Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| crystal structures of thermostable xylose isomerases from thermus caldophilus and thermus thermophilus: possible structural determinants of thermostability. | the crystal structures of highly thermostable xylose isomerases from thermus thermophilus (tthxi) and thermus caldophilus (tcaxi), both with the optimum reaction temperature of 90 degrees c, have been determined by x-ray crystallography. the model of tcaxi has been refined to an r-factor of 17.8 % for data extending to 2.3 a and that of tthxi to 17.1 % for data extending to 2.2 a. the tetrameric arrangement of subunits characterized by the 222-symmetry and the tertiary fold of each subunit in bo ... | 1999 | 10329168 |
| characterisation of a new host-vector system for fast-growing mycobacteria. | in this paper we describe the development of a host-vector system for genetic studies of fast-growing mycobacteria able to biotransform sterols. a wild strain mycobacterium smegmatis sn38 and a biotechnological mutant mycobacterium vaccae b3805 were transformed by electroporation with the psmt3 e. coli-mycobacterium shuttle plasmid harbouring the hygromycin resistance gene. both, the psmt3 plasmid and its derivative psmt3-ksdd carrying the 3-ketosteroid-delta 1-dehydrogenase gene (ksdd) from art ... | 1998 | 10333556 |
| cloning, sequencing and characterisation of a downstream region of ksddi operon of arthrobacter simplex. | an 8-kb region downstream of the ketosteroid dehydrogenase (ksdd)-ketosteroid isomerase (ksdi) genes of arthrobacter simplex was cloned. the nucleotide sequence of the first 3-kb segment downstream of ksdd-ksdi operon was determined. three open reading frames (orfs) preceded by shine-dalgarno (sd) sequences have been found. homology search revealed that the putative product encoded by orf3 has high level of similarity with the 3-oxosteroid dehydrogenases from a. simplex and p. testosteroni (90% ... | 1998 | 10333557 |
| cloning and sequencing of the fcbb gene encoding 4-chlorobenzoate-coenzyme a dehalogenase from pseudomonas sp. dj-12. | pseudomonas sp. dj-12 degrades 4-chlorobenzoate through hydrolytic dechlorination to produce 4-hydroxybenzoate and a chloride ion. the fcbb gene encoding the 4-chlorobenzoate-coenzyme a (4cba-coa) dehalogenase which catalyzes the nucleophilic substitution reaction to convert 4cba-coa to 4-hydroxybenzoate-coenzyme a (4hba-coa) in the consecutive steps of dechlorination was cloned from the chromosome of the organism. a nucleotide sequence analysis of the gene showed an open reading frame consistin ... | 1999 | 10340479 |
| mechanism of alanine hyperproduction by arthrobacter oxydans hap-1: metabolic shift to fermentation under nongrowth aerobic conditions | arthrobacter oxydans hap-1 hyperproduces dl-alanine in a non-growth-associated manner. we found that decreased activities of pyruvate dehydrogenase and of the enzyme catalyzing nadh oxidation in the stationary phase are paralleled by a shift of pyruvate metabolism to alanine synthesis by l-alanine dehydrogenase. we propose that this enzyme functions as an electron sink even under aerobic conditions. | 1999 | 10347080 |
| fractal analysis to discriminate between biotic and abiotic attacks on chalcopyrite and pyrolusite. | in the present paper, a model describing release and mobility of copper and manganese in chalcopyrite and pyrolusite powders due to bacterial bioleaching, i.e. thiobacillus ferrooxidans and arthrobacter sp., is proposed. sites where copper and manganese were released were examined by scanning electron microscopy (sem). the resulting micrographs were scanned and submitted to a point by point fractal analysis to verify if a discrimination between biological and chemical attack could be established ... | 1999 | 10353795 |
| analysis of the bacterial surface ripening flora of german and french smeared cheeses with respect to their anti-listerial potential. | the anti-listerial potential of 19 different french smeared cheese bacterial consortia was analyzed semi-quantitatively. comparison of the total viable cell count to the direct microscopic count yielded no indication that non-culturable bacteria contribute significantly to the undefined, complex ripening floras. from 2613 isolates, 48 showed clear inhibition of one or more listeria monocytogenes strains on solid medium, while only three isolates excreted an anti-listerial, soluble substance when ... | 1999 | 10357277 |
| effects of dfa iv in rats: calcium absorption and metabolism of dfa iv by intestinal microorganisms. | di-d-fructose-2,6':6,2'-dianhydride (dfa iv) is a disaccharide consisting of two fructose residues that can be prepared from levan by levan fructotransferase from arthrobacter nicotinovorans gs-9, and it can be expected to have novel physiological functions from its unique structure. in this study, the effects of dfa iv on calcium absorption and the metabolism of dfa iv by intestinal microorganisms were studied in rats to examine the physiological functions of dfa iv. the apparent calcium absorp ... | 1999 | 10361678 |
| biodegradation of diesel oil by cold-adapted microorganisms in presence of sodium dodecyl sulfate. | the effect of different concentrations of the anionic surfactant sodium dodecyl sulfate (sds) on biodegradation of diesel oil was assessed during 32 days at 10 degrees c, under simulated environmental conditions, in liquid culture and in an alpine soil. low sds concentrations (50-100 mg l-1) significantly enhanced oil biodegradation by a psychrotrophic inoculum in liquid culture, whereas higher sds concentrations (500-1000 mg l-1) inhibited hydrocarbon biodegradation. oil biodegradation by the i ... | 1999 | 10365429 |
| biochemical and phylogenetic analyses of psychrophilic isolates belonging to the arthrobacter subgroup and description of arthrobacter psychrolactophilus, sp. nov. | during our work on psychrophilic microorganisms we obtained a large collection of new isolates. in order to identify six of these, we examined their growth properties, cell wall compositions, and their 16s rrna gene sequences. the results showed that all of the isolates are gram-positive, aerobic, contain lysine in their cell walls, and belong to the high mol% g+c arthrobacter subgroup. phylogenetic analysis of the 16s rrna genes grouped five isolates obtained from a small geographical region in ... | 1999 | 10369891 |
| uptake of the herbicidal glyphosate by escherichia coli k-12. | the uptake of the aminoacid biosynthesis inhibitor, used as the broad-spectrum herbicide ingredient, glyphosate (n-[phosphonomethyl]-glycine) was investigated in e. coli as a model to study mechanisms of cell resistance to antimetabolites as drugs and pesticides. unlike the glyphosate-degrading arthrobacter sp. strain for which the first successful measurement of glyphosate uptake and its inhibition by orthophosphate was reported, e. coli k-12 cannot take up this inhibitor either in the presence ... | 1999 | 10379906 |
| cloning of a gene encoding hydroxyquinol 1,2-dioxygenase that catalyzes both intradiol and extradiol ring cleavage of catechol. | two escherichia coli transformants with catechol 1,2-dioxygenase activity were selected from a gene library of the benzamide-assimilating bacterium arthrobacter species strain ba-5-17, which produces four catechol 1,2-dioxygenase isozymes. a dna fragment isolated from one transformant contained a complete open reading frame (orf). the deduced amino acid sequence of the orf shared high identity with hydroxyquinol 1,2-dioxygenase. an enzyme expressed by the orf was purified to homogeneity and char ... | 1999 | 10380628 |
| a new route to l-threo-3-[4-(methylthio)phenylserine], a key intermediate for the synthesis of antibiotics: recombinant low-specificity d-threonine aldolase-catalyzed stereospecific resolution. | a new enzymatic resolution process was established for the production of l-threo-3-[4-(methylthio)phenylserine] (mtps), an intermediate for synthesis of antibiotics, florfenicol and thiamphenicol, using the recombinant low-specificity d-threonine aldolase from arthrobacter sp. dk-38. chemically synthesized dl-threo-mtps was efficiently resolved with either the purified enzyme or the intact recombinant escherichia coli cells overproducing the enzyme. under the optimized experimental conditions, 1 ... | 1999 | 10390816 |
