethanicum and hyphomicrobium chloromethanicum and contains a c-terminal corrinoid-binding motif and a ... | 2001 | 11282657 |
| re-face stereospecificity of nadp dependent methylenetetrahydromethanopterin dehydrogenase from methylobacterium extorquens am1 as determined by nmr spectroscopy. | mtda catalyzes the dehydrogenation of n(5),n(10)-methylenetetrahydromethanopterin (methylene-h4mpt) with nadp(+) as electron acceptor. in the reaction two prochiral centers are involved, c14a of methylene-h4mpt and c4 of nadp(+), between which a hydride is transferred. the two diastereotopic protons at c14a of methylene-h4mpt and at c4 of nadph can be seen separately in 1h-nmr spectra. this fact was used to determine the stereospecificity of the enzyme. with (14ar)-[14a-2h(1)]-[14a-13c]methylene ... | 2001 | 11297742 |
| [unique properties of highly radioresistant bacteria]. | in connection with the chernobyl nuclear power plant (chnpp) accident and the negative ecological after-effects for biota in this zone the interest has arisen to radioresistant bacteria, as to the most dynamic model of the given ecosystem, and to mechanisms which provide resistance of bacteria to ionizing radiation. the analysis of published data has shown that the radioresistant bacteria are not interrelated taxonomically and phylogenetically. the extreme radioresistant bacteria are represented ... | 2000 | 11300085 |
| variability and interactions between endophytic bacteria and fungi isolated from leaf tissues of citrus rootstocks. | fungi and bacteria were isolated from surface disinfected leaf tissues of several citrus rootstocks. the principal bacterial species isolated were alcaligenes sp., bacillus spp. (including b. cereus, b. lentus, b. megaterium, b. pumilus, and b. subtilis), burkholderia cepacia, curtobacterium flaccumfaciens, enterobacter cloacae, methylobacterium extorquens, and pantoea agglomerans, with p. agglomerans and b. pumilus being the most frequently isolated species. the most abundant fungal species wer ... | 2001 | 11315114 |
| [methylovorus mays--novel species of aerobic, obligatory methylotrophic bacteria associated with plants]. | a bacterial strain utilizing methanol as the sole source of carbon and energy was isolated from the maize phyllosphere. cells are nonpigmented gram-negative motile rods that do not form spores or prosthecae and reproduce by binary fission. the strain does not require vitamins or supplementary growth factors. it is obligately aerobic and urease-, oxidase-, and catalase-positive. the optimum growth temperature is 35-40 degrees c; the optimum ph is 7.0-7.5. the doubling time is 2 h. the bacterium i ... | 2000 | 11315676 |
| determination of the electron self-exchange rates of blue copper proteins by super-weft nmr spectroscopy. | an nmr approach for determining the electron self-exchange (ese) rate constants in blue copper proteins is presented. the approach uses the paramagnetic relaxation enhancement of resonances in 1d 1h super-weft spectra of partly oxidized (paramagnetic) proteins. these spectra allow a more precise determination of the relevant paramagnetic linebroadenings than conventional 1d 1h spectra and, thus, permit a more detailed investigation of the applicability of the linebroadenings for determining the ... | 2001 | 11330808 |
| [phylogenetic analysis of aerobic methylotrophic bacteria, using dichloromethane]. | the phylogenetic relationships of 12 aerobic dichloromethane-degrading bacteria that implement different c1-assimilation pathways was determined based on 16s ribosomal rna sequences and dna-dna hybridization data. the restricted facultative methylotroph "methylophilus leisingerii" dm11 with the ribulose monophosphate pathway was found to belong to the genus methylophilus cluster of the beta subdivision of the phylogenetic kingdom proteobacteria. the facultative methylotroph methylorhabdus multiv ... | 2001 | 11338843 |
| crystal structure of a novel red copper protein from nitrosomonas europaea. | nitrosocyanin (nc) is a mononuclear red copper protein isolated from the ammonia oxidizing bacterium nitrosomonas europaea. although nc exhibits some sequence homology to classic blue copper proteins, its spectroscopic and electrochemical properties are drastically different. the 1.65 a resolution crystal structure of oxidized nc reveals an unprecedented trimer of single domain cupredoxins. each copper center is partially covered by an unusual extended beta-hairpin structure from an adjacent mon ... | 2001 | 11341832 |
| chloromethane: tetrahydrofolate methyl transfer by two proteins from methylobacterium chloromethanicum strain cm4. | the cmua and cmub genes are required for growth of methylobacterium chloromethanicum strain cm4 with chloromethane as the sole carbon source. while cmub was previously shown to possess methylcobalamin:tetrahydrofolate methyltransferase activity, sequence analysis indicated that cmua represented a novel and so far unique two-domain methyltransferase/corrinoid-binding protein involved in methyl transfer from chloromethane to a corrin moiety. cmua was purified from wild-type m. chloromethanicum str ... | 2001 | 11358510 |
| molecular characterization of a blue-copper laccase, tila, of aspergillus nidulans. | laccases are blue-copper enzymes, which oxidize phenolic substrates and thereby reduce molecular oxygen. they are widespread within fungi and are involved in lignin degradation or secondary metabolism such as pigment biosynthesis. many fungi contain several laccases, not all of whose functions are known. in aspergillus nidulans one, ya, is expressed during asexual development and converts a yellow precursor to the green pigment. we identified a second laccase gene, which encodes a 66.3-kda prote ... | 2001 | 11377869 |
| [processes of plant colonization by methylobacterium strains and some bacterial properties ]. | the pink-pigmented facultative methylotrophic bacteria (ppfmb) of the genus methylobacterium are indespensible inhabitants of the plant phyllosphere. using maize zea mays as a model, the ways of plant colonization by ppfmb and some properties of the latter that might be beneficial to plants were studied. a marked strain, methylobacterium mesophilicum apr-8 (pulb113), was generated to facilitate the detection of the methylotrophic bacteria inoculated into the soil or applied to the maize leaves. ... | 2001 | 11386061 |
| gene synthesis, expression, and mutagenesis of zucchini mavicyanin: the fourth ligand of blue copper center is gln. | the gene coding for the 109-amino-acid, non-glycosylated form of mavicyanin was synthesized and expressed in escherichia coli. the recombinant protein refolded from e. coli inclusion bodies was purified and characterized. its spectroscopic properties are fully identical to those of mavicyanin isolated from zucchini, even in the absence of its carbohydrate moiety. the blue cooper center of mavicyanin strongly binds three ligands (2his and cys) as well as many blue copper proteins. to disclose the ... | 1998 | 9753643 |
