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impact of the cold shock phenomenon on quantification of intracellular metabolites in bacteria.in the present work the effect of quenching on quantification of intracellular metabolites in corynebacterium glutamicum was investigated. c. glutamicum showed a high sensitivity to cold shock. quenching of the cells by -50 degrees c buffered methanol prior to cell separation and extraction led to drastically reduced concentrations for free intracellular amino acids compared to those for nonquenched filtration. as demonstrated for glutamate and glutamine, this was clearly due to a more than 90% ...200415033521
a systematic method to identify genomic islands and its applications in analyzing the genomes of corynebacterium glutamicum and vibrio vulnificus cmcp6 chromosome i.some genomic islands contain horizontally transferred genes, which play critical roles in altering the genotypes and phenotypes of organisms, and horizontal gene transfer has been recognized as a universal event throughout bacterial evolution. a windowless method to display the distribution of genomic gc content, the cumulative gc profile, is proposed to identify genomic islands in genomes whose complete genome sequences are available. two new indices are proposed to assess the codon usage bias ...200415033867
projection structure and oligomeric state of the osmoregulated sodium/glycine betaine symporter betp of corynebacterium glutamicum.the high-affinity glycine betaine uptake system betp, an osmosensing and osmoregulated sodium-coupled symporter from corynebacterium glutamicum, was overexpressed in escherichia coli with an n-terminal strepii-tag, solubilized in beta-dodecylmaltoside and purified by streptactin affinity chromatography. analytical ultracentrifugation indicated that betp forms trimers in detergent solution. detergent-solubilized betp can be reconstituted into proteoliposomes without loss of function, suggesting t ...200415046983
clpc and clpp1p2 gene expression in corynebacterium glutamicum is controlled by a regulatory network involving the transcriptional regulators clgr and hspr as well as the ecf sigma factor sigmah.the atp-dependent protease clp plays important roles in the cell's protein quality control system and in the regulation of cellular processes. in corynebacterium glutamicum, the levels of the proteolytic subunits clpp1 and clpp2 as well as of the corresponding mrnas were drastically increased upon deletion of the clpc gene, coding for a clp atpase subunit. we identified a regulatory protein, designated clgr, binding to a common palindromic sequence motif in front of clpp1p2 as well as of clpc. d ...200415049827
lead biosorption by waste biomass of corynebacterium glutamicum generated from lysine fermentation process.biomass waste, mainly corynebacterium glutamicum, is generated from large-scale lysine fermentation process. in this study, protonated c. glutamicum biomass was evaluated as a biosorbent for the removal of lead from synthetic wastewater. as pb2+ were bound to the biomass, the solution ph deceased, indicating that protons in the biomass were exchanged with lead ions. the corynebacterium biomass bound pb2+ at up to 2.74 mmol g(-1) at ph 5, where lead does not precipitate. compared with other bioso ...200415055771
cation specificity of osmosensing by the betaine carrier betp of corynebacterium glutamicum.the na(+)/betaine carrier betp from corynebacterium glutamicum was purified and reconstituted in escherichia coli phospholipid liposomes and its osmosensory properties were studied with respect to the cation specificity of osmotic activation. to dissect the influence of the co-substrate na(+) on the energetics of uptake from its possible role as a putative trigger of osmolality-dependent betp activation, the internal na(+) concentration was varied without changing deltapna(+). studying betaine u ...200415063732
production of a novel polygalacturonic acid bioflocculant rea-11 by corynebacterium glutamicum.the production of a novel polygalacturonic acid bioflocculant rea-11 from a newly isolated strain, corynebacterium glutamicum cctcc m201005, was investigated. sucrose was chosen as a carbon source for rea-11 production. complex nitrogen sources containing urea and an organic nitrogen compound enhanced both bacterial growth and rea-11 production, among which urea plus corn steep liquor was shown to be the most efficient combination. a cost-effective medium for rea-11 production mainly comprised 1 ...200415081493
ramb, a novel transcriptional regulator of genes involved in acetate metabolism of corynebacterium glutamicum.the adaptation of corynebacterium glutamicum to acetate as a carbon and energy source involves transcriptional regulation of the pta-ack operon coding for the acetate-activating enzymes phosphotransacetylase and acetate kinase and of the acea and aceb genes coding for the glyoxylate cycle enzymes isocitrate lyase and malate synthase, respectively. deletion and mutation analysis of the respective promoter regions led to the identification of highly conserved 13-bp motifs (aa/gaactttgcaaa) as cis- ...200415090522
heterologous expression of lactose- and galactose-utilizing pathways from lactic acid bacteria in corynebacterium glutamicum for production of lysine in whey.the genetic determinants for lactose utilization from lactobacillus delbrueckii subsp. bulgaricus atcc 11842 and galactose utilization from lactococcus lactis subsp. cremoris mg 1363 were heterologously expressed in the lysine-overproducing strain corynebacterium glutamicum atcc 21253. the c. glutamicum strains expressing the lactose permease and beta-galactosidase genes of l. delbrueckii subsp. bulgaricus exhibited beta-galactosidase activity in excess of 1000 miller units/ml of cells and were ...200415128544
glutamate as an inhibitor of phosphoenolpyruvate carboxylase activity in corynebacterium glutamicum.the glutamate-producing bacterium, corynebacterium glutamicum is known to possess two anaplerotic enzymes: pyruvate carboxylase (pc) and phosphoenolpyruvate carboxylase (pepc). in vitro, this latter enzyme appeared to be inhibited by different glutamic acid salts, whereas ammonium-glutamate had no influence on pc activity. to investigate the in vivo relevance of pepc activity inhibition, the intracellular concentration of glutamate was determined throughout the glutamate-producing process. the i ...200415133716