| quantification of bacterial lead resistance via activity assays. | the level of microbial resistance to heavy metals is an important issue for the microbial ecology of heavy metal-contaminated habitats. however, assays based upon growth in nutrient media will overestimate the resistance level due to metal ion interactions with inorganic and organic components. the analysis of pb-resistant bacteria isolated from soils containing up to 38 mmol total pb x kg(-1) indicated that pyt80b medium which did not contain inorganic salts, contained low amounts of organic ma ... | 1999 | 10395460 |
| enhanced tolerance to light stress of transgenic arabidopsis plants that express the coda gene for a bacterial choline oxidase. | arabidopsis thaliana was transformed with the coda gene from arthrobacter globiformis. this gene encodes choline oxidase, an enzyme that converts choline to glycinebetaine. the photosynthetic activity, monitored in terms of chlorophyll fluorescence, of transformed plants was more tolerant to light stress than that of wild-type plants. this enhanced tolerance to light stress was caused by acceleration of the recovery of the photosystem ii (ps ii) complex from the photo-inactivated state. the tran ... | 1999 | 10412906 |
| characterization of the bacterial community of a zinc-polluted soil. | the bacterial community of a zinc-contaminated soil (maatheide soil in lommel, belgium) was studied using cultivation as well as cultivation-independent techniques. colony-forming units (cfu) were determined by plating on media with or without metals. dominant isolates were characterized by fatty acid methyl ester analysis (fame analysis) and pcr fingerprinting using repetitive extragenic palindromic sequences as primers. dna was directly extracted from soil samples and used as a template for th ... | 1999 | 10420584 |
| arthrobacter rhombi sp. nov., isolated from greenland halibut (reinhardtius hippoglossoides). | two strains of a hitherto undescribed gram-positive coryneform bacterium isolated from greenland halibut (reinhardtius hippoglossoides) were characterized by phenotypic and molecular taxonomic methods. comparative 16s rrna gene sequencing studies demonstrated that the unknown strains constitute a new line within the genus arthrobacter. the nearest relatives of the bacterium from fish were members of the arthrobacter nicotianael arthrobacter sulfureus group. the unknown bacterium was readily dist ... | 1999 | 10425782 |
| microbial mineralization of diisopropanolamine. | diisopropanolamine (dipa) is a "sweetening agent" used to remove hydrogen sulfide from sour natural gas, and it is a contaminant at some sour gas treatment facilities in western canada. to investigate the biodegradation of this alkanolamine, 14c-dipa was used in anaerobic and aerobic mineralization studies. between 3 and 78% of the radioactivity from this compound was released as 14co2 in sediment-enrichment cultures incubated under nitrate-reducing conditions. similarly, 12-78% of the label was ... | 1999 | 10446713 |
| structure determination and refinement of the al3+ complex of the d254,256e mutant of arthrobacter d-xylose isomerase at 2.40 a resolution. further evidence for inhibitor-induced metal ion movement. | the structure of the d254.256e double mutant of arthrobacter xylose isomerase with al3+ at both metal-binding sites was determined by the molecular replacement method at a conventional r-factor of 0.179. binding of the two al3+ does not alter the overall structure significantly. however, there are local rearrangements in the octahedral co-ordination sphere of the al3+. the inhibitor molecule moves somewhat away from the active site. furthermore, evidence was revealed for metal ion movement from ... | 1999 | 10456773 |
| manipulation of the dna coding for the desulphurizing activity in a new isolate of arthrobacter sp. | a new bacterial strain able to cleave c-s bonds from organosulphur heterocyclic compounds through the 4-s pathway and tentatively classified as arthrobacter sp. was recently isolated. in the present short article we describe the cloning and the characterization of the dna encoding the enzymes responsible for desulphurization in this microorganism, referred to as arthrobacter sp. ds7. the desulphurization operon was found to be located in a large plasmid that also bears the genes conferring cadmi ... | 1999 | 10461378 |
| biodegradation of 2-methyl, 2-ethyl, and 2-hydroxypyridine by an arthrobacter sp. isolated from subsurface sediment. | a bacterium capable of degrading 2-methylpyridine was isolated by enrichment techniques from subsurface sediments collected from an aquifer located at an industrial site that had been contaminated with pyridine and pyridine derivatives. the isolate, identified as an arthrobacter sp., was capable of utilizing 2-methylpyridine, 2-ethylpyridine, and 2-hydroxypyridine as primary c, n, and energy sources. the isolate was also able to utilize 2-, 3-, and 4-hydroxybenzoate, gentisic acid, protocatechui ... | 1999 | 10466198 |
| synthesis of bromoindolyl 4,7-di-o-methyl-neu5ac: specificity toward influenza a and b viruses. | n-acetylneuraminic acid (neu5ac) was converted into the methyl ester methyl ketoside-8,9-epoxy derivative (8). methylation of 8 followed by deprotection gave 4,7-di-o-methyl-neu5ac (10). compound 10 was converted into the corresponding methyl ester-chloroacetate derivative, which was subsequently coupled to 5-bromo-indol-3-ol to give the chromogenic product (13). deprotection of 13 gave 5-bromo-indol-3-yl 4,7-di-o-methyl-neu5ac (5). the product 5 was specifically cleaved by sialidase from either ... | 1999 | 10466215 |
| detection of genes for periplasmic nitrate reductase in nitrate respiring bacteria and in community dna. | a nested pcr primed by four degenerate oligonucleotides was developed for the specific amplification of sequences from the napa gene encoding the periplasmic nitrate reductase. this approach was used to amplify fragments of the napa gene from 10 pseudomonas species and one moraxella sp., previously shown to be able to express the periplasmic nitrate reductase activity, from rhodobacter capsulatus and from community dna extracted from a fresh-water sediment. amino acid sequences encoded by the na ... | 1999 | 10474192 |
| bacterial 2,4-dioxygenases: new members of the alpha/beta hydrolase-fold superfamily of enzymes functionally related to serine hydrolases. | 1h-3-hydroxy-4-oxoquinoline 2,4-dioxygenase (qdo) from pseudomonas putida 33/1 and 1h-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (hod) from arthrobacter ilicis rü61a catalyze an n-heterocyclic-ring cleavage reaction, generating n-formylanthranilate and n-acetylanthranilate, respectively, and carbon monoxide. amino acid sequence comparisons between qdo, hod, and a number of proteins belonging to the alpha/beta hydrolase-fold superfamily of enzymes and analysis of the similarity between the predict ... | 1999 | 10482514 |
| a practicable and accurate method to differentiate between intra- and extracellular water of microbial cells. | a thermographimetric method which allows for a quick and accurate estimation of intra- and extracellular water of microbial cells is reviewed and improved. knowledge of these fractions is important for physiological as well as for toxicological investigations. results of the study indicate that besides the species, nutrient availability and growth conditions affect the intracellular water content. intra- and extracellular water, dry matter, volume and density of a single cell of arthrobacter sp. ... | 1999 | 10483732 |