| dichloromethane mediated in vivo selection and functional characterization of rat glutathione s-transferase theta 1-1 variants. | methylobacterium dichloromethanicum dm4 is able to grow with dichloromethane as the sole carbon and energy source by using a dichloromethane dehalogenase/glutathione s-transferase (gst) for the conversion of dichloromethane to formaldehyde. mammalian homologs of this bacterial enzyme are also known to catalyze this reaction. however, the dehalogenation of dichloromethane by gst t1-1 from rat was highly mutagenic and toxic to methylotrophic bacteria. plasmid-driven expression of rat gst t1-1 in s ... | 2001 | 11453994 |
| [ nodulation of certain legumes of the genus crotalaria by the new species methylobacterium]. | we studied a collection of 126 rhizobial isolates from eight species of crotalaria (c. comosa, c. glaucoides, c. goreensis, c. hyssopifolia, c. lathyroides, c. perrottetii, c. podocarpa, and c. retusa) growing in senegal. nodulation and nitrogen-fixation tests on nine crotalaria species revealed two specificity groups within the genus crotalaria. group i consists of plants solely nodulated by very specific fast-growing strains. group ii plants are nodulated by slow-growing strains similar to pro ... | 2001 | 11469252 |
| methyl chloride utilising bacteria are ubiquitous in the natural environment. | enrichment and isolation of methyl chloride utilising bacteria from a variety of pristine terrestrial, freshwater, estuarine and marine environments resulted in the detection of six new methyl chloride utilising hyphomicrobium strains, strain cmc related to aminobacter spp. and to two previously isolated methyl halide utilising bacteria cc495 and imb-1, and a gram-positive isolate sac-4 phylogenetically related to nocardioides spp. all the pristine environments sampled for enrichment resulted in ... | 2001 | 11470354 |
| a mimic molecule of blue copper protein active site [(-)-sparteine-n,n'](maleonitriledithiolato-s,s')copper(ii). | | 2001 | 11487359 |
| dehalogenation of dichloromethane by dichloromethane dehalogenase/glutathione s-transferase leads to formation of dna adducts. | formation of dna adducts following conversion of dichloromethane by bacterial dichloromethane dehalogenase/glutathione s-transferase was demonstrated. adducts included dichloromethane carbon and glutathione sulfur atoms. a reaction with dna occurred preferentially at guanine bases. increased dna degradation in a pola mutant of methylobacterium dichloromethanicum dm4 grown with dichloromethane confirmed the genotoxicity associated with dichloromethane degradation, suggesting an important role of ... | 2001 | 11489877 |
| development of improved versatile broad-host-range vectors for use in methylotrophs and other gram-negative bacteria. | full exploitation of the information available in bacterial genome sequences requires the availability of facile tools for rapid genetic manipulation. one bacterium for which new genetic tools are needed is the methylotroph methylobacterium extorquens am1. incq and small incp vectors were shown to be unsuitable for use in this bacterium, but a spontaneous mutant of a small incp plasmid was isolated that functioned efficiently in m. extorquens am1. this plasmid was sequenced and used as a base fo ... | 2001 | 11495985 |
| site-directed mutagenesis and x-ray crystallography of the pqq-containing quinoprotein methanol dehydrogenase and its electron acceptor, cytochrome c(l). | two proteins specifically involved in methanol oxidation in the methylotrophic bacterium methylobacterium extorquens have been modified by site-directed mutagenesis. mutation of the proposed active site base (asp303) to glutamate in methanol dehydrogenase (mdh) gave an active enzyme (d303e-mdh) with a greatly reduced affinity for substrate and with a lower activation energy. results of kinetic and deuterium isotope studies showed that the essential mechanism in the mutant protein was unchanged, ... | 2001 | 11502173 |
| sequence and functional analysis of an escherichia coli dna fragment able to complement pqqe and pqqf mutants from methylobacterium organophilum. | a 7361 kb fragment of e coli chromosomal dna able to complement pqqe and pqqf mutants of methylobacterium organophilum has been sequenced. five open reading frames (orf) have been identified. four orfs (102, 103, 106 and 107), belong to a single transcription unit. they are separated by a transcription termination site from a fifth orf (orf109). polypeptides of 28, 85 and 82 kda encoded by orfs 102, 103 and 106 respectively were visualised in maxi-cell experiments. both orf106 and orf107 are req ... | 1996 | 9116051 |
| methylobacterium mesophilicum synovitis in an alcoholic. | | 1997 | 9142814 |
| identification of a novel determinant of glutathione affinity in dichloromethane dehalogenases/glutathione s-transferases. | bacterial dichloromethane dehalogenases catalyze the glutathione-dependent hydrolysis of dichloromethane to formaldehyde and are members of the enzyme superfamily of glutathione s-transferases involved in the detoxification of electrophilic compounds. numerous protein engineering studies have addressed questions pertaining to the substrate specificity, the reaction mechanism, and the kinetic pathway of glutathione s-transferases. in contrast, the molecular determinants for binding of the glutath ... | 1997 | 9299530 |
| cloning and analysis of methanol oxidation genes in the methylotroph hyphomicrobium methylovorum gm2. | the gene encoding the alpha-subunit of methanol dehydrogenase (mxaf) and its flanking region was isolated from a methylotrophic bacterium, hyphomicrobium methylovorum gm2. the deduced amino acid sequence of mxaf showed 80, 80, 74 and 66% identity with those of methylobacterium extorquens am1, m. organophilum xx, paracoccus denitrificans and methylophilus methylotrophus, respectively. the putative mxaf promoter sequence (-35 -aaagaca-, -10 -tagaa-) observed in other methylotrophs was not found in ... | 1997 | 9311140 |
| a novel pink-pigmented facultative methylotroph, methylobacterium thiocyanatum sp. nov., capable of growth on thiocyanate or cyanate as sole nitrogen sources. | the isolation and properties of a novel species of pink-pigmented methylotroph, methylobacterium thiocyanatum, are described. this organism satisfied all the morphological, biochemical, and growth-substrate criteria to be placed in the genus methylobacterium. sequencing of the gene encoding its 16s rrna confirmed its position in this genus, with its closest phylogenetic relatives being m. rhodesianum, m. zatmanii and m. extorquens, from which it differed in its ability to grow on several diagnos ... | 1998 | 9446686 |