detection of low levels of listeria monocytogenes cells by using a fiber-optic immunosensor.biosensor technology has a great potential to meet the need for sensitive and nearly real-time microbial detection from foods. an antibody-based fiber-optic biosensor to detect low levels of listeria monocytogenes cells following an enrichment step was developed. the principle of the sensor is a sandwich immunoassay where a rabbit polyclonal antibody was first immobilized on polystyrene fiber waveguides through a biotin-streptavidin reaction to capture listeria cells on the fiber. capture of cel ...200415466560
the c-terminal domain of the betaine carrier betp of corynebacterium glutamicum is directly involved in sensing k+ as an osmotic stimulus.the glycine betaine carrier betp of corynebacterium glutamicum was recently shown to function both as an osmosensor and as an osmoregulator in proteoliposomes by sensing changes in the internal k(+) concentration as a measure of hyperosmotic stress. in vivo analysis of mutants carrying deletions at the c-terminal extension of betp indicated that this domain participates in osmostress-dependent activity regulation. to address the question, whether a putative k(+) sensor is located within the c-te ...200415134432
utilization of creatinine as an alternative nitrogen source in corynebacterium glutamicum.in order to utilize different nitrogen sources and to survive situations of nitrogen limitation, microorganisms have developed several mechanisms to adapt their metabolism to changes in the nitrogen supply. in this communication, the use of creatinine as an alternative nitrogen source in corynebacterium glutamicum, the identification of a membrane protein involved in creatinine uptake, the transcriptional regulation of the corresponding gene, and expression regulation of the gene encoding the cr ...200415148566
identification and characterization of glxr, a gene involved in regulation of glyoxylate bypass in corynebacterium glutamicum.a corynebacterial clone, previously isolated by scoring repression of laczya fused to the aceb promoter of corynebacterium glutamicum, was analyzed further. in the clone, an open reading frame designated glxr, consisting of 681 nucleotides and encoding a 24,957-da protein, was found. the molecular mass of a native glxr protein was estimated by gel filtration column chromatography to be 44,000 da, suggesting that the protein formed dimers. the predicted amino acid sequence contained both cyclic a ...200415150232
evidence for an arginine exporter encoded by ygga (argo) that is regulated by the lysr-type transcriptional regulator argp in escherichia coli.the anonymous open reading frame ygga of escherichia coli was identified in this study as a gene that is under the transcriptional control of argp (previously called icia), which encodes a lysr-type transcriptional regulator protein. strains with null mutations in either ygga or argp were supersensitive to the arginine analog canavanine, and ygga-lac expression in vivo exhibited argp(+)-dependent induction by arginine. lysine supplementation phenocopied the argp null mutation in that it virtuall ...200415150242
high level expression of streptomyces mobaraensis transglutaminase in corynebacterium glutamicum using a chimeric pro-region from streptomyces cinnamoneus transglutaminase.we previously observed secretion of native-type streptomyces mobaraensis transglutaminase (mtgase) in corynebacterium glutamicum by co-expressing the subtilisin-like protease sam-p45 from s. albogriseolus which processes the pro-region. in the present study, we have used a chimeric pro-region consisting of s. mobaraensis and streptomyces cinnamoneus transglutaminases for the production of mtgase in c. glutamicum. as a result, secretion of mtgase using the chimeric pro-region is increased compare ...200415163512
streptomyces lividans and brevibacterium lactofermentum as heterologous hosts for the production of x22 xylanase from aspergillus nidulans.the aspergillus nidulans gene xlna coding for the fungal xylanase x22 has been cloned and expressed in two heterologous bacterial hosts: streptomyces lividans and brevibacterium lactofermentum. streptomyces strains yielded 10 units/ml of xylanase when the protein was produced with its own signal peptide, and 19 units/ml when its signal peptide was replaced by the one for xylanase xys1 from streptomyces halstedii. b. lactofermentum was also able to produce xylanase x22, affording 6 units/ml upon ...200415168093
functional identification of the gene locus (ncg12319 and characterization of catechol 1,2-dioxygenase in corynebacterium glutamicum.corynebacterium glutamicum assimilated phenol, benzoate, 4-hydroxybenzoate p-cresol and 3,4-dihydroxybenzoate. ring cleavage was by catechol 1,2-dioxygenase when phenol or benzoate was used and by protocatechuate 3,4-dioxygenase when the others were used as substrate. the locus ncg12319 of its genome was cloned and expressed in escherichia coli. enzyme assays showed that ncg12319 encodes a catechol 1,2-dioxygenase. this catechol 1,2-dioxygenase was purified and accepted catechol, 3-, or 4-methyl ...200415168857
integration of e. coli arog-phea tandem genes into corynebacterium glutamicum tyra locus and its effect on l-phenylalanine biosynthesis.to study the effect of integration of tandem arog-phea genes into the tyra locus of corynebacterium glutamicum (c. glutamicum) on the production of l-phenylalanine.200415534933
metabolic network analysis of lysine producing corynebacterium glutamicum at a miniaturized scale.we present a straightforward approach comprising (13)c tracer experiments at 200-microl volume in 96-well microtiter plates with on-line measurement of dissolved oxygen for quantitative high-throughput metabolic network analysis at a miniaturized scale. this method was successfully applied for cultivation and (13)c metabolic flux analysis of two mutants of lysine producing corynebacterium glutamicum (atcc 13287 and atcc 21543). microtiter-plate cultivations showed excellent accordance in kinetic ...200415211482
biochemical and molecular characterization of a ring fission dioxygenase with the ability to oxidize (substituted) salicylate(s) from pseudaminobacter salicylatoxidans.the gene coding for a dioxygenase with the ability to cleave salicylate by a direct ring fission mechanism to 2-oxohepta-3,5-dienedioic acid was cloned from pseudaminobacter salicylatoxidans strain bn12. the deduced amino acid sequence encoded a protein with a molecular mass of 41,176 da, which showed 28 and 31% sequence identity, respectively, to a gentisate 1,2-dioxygenase from pseudomonas alcaligenes ncimb 9867 and a 1-hydroxy-2-naphthoate 1,2-dioxygenase from nocardioides sp. kp7. the highes ...200415220336
