application of thermoalkalophilic xylanase from arthrobacter sp. mtcc 5214 in biobleaching of kraft pulp.a thermoalkalophilic and cellulase-free xylanase produced from arthrobacter sp. mtcc 5214 by solid-state fermentation using wheat bran as a carbon source was evaluated for prebleaching of kraft pulp. the uv absorption spectrum of the compounds released by enzyme treatment showed a characteristic peak at 280 nm, indicating the presence of lignin in the released colouring matter. enzymatic prebleaching of kraft pulp showed 20% reduction in kappa number of the pulp without much change in viscosity. ...200716617015
screening for microbial markers in miocene sediment exposed during open-cast brown coal mining.viable microorganisms were found in miocene lacustrine clays of the cypris formation excavated from 200-m below the surface as spoil during open-cast brown coal mining (sokolov brown coal basin, north-western bohemia, czech republic). both saprotrophic microfungi of the genera penicillium, verticillium, cladosporium and aspergillus as well as heterotrophic bacteria were isolated from an intact sediment cores. heterotrophic bacteria were classified by the mis sherlock system as representatives of ...200616622790
rapid analysis of two food-borne microbial communities at the species level by fourier-transform infrared microspectroscopy.the species composition of microbial communities in natural habitats may be extremely complex and therefore a quantitative analysis of the fraction each species contributes to the consortium has proven to be difficult. during recent years, the identification of bacterial pure cultures based on their infrared spectra has been established. fourier-transform infrared microspectroscopy now proceeds a step further and allows identification of microorganisms directly plated from community dilutions. i ...200616623742
molecular identification and differentiation of brevibacterium species and strains.amplified ribosomal dna restriction enzyme analysis (ardra), pulsed field gel electrophoresis (pfge) and ribotyping were used to differentiate among 24 strains of brevibacterium linens, brevibacterium casei and brevibacterium epidermidis obtained from type culture collections or isolated from various smear ripened cheeses. ardra was applied to the 16s rdna. b. linens was shown to be a quite heterogenic group with 2 to at least 4 copies of rrn operons per strain with aberrant nucleotide sequences ...200716624515
effects of site and plant species on rhizosphere community structure as revealed by molecular analysis of microbial guilds.the bacterial and fungal rhizosphere communities of strawberry (fragaria ananassa duch.) and oilseed rape (brassica napus l.) were analysed using molecular fingerprints. we aimed to determine to what extent the structure of different microbial groups in the rhizosphere is influenced by plant species and sampling site. total community dna was extracted from bulk and rhizosphere soil taken from three sites in germany in two consecutive years. bacterial, fungal and group-specific (alphaproteobacter ...200616629753
horizontal gene transfer of pib-type atpases among bacteria isolated from radionuclide- and metal-contaminated subsurface soils.aerobic heterotrophs were isolated from subsurface soil samples obtained from the u.s. department of energy's (doe) field research center (frc) located at oak ridge, tenn. the frc represents a unique, extreme environment consisting of highly acidic soils with co-occurring heavy metals, radionuclides, and high nitrate concentrations. four hundred isolates obtained from contaminated soil were assayed for heavy metal resistance, and a smaller subset was assayed for tolerance to uranium. the vast ma ...200616672448
a single monooxygenase, ese, is involved in the metabolism of the organochlorides endosulfan and endosulfate in an arthrobacter this paper we describe isolation of a bacterium capable of degrading both isomers of the organochloride insecticide endosulfan and its toxic metabolite, endosulfate. the bacterium was isolated from a soil microbial population that was enriched with continuous pressure to use endosulfate as the sole source of sulfur. analysis of the 16s rrna sequence of the bacterium indicated that it was an arthrobacter species. the organochloride-degrading activity was not observed in the presence of sodium ...200616672499
xylose utilization and short-chain fatty acid production by selected components of the intestinal microflora of a rodent pollinator (aethomys namaquensis).namaqua rock mice (aethomys namaquensis) consume nectar xylose when visiting protea flowers. whole-animal metabolism studies suggest that the gastrointestinal microflora plays an important role in xylose metabolism in a. namaquensis. we collected caecal contents under anaerobic conditions, cultured caecal microflora both aerobically and anaerobically, and assessed caecal microbial xylose utilization using a (14)c-xylose incubation assay. all four mice sampled hosted culturable caecal micro-organ ...200616676189
final steps in the catabolism of enzymes of nicotine catabolism instrumental in the detoxification of the tobacco alkaloid by arthrobacter nicotinovorans pao1 have been identified and characterized. nicotine breakdown leads to the formation of nicotine blue from the hydroxylated pyridine ring and of gamma-n-methylaminobutyrate (ch(3)-4-aminobutyrate) from the pyrrolidine ring of the molecule. surprisingly, two alternative pathways for the final steps in the catabolism of ch(3)-4-aminobutyrate could be identified. ch(3)-4-am ...200616689938
phylogenetic diversity of culturable bacteria from alpine permafrost in the tianshan mountains, northwestern china.microbes have been discovered in permafrost sediments for nearly a century. however, microbiological analyses of alpine permafrost are very scarce. this study is a first attempt to describe the phylogenetic diversity of a culturable bacterial community isolated from alpine permafrost in the tianshan mountains in northwestern china. aerobic 2.5-6.0x10(5) cfu/gdw (cfu per 1 gram of dry weight) on modified pygv medium were recovered from alpine permafrost samples at 4 degrees c; among these, 91 bac ...200616690258
the x-ray structure of the haloalcohol dehalogenase hhea from arthrobacter sp. strain ad2: insight into enantioselectivity and halide binding in the haloalcohol dehalogenase family.haloalcohol dehalogenases are bacterial enzymes that cleave the carbon-halogen bond in short aliphatic vicinal haloalcohols, like 1-chloro-2,3-propanediol, some of which are recalcitrant environmental pollutants. they use a conserved ser-tyr-arg catalytic triad to deprotonate the haloalcohol oxygen, which attacks the halogen-bearing carbon atom, producing an epoxide and a halide ion. here, we present the x-ray structure of the haloalcohol dehalogenase hhea(ad2) from arthrobacter sp. strain ad2 a ...200616707696
on the contribution of the positively charged headgroup of choline to substrate binding and catalysis in the reaction catalyzed by choline oxidase.recent kinetic studies established that the positive charge on the trimethylammonium group of choline plays an important role in substrate binding and specificity in the reaction catalyzed by choline oxidase. in the present study, ph and solvent viscosity effects with the isosteric analogue of choline 3,3-dimethyl-butan-1-ol have been used to further dissect the contribution of the substrate positive charge to substrate binding and catalysis in the reaction catalyzed by choline oxidase. both the ...200616713988