| sequence and characterization of mxab, a response regulator involved in regulation of methanol oxidation, and of mxaw, a methanol-regulated gene in methylobacterium extorquens am1. | in the facultative serine cycle methylotroph methylobacterium extorquens am1, mxab is required for regulation of methanol oxidation and is located at the end of a large cluster of methylotrophy genes that begins with mxaf. the sequence of mxab has been obtained and indicates that the gene product is a member of the response regulator family. none of the open reading frames near mxab showed sequence identity to sensor kinases. complementation studies suggest a promoter may be located adjacent to ... | 1998 | 9495022 |
| c1 transfer enzymes and coenzymes linking methylotrophic bacteria and methanogenic archaea. | methanogenic and sulfate-reducing archaea are considered to have an energy metabolism involving c1 transfer coenzymes and enzymes unique for this group of strictly anaerobic microorganisms. an aerobic methylotrophic bacterium, methylobacterium extorquens am1, was found to contain a cluster of genes that are predicted to encode some of these enzymes and was shown to contain two of the enzyme activities and one of the methanogenic coenzymes. insertion mutants were all unable to grow on c1 compound ... | 1998 | 9651254 |
| free energy for blue copper protein unfolding determined by electrospray ionisation mass spectrometry. | an electrospray ionisation (esi) mass spectrometric method for the determination of the free energy (deltag) of unfolding of proteins is described. the method was tested using three blue copper proteins: wild type azurin, cys-3ala/cys-26ala (c3a/c26a) azurin mutant and wild-type amicyanin. the time course of the denaturation process of the proteins dissolved in methanol/water (50:50, v/v, ph 3.5) was followed by recording esi mass spectra at time intervals. the spectra showed two series of peaks ... | 2001 | 11565099 |
| pseudo-outbreak of mycobacterium chelonae and methylobacterium mesophilicum caused by contamination of an automated endoscopy washer. | to evaluate an unusual number of rapidly growing acid-fast bacilli, later identified as mycobacterium chelonae, and pink bacteria, later identified as methylobacterium mesophilicum, from fungal cultures obtained by bronchoscopy. | 2001 | 11583208 |
| [ecological consequences of radioactive pollution for soil bacteria within the 10-km region around the chernobyl atomic energy station]. | the diversity of aerobic chemoorganotrophic (capable of growing on nutrient agar) bacteria in radioactive soil (0.3-17.0 microci/kg soil) sampled in the 10-km zone around the chernobyl nuclear power plant (cnpp) was found to be lower than that observed in control, uncontaminated soil with a radioactivity of 0.002-0.006 microci/kg soil. all the radioactive soil samples contained the bacteria bacillus cereus and methylobacterium extorquens or m. mesophillicum, which exhibited a high tolerance to 0 ... | 1998 | 9662700 |
| isolation of bacteria and 16s rdnas from lake vostok accretion ice. | lake vostok, the largest subglacial lake in antarctica, is separated from the surface by approximately 4 km of glacial ice. it has been isolated from direct surface input for at least 420 000 years, and the possibility of a novel environment and ecosystem therefore exists. lake vostok water has not been sampled, but an ice core has been recovered that extends into the ice accreted below glacial ice by freezing of lake vostok water. here, we report the recovery of bacterial isolates belonging to ... | 2001 | 11683867 |
| methylamine dehydrogenase. structure and function of electron transfer complexes. | | 2000 | 11192720 |
| [facultative and obligate aerobic methylobacteria synthesize cytokinins]. | the presence and expression of genes controlling the synthesis and secretion of cytokinins by the pink-pigmented facultative methylotroph methylobacterium mesophilicum vkm b-2143 with the serine pathway and nonpigmented obligate methylotroph methylovorus mays vkm b-2221 with the ribulose monophosphate pathway of c1 metabolism were shown using the polymerase chain reaction (pcr) and reverse transcription-pcr methods. the presence of the corresponding mrna in m. mesophilicum cells grown on methano ... | 2000 | 11195573 |
| duplicate copies of genes encoding methanesulfonate monooxygenase in marinosulfonomonas methylotropha strain tr3 and detection of methanesulfonate utilizers in the environment. | marinosulfonomonas methylotropha strain tr3 is a marine methylotroph that uses methanesulfonic acid (msa) as a sole carbon and energy source. the genes from m. methylotropha strain tr3 encoding methanesulfonate monooxygenase, the enzyme responsible for the initial oxidation of msa to formaldehyde and sulfite, were cloned and sequenced. they were located on two gene clusters on the chromosome of this bacterium. a 5.0-kbp hindiii fragment contained msma, msmb, and msmc, encoding the large and smal ... | 2002 | 11772638 |
| [aerobic methylotroph bacteria as phytosymbionts]. | this paper deals with the physiological, biochemical, and molecular genetic aspects of the interaction of aerobic methylotrophic bacteria with plants by means of phytohormones (such as cytokinins and auxins) and other physiologically active substances (vitamins, exopolysaccharides, bioprotectants). the state of the art and the prospects of research in the field of bacteria-plant interactions and the application of aerobic methylotrophs in plant biotechnology is discussed. | 2001 | 11785128 |
| discordant carbapenem susceptibility in methylobacterium species and its application as a method for phenotypic identification. | | 2001 | 11388170 |
| structural heterogeneity of blue copper proteins: an epr study of amicyanin and of wild-type and cys3ala/cys26ala mutant azurin. | a comparative investigation of the effects of cooling rate and solvent physicochemical properties on the structural heterogeneity of wild-type and disulfide bond depleted azurin (cys3ala/cys26ala) and of amicyanin has been performed by epr spectroscopy and computer simulation. by describing the spectral features of the epr spectra in terms of gaussian distributions of the components of the g and a tensors of the spin hamiltonian, we have shown that either the cooling rate or the solvent composit ... | 2001 | 11508836 |
| molecular basis for interprotein complex-dependent effects on the redox properties of amicyanin. | the quinoprotein methylamine dehydrogenase (madh), type i copper protein amicyanin, and cytochrome c-551i form a complex within which interprotein electron transfer occurs. it was known that complex formation significantly lowered the oxidation-reduction midpoint potential (em) value of amicyanin, which facilitated an otherwise thermodynamically unfavorable electron transfer to cytochrome c-551i. structural, mutagenesis, and potentiometric studies have elucidated the basis for this complex-depen ... | 1998 | 9860825 |
| methylobacterium bacteremia in aids. | | 1998 | 11864300 |