inhibitor-associated transposition events in corynebacterium glutamicum.in up to 100% of all bacteria grown in the presence of initially inhibitory concentrations of five diverse inhibitors, an extra copy of the resident insertion element is 31831 was found in specific chromosomal regions, the sites of which apparently depended on the inhibitor used. thus, in nine out of nine independently isolated cyanide-associated transpositions, the acquired copy was located within an orf encoding a protein related to the hypothetical but conserved protein yeih of escherichia co ...200415221457
transcriptional analysis of the groes-groel1, groel2, and dnak genes in corynebacterium glutamicum: characterization of heat shock-induced promoters.the appropriate conditions to switch on the heat shock promoters in corynebacterium glutamicum were defined by northern blot analysis. transcriptional patterns were characterized for the groel2 gene and the groes-groel1 and dnak operons. transcriptional start points of these genes were determined by primer extension analysis, allowing the identification of circe and hair boxes close to the -10 and -35 regions of the promoters. the presence of both circe and hair sequences within a single promote ...200415231814
impact of heterologous expression of escherichia coli udp-glucose pyrophosphorylase on trehalose and glycogen synthesis in corynebacterium glutamicum.trehalose is a disaccharide with a wide range of applications in the food industry. we recently proposed a strategy for trehalose production based on improved strains of the gram-positive bacterium corynebacterium glutamicum. this microorganism synthesizes trehalose through two major pathways, otsba and treyz, by using udp-glucose and adp-glucose, respectively, as the glucosyl donors. in this paper we describe improvement of the udp-glucose supply through heterologous expression in c. glutamicum ...200415240254
osmotic stress response: quantification of cell maintenance and metabolic fluxes in a lysine-overproducing strain of corynebacterium glutamicum.osmotic stress diminishes cell productivity and may cause cell inactivation in industrial fermentations. the quantification of metabolic changes under such conditions is fundamental for understanding and describing microbial behavior during bioprocesses. we quantified the gradual changes that take place when a lysine-overproducing strain of corynebacterium glutamicum is grown in continuous culture with saline gradients at different dilution rates. the use of compatible solutes depended on enviro ...200415240305
identification of the anabaena sp. strain pcc7120 cyanophycin synthetase as suitable enzyme for production of cyanophycin in gram-negative bacteria like pseudomonas putida and ralstonia eutropha.the cyanophycin synthetase gene cpha1 encoding the major cyanophycin synthetase (cpha) of anabaena sp. strain pcc7120 was expressed in escherichia coli conferring so far the highest specific cpha activity to e. coli (6.7 nmol arginine per min and mg protein). cpha1 and cpha genes of synechocystis sp. strains pcc6803 and pcc6308 and synechococcus strain ma19 were also expressed in wild types and polyhydroxyalkanoate-negative (pha) mutants of pseudomonas putida and ralstonia eutropha. recombinant ...200415244482
purification and characterization of o-acetylserine sulfhydrylase of corynebacterium glutamicum.we highly purified o-acetylserine sulfhydrylase from the glutamate-producing bacterium corynebacterium glutamicum. the molecular mass of the purified enzyme was 34,500 as determined by sds-polyacrylamide gel electrophoresis, and 70,800 as determined by gel filtration chromatography. it had an apparent km of 7.0 mm for o-acetylserine and a vmax of 435 micromol min-1 (mg x protein)-1. this is the first report of the cysteine biosynthetic enzyme of c. glutamicum in purified form.200415277766
betp of corynebacterium glutamicum, a transporter with three different functions: betaine transport, osmosensing, and osmoregulation.in order to circumvent deleterious effects of hypo- and hyperosmotic conditions in its environment, corynebacterium glutamicum has developed a number of mechanisms to counteract osmotic stress. the first response to an osmotic upshift is the activation of uptake mechanisms for the compatible solutes betaine, proline, or ectoine, namely betp, ectp, prop, lcop and putp. betp, the most important uptake system responds to osmotic stress by regulation at the level of both protein activity and gene ex ...200415282171
classification of hyper-variable corynebacterium glutamicum surface-layer proteins by sequence analyses and atomic force microscopy.the structural s-layer proteins of 28 different corynebacterium glutamicum isolates have been analyzed systematically. treatment of whole c. glutamicum cells with detergents resulted in the isolation of s-layer proteins with different apparent molecular masses, ranging in size from 55 to 66 kda. the s-layer genes analyzed were characterized by coding regions ranging from 1,473 to 1,533 nucleotides coding for s-layer proteins with a size of 490-510 amino acids. using pcr techniques, the correspon ...200415288952
genomewide expression analysis in amino acid-producing bacteria using dna microarrays.dna microarray technology has become an important research tool for biotechnology and microbiology. it is now possible to characterize genetic diversity and gene expression in a genomewide manner. dna microarrays have been applied extensively to study the biology of many bacteria including escherichia coli, but only recently have they been developed for the gram-positive corynebacterium glutamicum. both bacteria are widely used for biotechnological amino acid production. in this article, in addi ...200415304751
acyl-coa carboxylases (accd2 and accd3), together with a unique polyketide synthase (cg-pks), are key to mycolic acid biosynthesis in corynebacterianeae such as corynebacterium glutamicum and mycobacterium tuberculosis.the corynebacterianeae such as corynebacterium glutamicum and mycobacterium tuberculosis possess several unique and structurally diverse lipids, including the genus-specific mycolic acids. although the function of a number of genes involved in fatty acid and mycolic acid biosynthesis is known, information relevant to the initial steps within these biosynthetic pathways is relatively sparse. interestingly, the genomes of corynebacterianeae possess a high number of accd genes, whose gene products ...200415308633