protein engineering of a cold-active beta-galactosidase from arthrobacter sp. sb to increase lactose hydrolysis reveals new sites affecting low temperature activity.we examined variants of an especially cold-active beta-galactosidase (bgas) to better understand features affecting enzyme activity at temperature extremes. we targeted locations corresponding to a region in the lacz enzyme previously shown to increase activity and decrease thermostability. changes in this region of bgas consistently caused the elimination or reduction of activity. a gene (bgas3) encoding a loss of function variant was subjected to random mutagenesis to restore activity and disc ...200616736094
[investigation and analysis of the bacteria community in silkworm intestine].majority of the environmental microorganisms are still unculturable. to shed a light on the bacteria community in the silkworm intestine more completely, culture-dependent and culture-independent methods were used to perform the investigation. as the latter, 16s rrna gene was amplified and a library was constructed by using the meta-genomic dna extracted from the bacteria in the silkworm intestine as template. restriction fragment length polymorphism (rflp) method was used to screen recombinants ...200616736593
reclassification of arthrobacter duodecadis lochhead 1958 as tetrasphaera duodecadis comb. nov. and emended description of the genus tetrasphaera.phylogenetic analysis based on 16s rrna gene sequences and chemotaxonomic features of arthrobacter duodecadis lochhead 1958 indicated that the bacterium belonged within the genus tetrasphaera. a. duodecadis iam 14868(t) could be distinguished from other species by the presence of 3-hydroxy meso-diaminopimelic acid in the peptidoglycan and a series of 10-methyl fatty acids. in addition, dna-dna relatedness studies indicated that the strain belonged to a genomic species that could be readily disti ...200616738116
phenanthrene degradation in arthrobacter sp. p1-1: initial 1,2-, 3,4- and 9,10-dioxygenation, and meta- and ortho-cleavages of naphthalene-1,2-diol after its formation from naphthalene-1,2-dicarboxylic acid and hydroxyl naphthoic acids.arthrobacter sp. p1-1, isolated from a polycyclic aromatic hydrocarbon (pah)-contaminated site in hilo, hi, usa, can decompose phenanthrene (40 mg l(-1)) completely within 7 days. a detailed phenanthrene metabolism map was constructed based on metabolite analysis and replacement cultures. initial dioxygenation occurs on 1,2-, 3,4-, and 9,10-c of phenanthrene, dominantly on 3,4-c positions. rapid accumulation of 5,6- and 7,8-benzocoumarin suggests that phenanthrene-1,2- and -3,4-diols mainly unde ...200616777186
cloning and nucleotide sequence of carbaryl hydrolase gene (caha) from arthrobacter sp. rc100.a carbaryl hydrolase gene (caha) encoded on the plasmid prc1 in arthrobacter sp. rc100 was cloned and sequenced. the entire region of the deduced amino acid sequence was found to be homologous to that of an amidase family. parts of the consensus sequences of the amidase gene have been identified in caha from strain rc100. caha was overexpressed in escherichia coli jm109, and the enzyme was purified to homogeneity by protamine sulfate treatment, ammonium sulfate precipitation, and hydrophobic and ...200616781470
selective accumulation of light or heavy rare earth elements using gram-positive bacteria.the accumulation of samarium from a solution only containing samarium by arthrobacter nicotianae was examined. the amount of accumulated samarium was strongly affected by the concentration of samarium and ph of the solution. the accumulation of samarium by the strain was very rapid and reached equilibrium within 3h. the accumulation of samarium-europium or europium-gadolinium from the solution containing the two metals using various actinomycetes and gram-positive bacteria was also examined. mos ...200616797944
bacterial community in ancient siberian permafrost as characterized by culture and culture-independent methods.the microbial composition of ancient permafrost sediments from the kolyma lowland of northeast eurasia was examined through culture and culture-independent approaches. these sediments have been continuously frozen for 5,000 to 2-3 million years. a total of 265 bacteria 16s rrna gene sequences were amplified from the permafrost total-community genomic dna and screened by amplified ribosomal 16s rrna restriction analysis. members of three major lineages were found: gamma-proteobacteria (mostly xan ...200616805696
bacterial community structure of a pesticide-contaminated site and assessment of changes induced in community structure during bioremediation.the introduction of culture-independent molecular screening techniques, especially based on 16s rrna gene sequences, has allowed microbiologists to examine a facet of microbial diversity not necessarily reflected by the results of culturing studies. the bacterial community structure was studied for a pesticide-contaminated site that was subsequently remediated using an efficient degradative strain arthrobacter protophormiae rkj100. the efficiency of the bioremediation process was assessed by mon ...200616819955
a functional moba gene for molybdopterin cytosine dinucleotide cofactor biosynthesis is required for activity and holoenzyme assembly of the heterotrimeric nicotine dehydrogenases of arthrobacter nicotinovorans.two arthrobacter nicotinovorans molybdenum enzymes hydroxylate the pyridine ring of nicotine. molybdopterin cytosine dinucleotide (mcd) was determined to be a cofactor of these enzymes. a moba gene responsible for the formation of mcd could be identified and its function shown to be required for assembly of the heterotrimeric molybdenum enzymes.200616820521
lateral transfers of serine hydroxymethyltransferase (glya) and udp-n-acetylglucosamine enolpyruvyl transferase (mura) genes from free-living actinobacteria to the parasitic chlamydiae.the chlamydiae are important human and animal pathogens which form a phylogentically distinct lineage within the bacteria. there is evidence that some genes in these obligate intracellular parasites have undergone lateral exchange with other free-living organisms. in the present work, we describe two interesting cases of lateral gene transfer between chlamydiae and actinobacteria, which have been identified based on the shared presence of conserved inserts in two important proteins. in the enzym ...200616830093
a comparative study of the binding and inhibition of four copper-containing amine oxidases by azide: implications for the role of copper during the oxidative half-reaction.copper amine oxidases (cuaos) catalyze the oxidative deamination of primary amines operating through a ping-pong bi-bi mechanism. in this work, azide (an exogenous monodentate ligand) was used to probe the role of copper during the oxidative half-reaction of cuao catalysis. the effects of azide on both the reductive and oxidative half-reactions of pea seedling amine oxidase (psao), the recombinant human kidney diamine oxidase (rhdao), arthrobacter globiformis amine oxidase (agao), and pichia pas ...200616846222
[bacterial communities of brown and red algae from peter the great bay, the sea of japan].the structure of microbial communities of brown algae, red algae, and of the red alga gracilaria verrucosa, healthy and affected with rotten thallus, were comparatively investigated; 61 strains of heterotrophic bacteria were isolated and characterized. most of them were identified to the genus level, some vibrio spp., to the species level according to their phenotypic properties and the fatty acid composition of cellular lipids. the composition of the microflora of two species of brown algae was ...200616871810