| glyoxylate regeneration pathway in the methylotroph methylobacterium extorquens am1. | most serine cycle methylotrophic bacteria lack isocitrate lyase and convert acetyl coenzyme a (acetyl-coa) to glyoxylate via a novel pathway thought to involve butyryl-coa and propionyl-coa as intermediates. in this study we have used a genome analysis approach followed by mutation to test a number of genes for involvement in this novel pathway. we show that methylmalonyl-coa mutase, an r-specific crotonase, isobutyryl-coa dehydrogenase, and a gtpase are involved in glyoxylate regeneration. we a ... | 2002 | 11872727 |
| plants in the pink: cytokinin production by methylobacterium. | | 2002 | 11889085 |
| trna is the source of low-level trans-zeatin production in methylobacterium spp. | pink-pigmented facultatively methylotrophic bacteria (ppfms), classified as methylobacterium spp., are persistent colonizers of plant leaf surfaces. reports of ppfm-plant dialogue led us to examine cytokinin production by ppfms. using immunoaffinity and high-performance liquid chromatography (hplc) purification, we obtained 22 to 111 ng of trans-zeatin per liter from culture filtrates of four ppfm leaf isolates (from arabidopsis, barley, maize, and soybean) and of a methylobacterium extorquens t ... | 2002 | 11889088 |
| quantum chemical calculations of the reorganization energy of blue-copper proteins. | the inner-sphere reorganization energy for several copper complexes related to the active site in blue-copper protein has been calculated with the density functional b3lyp method. the best model of the blue-copper proteins, cu(im)2(sch3)(s(ch3)2)(0/+), has a self-exchange inner-sphere reorganization energy of 62 kj/mol, which is at least 120 kj/mol lower than for cu(h2o)4(+/2+). this lowering of the reorganization energy is caused by the soft ligands in the blue-copper site, especially the cyste ... | 1998 | 9865961 |
| an outer-sphere hydrogen-bond network constrains copper coordination in blue proteins. | in azurins and other blue copper proteins with relatively low reduction potentials (e(0) [cu(ii)/cu(i)]<400 mv vs. normal hydrogen electrode), the folded polypeptide framework constrains both copper(ii) and copper(i) in such a way as to tune the reduction potentials to values that differ greatly from those for most copper complexes. largely conserved networks of hydrogen bonds organize and lock the rest of the folded protein structure to a loop that contains three of the ligands to copper. chang ... | 2002 | 11897353 |
| the biochemistry, physiology and genetics of pqq and pqq-containing enzymes. | pyrrolo-quinoline quinone (pqq) is the non-covalently bound prosthetic group of many quinoproteins catalysing reactions in the periplasm of gram-negative bacteria. most of these involve the oxidation of alcohols or aldose sugars. pqq is formed by fusion of glutamate and tyrosine, but details of the biosynthetic pathway are not known; a polypeptide precursor in the cytoplasm is probably involved, the completed pqq being transported into the periplasm. in addition to the soluble methanol dehydroge ... | 1998 | 9889976 |
| [new evidence for the ability of methylobacteria and methanotrophs to synthesize auxins]. | | 2002 | 11910802 |
| methylamine dehydrogenase: structure and function of electron transfer complexes. | | 1999 | 10093734 |
| identification of a new reaction intermediate in the oxidation of methylamine dehydrogenase by amicyanin. | the two-electron oxidation of tryptophan tryptophylquinone (ttq) in substrate-reduced methylamine dehydrogenase (madh) by amicyanin is known to proceed via an n-semiquinone intermediate in which the substrate-derived amino group remains covalently attached to ttq [bishop, g. r., and davidson, v. l. (1996) biochemistry 35, 8948-8954]. a new method for the stoichiometric formation of the n-semiquinone in vitro has allowed the study of the oxidation of the n-semiquinone by amicyanin in greater deta ... | 1999 | 10200175 |
| a methenyl tetrahydromethanopterin cyclohydrolase and a methenyl tetrahydrofolate cyclohydrolase in methylobacterium extorquens am1. | recently it was found that methylobacterium extorquens am1 contains both tetrahydromethanopterin (h4mpt) and tetrahydrofolate (h4f) as carriers of c1 units. in this paper we report that the aerobic methylotroph contains a methenyl h4mpt cyclohydrolase (0.9 u x mg-1 cell extract protein) and a methenyl h4f cyclohydrolase (0.23 u x mg-1). both enzymes, which were specific for their substrates, were purified and characterized and the encoding genes identified via the n-terminal amino acid sequence. ... | 1999 | 10215859 |
| [ethanol formation by methane-utilizing bacteria at ethane co-metabolism]. | it was established, that edta (1.0 mm) and formamide (100 mm) are inhibitors of methanol dehydrogenase in methylobacter luteus 12b, methylomonas rubra 15sh and methylococcus thermophilus 111p. the investigated strains co-metabolised ethane with the use of formate as the co-substrate. the application of formamide (or edta) as inhibitors of methanol dehydrogenase prevented from further transformation of ethanol and resulted in accumulation of extracellular ethanol. it was shown, that m. rubra 15sh ... | 2002 | 11944346 |
| a new molecular mechanics force field for the oxidized form of blue copper proteins. | a molecular mechanics force field for blue copper proteins has been developed, based on a rigid potential energy surface scan of the cu(ii)/his/his/cys/met chromophore, using dft (b3lyp) calculations and the amber force field for the protein backbone. the strain-energy-minimized structures of the model chromophore alone are in excellent agreement with the dft-optimized structure, and those of the entire set of cupredoxins (five structures are considered) are, within the experimental error limits ... | 2002 | 11948587 |
| electronic excitations of biomolecules studied by quantum chemistry. | significant methodological advances have been made over the past ten years in developing reliable quantum chemical methods for the treatment of electronically excited states. these methods can nowadays be used routinely by the experienced researcher to accurately compute excitation spectra of medium-sized organic molecules; results have been reported for several popular photobiological systems, including green fluorescent protein. first steps are currently being taken to account for the solvochr ... | 2002 | 11959493 |
| population dynamics of type i and ii methanotrophic bacteria in rice soils. | methane-oxidizing bacteria (methanotrophs) consume a significant but variable fraction of greenhouse-active methane gas produced in wetlands and rice paddies before it can be emitted to the atmosphere. temporal and spatial dynamics of methanotroph populations in california rice paddies were quantified using phospholipid biomarker analyses in order to evaluate the relative importance of type i and type ii methanotrophs with depth and in relation to rice roots. methanotroph population fluctuations ... | 2002 | 12000315 |