lcop, an osmoregulated betaine/ectoine uptake system from corynebacterium glutamicum.in corynebacterium glutamicum, four uptake systems for compatible solutes have been characterized so far. dhpe (deltabetpdeltaputpdeltapropdeltaectp), a derivative of the c. glutamicum type strain atcc 13032 carrying deletions in the corresponding genes, still showed a low betaine uptake rate of 1.4 nmol/(min mg cdm). genome analyses revealed the presence of a putative carrier, named low capacity osmoregulated permease (lcop), which shows similarities to compatible solute transporters of the bet ...200415327991
comparative genomics identified two conserved dna modules in a corynebacterial plasmid family present in clinical isolates of the opportunistic human pathogen corynebacterium jeikeium.investigation of 62 clinical isolates of the opportunistic human pathogen corynebacterium jeikeium revealed that 17 possessed plasmids ranging in size from 7.6 to 14.9 kb. the plasmids formed four groups on dna restriction analysis. the complete nucleotide sequence of a representative from each group (pk43, pk64, pcj84, and pb85766) was subsequently determined. additionally, two plasmids (pco455 and pco420) were shown to be derivatives of pk43 and pk64 carrying insertion sequences of the is3 fam ...200415336488
roles of pyruvate kinase and malic enzyme in corynebacterium glutamicum for growth on carbon sources requiring gluconeogenesis.in many bacteria, pyruvate kinase serves a well-defined function in glycolysis, catalyzing an atp-generating reaction. however, its role during growth on carbon sources requiring glucoeneogenesis is less well investigated. we analyzed a defined pyruvate kinase gene (pyk) deletion mutant of corynebacterium glutamicum, which is unable to grow on ribose as sole carbon source. unexpectedly, the pyk deletion mutant was also unable to grow on acetate or citrate as sole carbon sources unless low amount ...200415375646
metabolic analysis of corynebacterium glutamicum during lactate and succinate productions under oxygen deprivation conditions.lactate and succinate were produced from glucose by corynebacterium glutamicum under oxygen deprivation conditions without growth. addition of bicarbonate to the reaction mixture led not only to a 3.6-fold increase in succinate production rate, but also to a 2.3- and 2.5-fold increase, respectively, of the rates of lactate production and glucose consumption, compared to the control. furthermore, when small amounts of pyruvate were added to the reaction mixture, acid production rates and the gluc ...200415383716
regulation of glnk activity: modification, membrane sequestration and proteolysis as regulatory principles in the network of nitrogen control in corynebacterium glutamicum.p(ii)-type signal transduction proteins play a central role in nitrogen regulation in many bacteria. in response to the intracellular nitrogen status, these proteins are rendered in their function and interaction with other proteins by modification/demodification events, e.g. by phosphorylation or uridylylation. in this study, we show that glnk, the only p(ii)-type protein in corynebacterium glutamicum, is adenylylated in response to nitrogen starvation and deadenylylated when the nitrogen suppl ...200415458411
deletion of the genes encoding the mtra-mtrb two-component system of corynebacterium glutamicum has a strong influence on cell morphology, antibiotics susceptibility and expression of genes involved in osmoprotection.the mtrab two-component signal transduction system is highly conserved in sequence and genomic organization in mycobacterium and corynebacterium species, but its function is completely unknown. here, the role of mtrab was studied with c. glutamicum as model organism. in contrast to m. tuberculosis, it was possible to delete the mtrab genes in c. glutamicum. the mutant cells showed a radically different cell morphology and were more sensitive to penicillin, vancomycin and lysozyme but more resist ...200415469514
evolutionary process of amino acid biosynthesis in corynebacterium at the whole genome level.corynebacterium glutamicum, which is the closest relative of corynebacterium efficiens, is widely used for the large scale production of many kinds of amino acids, particularly glutamic acid and lysine, by fermentation. corynebacterium diphtheriae, which is well known as a human pathogen, is also closely related to these two species of corynebacteria, but it lacks such productivity of amino acids. it is an important and interesting question to ask how those closely related bacterial species have ...200415163767
cloning of the o-acetylhomoserine sulfhydrylase gene from the ruminal bacterium selenomonas ruminantium hd4.the o-acetylhomoserine sulfhydrylase (oahs) gene was cloned from a selenomonas ruminantium hd4 lambda zap ii genomic library by degenerative probe hybridization and complementation. sequence analysis revealed an 869-bp orf with a g + c content of 53%. the orf had significant homology with enzymes involved in homocysteine biosynthesis. a curablastn homology search showed that the orf has 63% nucleotide identity with the oahs of bacillus stearothermophilus, corynebacterium glutamicum, and acremoni ...200415057458
characterization and chromosomal organization of the murd-murc-ftsq region of corynebacterium glutamicum atcc 13869.the sequence of a 4.6-kb region of dna from corynebacterium glutamicum atcc 13869 lying upstream from the ftsq-ftsz region has been determined. the region contains four genes with high similarity to the murd, ftsw, murg, and murc genes from different microorganisms. the products of these mur genes probably catalyse several steps in the formation of the precursors for peptidoglycan synthesis in c. glutamicum, whereas ftsw might play also a role in the stabilisation of the ftsz ring during cell di ...200415059630