[biosynthetic features and properties of xylose isomerases from arthrobacter nicotianae, escherichia coli, and erwinia carotovota subsp. atroseptica].the characteristics of xylose isomerase biosynthesis in the bacteria arthrobacter nicotianae bim b-5, erwinia carotovota subsp atroseptica jn42xyla, and escherichia coli hb101xyla have been studied. the bacteria formed the enzyme constitutively. out of the carbon sources studied, d-glucose and d-xylose were most favorable for the biosynthesis of xylose isomerase in e. carotovota subsp atroseptica, but the least appropriate in terms of the enzyme production efficiency in e. coli. minimum and maxi ...200616878542
multiple microbial activities for volatile organic compounds reduction by the northeast of italy, high volatile organic carbon (voc) emissions originate from small-medium companies producing furniture. in these conditions it is difficult to propose a single, efficient, and economic system to reduce pollution. among the various choices, the biofiltration method could be a good solution, because microbial populations possess multiple voc degradation potentials used to oxidize these compounds to co2. starting from the air emissions of a typical industrial wood-paintin ...200616878585
effectiveness of biodegradation of petroleum products by mixed bacterial populations in liquid medium at different ph values.the possibility of using mineral oils as a carbon source by bacteria adapted to high oil concentrations was tested in liquid media with different ph values (ph = 5, 7 and 9). two types of inocula were tested: inoculum i consisted of selected strains used in the bioremediation of oil-contaminated soils and inoculum ii contained bacteria isolated from soil samples previously bioremediated at ph = 5, 7 and 9. biodegradation was observed in all the investigated media independently of initial ph valu ...200616878607
microbial production of optically active beta-phenylalanine through stereoselective degradation of racemic beta-phenylalanine.the ability to produce (r)- or (s)-beta-phenylalanine from racemic beta-phenylalanine through stereoselective degradation was screened for. variovorax sp. jh2 and arthrobacter sp. the faculty of agriculture, kyoto university (aku) 638 were found to be potential catalysts for (r)- and (s)-beta-phenylalanine production respectively. on 192 h cultivation of variovorax sp. in medium containing 1.0% (w/v) racemic beta-phenylalanine, 0.46% (w/v) (r)-beta-phenylalanine with an enantiomeric purity of 99 ...200616880592
trzn from arthrobacter aurescens tc1 is a zinc amidohydrolase.trzn, the broad-specificity triazine hydrolase from arthrobacter and nocardioides spp., is reportedly in the amidohydrolase superfamily of metalloenzymes, but previous studies suggested that a metal was not required for activity. to help resolve that conundrum, a double chaperone expression system was used to produce multimilligram quantities of functionally folded, recombinant trzn. the trzn obtained from escherichia coli (trzn) cells cultured with increasing zinc in the growth medium showed co ...200616885454
arthrobacter sp. lipase immobilization for improvement in stability and enantioselectivity.arthrobacter sp. lipase (abl, mtcc no. 5125) is being recognized as an efficient enzyme for the resolution of drugs and their intermediates. the immobilization of abl on various matrices for its enantioselectivity, stability, and reusability has been studied. immobilization by covalent bonding on sepharose and silica afforded a maximum of 380 and 40 iu/g activity, respectively, whereas sol-gel entrapment provided a maximum of 150 iu/g activity in dry powder. the immobilized enzyme displayed exce ...200616896604
genetic diversity of dioxygenase genes in polycyclic aromatic hydrocarbon-degrading bacteria isolated from mangrove investigate the diversity of dioxygenase genes involved in polycyclic aromatic hydrocarbon (pah)-degradation, a total of 32 bacterial strains were isolated from surface mangrove sediments, from the genera mycobacterium, sphingomonas, terrabacter, sphingopyxis, sphingobium and rhodococcus. two sets of pcr primers were constructed to detect the nida-like and nahac-like sequences of the alpha subunit of the pah ring-hydroxylating dioxygenase. pcr amplified the dna fragments from all gram-positiv ...200616923069
studies on biodegradation of nicotine by arthrobacter sp. strain hf-2.a nicotine-degrading bacterium, strain hf-2, was isolated from tobacco waste-contaminated soil and identified as a member of arthrobacter sp. based on morphology, physiological tests, 16s rdna sequence and phylogenetic characteristics. at thermal denaturation test indicated that the g + c mol% of strain hf-1 was 63.5. the relationship between the growth of the isolate and the nicotine degradation suggested that strain hf-2 could utilize nicotine as sole sources of carbon, nitrogen and energy. bl ...200616923598
intramolecular electron transfer rate between active-site copper and tpq in arthrobacter globiformis amine oxidase.copper amine oxidases catalyze the oxidative deamination of primary amines operating through a ping-pong bi bi mechanism, divided into reductive and oxidative half-reactions. considerable debate still exists regarding the role of copper in the oxidative half-reaction, where o2 is reduced to h2o2. substrate-reduced amine oxidases display an equilibrium between a cu(ii) aminoquinol and a cu(i) semiquinone, with the magnitude of the equilibrium constant being dependent upon the enzyme source. the i ...200616924556
characterization of a carbohydrate epitope defined by the monoclonal antibody h185: sialic acid o-acetylation on epithelial cell-surface mucins.sialic acids comprise a large family of derivatives of neuraminic acid containing methyl, acetyl, sulfate, and phosphate among other groups, which confer specific physicochemical properties (e.g., hydrophobicity and resistance to hydrolases) to the molecules carrying them. several years ago, a monoclonal antibody, designated h185, was developed, which binds to cell membranes of human corneal, conjunctival, laryngeal, and vaginal epithelia and whose distribution is altered on the ocular surface o ...200616940404
changes of bacterial diversity and main flora in chilled pork during storage using pcr-dgge.this study was designed to explore the bacterial diversity and the main flora in chilled pork by polymerase chain reaction-denaturing gradient gel electrophoresis (pcr-dgge). longissimus muscle was removed from pork carcasses at 24 h postmortem. the muscle was tray- and vacuum-packaged at 4 degrees c for 2, 4, 7 days to extract the bacteria total dna, respectively. the results indicated that the bacterial diversity of chilled pork decreased with storage time regardless of packaging method. nine ...200616943058
biotransformation of isoeugenol to vanillin by pseudomonas putida ie27 cells.the ability to produce vanillin and/or vanillic acid from isoeugenol was screened using resting cells of various bacteria. the vanillin- and/or vanillic-acid-producing activities were observed in strains belonging to the genera achromobacter, aeromonas, agrobacerium, alcaligenes, arthrobacter, bacillus, micrococcus, pseudomonas, rhodobacter, and rhodococcus. strain ie27, a soil isolate showing the highest vanillin-producing activity, was identified as pseudomonas putida. we optimized the culture ...200716944125
mutational analysis of 6-aminohexanoate-dimer hydrolase: relationship between nylon oligomer hydrolytic and esterolytic activities.carboxylesterase (eii') from arthrobacter sp. ki72 has 88% homology to 6-aminohexanoate-dimer hydrolase (eii) and possesses ca. 0.5% of the level of 6-aminohexanoate-linear dimer (ald)-hydrolytic activity of eii. to study relationship between ald-hydrolytic and esterolytic activities, random mutations were introduced into the gene for hyb-24 (an eii/eii' hybrid with the majority of the sequence deriving for eii' and possessing an eii'-like level of ald-hydrolytic activity). either a g181d or a d ...200616949580