| the molecular structure of an unusual cytochrome c2 determined at 2.0 a; the cytochrome ch from methylobacterium extorquens. | cytochrome ch is the electron donor to the oxidase in methylotrophic bacteria. its amino acid sequence suggests that it is a typical class 1 cytochrome c, but some features of the sequence indicated that its structure might be of special interest. the structure of oxidized cytochrome ch has been solved to 2.0 a resolution by x-ray diffraction. it has the classical tertiary structure of the class 1 cytochromes c but bears a closer gross resemblance to mitochondrial cytochrome c than to the bacter ... | 1999 | 10386873 |
| [methanotrophic communities in the soils of russian northern taiga and subarctic tundra]. | the pcr analysis of dna extracted from soil samples taken in russian northern taiga and subarctic tundra showed that the dna extracts contain genes specific to methanotrophic bacteria, i.e., the mmox gene encoding the conserved alpha-subunit of the hydroxylase component of soluble methane monooxygenase, the pmoa gene encoding the alpha-subunit of particulate methane monooxygenase, and the mxaf gene encoding the alpha-subunit of methanol dehydrogenase. pcr analysis with group-specific primers als ... | 2002 | 12024830 |
| methylobacterium suomiense sp. nov. and methylobacterium lusitanum sp. nov., aerobic, pink-pigmented, facultatively methylotrophic bacteria. | two aerobic, pink-pigmented, facultatively methylotrophic bacteria, strains f20t and rxm(t), are described taxonomically. on the basis of their phenotypic and genotypic properties, the isolates are proposed as novel species of the genus methylobacterium, methylobacterium suomiense sp. nov. (type strain f20t = vkm b-2238t = ncimb 13778t) and methylobacterium lusitanum sp. nov. (type strain rxmt = vkm b-2239t = ncimb 13779t). | 2002 | 12054237 |
| protein strain in blue copper proteins studied by free energy perturbations. | free energy perturbations have been performed on two blue copper proteins, plastocyanin and nitrite reductase. by changing the copper coordination geometry, force constants, and charges, we have estimated the maximum energy with which the proteins may distort the copper coordination sphere. by comparing this energy with the quantum chemical energy cost for the same perturbation on the isolated copper complex, various hypotheses about protein strain have been tested. the calculations show that th ... | 1999 | 10398364 |
| chloromethane-induced genes define a third c1 utilization pathway in methylobacterium chloromethanicum cm4. | methylobacterium chloromethanicum cm4 is an aerobic alpha-proteobacterium capable of growth with chloromethane as the sole carbon and energy source. two proteins, cmua and cmub, were previously purified and shown to catalyze the dehalogenation of chloromethane and the vitamin b12-mediated transfer of the methyl group of chloromethane to tetrahydrofolate. three genes located near cmua and cmub, designated metf, fold and puru and encoding homologs of methylene tetrahydrofolate (methylene-h4folate) ... | 2002 | 12057941 |
| the occurrence and persistence of mixed biofilms in automobile air conditioning systems. | twelve automobile air conditioner systems from six manufacturers and three countries, selected mostly because of complaints of unpleasant odors in the passenger compartment, were examined for microbial growth by direct microscopy and enrichment culture. mixed populations of fungi and bacteria (with occasional protozoa) were observed in biofilms in at least some of the components from all used units. the aluminum heat exchanger fins from ten evaporators demonstrated bacterial biofilms that yielde ... | 1999 | 10441727 |
| selection of microbial consortia for treating metal-working fluids. | the aim of this research was to determine the effectiveness of a strategy for constructing microbial consortia for treating chemically mixed industrial effluent, based on a more thorough understanding of communities within waste metal-working fluids (mwfs). complementary phenotypic and genotypic methods revealed that the microbial communities in spent mwfs had low diversity and were very similar in species composition in samples originating from different locations and uses. of 65 bacterial isol ... | 2002 | 12080423 |
| generation of formate by the formyltransferase/hydrolase complex (fhc) from methylobacterium extorquens am1. | methylobacterium extorquens am1 possesses a formyltransferase (ftr) complex that is essential for growth in the presence of methanol and involved in formaldehyde oxidation to co(2). one of the subunits of the complex carries the catalytic site for transfer of the formyl group from tetrahydromethanopterin to methanofuran (mfr). we now found via nuclear magnetic resonance-based studies that the ftr complex also catalyzes the hydrolysis of formyl-mfr and generates formate. the enzyme was therefore ... | 2002 | 12123819 |
| purification, overproduction, and partial characterization of beta-rfap synthase, a key enzyme in the methanopterin biosynthesis pathway. | methanopterin is a folate analog involved in the c1 metabolism of methanogenic archaea, sulfate-reducing archaea, and methylotrophic bacteria. although a pathway for methanopterin biosynthesis has been described in methanogens, little is known about the enzymes and genes involved in the biosynthetic pathway. the enzyme beta-ribofuranosylaminobenzene 5'-phosphate synthase (beta-rfap synthase) catalyzes the first unique step to be identified in the pathway of methanopterin biosynthesis, namely, th ... | 2002 | 12142414 |
| properties of the methylcobalamin:h4folate methyltransferase involved in chloromethane utilization by methylobacterium sp. strain cm4. | methylobacterium sp. strain cm4 is a strictly aerobic methylotrophic proteobacterium growing with chloromethane as the sole carbon and energy source. genetic evidence and measurements of enzyme activity in cell-free extracts have suggested a multistep pathway for the conversion of chloromethane to formate. the postulated pathway is initiated by a corrinoid-dependent methyltransferase system involving methyltransferase i (cmua) and methyltransferase ii (cmub), which transfer the methyl group of c ... | 1999 | 10447694 |
| structure of methylene-tetrahydromethanopterin dehydrogenase from methylobacterium extorquens am1. | nadp-dependent methylene-h(4)mpt dehydrogenase, mtda, from methylobacterium extorquens am1 catalyzes the dehydrogenation of methylene-tetrahydromethanopterin and methylene-tetrahydrofolate with nadp(+) as cosubstrate. the x-ray structure of mtda with and without nadp bound was established at 1.9 a resolution. the enzyme is present as a homotrimer. the alpha,beta fold of the monomer is related to that of methylene-h(4)f dehydrogenases, suggesting a common evolutionary origin. the position of the ... | 2002 | 12176390 |