| purification and characterization of an extracellular proline iminopeptidase from arthrobacter nicotianae 9458. | an extracellular proline iminopeptidase, with a molecular mass of about 53 kda, was purified from arthrobacter nicotianae 9458 and characterized. the enzyme had temperature and ph optima of 37 degrees c and 8.0, respectively, was completely inactivated by heating for 1 min at 80 degrees c and showed highest activity on pro-pna. the proline iminopeptidase was characterized by activity at low temperature, nacl concentrations up to 7.5% and by high sensitivity to ph values 6.0, serine enzyme inhibi ... | 1999 | 10483739 |
| ganglioside gm(1a) on the cell surface is involved in the infection by human rotavirus kun and mo strains. | rotavirus is the most common cause of severe gastroenteritis in infants and children worldwide. the cell attachment of most animal rotaviruses, which belong to the neuraminidase-sensitive strains, requires sialic acid residues on the host cell membranes. on the other hand, most human rotaviruses are classified as neuraminidase-insensitive strains. the involvement of gangliosides on the host cell surface in human rotavirus infection was investigated by immunostaining analysis of target cells, and ... | 1999 | 10502675 |
| adaptive characteristics of salt-induced myceloids of arthrobacter globiformis. | when arthrobacter globiformis is grown in medium containing increased concentrations of nacl or decreased levels of cations, the bacteria grow as clusters of branching myceloid cells. the sensitivities of salt-induced and citrate-induced myceloids to several environmental stresses were compared to those of normal exponential-phase bacilli and stationary-phase cocci. salt-induced myceloids were more resistant than normal cells to ultraviolet light or heat shock at 45 degrees c but not to osmotic ... | 1999 | 10510721 |
| assessment of bacterial community structure in soil by polymerase chain reaction and denaturing gradient gel electrophoresis. | bacterial community structure was studied in a flevo silt loam (fsl) soil microplot, as well as in 15 other soils, by using dna extraction followed by molecular fingerprinting. total community dna was extracted and purified by a direct method, which yielded amplifiable dna of high molecular weight for all soils. a variable region of the 16s rrna gene was then amplified by pcr with bacterial primers, resulting in a mixture of amplicons separable via denaturing gradient gel electrophoresis (dgge). ... | 1999 | 10520580 |
| molecular cloning of isomaltotrio-dextranase gene from brevibacterium fuscum var. dextranlyticum strain 0407 and its expression in escherichia coli. | the gene encoding an extracellular isomaltotrio-dextranase (imtd), designed dext, was cloned from the chromosomal dna of brevibacterium fuscum var. dextranlyticum strain 0407, and expressed in escherichia coli. a single open reading frame consisting of 1923 base pairs that encoded a polypeptide composed of a signal peptide of 37 amino acids and a mature protein of 604 amino acids (m(r), 68,300) was found. the primary structure had no significant similarity with the structure of two other reporte ... | 1999 | 10540747 |
| the use of fatty acid methyl ester analysis (fame) for the identification of heterotrophic bacteria present on three mural paintings showing severe damage by microorganisms. | mural paintings in carmona (spain), herberstein (austria) and greene (germany), showing visible deterioration by microorganisms, were sampled to investigate the biodiversity of the heterotrophic bacteria present. four hundred twenty-eight bacterial strains were isolated from which 385 were characterized by fatty acid methyl ester analysis (fame). the isolates were grouped into 41 clusters on the basis of their fame profiles, 20 isolates remained ungrouped. the majority (94%) of the isolates comp ... | 1999 | 10564789 |
| spectroscopic characterization of carbon monoxide complexes generated for copper/topa quinone-containing amine oxidases. | carbon monoxide complexes have been generated for copper/topa quinone (tpq)-containing amine oxidases from arthrobactor globiformis (agao) and aspergillus niger (ao-i) and characterized by various spectroscopic measurements. addition of co to agao anaerobically reduced with its substrate 2-phenylethylamine led to a slight increase of absorption bands at 440 and 470 nm derived from the semiquinone form (tpq(sq)) of the tpq cofactor, concomitantly giving rise to new co-related absorption bands at ... | 1999 | 10571999 |
| characterization and radiation resistance of new isolates of rubrobacter radiotolerans and rubrobacter xylanophilus. | in this study we characterized new strains of the slightly thermophilic species rubrobacter radiotolerans and the thermophilic species rubrobacter xylanophilus, both of which were previously represented only by the type strains isolated, respectively, from japan and the united kingdom. the new isolates were recovered from two hot springs in central portugal after gamma irradiation of water and biofilm samples. we assessed biochemical characteristics, performed dna-dna hybridization, and carried ... | 1999 | 10591012 |
| phylogenetic and phenotypic diversity of 4-chlorobenzoate-degrading bacteria isolated from soils. | twenty numerically dominant 4-chlorobenzoate (4-cba)-degrading bacteria were isolated from agricultural soils. the isolates were able to utilize 4-cba as a sole source of carbon and energy. a total of 65% of the isolates was identified to the species level by fatty acid methyl ester (fame) analysis, and the isolates were strains of micrococcus, pseudomonas, oerskovia, cellulomonas, and arthrobacter species. the chromosomal dna patterns of the isolates obtained by polymerase chain reaction (pcr) ... | 2000 | 10620719 |
| synthesis of neoglycoenzymes with homogeneous n-linked oligosaccharides using immobilized endo-beta-n-acetylglucosaminidase a. | a procedure for the enzymatic synthesis of neoglycoenzymes is described. the gene encoding endo-beta-n-acetylglucosaminidase from arthrobacter protophormiae (endo-a) was overexpressed in escherichia coli as a fusion protein linked to glutathione s-transferase (gst). gst-endo-a fusion was extracted as a soluble protein. the fusion protein was purified to homogeneity with glutathione-sepharose 4b and showed transglycosylation activity toward high-mannose-type glycopeptides without removing the gst ... | 2000 | 10623587 |
| degradation of o-nitrobenzoate via anthranilic acid (o-aminobenzoate) by arthrobacter protophormiae: a plasmid-encoded new pathway. | an arthrobacter protophormiae strain rkj100, isolated by selective enrichment, was capable of utilizing o-nitrobenzoate (onb(+)) as the sole carbon, nitrogen, and energy source. the degradation of onb proceeds through an oxygen insensitive reductive route as shown by the release of ammonia in the culture medium aerobically rather than nitrite ions. thin-layer chromatography, gas chromatography, and gas chromatography-mass spectrometry of the intermediates have shown that onb is degraded by a two ... | 2000 | 10623604 |
| humus bacteria of norway spruce stands: plant growth promoting properties and birch, red fescue and alder colonizing capacity. | we studied the potential of the humus layer of the norway spruce stands to supply beneficial rhizobacteria to birch (betula pendula), alder (alnus incana) and fescue grass (festuca rubra), representatives of pioneer vegetation after clear-cutting of the coniferous forest. axenically grown seedlings of these species were inoculated with the acid spruce humus, ph 3.7-5.3. actinorhizal propagules, capable of nodulating alder, were present in high density (10(3) g(-1)) in humus of long-term limed pl ... | 2000 | 10640667 |
| degradation of phenanthrene by different bacteria: evidence for novel transformation sequences involving the formation of 1-naphthol. | four polycyclic aromatic hydrocarbon (pah)-degrading bacteria, namely arthrobacter sulphureus rkj4, acidovorax delafieldii p4-1, brevibacterium sp. hl4 and pseudomonas sp. dlc-p11, capable of utilizing phenanthrene as the sole source of carbon and energy, were tested for its degradation using radiolabelled phenanthrene. [9-14c]phenanthrene was incubated with microorganisms containing 100 mg/l unlabelled phenanthrene and the evolution of 14co2 was monitored: within 18 h of incubation, 30.1, 35.6, ... | 1999 | 10645629 |