chromium(v) complexes generated in arthrobacter oxydans by simulation analysis of epr spectra.chromium(v) is an intermediate formed during the reduction of cr(vi) to cr(iii) compounds by various bacteria. however, little is known about the nature, localization and reactivity of cr(v) species in microbial systems. electron paramagnetic resonance (epr) spectroscopy was used to study the nature of cr(v) complexes generated in basalt-inhabiting gram-positive arthrobacter oxydans bacteria after exposure to high concentrations of cr(vi). numerical simulations of the epr spectroscopic data prov ...200616959323
characterization of bacterial isolates from industrial wastewater according to probable modes of hexadecane uptake.bacterial isolates from industrial wastewater were characterized according to probable modes of hexadecane uptake based on data for cell surface hydrophobicity, emulsifying activity, glycoside content and surface tension of cell-free culture medium. the results obtained suggested that both modes of biosurfactant-enhanced hexadecane uptake by bacterial strains take place, direct uptake and alkane transfer. the increase in cell surface hydrophobicity and glycoside production by the strains suggest ...200816962302
6-hydroxy-nicotine-inducible multilevel transgene control in mammalian cells.the precise control of transgene expression is essential for biopharmaceutical manufacturing, gene therapy and tissue engineering. we have designed a novel conditional transcription technology, which enables reversible induction, repression and adjustment of desired transgene expression using the clinically inert 6-hydroxy-nicotine (6hnic). the 6-hydroxy-nicotine oxidase (6hno) repressor (hdnor), which manages nicotine metabolism in arthrobacter nicotinovorans pao1 by binding to a specific opera ...200616962351
mechanism of fad reduction and role of active site residues his-225 and tyr-259 in arthrobacter globiformis dimethylglycine oxidase: analysis of mutant structure and catalytic function.residues his-225 and tyr-259 are located close to the fad in the dehydrogenase active site of the bifunctional dimethylglycine oxidase (dmgo) of arthrobacter globiformis. we have suggested [leys, d., basran, j., and scrutton, n. s. (2003) embo j. 22, 4038-4048] that these residues are involved in abstraction of a proton from the substrate amine group of dimethylglycine prior to c-h bond breakage and fad reduction. to investigate this proposal, we have isolated two mutant forms of dmgo in which ( ...200616964976
epithermal neutron activation analysis of cr(vi)-reducer basalt-inhabiting bacteria.epithermal neutron activation analysis (enaa) has been applied to study elemental composition of cr(vi)-reducer bacteria isolated from polluted basalts from the republic of georgia. cr(vi)-reducing ability of the bacteria was examined by electron spin resonance, demonstrating that the bacteria differ in their rates of cr(vi) reduction. a well-pronounced correlation between the ability of the bacteria to accumulate cr(v) and their ability to reduce cr(v) to cr(iii) observed in our experiments is ...200616970299
functional analysis of the twin-arginine translocation pathway in corynebacterium glutamicum atcc 13869.compared to those of other gram-positive bacteria, the genetic structure of the corynebacterium glutamicum tat system is unique in that it contains the tate gene in addition to tata, tatb, and tatc. the tate homologue has been detected only in the genomes of gram-negative enterobacteria. to assess the function of the c. glutamicum tat pathway, we cloned the tata, tatb, tatc, and tate genes from c. glutamicum atcc 13869 and constructed mutants carrying deletions of each tat gene or of both the ta ...200616997984
plantibacter auratus sp. nov., in the family microbacteriaceae.strain ncimb 9991(t) is a gram-positive, short rod-shaped, yellow-pigmented bacterium, with a high dna g+c content, and was originally deposited in 1967 as arthrobacter sp. the bacterium is aerobic, non-motile, catalase-positive and oxidase-negative. comparative 16s rrna gene sequencing studies demonstrated that this strain was highly related genealogically to plantibacter flavus dsm 14012(t). strain iam 14817(t) (=ncimb 9991(t)) has the following characteristics: the predominant menaquinones ar ...200617012557
cultivation-independent examination of horizontal transfer and host range of an incp-1 plasmid among gram-positive and gram-negative bacteria indigenous to the barley rhizosphere.the host range and transfer frequency of an incp-1 plasmid (pkjk10) among indigenous bacteria in the barley rhizosphere was investigated. a new flow cytometry-based cultivation-independent method for enumeration and sorting of transconjugants for subsequent 16s rrna gene classification was used. indigenous transconjugant rhizosphere bacteria were collected by fluorescence-activated cell sorting and identified by cloning and sequencing of 16s rrna genes from the sorted cells. the host range of th ...200617021220
growth kinetics of microorganisms isolated from alaskan soil and permafrost in solid media frozen down to -35 degrees c.we developed a procedure to culture microorganisms below freezing point on solid media (cellulose powder or plastic film) with ethanol as the sole carbon source without using artificial antifreezes. enrichment from soil and permafrost obtained on such frozen solid media contained mainly fungi, and further purification resulted in isolation of basidiomycetous yeasts of the genera mrakia and leucosporidium as well as ascomycetous fungi of the genus geomyces. contrary to solid frozen media, the enr ...200717026514
n-acetylanthranilate amidase from arthrobacter nitroguajacolicus rü61a, an alpha/beta-hydrolase-fold protein active towards aryl-acylamides and -esters, and properties of its cysteine-deficient variant.n-acetylanthranilate amidase (amq), a 32.8-kda monomeric amide hydrolase, is involved in quinaldine degradation by arthrobacter nitroguajacolicus rü61a. sequence analysis and secondary structure predictions indicated that amq is related to carboxylesterases and belongs to the alpha/beta-hydrolase-fold superfamily of enzymes; inactivation of (his(6)-tagged) amq by phenylmethanesulfonyl fluoride and diethyl pyrocarbonate and replacement of conserved residues suggested a catalytic triad consisting ...200617041061
high-performance ce: an effective method to study lactonization of alpha2,8-linked oligosialic acid.a sensitive and efficient method using high-performance ce (hpce) and neuraminidase hydrolysis was developed to study the lactonization and hydrolysis of alpha2,8-pentasialic acid. eleven lactone species of pentasialic acid formed in glacial acetic acid were detected and classified into three groups based on the number of carboxylic acids: monolactones with four carboxylic acids, dilactones with three carboxylic acids, and trilactones with two carboxylic acids. these lactones eluted between the ...200617054086
contribution of ethylamine degrading bacteria to atrazine degradation in soils.bacterial communities that cooperatively degrade atrazine commonly consist of diverse species in which the genes for atrazine dechlorination and dealkylation are variously distributed among different species. normally, the first step in degradation of atrazine involves dechlorination mediated by atza, followed by stepwise dealkylation to yield either n-ethylammelide or n-isopropylammelide. as the liberated alkylamine moieties are constituents of many organic molecules other than atrazine, it is ...200617064268