| diversity of endophytic bacterial populations and their interaction with xylella fastidiosa in citrus plants. | citrus variegated chlorosis (cvc) is caused by xylella fastidiosa, a phytopathogenic bacterium that can infect all citrus sinensis cultivars. the endophytic bacterial communities of healthy, resistant, and cvc-affected citrus plants were studied by using cultivation as well as cultivation-independent techniques. the endophytic communities were assessed in surface-disinfected citrus branches by plating and denaturing gradient gel electrophoresis (dgge). dominant isolates were characterized by fat ... | 2002 | 12324338 |
| purification and characterization of methylmalonyl-coa mutase from a methanol-utilizing bacterium, methylobacterium extorquens nr-1. | high activity (about 50 mu x mg protein(-1)) of methylmalonyl-coa mutase (82-95% apo-enzyme) was constantly found during the cell growth of a methanol-utilizing bacterium, methylobacterium extorquens nr-1. the apo-enzyme was purified to homogeneity and characterized. the purified enzyme was colorless. an apparent mr of m. extorquens nr-1 enzyme was calculated to be 150,000 +/- 5,000 by superdex 200 hr gel filtration. sds-polyacrylamide gel electrophoresis of the purified enzyme gave two protein ... | 2002 | 12350084 |
| tetraponera ants have gut symbionts related to nitrogen-fixing root-nodule bacteria. | some tetraponera ants (formicidae, pseudomyrmecinae) subsist almost entirely on amino acid deficient honeydew secretions of pseudococcids and harbour a dense aggregation of bacterial symbionts in a unique pouch-shaped organ at the junction of the midgut and the intestine. the organ is surrounded by a network of intruding tracheae and malpighian tubules, suggesting that these bacteria are involved in the oxidative recycling of nitrogen-rich metabolic waste. we have examined the ultrastructure of ... | 2002 | 12396501 |
| poly-beta-hydroxybutyrate biosynthesis in the facultative methylotroph methylobacterium extorquens am1: identification and mutation of gap11, gap20, and phar. | methylobacterium extorquens am1, a serine cycle facultative methylotroph, accumulates poly-beta-hydroxybutyrate (phb) as a carbon and energy reserve material during growth on both multicarbon- and single-carbon substrates. recently, the identification and mutation of the genes involved in the biosynthesis and degradation of phb have been described for this bacterium, demonstrating that two of the genes of the phb cycle (phaa and phab) are also involved in c(1) and c(2) metabolism, as part of a n ... | 2002 | 12399487 |
| paramagnetic nmr investigations of co(ii) and ni(ii) amicyanin. | the paramagnetic 1h nmr spectra of the co(ii) and ni(ii) substituted forms of the type 1 blue copper protein (cupredoxin) amicyanin have been assigned. this is the first such analysis of a cupredoxin, which has a distorted tetrahedral active site with the ligands provided by two histidines, a cysteine and a methionine. the isotropic shifts of the resonances in these spectra are compared with those of co(ii) and ni(ii) azurin. a number of interesting similarities and differences are found. the co ... | 1999 | 10555580 |
| characterization of pigmented methylotrophic bacteria which nodulate lotononis bainesii. | root nodule isolates from a shrubby legume, lotononis bainesii, were characterized by 16s rrna gene sequencing and morphologically by substrate utilization patterns. the symbiotic genome of these isolates was analysed by partial sequencing of the nifh gene. based on the results of numerical taxonomy, the isolates formed a closely related cluster, showing no correspondence to any of the known rhizobial clusters. analysis of nearly full-length 16s rdna sequences demonstrated that these isolates we ... | 2002 | 12421082 |
| mutation of alphaphe55 of methylamine dehydrogenase alters the reorganization energy and electronic coupling for its electron transfer reaction with amicyanin. | methylamine dehydrogenase (madh) possesses an alpha(2)beta(2) structure with each smaller beta subunit possessing a tryptophan tryptophylquinone (ttq) prosthetic group. phe55 of the alpha subunit is located where the substrate channel from the enzyme surface opens into the active site. site-directed mutagenesis of alphaphe55 has revealed roles for this residue in determining substrate specificity and binding monovalent cations at the active site. it is now shown that the alphaf55a mutation also ... | 2002 | 12437349 |
| pqqc/d, which converts a biosynthetic intermediate to pyrroloquinoline quinone. | pqqc/d was purified from escherichia coli transformant. the purified enzyme converted an intermediate that accumulated in a pqqc mutant of methylobacterium extorquens am1 to pqq. the reaction did not show any dependence of nad(p)h that was observed in the crude extract before purification. pqqc/d reacted with the intermediate stoichiometrically, but not catalytically. when partially purified proteins from the crude extract of e. coli were added to the reaction mixture, the rate of pqq production ... | 2002 | 12437981 |
| molecular analyses of novel methanotrophic communities in forest soil that oxidize atmospheric methane. | forest and other upland soils are important sinks for atmospheric ch(4), consuming 20 to 60 tg of ch(4) per year. consumption of atmospheric ch(4) by soil is a microbiological process. however, little is known about the methanotrophic bacterial community in forest soils. we measured vertical profiles of atmospheric ch(4) oxidation rates in a german forest soil and characterized the methanotrophic populations by pcr and denaturing gradient gel electrophoresis (dgge) with primer sets targeting the ... | 2000 | 10788342 |
| detection and classification of atmospheric methane oxidizing bacteria in soil. | well-drained non-agricultural soils mediate the oxidation of methane directly from the atmosphere, contributing 5 to 10% towards the global methane sink. studies of methane oxidation kinetics in soil infer the activity of two methanotrophic populations: one that is only active at high methane concentrations (low affinity) and another that tolerates atmospheric levels of methane (high affinity). the activity of the latter has not been demonstrated by cultured laboratory strains of methanotrophs, ... | 2000 | 10821271 |
| [utilization of methane and carbon dioxide by symbiotrophic bacteria in gills of mytilidae (bathymodiolus) from the rainbow and logachev hydrothermal fields on the mid-atlantic ridge]. | bivalve mollusks bathymodiolus asoricus and bathymodiolus puteoserpentis collected from the rainbow and logachev hydrothermal fields during dives of mir 1 and mir 2 deep-sea manned submersibles were studied. rates of methane oxidation and carbon dioxide assimilation in mussel gill tissue were determined by radiolabel analysis. during oxidation of 14ch4, radiocarbon was detected in significant quantities not only in carbon dioxide but also in dissolved organic matter, most notably 14c-formate and ... | 2002 | 12449636 |