| cloning and sequence analysis of the gene for glucodextranase from arthrobacter globiformis t-3044 and expression in escherichia coli cells. | the gld gene for glucodextranase from arthrobacter globiformis t-3044 was cloned by using a combination of gene walking and probe methods and expressed on the recombinant plasmid pgd8, which was constructed with puc118, in escherichia coli cells. the enzyme gene consisted of a unique open reading frame of 3,153 bp. the comparison of the dna sequence data with the n-terminal and 6 internal amino acid sequences of the purified enzyme secreted from a. globiformis t-3044 suggested the enzyme was tra ... | 1999 | 10664850 |
| cloning and nucleotide sequence of a gene encoding a glycogen debranching enzyme in the trehalose operon from arthrobacter sp. q36. | a gene located just upstream of the treyz operon was isolated from arthrobacter sp. strain q36. the gene, designated trex, encoded an 823-amino acid protein. the amino acid sequence of the protein had 50% identity with the trex protein (isoamylase) from sulfolobus acidocaldarius atcc 33909 which has a trezxy operon on the genome. we suggest that arthrobacter trex is an isoamylase gene, and that it is a component of a trexyz operon. | 2000 | 10669803 |
| purification of recombinant hydantoinase and l-n-carbamoylase from arthrobacter aurescens expressed in escherichia coli: comparison of wild-type and genetically modified proteins. | two enzymes, hydantoinase (hyuh) and l-n-carbamoylase (hyuc), are required for the biocatalytic production of natural and unnatural, optically pure l-amino acids starting from d,l-5-monosubstituted hydantoins using the so called 'hydantoinase-method'. for the preparation of immobilized enzymes, which omit several drawbacks of whole cell biocatalysts, purified or at least enriched hyuh and hyuc have to be provided. in order to simplify existing purification protocols several genetically modified ... | 2000 | 10681054 |
| kinetic studies of the mechanism of carbon-hydrogen bond breakage by the heterotetrameric sarcosine oxidase of arthrobacter sp. 1-in. | the reaction of heterotetrameric sarcosine oxidase (tsox) of arthrobactor sp. 1-in has been studied by stopped-flow spectroscopy, with particular emphasis on the reduction of the enzyme by sarcosine. expression of the cloned gene encoding tsox in escherichia coli enables the production of tsox on a scale suitable for stopped-flow studies. treatment of the enzyme with sulfite provides the means for selective formation of a flavin-sulfite adduct with the covalent 8alpha-(n(3)-histidyl)-fmn. format ... | 2000 | 10684595 |
| [conjugative transfer of a plasmid from escherichia coli to various strains of the order actinomycetales]. | the conjugal transfer of autonomous and integrative plasmids from the donor strain escherichia coli s17-1 to strains of genera actinomadura, arthrobacter, kitasatoa, micromonospora, nocardia, rhodococcus, saccharopolyspora, and to 16 strains of the genus streptomyces was demonstrated. the status of plasmids in recipient strains and the stability of their inheritance were analyzed. plasmids constructed for strains of the genus streptomyces were shown to function in a large number of strains belon ... | 1999 | 10687092 |
| inverting enantioselectivity by directed evolution of hydantoinase for improved production of l-methionine. | using directed evolution, we have improved the hydantoinase process for production of l-methionine (l-met) in escherichia coli. this was accomplished by inverting the enantioselectivity and increasing the total activity of a key enzyme in a whole-cell catalyst. the selectivity of all known hydantoinases for d-5-(2-methylthioethyl)hydantoin (d-mteh) over the l-enantiomer leads to the accumulation of intermediates and reduced productivity for the l-amino acid. we used random mutagenesis, saturatio ... | 2000 | 10700149 |
| molecular cloning, sequencing, expression, and site-directed mutagenesis of the 1h-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase gene from arthrobacter spec. rü61a. | the ring cleaving enzyme 1h-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (hod)) of arthrobacter spec. rü61a is part of the quinaldine degradation pathway. carbon monoxide and n-acetyl-anthranilate are the products formed by dioxygenolytic cleavage of two c-c bonds in the substrate's pyridine ring. the gene coding for hod was cloned and sequenced. an isoelectric point of ph 5.40 and a molecular mass of 31,838 da was deduced from the sequence. hod is shown to be remarkably similar to 1h-3-hydroxy-4-o ... | 2000 | 10746195 |
| identification of coryneform bacterial isolates by ribosomal dna sequence analysis. | identification of coryneform bacteria to the species level is important in certain circumstances for differentiating contamination and/or colonization from infection, which influences decisions regarding clinical intervention. however, methods currently used in clinical microbiology laboratories for the species identification of coryneform bacteria are often inadequate. we evaluated the microseq 500 16s bacterial sequencing kit (perkin-elmer biosystems, foster city, calif.), which is designed to ... | 2000 | 10747168 |
| microbial responses to environmentally toxic cadmium. | we analyzed the soil microbial communities from one uncontaminated and two metal-impacted soils and found that while cadmium adversely affected the numbers of culturable bacteria in all soils, cadmium-resistant isolates were found from each of the soils. with exposure to 24 and 48 µg ml(-1) soluble cadmium, the metal-contaminated soil communities were more resistant than the uncontaminated soil community. in addition, in one metal-stressed soil, the resistant population became more resistant wit ... | 1999 | 10758182 |
| plasmid-encoded degradation of p-nitrophenol and 4-nitrocatechol by arthrobacter protophormiae. | arthrobacter protophormiae strain rkj100 is capable of utilizing p-nitrophenol (pnp) as well as 4-nitrocatechol (nc) as the sole source of carbon, nitrogen and energy. the degradation of pnp and nc by this microorganism takes place through an oxidative route, as stoichiometry of nitrite molecules was observed when the strain was grown on pnp or nc as sole carbon and energy sources. the degradative pathways of pnp and nc were elucidated on the basis of enzyme assays and chemical characterization ... | 2000 | 10772893 |
| structural analysis of the elongation factor g protein from the low-temperature-adapted bacterium arthrobacter globiformis si55. | the first structural analysis of elongation factor g (ef-g) from a cold-adapted bacterium is presented. ef-g is an essential protein involved in the elongation process during protein synthesis and is therefore thought to play a crucial role in the low-temperature adaptation of cold-adapted microorganisms. to define its importance, the ef-g gene (fus) from the psychrotolerant bacterium arthrobacter globiformis si55 was cloned and sequenced. the deduced primary structure of the elongation factor i ... | 2000 | 10805567 |
| identification of arthrobacter oxydans, arthrobacter luteolus sp. nov., and arthrobacter albus sp. nov., isolated from human clinical specimens. | five arthrobacter isolates from clinical specimens were studied by phenotypic, chemotaxonomic, and genetic characterization. two strains had characteristics consistent with those of arthrobacter oxydans. one strain was related to a. citreus; however, dna-dna hybridization and phenotypic characteristics indicated that this strain belongs to a new species, for which the name arthrobacter luteolus sp. nov. is proposed. two strains were closely related to a. cumminsii by 16s rrna gene sequencing, bu ... | 2000 | 10835019 |