ecotoxicological assessment of sediment, suspended matter and water samples in the upper danube river. a pilot study in search for the causes for the decline of fish catches.goals, scope and background: fish populations, especially those of the grayling (thymallus thymallus), have declined over the last two decades in the upper danube river between sigmaringen and ulm, despite intensive and continuous stocking and improvement of water quality since the 1970s. similar problems have been reported for other rivers, e.g. in switzerland, great britain, the united states and canada. in order to assess if ecotoxicological effects might be related to the decline in fish cat ...200617067025
the copper-containing amine oxidase from arthrobacter globiformis: refinement at 1.55 and 2.20 a resolution in two crystal forms.copper-containing amine oxidases are found in all the major kingdoms of life. they catalyse the oxidation of organic amines in the presence of molecular dioxygen to aldehydes and hydrogen peroxide. the catalytic centres contain a cu atom and a topaquinone cofactor formed autocatalytically from a tyrosine residue in the presence of cu and molecular oxygen. the structure of the cu-containing amine oxidase from arthrobacter globiformis, which was previously refined at 1.8 a resolution in space grou ...200617077478
evolution of catabolic pathways: genomic insights into microbial s-triazine metabolism. 200717114259
n-ethylmaleimide-resistant acyl-coenzyme a oxidase from arthrobacter ureafaciens nbrc 12140: molecular cloning, gene expression and characterization of the recombinant enzyme.n-ethylmaleimide (nem)-resistant acyl-coenzyme a oxidase (aco) has been desired for the determination of free fatty acids (ffas). in order to meet this demand, we prepared recombinant aco from arthrobacter ureafaciens nbrc 12140. the coding region of the gene was 2109, encoding a protein of 703 amino acids with a predicted molecular mass of 76.5 kda. the heterologous expression level in escherichia coli was 520-fold higher than that in the native strain. the purified enzyme retained more than 60 ...200717141592
crystallization and x-ray diffraction analysis of 6-aminohexanoate-cyclic-dimer hydrolase from arthrobacter sp. ki72.6-aminohexanoate-cyclic-dimer hydrolase (ei) from arthrobacter sp. ki72 was expressed in escherichia coli and purified by anion-exchange chromatography. ei was crystallized by the sitting-drop vapour-diffusion method with sodium citrate as precipitant in imidazole buffer ph 8.0. the crystal is hexagonal, with unit-cell parameters a = b = 130.75, c = 58.23 a. diffraction data were collected from native and mercury(ii) dichloride-derivative crystals to resolutions of 1.90 and 2.06 a, respectively.200617142898
trans-generational immune priming in a social insect.detecting functional homology between invertebrate and vertebrate immunity is of interest in terms of understanding the dynamics and evolution of immune systems. trans-generational effects on immunity are well known from vertebrates, but their existence in invertebrates remains controversial. earlier work on invertebrates has interpreted increased offspring resistance to pathogens as trans-generational immune priming. however, interpretation of these earlier studies involves some caveats and thu ...200517148213
coryneform bacteria in semen of chronic prostatitis patients.our aim was to compare the presence and species composition of coryneform bacteria in chronic prostatitis patients and controls. semen of 50 men with inflammatory prostatitis and 59 controls (without pelvic pain/discomfort complaints and leukocytospermia) was investigated. first-catch urine was additionally investigated in 36 men (30 with and 6 without prostatitis). coryneform bacteria were found in semen of 76% men with inflammatory prostatitis and 83% controls. more than half of the isolates w ...200717163953
microbially mediated cadmium sorption/desorption processes in soil amended with sewage sludge.a multi-compartment system was used to study the importance of microorganisms for cd desorption from soil amended with sewage sludge and simultaneous resorption of the mobilized metal by soil constituents. using this system made it possible to study the participation of microorganisms (arthrobacter, trichoderma), montmorillonite, humic acids, and iron oxides in resorption of the released cd. a filter-sterilized water extract of root-free soil of ph 6.7 (rf) or rf supplemented with glucose (rfg) ...200717182077
biodiversity of bacterial ecosystems in traditional egyptian domiati cheese.bacterial biodiversity occurring in traditional egyptian soft domiati cheese was studied by pcr-temporal temperature gel electrophoresis (ttge) and pcr-denaturing gradient gel electrophoresis (dgge). bands were identified using a reference species database (j.-c. ogier et al., appl. environ. microbiol. 70:5628-5643, 2004); de novo bands having nonidentified migration patterns were identified by dna sequencing. results reveal a novel bacterial profile and extensive bacterial biodiversity in domia ...200717189434
secrets of soil survival revealed by the genome sequence of arthrobacter aurescens tc1.arthrobacter sp. strains are among the most frequently isolated, indigenous, aerobic bacterial genera found in soils. member of the genus are metabolically and ecologically diverse and have the ability to survive in environmentally harsh conditions for extended periods of time. the genome of arthrobacter aurescens strain tc1, which was originally isolated from soil at an atrazine spill site, is composed of a single 4,597,686 basepair (bp) circular chromosome and two circular plasmids, ptc1 and p ...200617194220
variations in t-rflp profiles with differing chemistries of fluorescent dyes used for labeling the pcr primers.culture independent molecular methods have emerged as indispensable tools for studying microbial community structure and dynamics in natural habitats, since they allow a closer look at microbial diversity that is not reflected by culturing techniques. terminal restriction fragment length polymorphism (t-rflp) analysis is one of the informative and widely used techniques for such studies. however, the method has a few limitations to predict microbial community structure with significant accuracy. ...200717196691
nod2/card15 disease associations other than crohn's this moment, few confirmed associations between nod2 mutations and diseases other than crohn's disease (cd) and blau syndrome (bs) have been reported, but research is ongoing in several fields where a genetic susceptibility factor and/or a role for the innate immune system is suspected. whether the crohn's-associated card15 mutations lead to a loss or gain of function of the nod2 receptor is subject to controversy, and by which mechanisms this change in function might increase the susceptibil ...200717206682
strong impact on the polycyclic aromatic hydrocarbon (pah)-degrading community of a pah-polluted soil but marginal effect on pah degradation when priming with bioremediated soil dominated by mycobacteria.bioaugmentation of soil polluted with polycyclic aromatic hydrocarbons (pahs) is often disappointing because of the low survival rate and low activity of the introduced degrader bacteria. we therefore investigated the possibility of priming pah degradation in soil by adding 2% of bioremediated soil with a high capacity for pah degradation. the culturable pah-degrading community of the bioremediated primer soil was dominated by mycobacterium spp. a microcosm containing pristine soil artificially ...200717209064