| a direct-method ab initio phasing of a protein, cupredoxin amicyanin, at 1.31 a resolution. | the direct-methods program multan88 has been applied successfully to redetermine the structure of a protein, cupredoxin amicyanin, containing 808 non-h atom sites, one cu atom and 132 ordered water molecules in the asymmetric unit using data at 1.31 a resolution. starting with initially random phases, useful phase sets selected by figures of merit could be obtained from multiple trials. the e maps corresponding to the best eight phase sets in order of combined figures of merit (cfom2) revealed a ... | 2001 | 11526319 |
| thermodynamics of the acid transition in blue copper proteins. | the thermodynamic parameters of the conformational transition occurring at low ph (acid transition, at) in blue copper proteins, involving protonation and detachment from the cu(i) ion of one histidine ligand, have been determined electrochemically for spinach and cucumber plastocyanins, rhus vernicifera stellacyanin, cucumber basic protein (cbp), and paracoccus versutus amicyanin. these data were obtained from direct protein electrochemistry experiments carried out at varying ph and temperature ... | 2002 | 12450394 |
| a methylobacterium-like organism from algal crusts covering silicone rubber electric insulators in africa. | the primary goals of this study were to isolate, identify and characterize culturable bacteria living in a close association with microalgae within green crusts covering silicone rubber electric insulators in tanzania. | 2002 | 12452957 |
| metal-ligand interactions in perturbed blue copper sites: a paramagnetic (1)h nmr study of co(ii)-pseudoazurin. | pseudoazurin is an electron transfer copper protein, a member of the cupredoxin family. the protein is frequently found in denitrifying bacteria, where it is the electron donor of nitrite reductase. the copper at the active site is coordinated to his40, cys78, his81 and met86 in a distorted tetragonal geometry. we have recorded and assigned the (1)h nmr spectra of co(ii)-substituted pseudoazurin from achromobacter cycloclastes. the (1)h nmr spectrum of co(ii)-pseudoazurin closely resembles that ... | 2003 | 12459901 |
| overexpression of a heterologous protein, haloalkane dehalogenase, in a poly-beta-hydroxybutyrate-deficient strain of the facultative methylotroph methylobacterium extorquens am1. | using an expression vector containing p(mxaf'), a strong native promoter, expression of a model heterologous protein, haloalkane dehalogenase, from xanthobacter autotrophicus gj10 was achieved in the methylotrophic bacterium, methylobacterium extorquens am1. although expression using the wild-type strain was <5% of total cell protein, expression at a level of 10% of the total cell protein was achieved in a mutant unable to synthesize poly-beta-hydroxybutyrate granules. two other tested heterolog ... | 2003 | 12474248 |
| characterization of the formyltransferase from methylobacterium extorquens am1. | methylobacterium extorquens am1 possesses a formaldehyde-oxidation pathway that involves enzymes with high sequence identity with enzymes from methanogenic and sulfate-reducing archaea. here we describe the purification and characterization of formylmethanofuran-tetrahydromethanopterin formyltransferase (ftr), which catalyzes the reversible formation of formylmethanofuran (formylmfr) and tetrahydromethanopterin (h4mpt) from n5-formylh4mpt and methanofuran (mfr). formyltransferase from m. extorqu ... | 2001 | 11532013 |
| identification of the methylhopanes in sediments and petroleum. | three c31 methylhopanes have been prepared by partial synthesis from appropriate diplopterol precursors. 2 alpha-methyldiplopterol (prepared from 22-hydroxyhopan-3-one), 2 beta-methyldiplopterol (isolated from methylobacterium organophilum), and a mixture of diplopterol and 3 beta-methyldiplopterol (isolated from methylococcus capsulatus) were each converted to the corresponding 17 alpha(h), 21 beta(h)-hopane. comparison of these standards, using gas chromatography--mass spectrometry with mult ... | 1990 | 11537193 |
| novel methylotrophy genes of methylobacterium extorquens am1 identified by using transposon mutagenesis including a putative dihydromethanopterin reductase. | ten novel methylotrophy genes of the facultative methylotroph methylobacterium extorquens am1 were identified from a transposon mutagenesis screen. one of these genes encodes a product having identity with dihydrofolate reductase (dhfr). this mutant has a c(1)-defective and methanol-sensitive phenotype that has previously only been observed for strains defective in tetrahydromethanopterin (h(4)mpt)-dependent formaldehyde oxidation. these results suggest that this gene, dmra, may encode dihydrome ... | 2003 | 12511515 |
| qscr, a lysr-type transcriptional regulator and cbbr homolog, is involved in regulation of the serine cycle genes in methylobacterium extorquens am1. | a new gene, qscr, encoding a lysr-type transcriptional regulator that is a homolog of cbbr, has been characterized from the facultative methylotroph methylobacterium extorquens am1 and shown to be the major regulator of the serine cycle, the specific c1 assimilation pathway. the qscr mutant was shown to be unable to grow on c1 compounds, and it lacked the activity of serine-glyoxylate aminotransferase, a key enzyme of the serine cycle. activities of other serine cycle enzymes were decreased duri ... | 2003 | 12562792 |
| [microbial destruction of harmful organic contaminants inherent to atmosphere of living space]. | the investigation into the microbial destruction of harmful organic contaminants in the air of habitable rooms was performed with the assumption that microorganisms have labile metabolism and synthesize inducible enzymes involved in transformation of organics compounds. based on our observations, methylobacterium d-08 and arthrobacter pastens are able to synthesize inducible enzymes and transform ethanol, acetic acid, acetone, and aldehyde. association of these microorganisms does not reveal acu ... | 2002 | 12572127 |
| effects of engineering uphill electron transfer into the methylamine dehydrogenase-amicyanin-cytochrome c-551i complex. | within the methylamine dehydrogenase-amicyanin-cytochrome c-551i complex, electrons are transferred from tryptophan tryptophylquinone (ttq) to heme via the type i copper center of amicyanin. mutation of pro94 of amicyanin to phe increases the redox potential of the copper center within the protein complex by approximately 195 mv. this introduces a large energy barrier for the second electron transfer (et) step in this three-protein et chain. as a consequence of this mutation, the et rate from tt ... | 2003 | 12578392 |
| the tungsten-containing formate dehydrogenase from methylobacterium extorquens am1: purification and properties. | nad-dependent formate dehydrogenase (fdh1) was isolated from the alpha-proteobacterium methylobacterium extorquens am1 under oxic conditions. the enzyme was found to be a heterodimer of two subunits (alpha1beta1) of 107 and 61 kda, respectively. the purified enzyme contained per mol enzyme approximately 5 mol nonheme iron and acid-labile sulfur, 0.6 mol noncovalently bound fmn, and approximately 1.8 mol tungsten. the genes encoding the two subunits of fdh1 were identified on the m. extorquens am ... | 2003 | 12605683 |