| purification and characterization of a novel dna repair enzyme from the extremely radioresistant bacterium rubrobacter radiotolerans. | rubrobacter radiotolerans is an extremely radioresistant bacterium. it exhibits higher resistance than the well-known radioresistant bacterium deinococcus radiodurans, but the molecular mechanisms responsible for the radio-resistance of r. radiotolerans remain unknown. in the present study, we have demonstrated the presence of a novel dna repair enzyme in r. radiotolerans cells that recognizes radiation-induced dna damages such as thymine glycol, urea residues, and abasic sites. the enzyme was p ... | 2000 | 10838807 |
| phylogenetic and physiological diversity of arthrobacter strains isolated from unconsolidated subsurface sediments. | forty strains of gram-positive, aerobic, heterotrophic bacteria isolated from saturated subsurface lacustrine, paleosol and fluvial sediments at the us department of energy's hanford site in south central washington state were characterized by phylogenetic analysis of 16s rrna gene sequences and by determination of selected morphological, physiological and biochemical traits. phylogenetic analyses of 16s rdna sequences from subsurface isolates in the context of similar sequences from previously ... | 2000 | 10846209 |
| transformation of arabidopsis with the coda gene for choline oxidase enhances freezing tolerance of plants. | arabidopsis thaliana was transformed with the coda gene from arthrobacter globiformis, which encodes choline oxidase, the enzyme that synthesizes glycinebetaine from choline. the transformation enabled the plants to accumulate glycinebetaine in chloroplasts, and significantly enhanced the freezing tolerance of plants. furthermore, the photosynthetic machinery of transformed plants was more tolerant to freezing stress than that of wild-type plants. exogenous application of glycinebetaine also inc ... | 2000 | 10849360 |
| determination of n-acetyl- and n-glycolylneuraminic acids in gangliosides by combination of neuraminidase hydrolysis and fluorometric high-performance liquid chromatography using a gm3 derivative as an internal standard. | a highly sensitive method for quantification of sialic acids in gangliosides was developed. the sialic acids, released by hydrolysis of gangliosides, were converted to fluorescent derivatives with 1,2-diamino-4,5-(methylenedioxy)benzene (dmb) and separated on a reversed-phase c18 column with an isocratic elution. as little as 0.1-1.0 nmol of sialic acid in ganglioside was quantified. the use of acetate buffer instead of water in the mobile phase could prevent damage on the column and reduce back ... | 2000 | 10870835 |
| dimethylsulfone as a growth substrate for novel methylotrophic species of hyphomicrobium and arthrobacter. | dimethylsulfone is a major product of the chemical oxidation in the atmosphere of the principal biogenic sulfur gas, dimethylsulfide, but no studies have been reported on the mechanisms for its microbiological degradation. three novel strains of bacteria have been isolated from enrichment cultures provided with dimethylsulfone as the only carbon and energy substrate. these are novel facultatively methylotrophic species of hyphonmicrobium and arthobacter, capable of growth on a range of one-carbo ... | 2000 | 10896224 |
| characteristics of levan fructotransferase from arthrobacter ureafaciens k2032 and difructose anhydride iv formation from levan. | a microorganism producing levan fructotransferase was isolated from sugar-disclosed soil and it was identified as arthrobacter ureafaciens. the major product from levan by enzyme reaction was identified as di-d-fructofuranose 2,6':6,2' dianhydride by mass spectrometry, nuclear magnetic resonance, and chemical analyses. small amounts of several oligosaccharides and free fructose were also formed by enzyme reaction. an extracellular enzyme that produces di-d-fructofuranose 2,6':6,2' dianhydride fr ... | 2000 | 10899545 |
| specific detection of p-chlorobenzoic acid by escherichia coli bearing a plasmid-borne fcba'::lux fusion. | in this communication we report on a genetically engineered bacterium that reacts by light emission to the presence of 4-chlorobenzoic acid. to construct this strain, dna fragment (1.7 kb) upstream from the 4-chlorobenzoic acid dehalogenase (fcb) operon of arthrobacter su was fused to vibriofischeri luxcdabe genes. an escherichia coli strain transformed with a multi-copy plasmid (pasu) bearing this fusion responded to the presence of 4-chlorobenzoic acid and a few closely related compounds by in ... | 1999 | 10901680 |
| comparison of colony lift with direct spotting methods of blot preparation on the effect of colony hybridization in the detection of environmental organisms. | nucleic acid probes are used on site to detect or to identify individual microbial cells without cultivation. this molecular technique can avoid some limitations of traditional identification methods including time consuming and imprecise. this study examined the factors affecting colony hybridization and compared the effectiveness of membrane prepared by colony lifting with direct spotting procedures using the universal probe eub 338. the results of hybridization varied depending on the type of ... | 2000 | 10917884 |
| genetic diversity among arthrobacter species collected across a heterogeneous series of terrestrial deep-subsurface sediments as determined on the basis of 16s rrna and reca gene sequences. | this study was undertaken in an effort to understand how the population structure of bacteria within terrestrial deep-subsurface environments correlates with the physical and chemical structure of their environment. phylogenetic analysis was performed on strains of arthrobacter that were collected from various depths, which included a number of different sedimentary units from the yakima barricade borehole at the u.s. department of energy's hanford site, washington, in august 1992. at the same t ... | 2000 | 10919806 |
| effect of field inoculation with sinorhizobium meliloti l33 on the composition of bacterial communities in rhizospheres of a target plant (medicago sativa) and a non-target plant (chenopodium album)-linking of 16s rrna gene-based single-strand conformation polymorphism community profiles to the diversity of cultivated bacteria. | fourteen weeks after field release of luciferase gene-tagged sinorhizobium meliloti l33 in field plots seeded with medicago sativa, we found that the inoculant also occurred in bulk soil from noninoculated control plots. in rhizospheres of m. sativa plants, s. meliloti l33 could be detected in noninoculated plots 12 weeks after inoculation, indicating that growth in the rhizosphere preceded spread into bulk soil. to determine whether inoculation affected bacterial diversity, 1,119 bacteria were ... | 2000 | 10919821 |
| [reproductive resting forms of arthrobacter globiformis]. | submerged cultures of arthrobacter globiformis grown in media unbalanced with respect to carbon and nitrogen sources were found to contain cells exhibiting features typical of resting forms: long-term viability, specific ultrastructure, dormant metabolism, and thermoresistance. such cells were produced not only in the collection strain vkm b-1112, but also in the a. globiformis strains isolated from 2- to 3-million-year-old permafrost sediments. | 2000 | 10920808 |
| [formation of resting forms of arthrobacter globiformis in autolysing cell suspensions]. | under conditions of spontaneous or induced autolysis of thick cell suspensions, arthrobacter globiformis strains produced cells exhibiting features typical of resting microbial forms. the number of viable resting cells was greater under conditions of induced rather than spontaneous autolysis. the thermoresistance of the resting cells of a. globiformis strains isolated from 2- to 3 million-year-old permafrost was higher than that of the collection a. globiformis strain. | 2000 | 10920809 |