amperometric biosensor for the determination of amperometric biosensor for the determination of creatine was developed. the carbon rod electrode surface was coated with sarcosine oxidase (sox) and creatine amidinohydrolase by cross-linking under glutaraldehyde vapour. the sox from arthrobacter sp. 1-1 n was purified and previously used for creation of a creatine biosensor. the natural sox electron acceptor, oxygen, was replaced by an [fe(cn)(6)](3-) /[ fe(cn)(6)](4-) redox mediating system, which allowed amperometric detection of an analyt ...200717221239
adaptation of the psychrotroph arthrobacter chlorophenolicus a6 to growth temperature and the presence of phenols by changes in the anteiso/iso ratio of branched fatty acids.arthrobacter chlorophenolicus is a previously described gram-positive bacterium capable of degrading high concentrations of several phenolic compounds under optimal mesophilic (28 degrees c) as well as psychrophilic (5 degrees c) conditions. however, the exact mechanisms by which this organism is able to tolerate such extremes in temperature and high levels of toxic compounds are currently not known. in this study, we monitored changes in the fatty acid composition of the cell membrane under dif ...200717233723
utilization and degradation of imazaquin by a naturally occurring isolate of arthrobacter crystallopoietes.a species of bacteria that is capable of utilizing imazaquin as the sole carbon source was isolated from soil with repeated imazaquin applications, and was identified as arthrobacter crystallopoietes (designated as strain "wwx-1"). this isolate degrades imazaquin as high as 200 microg ml-1, and the estimated dissipation half-lives increased from 1.51 d for the treatment at 50 microg ml-1 to 4.75 d for 200 microg ml-1. optimal growth of wwx-1 in mineral salt medium with 50 microg ml-1 imazaquin w ...200717267013
structure and action of a c-c bond cleaving alpha/beta-hydrolase involved in nicotine degradation.the enzyme 2,6-dihydroxy-pseudo-oxynicotine hydrolase from the nicotine-degradation pathway of arthrobacter nicotinovorans was crystallized and the structure was determined by an x-ray diffraction analysis at 2.1 a resolution. the enzyme belongs to the alpha/beta-hydrolase family as derived from the chain-fold and from the presence of a catalytic triad with its oxyanion hole at the common position. this relationship assigns a pocket lined by the catalytic triad as the active center. the asymmetr ...200717275835
heavy metal resistance and genotypic analysis of metal resistance genes in gram-positive and gram-negative bacteria present in ni-rich serpentine soil and in the rhizosphere of alyssum murale.forty-six bacterial cultures, including one culture collection strain, thirty from the rhizosphere of alyssum murale and fifteen from ni-rich soil, were tested for their ability to tolerate arsenate, cadmium, chromium, zinc, mercury, lead, cobalt, copper, and nickel in their growth medium. the resistance patterns, expressed as minimum inhibitory concentrations, for all cultures to the nine different metal ions were surveyed by using the agar dilution method. a large number of the cultures were r ...200717276484
overproduction and characterization of a recombinant d-amino acid oxidase from arthrobacter protophormiae.a screening of soil samples for d-amino acid oxidase (d-aao) activity led to the isolation and identification of the gram-positive bacterium arthrobacter protophormiae. after purification of the wild-type d-aao, the gene sequence was determined and designated dao. an alignment of the deduced primary structure with eukaryotic d-aaos and d-aspartate oxidases showed that the d-aao from a. protophormiae contains five of six conserved regions; the c-terminal type 1 peroxisomal targeting signal that i ...200717279391
an nad(p)h-nicotine blue oxidoreductase is part of the nicotine regulon and may protect arthrobacter nicotinovorans from oxidative stress during nicotine nad(p)h-nicotine blue (quinone) oxidoreductase was discovered as a member of the nicotine catabolic pathway of arthrobacter nicotinovorans. transcriptional analysis and electromobility shift assays showed that the enzyme gene was expressed in a nicotine-dependent manner under the control of the transcriptional activator pmfr and thus was part of the nicotine regulon of a. nicotinovorans. the flavin mononucleotide-containing enzyme uses nadh and, with lower efficiency, nadph to reduce, by a tw ...200717293530
esta from arthrobacter nitroguajacolicus rü61a, a thermo- and solvent-tolerant carboxylesterase related to class c beta-lactamases.the esta gene encoding a novel cytoplasmic carboxylesterase from arthrobacter nitroguajacolicus rü61a was expressed in escherichia coli. sequence analysis and secondary structure predictions suggested that esta belongs to the family viii esterases, which are related to class c beta-lactamases. the s-x-x-k motif that in beta-lactamases contains the catalytic nucleophile, and a putative active-site tyrosine residue are conserved in esta. the native molecular mass of hexahistidine-tagged (his6) est ...200717294326
[isolation, degradation and phylogenetic analysis of methylparathion degradative strain x4].the strain x4 was isolated from polluted wastes of shandong huayang pesticide chemical industry group co., ltd. it was cultured with methylparathion and p-nitrophenol, a kind of intermediate during methylparathion degrading process, and used them as the sole carbon source and decomposed them into carbon dioxide and wastes. it is identified as arthrobacter sp. by means of a series of tests, and it has visible sphere-pole variable cycle. it is bacilliform when it is cultured in nutrient broth medi ...200617302165
isolation and characterization of novel atrazine-degrading microorganisms from an agricultural soil.six previously undescribed microorganisms capable of atrazine degradation were isolated from an agricultural soil that received repeated exposures of the commonly used herbicides atrazine and acetochlor. these isolates are all gram-positive and group with microorganisms in the genera nocardioides and arthrobacter, both of which contain previously described atrazine degraders. all six isolates were capable of utilizing atrazine as a sole nitrogen source when provided with glucose as a separate ca ...200717318536
microorganisms isolated from the water phase of tropospheric clouds at the puy de dôme: major groups and growth abilities at low temperatures.this work constitutes the first large report on aerobic cultivable microorganisms present in cloud water. seven cloud-event samples were collected at the puy de dôme summit, and cultivation was performed leading to the isolation of 71 bacterial, 42 fungal and 15 yeast strains. most of the fungi isolated were of cladosporium or trametes affiliation, and yeasts were of cryptococcus affiliation. bacteria, identified on the basis of their 16s rrna gene sequence, were found to belong to actinobacteri ...200717328765
mineralization of diuron [3-(3,4-dichlorophenyl)-1, 1-dimethylurea] by co-immobilized arthrobacter sp. and delftia acidovorans.mineralization of diuron has not been previously demonstrated despite the availability of some bacteria to degrade diuron into 3,4-dichloroaniline (3,4-dca) and others that can mineralize 3,4-dca. a bacterial co-culture of arthrobacter sp. n4 and delftia acidovorans w34, which respectively degraded diuron (20 mg l(-1)) to 3,4-dca and mineralized 3,4-dca, were able to mineralize diuron. total diuron mineralization (20 mg l(-1)) was achieved with free cells in co-culture. when the bacteria were im ...200717333465