| evidence for substrate activation of electron transfer from methylamine dehydrogenase to amicyanin. | electron transfer (et) from methylamine dehydrogenase (madh) to amicyanin may be true or gated et, depending upon the redox form of madh. et from the substrate-reduced aminoquinol form of madh is gated, and the reaction rate is dependent on the presence of monovalent cations. this et reaction has been studied in buffer free of monovalent cations. the reaction rate is orders of magnitude less than with saturating concentrations of monovalent cation. analysis of the temperature dependence of this ... | 2003 | 12630872 |
| reconstruction of c(3) and c(4) metabolism in methylobacterium extorquens am1 using transposon mutagenesis. | the growth of methylobacterium extorquens am1 on c(1) compounds has been well-studied, but little is known about how this methylotroph grows on multicarbon compounds. a tn5 transposon mutagenesis procedure was performed to identify genes involved in the growth of m. extorquens am1 on succinate and pyruvate. of the 15000 insertion colonies screened, 71 mutants were found that grew on methanol but either grew slowly or were unable to grow on one or both of the multicarbon substrates. for each of t ... | 2003 | 12634329 |
| [growth of mesophilic methanotrophs at low temperatures]. | the optimal growth of mesophilic methanotrophic bacteria (collection strains of the genera methylocystis, methylomonas, methylosinus, and methylobacter) occurred within temperature ranges of 31-34 degrees c and 23-25 degrees c. none of the strains studied were able to grow at 1.5 or 4 degrees c. representatives of six methanotrophic species (strains mcs. echinoides 2, mm. methanica 12, mb. bovis 89, mcs. pyriformis 14, mb. chroococcum 90, and mb. vinelandii 87) could grow at 10 degrees c (with a ... | 2001 | 11558268 |
| [aerobic methylobacteria are capable of synthesizing auxins]. | obligately and facultatively methylotrophic bacteria with different pathways of c1 metabolism were found to be able to produce auxins, particularly indole-3-acetic acid (iaa), in amounts of 3-100 micrograms/ml. indole-3-pyruvic acid and indole-3-acetamide were detected only in methylobacteria with the serine pathway of c1 metabolism, methylobacterium mesophilicum and aminobacter aminovorans. the production of auxins by methylobacteria was stimulated by the addition of tryptophan to the growth me ... | 2001 | 11558269 |
| promoters and transcripts for genes involved in methanol oxidation in methylobacterium extorquens am1. | twenty-five genes are involved in methanol oxidation to formaldehyde by the methanol dehydrogenase system in the facultative methylotroph methylobacterium extorquens am1 organized in five gene clusters. rt-pcr was used to assess the transcripts for the main gene clusters that encode methanol dehydrogenase and proteins required for its activity (mxafgjirsackldehb), and the enzymes that are required for the synthesis of the methanol dehydrogenase prosthetic group, pyrroloquinoline quinone (pqqabc/ ... | 2003 | 12686645 |
| loop-contraction mutagenesis of a type 1 copper site. | loop-contraction mutagenesis has been applied to the cupredoxin pseudoazurin to introduce the active-site loop of amicyanin. the mutation has a limited effect on the spectroscopic properties, and therefore structure, of the cupric protein. the loop contraction results in the increase of the pka for the detachable his ligand of pseudoazurin by two ph units, similar to the value as found in amicyanin. | 2003 | 12708836 |
| frozen density functional free energy simulations of redox proteins: computational studies of the reduction potential of plastocyanin and rusticyanin. | the evaluation of reduction potentials of proteins by ab initio approaches presents a major challenge for computational chemistry. this is addressed in the present investigation by reporting detailed calculations of the reduction potentials of the blue copper proteins plastocyanin and rusticyanin using the qm/mm all-atom frozen density functional theory, fdft, method. the relevant ab initio free energies are evaluated by using a classical reference potential. this approach appears to provide a g ... | 2003 | 12708852 |
| microvirga subterranea gen. nov., sp. nov., a moderate thermophile from a deep subsurface australian thermal aquifer. | a strictly aerobic bacterium, strain fail4t, was isolated from free-flowing geothermal waters of a bore (bore register no. 3768) tapping the great artesian basin of australia. the non-sporulating, gram-negative cells of strain fail4t produced light-pink colonies, were rod-shaped (1 x 1.5-4 microm) and were motile by a single polar flagellum. strain fail4t grew optimally at 41 degrees c at a ph of 7.0 and had an absolute requirement for yeast extract. the strain grew on casein hydrolysate, trypto ... | 2003 | 12710604 |
| methylotrophy in methylobacterium extorquens am1 from a genomic point of view. | | 2003 | 12730156 |
| construction of biofilms with defined internal architecture using dielectrophoresis and flocculation. | a novel approach was developed for the construction of biofilms with defined internal architecture using ac electrokinetics and flocculation. artificial structured microbial consortia (asmc) consisting of localized layered microcolonies of different cell types were formed by sequentially attracting different cell types to high field regions near microelectrodes using dielectrophoresis. stabilization of the microbial consortia on the electrode surface was achieved by crosslinking the cells using ... | 2003 | 12740931 |
| [the biology of aerobic methylobacteria capable of degrading halomethanes]. | recent data on the biology of aerobic methylotrophic bacteria capable of utilizing toxic halogenated methane derivatives as sources of carbon and energy are reviewed, with particular emphasis on the taxonomic, physiological, and biochemical diversity of mono- and dihalomethane-degrading methylobacteria and the enzymatic and genetic aspects of their primary metabolism. the initial steps of chloromethane dehalogenation to formate and hcl through a methylated corrinoid and methyletrahydrofolate are ... | 2003 | 12751236 |
| monitoring of unfolding of metallo-proteins by electrospray ionization mass spectrometry. | an electrospray ionisation (esi) mass spectrometric method for the determination of the equilibrium constant and free energy (deltag) of protein unfolding was used to monitor the denaturation process at different ph of three metallo-proteins, i.e. wild-type copper azurin, zinc azurin and wild-type amicyanin. the time course of the unfolding process was followed by dissolving the proteins under denaturing conditions (methanol-water (1 : 1, v/v)) at different ph (2.5, 3.0, 3.5) and recording esi s ... | 2003 | 12794870 |