| kinetics of biodegradation of p-nitrophenol by different bacteria. | three bacterial species, i.e., ralstonia sp. sj98, arthrobacter protophormiae rkj100, and burkholderia cepacia rkj200, have been examined for their efficiency and kinetics behavior toward pnp degradation. all the three bacteria utilized pnp as the sole source of carbon, nitrogen, and energy. the rates of radiolabeled [u-(14)c]pnp degradation by all the bacteria were higher in the nitrogen-free medium compared to the medium with nitrogen. the apparent k(m) values of pnp degradation by sj98, rkj10 ... | 2000 | 10924328 |
| genetic engineering of glycinebetaine synthesis in plants: current status and implications for enhancement of stress tolerance. | metabolic acclimation via the accumulation of compatible solutes is regarded as a basic strategy for the protection and survival of plants in extreme environments. certain plants accumulate significant amounts of glycinebetaine (betaine), a compatible quaternary amine, in response to high salinity, cold and drought. it is likely that betaine is involved in the protection of macrocomponents of plant cells, such as protein complexes and membranes, under stress conditions. genetic engineering of th ... | 2000 | 10938798 |
| arthrobacter flavus sp. nov., a psychrophilic bacterium isolated from a pond in mcmurdo dry valley, antarctica. | cms 19yt, a psychrophilic bacterium, was isolated from a cyanobacterial mat sample from a pond in antarctica and was characterized taxonomically. the bacterium was aerobic, gram-positive, non-spore-forming, non-motile, exhibited a rod-coccus growth cycle and produced a yellow pigment that was insoluble in water but soluble in methanol. no growth factors were required and it was able to grow between 5 and 30 degrees c, between ph 6 and ph 9 and tolerated up to 11.5% nacl. the cell wall peptidogly ... | 2000 | 10939663 |
| difructose anhydrides: their mass-production and physiological functions. | difructose anhydrides (dfas) are the smallest cyclic disaccharides consisting of two fructose residues, and are expected to have novel physiological functions from their unique structures and properties. for mass-production of alpha-d-fructofuranose-beta-d-fructofuranose-2',1:2,3'-dianhydride (dfa iii) and beta-d-fructofuranose-beta-d-fructofuranose-2',6:2,6'-dianhydride (dfa iv), arthrobacter sp. h65-7 and a. nicotinovorans gs-9 were selected as the best producers of inulase ii, which produced ... | 2000 | 10945246 |
| overexpression, purification, and characterization of bacillus subtilis n-acetylmuramoyl-l-alanine amidase cwlc. | n-acetylmuramoyl-l-alanine amidase cwlc of bacillus subtilis was overproduced in escherichia coli and purified 21-fold. the amidase hydrolyzed type a cell walls such as b. subtilis. the amidase bound slightly to the microbacterium lacticum cell wall (type b), but did not entirely hydrolyze it. the presence of calcium or magnesium ion increased the resistance of the amidase to heat denaturation. | 2000 | 10945275 |
| hydantoin racemase from arthrobacter aurescens dsm 3747: heterologous expression, purification and characterization. | in arthrobacter aurescens dsm 3747 three enzymes are involved in the complete conversion of slowly racemizing 5'-monosubstituted d,l-hydantoins to l-amino acids, a stereoselective hydantoinase, a stereospecific l-n-carbamoylase and a hydantoin racemase. the gene encoding the hydantoin racemase, designated hyua, was identified upstream of the previously described l-n-carbamoylase gene in the plasmid paw16 containing genomic dna of a. aurescens. the gene hyua which encodes a polypeptide of 25.1 kd ... | 2000 | 10949312 |
| effect of associative bacteria on element composition of barley seedlings grown in solution culture at toxic cadmium concentrations. | the response of barley seedlings to inoculation with associative rhizobacteria azospirillum lipoferum 137, arthrobacter mysorens 7, agrobacterium radiobacter 10 and flavobacterium sp. l30 was studied in hydroponic and quartz sand cultures in the presence of 50 microm cdcl2. cadmium caused severe inhibition in the growth and uptake of nutrient elements by the plants. inoculation with the bacteria slightly stimulated root length and biomass of hydroponically grown cd-treated seedlings. the bacteri ... | 2000 | 10950194 |
| gene cloning and overproduction of low-specificity d-threonine aldolase from alcaligenes xylosoxidans and its application for production of a key intermediate for parkinsonism drug. | the dtaax gene encoding a pyridoxal 5'-phosphate (pyridoxal-p)-dependent low-specificity d-threonine aldolase was cloned from the chromosomal dna of alcaligenes xylosoxidans ifo 12669. it contains an open reading frame consisting of 1,134 nucleotides corresponding to 377 amino acid residues. the predicted amino acid sequence displayed 54% identity with that of d-threonine aldolase from gram-positive bacteria arthrobacter sp. dk-38, but showed no significant similarity with those of other known p ... | 2000 | 10952004 |
| changes of cell size distribution during the batch culture of arthrobacter strain pi/1-95. | the size distributions of an arthrobacter, approximately 1 microm in diameter, were analysed using a coulter multisizer ii instrument thereby making it possible to distinguish between the different stages in the morphological cycle. the results indicated that at the beginning of exponential phase a shift occurred from large to smaller cells, the cell size distributions in both categories were asymmetric, skewed towards higher values than the means. during the course of the batch culture the cell ... | 2000 | 10959562 |
| microbiology of the stalactites from grotta dei cervi, porto badisco, italy. | the active stalactites from grotta dei cervi, porto badisco, southeastern italy, were sampled to investigate the microbial communities present in these speleothems. sampling was carried out in a transect about 150 m long in the central gallery, where numerous gram-positive bacteria were isolated. actinomycetes of the genus streptomyces were the most abundant, followed by members of the genus bacillus. further isolates were assigned to the genera amycolatopsis, arthrobacter; agromyces. micrococcu ... | 2000 | 10963330 |
| expression of podocalyxin inhibits cell-cell adhesion and modifies junctional properties in madin-darby canine kidney cells. | podocalyxin is a major membrane protein of the glomerular epithelium and is thought to be involved in maintenance of the architecture of the foot processes and filtration slits characteristic of this unique epithelium by virtue of its high negative charge. however, until now there has been no direct evidence for podocalyxin's function. podocalyxin is a type 1 transmembrane sialoprotein with an n-terminal mucin-like domain. to assess its function, we cloned rat podocalyxin and examined the effect ... | 2000 | 10982412 |
| microbial species associated with different sections of broccoli harvested from three regions in australia. | the microbial populations associated with the different sections of broccoli harvested from three locations in australia were studied during storage at 5, 15 and 20 degrees c. bacterial and yeast populations associated with the outer florets and cut surfaces of the stem were generally 10-fold or more higher than those associated with inner florets or non-cut stems, respectively. the predominating bacterial species varied with the origin of the broccoli. pseudomonas fluorescens, ps. corrugata and ... | 2000 | 11014518 |
| microbial diversity during maturation and natural processing of coffee cherries of coffea arabica in brazil. | the magnitude and diversity of the microbial population associated with dry (natural) processing of coffee (coffea arabica) has been assessed during a 2-year period on 15 different farms in the sul de minas region of brazil. peptone water-washed samples were taken of maturing cherries on trees (cherries, raisins and dried cherries) and from ground fermentations. the microbial load varied from 3 x 10(4) to 2.2 x 10(9) cfu/cherry with a median value of 1.6 x 10(7) cfu/cherry. the microbial load in ... | 2000 | 11016614 |