complete nucleotide sequence of the 113-kilobase linear catabolic plasmid pal1 of arthrobacter nitroguajacolicus rü61a and transcriptional analysis of genes involved in quinaldine degradation.the nucleotide sequence of the linear catabolic plasmid pal1 from the 2-methylquinoline (quinaldine)-degrading strain arthrobacter nitroguajacolicus rü61a comprises 112,992 bp. a total of 103 open reading frames (orfs) were identified on pal1, 49 of which had no annotatable function. the orfs were assigned to the following functional groups: (i) catabolism of quinaldine and anthranilate, (ii) conjugation, and (iii) plasmid maintenance and dna replication and repair. the genes for conversion of q ...200717337569
solar-based detoxification of phenol and p-nitrophenol by sequential tio2 photocatalysis and photosynthetically aerated biological treatment.simulated solar uv/tio(2) photocatalysis was efficient to detoxify a mixture of 100 mgphenoll(-1) and 50 mgp-nitrophenol (pnp) l(-1) and allow the subsequent biodegradation of the remaining pollutants and their photocatalytic products under photosynthetic aeration with chlorella vulgaris. photocatalytic degradation of phenol and pnp was well described by pseudo-first order kinetics (r(2)>0.98) with removal rate constants of 1.9x10(-4) and 2.8x10(-4)min(-1), respectively, when the pollutants were ...200717350074
[function and structure of nad kinase: the key enzyme for biosynthesis of nadp (h)]. 200717352189
[a model study of pesticide biodegradation in soil].this study addresses the efficiency of microbial preparations to degrade pesticide residues in soil. a method to degrade pesticides dnoc and pendimethalin using pseudomonas and arthrobacter bacteria with a fertilizer is described.200717352205
the coda transgene for glycinebetaine synthesis increases the size of flowers and fruits in tomato.the tolerance of various species of plant to abiotic stress has been enhanced by genetic engineering with certain genes. however, the use of such transgenes is often associated with negative effects on growth and productivity under non-stress conditions. the coda gene from arthrobacter globiformis is of particular interest with respect to the engineering of desirable productive traits in crop plants. the expression of this gene in tomato plants resulted in significantly enlarged flowers and frui ...200717362485
biosorption of cr (vi) using a bacterial biofilm supported on granular activated carbon and on zeolite.two mini-columns partially filled with granular activated carbon (gac) and/or a natural zeolite, covered by a bacterial biofilm of arthrobacter viscosus, were used in a continuous flow system to remove cr (vi) from solutions with initial concentration of 70mg/l and a working ph ranging between 4.5 and 5.5. three different set-up's were used: two columns in series filled gac covered with a biofilm, two columns in series filled with zeolite covered with a biofilm and a column filled with gac follo ...200817368891
seasonal variation of sediment toxicity in the rivers dommel and elbe.contaminated sediment in the river basin has become a source of pollution with increasing importance to the aquatic ecosystem downstream. to monitor the temporal changes of the sediment bound contaminants in the river elbe and the river dommel monthly toxicity tests were applied to layered sediment and river water samples over the course of 10 months. there is an indication that contaminated sediments upstream adversely affected sediments downstream, but this process did not cause a continuous i ...200717379366
cloning of the arthrobacter sp. fg1 dehalogenase genes and construction of hybrid pathways in pseudomonas putida arthrobacter strain, able to utilize 4-chlorobenzoic acid as the sole carbon and energy source, was isolated and characterized. the first step of the catabolic pathway was found to proceed via a hydrolytic dehalogenation that leads to the formation of 4-hydroxybenzoic acid. the dehalogenase encoding genes (fcb) were sequenced and found highly homologous to and organized as those of other 4-chlorobenzoic acid degrading arthrobacter strains. the fcb genes were cloned and successfully expressed ...200717384944
growth and physiological response of arthrobacter protophormiae rkj100 toward higher concentrations of o-nitrobenzoate and p-hydroxybenzoate.bioremediation of sites that are heavily contaminated with pollutant chemicals is a challenge as most of the microorganisms cannot tolerate higher concentrations of toxic compounds. only a few strains of the genus pseudomonas have been studied for their tolerance toward the higher concentrations of aromatic pollutant compounds, a phenomenon that is accompanied by various physiological changes. in the present study we have characterized the growth response and physiological changes (adaptations) ...200717391368
isolation and characterization of four gram-positive nickel-tolerant microorganisms from contaminated sediments.microbial communities from riparian sediments contaminated with high levels of ni and u were examined for metal-tolerant microorganisms. isolation of four aerobic ni-tolerant, gram-positive heterotrophic bacteria indicated selection pressure from ni. these isolates were identified as arthrobacter oxydans nr-1, streptomyces galbus nr-2, streptomyces aureofaciens nr-3, and kitasatospora cystarginea nr-4 based on partial 16s rdna sequences. a functional gene microarray containing gene probes for fu ...200717404787
metabolic activity and phylogenetic diversity of reed (phragmites australis) periphyton bacterial communities in a hungarian shallow soda the present study, the species composition and potential metabolic activities of bacterial communities of reed phragmites australis (cav.) (trin. ex steudel) periphyton from lake velencei were studied by cultivation-based and metabolic fingerprinting methods. serially diluted spring biofilm samples were used to test the community-level physiological profiling (clpp) using biolog microplates, and for plating onto different media. on the basis of their morphological, biochemical, and physiologi ...200717406774
the characteristics of rhizosphere microbes associated with plants in arsenic-contaminated soils from cattle dip sites.soil microorganisms and plants were studied in samples of arsenic-contaminated soil from two cattle dip sites. the aim was to delineate the parameters that will determine the feasibility of future remediation by growing arsenic-accumulating plants, including the identity and characteristics of some rhizosphere soil microbes. the soil samples contained high total, but low soluble arsenic concentrations which, together with other properties, resembled the previously reported characteristics of dip ...200717407787
[reaction of microorganisms to the digestive fluid of the earthworms].the reaction of soil bacteria and fungi to the digestive fluid of the earthworm aporrectodea caliginosa was studied. the fluid was obtained by centrifugation of the native enzymes of the digestive tract. the inhibition of growth of certain bacteria, spores, and fungal hyphae under the effect of extracts from the anterior and middle sections of the digestive tract of a. caliginosa was discovered for the first time. in bacteria, microcolony formation was inhibited as early as 20-30 s after the app ...200717410875
[obtaining and characterization of dna-containing micromummies of yeasts and gram-positive bacteria with enhanced cell wall permeability: application in pcr].the procedure of obtaining dna-containing cell envelopes ("micromummies") of bacteria, yeasts, and fungi using chaotropic salts has been developed previously and the possibility of their direct application in pcr has been demonstrated. the fine structure of micromummies has been studied by electron microscopic methods. this work has demonstrated that additional treatment of micromummies of yeasts and gram-positive bacteria with proteinase k results in hydrolytic degradation of cell proteins and ...200717410877