the glycosylated cell surface protein rpf2, containing a resuscitation-promoting factor motif, is involved in intercellular communication of corynebacterium glutamicum.the genome of corynebacterium glutamicum atcc 13032 contains two genes, rpf1 and rpf2, encoding proteins with similarities to the essential resuscitation-promoting factor (rpf) of micrococcus luteus. both the rpf1 (20.4 kda) and rpf2 (40.3 kda) proteins share the so-called rpf motif, a highly conserved protein domain of approximately 70 amino acids, which is also present in rpf-like proteins of other gram-positive bacteria with a high g+c content of the chromosomal dna. purification of the c. gl ...200415480574
metabolic network simulation using logical loop algorithm and jacobian matrix.a novel method to accomplish efficient numerical simulation of metabolic networks for flux analysis was developed. the only inputs required are the set of stoichiometric balances and the atom mapping matrices of all components of the reaction network. the latter are used to automatically calculate isotopomer mapping matrices. using the symbolic toolbox of matlab the analytical solution of the stoichiometric balance equation system, isotopomer balances and the analytical jacobian matrix of the to ...200415491855
comprehensive analysis of metabolites in corynebacterium glutamicum by gas chromatography/mass spectrometry.an analytical method based on gas chromatography/mass spectrometry was developed for metabolome investigation of corynebacterium glutamicum. for the first time a fast method for metabolic screening that can be automated is described for this organism. more than 1000 compounds could be detected per experiment, ca. 330 of those showed a peak area significantly above background. out of these 164 compounds were identified so far, representing derivatives of 121 different metabolites, which were quan ...200415493881
dynamics of glutamate synthesis and excretion fluxes in batch and continuous cultures of temperature-triggered corynebacterium glutamicum.corynebacterium glutamicum 2262 strain, when triggered for glutamate excretion, experiences a rapid decrease in growth rate and increase in glutamate efflux. in order to gain a better quantitative understanding of the factors controlling the metabolic transition, the fermentation dynamics was investigated for a temperature-sensitive strain cultivated in batch and glucose-limited continuous cultures. for non-excreting cells at 33 degrees c, increasing the growth rate resulted in strong increases ...200415614534
a novel gnd mutation leading to increased l-lysine production in corynebacterium glutamicum.toward more efficient l-lysine production, we have been challenging genome-based strain breeding by the approach of assembling only relevant mutations in a single wild-type background. following the creation of a new l-lysine producer corynebacterium glutamicum ahp-3 that carried three useful mutations (lysc311, hom59, and pyc458) on the relevant downstream pathways, we shifted our target to the pentose phosphate pathway. comparative genomic analysis for the pathway between a classically derived ...200515621447
feedback-resistant acetohydroxy acid synthase increases valine production in corynebacterium glutamicum.acetohydroxy acid synthase (ahas), which catalyzes the key reactions in the biosynthesis pathways of branched-chain amino acids (valine, isoleucine, and leucine), is regulated by the end products of these pathways. the whole corynebacterium glutamicum ilvbnc operon, coding for acetohydroxy acid synthase (ilvbn) and aceto hydroxy acid isomeroreductase (ilvc), was cloned in the newly constructed escherichia coli-c. glutamicum shuttle vector pecka (5.4 kb, km(r)). by using site-directed mutagenesis ...200515640189
isolation and characterization of a native composite transposon, tn14751, carrying 17.4 kilobases of corynebacterium glutamicum chromosomal dna.a native composite transposon was isolated from corynebacterium glutamicum atcc 14751. this transposon comprises two functional copies of a corynebacterial is31831-like insertion sequence organized as converging terminal inverted repeats. this novel 20.3-kb element, tn14751, carries 17.4 kb of c. glutamicum chromosomal dna containing various genes, including genes involved in purine biosynthesis but not genes related to bacterial warfare, such as genes encoding mediators of antibiotic resistance ...200515640215
pyruvate:quinone oxidoreductase from corynebacterium glutamicum: purification and biochemical characterization.pyruvate:quinone oxidoreductase catalyzes the oxidative decarboxylation of pyruvate to acetate and co2 with a quinone as the physiological electron acceptor. so far, this enzyme activity has been found only in escherichia coli. using 2,6-dichloroindophenol as an artificial electron acceptor, we detected pyruvate:quinone oxidoreductase activity in cell extracts of the amino acid producer corynebacterium glutamicum. the activity was highest (0.055 +/- 0.005 u/mg of protein) in cells grown on compl ...200515659664
heat shock proteome analysis of wild-type corynebacterium glutamicum atcc 13032 and a spontaneous mutant lacking groel1, a dispensable chaperone.proteome analysis of corynebacterium glutamicum atcc 13032 showed that levels of several proteins increased drastically in response to heat shock. these proteins were identified as dnak, groel1, groel2, clpb, grpe, and poxb, and their heat response was in agreement with previous transcriptomic results. a major heat-induced protein was absent in the proteome of strain 13032b of c. glutamicum, used for genome sequencing in germany, compared with the wild-type atcc 13032 strain. the missing protein ...200515659666
electron transfer ability from nadh to menaquinone and from nadph to oxygen of type ii nadh dehydrogenase of corynebacterium glutamicum.type ii nadh dehydrogenase of corynebacterium glutamicum (ndh-2) was purified from an ndh overexpressing strain. purification conferred 6-fold higher specific activity of nadh:ubiquinone-1 oxidoreductase with a 3.5-fold higher recovery than that previously reported (k. matsushita et al., 2000). uv-visible and fluorescence analyses of the purified enzyme showed that ndh-2 of c. glutamicum contained non-covalently bound fad but not covalently bound fmn. this enzyme had an ability to catalyze elect ...200515665480
formation of volutin granules in corynebacterium glutamicum.volutin granules are intracellular storages of complexed inorganic polyphosphate (poly p). histochemical staining procedures differentiate between pathogenic corynebacteria such as corynebacterum diphtheriae (containing volutin) and non-pathogenic species, such as c. glutamicum. here we report that strains atcc13032 and mh20-22b of the non-pathogenic c. glutamicum also formed subcellular entities (18-37% of the total cell volume) that had the typical characteristics of volutin granules: (i) volu ...200515668011