| renibacterium salmoninarum isolates from different sources possess two highly conserved copies of the rrna operon . | the nucleotide sequences of the rrna genes and the 5' flanking region were determined for r. salmoninarum atcc 33209t from overlapping products generated by pcr amplification from the genomic dna. comparison of the sequences with rrna genes from a variety of bacteria demonstrated the close relatedness between r. salmoninarum and the high g+c group of the actinobacteria, in particular, arthrobacter species. a regulatory element within the 5' leader of the rrna operon was identical to an element, ... | 2000 | 11016696 |
| 3-carbamoyl-alpha-picolinic acid production by imidase-catalyzed regioselective hydrolysis of 2,3-pyridinedicarboximide in a water-organic solvent, two-phase system. | 3-carbamoyl-alpha-picolinic acid, a versatile building block for the synthesis of agrochemicals and pharmaceuticals, was prepared by imidase-catalyzed regiospecific hydrolysis of 2,3-pyridinedicarboximide with intact arthrobacter ureafaciens o-86 cells. reactions were carried out in a water-organic solvent, two-phase system containing cyclohexanone at low ph to avoid spontaneous random hydrolysis. under the optimized conditions, with the periodic addition of 2,3-pyridinedicarboximide (in total, ... | 2000 | 11030568 |
| a mutant sarcosine oxidase in which activity depends on flavin adenine dinucleotide. | the covalent flavin attachment site in the arthrobacter sarcosine oxidase (cysteine at position 318) was replaced with serine, and the mutational effect of c318s was analyzed. wild type and c318s with a c-terminal 6-histidine tag were constructed and homogeneously purified by the single step. the covalently binding to flavin was not essential to the enzyme activity because the c318s mutant exhibited extremely weak activity. moreover, the activity of the mutant was recovered in the presence of fl ... | 2000 | 11035956 |
| measuring growth of a phenanthrene-degrading bacterial inoculum in soil with a quantitative competitive polymerase chain reaction method. | we measured growth of a phenanthrene-degrading bacterium, arthrobacter, strain rp17, in forbes soil, amended with 500 µg g(-1) phenanthrene using a quantitative competitive polymerase chain reaction method. the inoculum, which was not indigenous to forbes soil, grew from 5.55x10(5) colony forming units (cfu) g(-1) to 1.97x10(7) cfu g(-1) within 100 h after the cells were added to the soil. maximum population density was reached before the highest degradation rate was observed 150 h after the cel ... | 2000 | 11053730 |
| enzymatic assay of histamine by amperometric detection of h2o2 with a peroxidase-based sensor. | a method for an enzymatic assay of histamine by using histamine oxidase from arthrobacter globiformis in combination with amperometric determination of h2o2 is described. histamine could be quantified at a level as low as 10(-7) m. the assay is adaptable to determine histamine in food samples including tuna fish with good sensitivity and selectivity. | 2000 | 11055403 |
| monitoring bacterial transport by stable isotope enrichment of cells. | understanding the transport and behavior of bacteria in the environment has broad implications in diverse areas, ranging from agriculture to groundwater quality, risk assessment, and bioremediation. the ability to reliably track and enumerate specific bacterial populations in the context of native communities and environments is key to developing this understanding. we report a novel bacterial tracking approach, based on altering the stable carbon isotope value (delta(13)c) of bacterial cells, w ... | 2000 | 11055946 |
| enhanced tolerance of transgenic brassica juncea to choline confirms successful expression of the bacterial coda gene. | brassica juncea cv. pusa jaikisan was transformed with the coda gene for choline oxidase from arthrobacter globiformis with an aim to introduce glycine betaine biosynthetic pathway, as it lacks any means to synthesize glycine betaine. western blot analysis revealed the presence of choline oxidase in the protein extract from the coda transgenic lines, demonstrating that the bacterial coda gene had been successfully transcribed and translated in transgenic lines. good activity of choline oxidase i ... | 2000 | 11074276 |
| diversity of l-methionine catabolism pathways in cheese-ripening bacteria. | enzymatic activities that could be involved in methanethiol generation in five cheese-ripening bacteria were assayed, and the major sulfur compounds produced were identified. l-methionine and alpha-keto-gamma-methyl-thio-butyric acid demethiolating activities were detected in whole cells and cell extracts (cfes) of all the bacteria tested. no l-methionine deaminase activity could be detected in any of the ripening bacteria and l-methionine aminotransferase was detected in cfes of brevibacterium ... | 2000 | 11097940 |
| bacterial release of arsenic ions and organoarsenic compounds from soil contaminated by chemical warfare agents. | the objective of this paper was to investigate possible participation of microorganisms in the release of soluble arsenical compounds from organoarsenic warfare agents in contaminated soil. a number of bacterial strains were isolated with high resistance against as3+ and as5+ ions which are able to degrade the water insoluble compounds triphenylarsine (tp) and triphenylarsineoxide (tpo). these strains belong to different genera of bacteria. release of arsenic ions and soluble organoarsenic compo ... | 2001 | 11100795 |
| change in receptor-binding specificity of recent human influenza a viruses (h3n2): a single amino acid change in hemagglutinin altered its recognition of sialyloligosaccharides. | human h3n2 influenza a viruses were known to preferentially bind to sialic acid (sa) in alpha2,6gal linkage on red blood cells (rbc). however, h3n2 viruses isolated in mdck cells after 1992 did not agglutinate chicken rbc (crbc). experiments with point-mutated hemagglutinin (ha) of a/aichi/51/92, one of these viruses, revealed that an amino acid change from glu to asp at position 190 (e190d) was responsible for the loss of ability to bind to crbc. a/aichi/51/92 did not agglutinate crbc treated w ... | 2000 | 11118381 |
| trypsin inhibitory activity of bovine fetuin de-o-glycosylated by endo-alpha-n-acetylgalactosaminidase. | the effects of bovine fetuin o-glycans on its trypsin inhibitory activity were examined. de-sialylated (asialo-) and de-o-glycosylated fetuin were prepared from native fetuin using arthrobacter neuraminidase and the mixture of it and bacillus endo-alpha-n-acetylgalactosaminidase, respectively. de-sialylation and de-o-glycosylation from fetuin were confirmed with sds-page followed by western blotting using anti-human thomsen-friedenreich antigen (t antigen) antibody which recognizes o-linked gala ... | 2000 | 11129611 |
| analysis of bacterial communities in the rhizosphere of chrysanthemum via denaturing gradient gel electrophoresis of pcr-amplified 16s rrna as well as dna fragments coding for 16s rrna. | the effect of developing chrysanthemum roots on the presence and activity of bacterial populations in the rhizosphere was examined by using culture-independent methods. nucleic acids were extracted from rhizosphere soil samples associated with the bases of roots or root tips of plants harvested at different stages of development. pcr and reverse transcriptase (rt) pcr were used to amplify 16s ribosomal dna (rdna) and 16s rrna, respectively, and the products were subjected to denaturing gradient ... | 2001 | 11133442 |
| glucose isomerase: insights into protein engineering for increased thermostability. | thermostable glucose isomerases are desirable for production of 55% fructose syrups at >90 degrees c. current commercial enzymes operate only at 60 degrees c to produce 45% fructose syrups. protein engineering to construct more stable enzymes has so far been relatively unsuccessful, so this review focuses on elucidation of the thermal inactivation pathway as a future guide. the primary and tertiary structures of 11 class 1 and 20 class 2 enzymes are compared. within each class the structures are ... | 2000 | 11150612 |