chlamydomonas reinhardtii, a model system for functional validation of abiotic stress responsive genes.stress tolerance is a multigenic character and there are many stress responsive genes, which are stress specific. although many of these have been cloned, their functional significance remains fragmentary. hence it is important to identify the relevant stress genes involved in altering the metabolism for adaptation. overexpression is one of the several approaches and chlamydomonas is a suitable system to study the functional relevance of stress genes. stress responses can only be assessed on pri ...200717431668
structure and denaturation of 4-chlorobenzoyl coenzyme a dehalogenase from arthrobacter sp. strain tm-1.the secondary structure of the trimeric protein 4-chlorobenzoyl coenzyme a dehalogenase from arthrobacter sp. strain tm-1, the second of three enzymes involved in the dechlorination of 4-chlorobenzoate to form 4-hydroxybenzoate, has been examined. e(mm) for the enzyme was 12.59. analysis by circular dichroism spectrometry in the far uv indicated that 4-chlorobenzoyl coenzyme a dehalogenase was composed mostly of alpha-helix (56%) with lesser amounts of random coil (21%), beta-turn (13%) and beta ...200817431803
expression of ksdd gene encoding 3-ketosteroid-delta1-dehydrogenase from arthrobacter simplex in bacillus improve ksdh enzyme activity and the transformation level for androst-4-ene-3,17-dione.200717451526
overexpression and functional analysis of cold-active beta-galactosidase from arthrobacter psychrolactophilus strain f2.cold-active beta-galactosidase from arthrobacter psychrolactophilus strain f2 was overexpressed in escherichia coli using the cold expression system and the recombinant enzyme, rbglap, was characterized. the purified rbglap exhibited similar enzymatic properties to the native enzyme, e.g., (i) it had high activity at 0 degrees c, (ii) its optimum temperature and ph were 10 degrees c and 8.0, respectively, and (iii) it was possible to rapidly inactivate the rbglap at 50 degrees c in 5 min. moreov ...200717459724
a two-component small multidrug resistance pump functions as a metabolic valve during nicotine catabolism by arthrobacter nicotinovorans.the genes nepab of a small multidrug resistance (smr) pump were identified as part of the pao1-encoded nicotine regulon responsible for nicotine catabolism in arthrobacter nicotinovorans. when [(14)c]nicotine was added to the growth medium the bacteria exported the (14)c-labelled end product of nicotine catabolism, methylamine. in the presence of the proton-motive force inhibitors 2,4-dinitrophenol (dnp), carbonyl cyanide m-chlorophenylhydrazone (cccp) or the proton ionophore nigericin, export o ...200717464069
an internal equilibrium preorganizes the enzyme-substrate complex for hydride tunneling in choline oxidase.the hydride transfer reaction catalyzed by choline oxidase under irreversible regime, i.e., at saturating oxygen, was shown in a recent study to occur quantum mechanically within a highly preorganized active site, with the reactive configuration for hydride tunneling being minimally affected by environmental vibrations of the reaction coordinate other than those affecting the distance between the alpha-carbon of the choline alkoxide substrate and the n(5) atom of the enzyme-bound flavin cofactor ...200717472346
biotransformation of d-methionine into l-methionine in the cascade of four enzymes.d-methionine was converted to l-methionine in a reaction system where four enzymes were used. d-amino acid oxidase (d-aao) from arthrobacter protophormiae was used for the complete conversion of d-methionine to 2-oxo-4-methylthiobutyric acid. catalase was added to prevent 2-oxo-4-methylthiobutyric acid decarboxylation. in the second reaction step, l-phenylalanine dehydrogenase (l-phedh) from rhodococcus sp. was used to convert 2- oxo-4-methylthiobutyric acid to l-methionine, and formate dehydrog ...200717534960
a novel strategy for enzymatic synthesis of 4-hydroxyisoleucine: identification of an enzyme possessing hmkp (4-hydroxy-3-methyl-2-keto-pentanoate) aldolase activity.a two-step enzymatic synthesis process of 4-hydroxyisoleucine is suggested. in the first step, the aldol condensation of acetaldehyde and alpha-ketobutyrate catalyzed by specific aldolase results in the formation of 4-hydroxy-3-methyl-2-keto-pentanoate (hmkp). in the second step, amination of hmkp by the branched-chain amino acid aminotransferase leads to synthesis of 4-hydroxyisoleucine. an enzyme possessing hmkp aldolase activity (ashpal) was purified 2500-fold from a crude extract of arthroba ...200717559390
crystallization and diffraction data of 1h-3-hydroxy-4-oxoquinoline 2,4-dioxygenase: a cofactor-free oxygenase of the alpha/beta-hydrolase family.1h-3-hydroxy-4-oxoquinoline 2,4-dioxygenase (qdo) from pseudomonas putida 33/1 catalyses the oxygenolysis of 1h-3-hydroxy-4-oxoquinoline to form n-formylanthranilic acid and carbon monoxide without the aid of cofactors. both n-terminally his6-tagged and native qdo were overexpressed in escherichia coli and purified by conventional chromatographic procedures. untagged qdo, but not his6-tagged qdo, was crystallized by the vapour-diffusion method, giving hexagonal bipyramid crystals belonging to sp ...200717565175
crystallization and preliminary x-ray analysis of 1h-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase from arthrobacter nitroguajacolicus rü61a: a cofactor-devoid dioxygenase of the alpha/beta-hydrolase-fold superfamily.1h-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (hod) is a cofactor-devoid dioxygenase that is involved in the anthranilate pathway of quinaldine degradation. hod has been proposed to belong to the alpha/beta-hydrolase-fold superfamily of enzymes. n-terminally his6-tagged hod has been crystallized by the hanging-drop vapour-diffusion method using sodium/potassium tartrate as a precipitant and cucl2 as an additive. the structure was solved by the single anomalous dispersion (sad) technique using dat ...200717565176
identification of the catalytic acid base residue of arthrobacter endo-beta-n-acetylglucosaminidase by chemical rescue of an inactive mutant.arthrobacter endo-beta-n-acetylglucosaminidase (endo-a), a member of glycoside hydrolase (gh) family 85, catalyses the hydrolysis and transglycosylation of asparagine-linked oligosaccharides of glycoproteins with retention of anomeric configuration. glu-173 of endo-a is a catalytically essential amino acid residue, and the corresponding residue is conserved in all gh family 85 members. the catalytic activity of endo-a e173a mutant was rescued by the addition of sodium azide or sodium formate. fu ...200717567654
characterization of aerobic bacterial and fungal microbiota on surfaces of historic scottish monuments.twenty samples were taken from the inner or outer surfaces of stone monuments of six historic scottish buildings and ruins. biofilms developing on mineral substrates were analysed by in situ scanning electron microscopy and cultivation. various methods were used to characterize the isolates including automated ribotyping, rapd and sequencing of the 16s rrna gene for bacteria, and stereomicroscopy and sequencing of the internal transcribed spacers (its) for fungi. most samples contained microbes ...200717583461
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