large-scale engineering of the corynebacterium glutamicum genome.the engineering of corynebacterium glutamicum is important for enhanced production of biochemicals. to construct an improved c. glutamicum genome, we developed a precise genome excision method based on the cre/loxp recombination system and successfully deleted 11 distinct genomic regions identified by comparative analysis of c. glutamicum genomes. despite the loss of several predicted open reading frames, the mutant cells exhibited normal growth under standard laboratory conditions. with a total ...200515933044
single-gene knockout of a novel regulatory element confers ethionine resistance and elevates methionine production in corynebacterium glutamicum.despite the availability of genome data and recent advances in methionine regulation in corynebacterium glutamicum, sulfur metabolism and its underlying molecular mechanisms are still poorly characterized in this organism. here, we describe the identification of an orf coding for a putative regulatory protein that controls the expression of genes involved in sulfur reduction dependent on extracellular methionine levels. c. glutamicum was randomly mutagenized by transposon mutagenesis and 7,000 m ...200515668756
production of organic acids by corynebacterium glutamicum under oxygen deprivation.under oxygen deprivation, aerobic corynebacterium glutamicum produce organic acids from glucose at high yields in mineral medium even though their proliferation is arrested. to develop a new, high-productivity bioprocess based on these unique features, characteristics of organic acid production by c. glutamicum under oxygen deprivation were investigated. the main organic acids produced from glucose under these conditions were lactic acid and succinic acid. addition of bicarbonate, which is a co- ...200515672268
tetracycline-inducible gene regulation in mycobacteria.a system for the tetracycline-inducible regulation of gene expression in mycobacteria has been developed. we have sub-cloned the tetro region from the corynebacterium glutamicum tetz locus into a mycobacterial shuttle plasmid, making expression of genes cloned downstream of tetro responsive to tetracycline. using the luxab-encoded luciferase from vibrio harveyi as a reporter (pmind-lx), we observed a 40-fold increase in light output from mycobacterium smegmatis cultures 2 h after adding 20 ng ml ...200515687380
a new insertion sequence, is14999, from corynebacterium glutamicum.a new insertion sequence from corynebacterium glutamicum atcc 14999 was isolated and characterized. this is element, designated is14999, comprised a 1149 bp nucleotide sequence with 22 bp imperfect terminal inverted repeats. is14999 carries a single open reading frame of 345 amino acids encoding a putative transposase that appears to have partial homology to is642, an is630/tc1 superfamily element, at the c-terminal region in the amino acid sequence. this indicated that is14999 belonged to the i ...200515699199
identification of acnr, a tetr-type repressor of the aconitase gene acn in corynebacterium glutamicum.in corynebacterium glutamicum, the activity of aconitase is 2.5-4-fold higher on propionate, citrate, or acetate than on glucose. here we show that this variation is caused by transcriptional regulation. in search for putative regulators, a gene (acnr) encoding a tetr-type transcriptional regulator was found to be encoded immediately downstream of the aconitase gene (acn) in c. glutamicum. deletion of the acnr gene led to a 5-fold increased acn-mrna level and a 5-fold increased aconitase activit ...200515494411
gene expression systems in corynebacteria.corynebacterium belongs to a group of gram-positive bacteria having moderate to high g+c content, the other members being mycobacterium, nocardia, and rhodococcus. considerable information is now available on the plasmids, gene regulatory elements, and gene expression in corynebacteria, especially in soil corynebacteria such as corynebacterium glutamicum. these bacteria are non-pathogenic and, unlike bacillus and streptomyces, are low in proteolytic activity and thus have the potential of becomi ...200515766862
effect of cysteine on methionine production by a regulatory mutant of corynebacterium lilium.the production of methionine by submerged fermentation using a mutant strain of corynebacterium lilium was studied to determine suitable conditions for obtaining high productivity. the mutant strain resistant to the methionine analogues ethionine, norleucine, methionine sulfoxide and methionine methylsulfonium chloride produced 2.34 g l(-1) of methionine in minimal medium containing glucose as carbon source. the effect of cysteine on methionine production in a 15 l bioreactor was studied by supp ...200515474928
amplified expression of fructose 1,6-bisphosphatase in corynebacterium glutamicum increases in vivo flux through the pentose phosphate pathway and lysine production on different carbon sources.the overexpression of fructose 1,6-bisphosphatase (fbpase) in corynebacterium glutamicum leads to significant improvement of lysine production on different sugars. amplified expression of fbpase via the promoter of the gene encoding elongation factor tu (eftu) increased the lysine yield in the feedback-deregulated lysine-producing strain c. glutamicum lyscfbr by 40% on glucose and 30% on fructose or sucrose. additionally formation of the by-products glycerol and dihydroxyacetone was significantl ...200516332851
the impact of fluid mechanical stress on corynebacterium glutamicum during continuous cultivation in an agitated bioreactor.the effect of mechanical stresses generated by an extreme agitation intensity or a high aeration rate on growth parameters and cell physiology were studied during continuous cultivation of the gram-positive bacterium corynebacterium glutamicum. it is concluded that variations in agitation, aeration rate, or do2 concentrations down to about 1% of saturation do not damage the bacterial cells or cause a significant change in physiological response, as measured by flow cytometry, even though the cel ...200516049736