| bioremediation of polychlorinated biphenyl-contaminated soil using carvone and surfactant-grown bacteria. | partial bioremediation of polychlorinated biphenyl (pcb)-contaminated soil was achieved by repeated applications of pcb-degrading bacteria and a surfactant applied 34 times over an 18-week period. two bacterial species, arthrobacter sp. strain b1b and ralstonia eutrophus h850, were induced for pcb degradation by carvone and salicylic acid, respectively, and were complementary for the removal of different pcb congeners. a variety of application strategies was examined utilizing a surfactant, sorb ... | 2000 | 11152078 |
| arthrobacter chlorophenolicus sp. nov., a new species capable of degrading high concentrations of 4-chlorophenol. | a micro-organism was isolated from soil which could grow on high concentrations [up to 350 p.p.m. (2.7 mm)] of 4-chlorophenol (4-cp). the isolate, designated strain a6t, was obtained from a soil suspension that had been selectively enriched with gradually increasing concentrations of 4-cp. strain a6t could also grow on several other para-substituted phenols. characterization of strain a6t with respect to chemical, biochemical and morphological properties, 16s rdna sequencing and dna-dna hybridiz ... | 2000 | 11155983 |
| cloning, sequences, and characterization of two chitinase genes from the antarctic arthrobacter sp. strain tad20: isolation and partial characterization of the enzymes. | arthrobacter sp. strain tad20, a chitinolytic gram-positive organism, was isolated from the sea bottom along the antarctic ice shell. arthrobacter sp. strain tad20 secretes two major chitinases, chia and chib (archia and archib), in response to chitin induction. a single chromosomal dna fragment containing the genes coding for both chitinases was cloned in escherichia coli. dna sequencing analysis of this fragment revealed two contiguous open reading frames coding for the precursors of archia (8 ... | 2001 | 11160110 |
| a unique sialidase that cleaves the neu5gcalpha2-->5-o(glycolyl)neu5gc linkage: comparison of its specificity with that of three microbial sialidases toward four sialic acid dimers. | we found that the hepatopancreas of oyster, crassostrea virginica, contained a sialidase capable of releasing neu5gc from the novel polysialic acid chain (-->5-o(glycolyl)neu5gcalpha2-->)n more efficiently than from the conventional type of polysialic acid chains, (-->8neu5acalpha2-->)n, or (-->8neu5gcalpha2-->)n. we have partially purified this novel sialidase and compared its reactivity with that of microbial sialidases using four different sialic acid dimers, neu5gcalpha2-->5-o(glycolyl)neu5g ... | 2001 | 11162485 |
| study of the structure-activity relationships for the pyrazinamidase (pnca) from mycobacterium tuberculosis. | in an attempt to investigate the molecular basis of pyrazinamide hydrolysis by the pnca protein from mycobacterium tuberculosis, we determined the pyrazinamidase activity of nine pnca mutants bearing a single amino acid substitution. among them, three mutants (d8g, k96t and s104r) had virtually no activity (< or =0.004 unit/mg), five (f13s, t61p, p69l, y103s and a146v) retained a low level of activity (0.06-0.25 unit/mg) and one (t167l) exhibited a wild-type activity (1.51 units/mg). the possibl ... | 2001 | 11171040 |
| secretory production of arthrobacter levan fructotransferase from recombinant escherichia coli. | levan fructotransferase (lftase) from arthrobacter ureafaciens k2032 was expressed with n-terminal fusion of a lacz-derived secretion motif (tmitnsssvp) using the lac promoter system in recombinant escherichia coli jm109 [pudf-a81]. in flask cultures, recombinant enzyme activity was detected in culture media, and sequence analysis of n-terminal residues showed that about 40% of the extracellular recombinant lftase had an authentic n-terminus. in a fed-batch bioreactor containing recombinant e. c ... | 2001 | 11179640 |
| purification and characterization of aminopropionaldehyde dehydrogenase from arthrobacter sp. tmp-1. | aminopropionaldehyde dehydrogenase was purified to apparent homogeneity from 1,3-diaminopropane-grown cells of arthrobacter sp. tmp-1. the native molecular mass and the subunit molecular mass of the enzyme were approximately 20,5000 and 52,000, respectively, suggesting that the enzyme is a tetramer of identical subunits. the apparent michaelis constant (k(m)) for 1,3-diaminopropane was approximately 3 microm. the enzyme equally used both nad(+) and nadp(+) as coenzymes. the apparent k(m) values ... | 2001 | 11179651 |
| [two different fermentation techniques of steriod 1,4-dehydrogenation and 11 alpha-hydroxylation]. | two kinds of micro-organism, arthrobacter sp. ax86(1,4-dehdrogenator) and absidia sp. a28(11 alpha-hydroxylator) were used in this experiment. two different fermentation techniques were performed to accomplish the multiple conversional reactions for producing 16 beta-methyl-11 alpha,17 alpha,21-trihydroxy-1,4-pregnadiene-3,20-dione(iii) from 16 beta-methyl-3 beta,17 alpha,21-trihydroxy-5 alpha-pregnane-20-one-21-acetate(i): 1) to produce product(iii) by means of a two-step fermentation method wh ... | 2000 | 11191778 |
| degradation of o-methoxybenzoate by a two-member consortium made up of a gram-positive arthrobacter strain and a gram-negative pantotea strain. | aromatic carboxylic acids substituted with methoxylated groups are among the most abundant products in "alpechin", the wastes resulting from pressing olives to obtain olive oil. degradation of o-methoxybenzoate by an stable consortium made of a gram positive bacterium, arthrobacter oxydans, and gram negative one, pantotea agglomerans, was shown to mineralize this compound efficiently. the concerted action of both microorganisms was needed for the two first steps in the process, namely, the conve ... | 2000 | 11194973 |
| cultivatable microbial biodiversity: gnawing at the gordian knot. | rapid and inexpensive sorting of bacterial isolates may be achieved using fourier transform infrared spectroscopy (ft-ir), a method that has hitherto been applied to identification and classification. the comprehensive characterization of environmental samples requires the isolation of large numbers of isolates using different growth media and growth conditions. in such cases, sorting the isolates is critical before isolates are subjected to more detailed studies. using ft-ir, isolates are grown ... | 2000 | 11200432 |
| arthrobacter siderocapsulatus dubinina and zhdanov 1975al is a later subjective synonym of pseudomonas putida (trevisan 1889) migula 1895al. | the taxonomic position of arthrobacter siderocapsulatus dubinina and zhdanov 1975al was investigated using 16s rdna, fatty acid and phenotypic analyses. the type strain (ncimb 11286t) showed 99.85% 16s rdna similarity to the type strain of pseudomonas putida. phenotypic properties of the two strains were compared using api 20ne and biolog kits. identical reactions were recorded for all tests, except for assimilation of malonic acid. the two strains also showed almost identical cellular fatty aci ... | 2001 | 11211254 |
| development of an escherichia coli whole cell biocatalyst for the production of l-amino acids. | a whole cell biocatalyst for the enzymatic production of l-amino acids from hydantoins was created by coexpressing the genes encoding the l-hydantoinase, the l-n-carbamoylase and the hydantoin racemase from arthrobacter aurescens in escherichia coli. in order to construct a well balanced reaction system the enzymatic activity in the cells was varied by using vectors with different copy numbers for expression of the genes. derivatives of psc101, pacyc184 and pbr322 were employed for the various c ... | 2001 | 11223141 |