phosphate starvation-inducible gene usha encodes a 5' nucleotidase required for growth of corynebacterium glutamicum on media with nucleotides as the phosphorus source.phosphorus is an essential component of macromolecules, like dna, and central metabolic intermediates, such as sugar phosphates, and bacteria possess enzymes and control mechanisms that provide an optimal supply of phosphorus from the environment. udp-sugar hydrolases and 5' nucleotidases may play roles in signal transduction, as they do in mammals, in nucleotide salvage, as demonstrated for usha of escherichia coli, or in phosphorus metabolism. the corynebacterium glutamicum gene usha was found ...200516085822
key enzymes of the protocatechuate branch of the beta-ketoadipate pathway for aromatic degradation in corynebacterium glutamicum.although the protocatechuate branch of the beta-ketoadipate pathway in gram+ bacteria has been well studied, this branch is less understood in gram+ bacteria. in this study, corynebacterium glutamicum was cultivated with protocatechuate, p-cresol, vanillate and 4-hydroxybenzoate as sole carbon and energy sources for growth. enzymatic assays indicated that growing cells on these aromatic compounds exhibited protocatechuate 3,4-dioxygenase activities. data-mining of the genome of this bacterium re ...200516092756
enhanced glutamic acid production by a h+-atpase-defective mutant of corynebacterium glutamicum.previously we reported that a mutant of corynebacterium glutamicum atcc14067 with reduced h+-atpase activity, f172-8, showed an approximately two times higher specific rate of glucose consumption than the parent, but no glutamic acid productivity under the standard biotin-limited culture conditions, where biotin concentration was set at 5.5 microg/l in the production medium (sekine et al., appl. microbiol. biotechnol., 57, 534-540 (2001)). in this study, various culture conditions were tested to ...200516116273
functional genomics and expression analysis of the corynebacterium glutamicum fpr2-cysixhdnyz gene cluster involved in assimilatory sulphate reduction.corynebacterium glutamicum is a high-gc gram-positive soil bacterium of great biotechnological importance for the production of amino acids. to facilitate the rational design of sulphur amino acid-producing strains, the pathway for assimilatory sulphate reduction providing the necessary reduced sulfur moieties has to be known. although this pathway has been well studied in gram-negative bacteria like escherichia coli and low-gc gram-positives like bacillus subtilis, little is known for the actin ...200516159395
the cgl2612 protein from corynebacterium glutamicum is a drug resistance-related transcriptional repressor: structural and functional analysis of a newly identified transcription factor from genomic dna analysis.the emergence of antibiotic-resistant bacteria often causes serious clinical problems. the tetr family is one of the major transcription factor families that regulate expression of genes involved in bacterial antimicrobial resistance systems. cgl2612 protein is a transcription factor newly identified by genomic dna analysis on corynebacterium glutamicum, which belongs to the mycolic acid-containing actinomycetales, including the well known pathogens corynebacterium diphtheriae and mycobacterium ...200516166084
the arac-type regulator ripa represses aconitase and other iron proteins from corynebacterium under iron limitation and is itself repressed by dtxr.the mrna level of the aconitase gene acn of corynebacterium glutamicum is reduced under iron limitation. here we show that an arac-type regulator, termed ripa for "regulator of iron proteins a," is involved in this type of regulation. a c. glutamicum deltaripa mutant has a 2-fold higher aconitase activity than the wild type under iron limitation, but not under iron excess. comparison of the mrna profiles of the deltaripa mutant and the wild type revealed that the acn mrna level was increased in ...200516179344
identification and characterization of porh, a new cell wall channel of corynebacterium glutamicum.the cell wall of corynebacterium glutamicum contains the cation-selective channel (porin) pora(c.glut) and the anion-selective channel porb(c.glut) for the passage of hydrophilic solutes. lipid bilayer experiments with organic solvent extracts of whole c. glutamicum cells cultivated in minimal medium suggested that also another cation-selective channel-forming protein, named porh(c.glut), is present in c. glutamicum. the protein was purified to homogeneity by fast-protein liquid chromatography a ...200516112217
overexpression of the ftsz gene from corynebacterium glutamicum (brevibacterium lactofermentum) in escherichia coli.our goal in this work was to overexpress the essential cell division ftsz protein from corynebacterium glutamicum (brevibacterium lactofermentum) (ftszcg) in escherichia coli to produce anti-ftszcg polyclonal antibodies. previous results from our laboratory showed that ftszcg was not expressed in e. coli in a sufficient amount to purify ftszcg. however, when ftszcg (without upstream sequences) was transcriptionally fused to the t7 promoter, different truncated ftszcg proteins (28-32 kda) were ov ...200515782238
resistance of corynebacterial strains to infection and lysis by corynephage bfk 20.defence mechanisms of the corynebacterial strains against corynephage bfk 20, which causes lysis of brevibacterium flavum ccm 251.200515610431
the transcriptional regulator ssur activates expression of the corynebacterium glutamicum sulphonate utilization genes in the absence of sulphate.in a recent study, the putative regulatory gene cg0012 was shown to belong to the regulon of mcbr, a global transcriptional regulator of sulphur metabolism in corynebacterium glutamicum atcc 13032. a deletion of cg0012, now designated ssur (sulphonate sulphur utilization regulator), led to the mutant strain c. glutamicum dk100, which was shown to be blocked in the utilization of sulphonates as sulphur sources. according to dna microarray hybridizations, transcription of the ssu and seu genes, en ...200516194234
altered morphology produced by ftsz expression in corynebacterium glutamicum atcc 13869.corynebacterium glutamicum is a gram-positive bacterium that lacks the cell division ftsa protein and actin-like mreb proteins responsible for determining cylindrical cell shape. when the cell division ftsz gene from c. glutamicum (ftsz(cg)) was cloned in different multicopy plasmids, the resulting constructions could not be introduced into c. glutamicum; it was assumed that elevated levels of ftsz(cg) result in lethality. the presence of a truncated ftsz(cg) and a complete ftsz(cg) under the co ...200516079335
regulation of amtr-controlled gene expression in corynebacterium glutamicum: mechanism and characterization of the amtr regulon.amtr, the master regulator of nitrogen control in corynebacterium glutamicum, represses transcription of a number of genes during nitrogen surplus. repression is released by an interaction of amtr with signal transduction protein glnk. as shown by pull-down assays and gel retardation experiments, only adenylylated glnk, which is present in the cells during nitrogen limitation, is able to bind to amtr. the amtr regulon was characterized in this study by a combination of bioinformatics, transcript ...200516194241
characterization of bacterial drug antiporters homologous to mammalian neurotransmitter transporters.multidrug transporters are ubiquitous proteins, and, based on amino acid sequence similarities, they have been classified into several families. here we characterize a cluster of archaeal and bacterial proteins from the major facilitator superfamily (mfs). one member of this family, the vesicular monoamine transporter (vmat) was previously shown to remove both neurotransmitters and toxic compounds from the cytoplasm, thereby conferring resistance to their effects. a blast search of the available ...200516237035
biotechnological production of amino acids and derivatives: current status and prospects.for almost 50 years now, biotechnological production processes have been used for industrial production of amino acids. market development has been particularly dynamic for the flavor-enhancer glutamate and the animal feed amino acids l: -lysine, l: -threonine, and l: -tryptophan, which are produced by fermentation processes using high-performance strains of corynebacterium glutamicum and escherichia coli from sugar sources such as molasses, sucrose, or glucose. but the market for amino acids in ...200516195792
high expression with corynebacterium glutamicum for nuclear magnetic resonance sample preparation. 200515979559
characterization of a corynebacterium glutamicum lactate utilization operon induced during temperature-triggered glutamate production.gene expression changes of glutamate-producing corynebacterium glutamicum were identified in transcriptome comparisons by dna microarray analysis. during glutamate production induced by a temperature shift, c. glutamicum strain 2262 showed significantly higher mrna levels of the ncgl2816 and ncgl2817 genes than its non-glutamate-producing derivative 2262np. reverse transcription-pcr analysis showed that the two genes together constitute an operon. ncgl2816 putatively codes for a lactate permease ...200516204505
role of the ssu and seu genes of corynebacterium glutamicum atcc 13032 in utilization of sulfonates and sulfonate esters as sulfur sources.corynebacterium glutamicum atcc 13032 was found to be able to utilize a broad range of sulfonates and sulfonate esters as sulfur sources. the two gene clusters potentially involved in sulfonate utilization, ssud1cba and ssui-seuabc-ssud2, were identified in the genome of c. glutamicum atcc 13032 by similarity searches. while the ssu genes encode proteins resembling ssu proteins from escherichia coli or bacillus subtilis, the seu gene products exhibited similarity to the dibenzothiophene-degradin ...200516204527
the whce gene of corynebacterium glutamicum is important for survival following heat and oxidative stress.in this study, we have analyzed an orf from corynebacterium glutamicum, which codes for a homologue of the streptomyces coelicolor whib-family of proteins known to be involved in sporulation. this orf encoded a putative protein which harbors a helix-turn-helix dna-binding motif and a probable redox-sensing motif, and has been designated whce. we constructed a whce mutant strain and analyzed the strain under a variety of growth conditions. this mutant strain exhibited a prolonged lag phase and ea ...200516212936
the osmotic activation of transporter prop is tuned by both its c-terminal coiled-coil and osmotically induced changes in phospholipid composition.transporter prop of escherichia coli (propec) senses extracellular osmolality and mediates osmoprotectant uptake when it is rising or high. a replica of the propec c terminus (asp468-arg497) forms an intermolecular alpha-helical coiled-coil. this structure is implicated in the osmoregulation of intact propec, in vivo. like that from corynebacterium glutamicum (propcg), the prop orthologue from agrobacterium tumefaciens (propat) sensed and responded to extracellular osmolality after expression in ...200516239220
class 1 integrons and tetracycline resistance genes in alcaligenes, arthrobacter, and pseudomonas spp. isolated from pigsties and manured soil.the presence of tetracycline resistance (tc(r)) genes and class i integrons (in-1), and their ability to cotransfer were investigated in tc(r) gram-negative (185 strains) and gram-positive (72 strains) bacteria from danish farmland and pigsties. the isolates belonged to the groups or species escherichia coli, enterobacter spp., arthrobacter spp., alcaligenes spp., pseudomonas spp., and corynebacterium glutamicum. the 257 isolates were screened for in-1. eighty-one of the gram-negative isolates w ...200516332771
multiple large segment deletion method for corynebacterium glutamicum.a precise and scarless genome excision method, employing the cre/loxp system in concert with double-strand break (dsb)-stimulated intramolecular recombination was developed. the dsbs were mediated by the restriction endonuclease, i-scei. it permitted multiple deletions of independent 14-, 43-, and 10-kb-long genomic regions on the corynebacterium glutamicum genome. accuracy of deletion was confirmed by the loss of marker genes, pcr, and sequencing of new genome joints. eleven, 58, and 4 genes we ...200515843930
the mcbr repressor modulated by the effector substance s-adenosylhomocysteine controls directly the transcription of a regulon involved in sulphur metabolism of corynebacterium glutamicum atcc 13032.in a recent proteomics study we have shown that the mcbr gene of corynebacterium glutamicum atcc 13032 most probably encodes a transcriptional repressor of the tetr type, which regulates the expression of at least six genes involved in the synthesis of sulphur-containing amino acids. by means of dna microarray hybridizations we detected 86 genes with enhanced transcription in an mcbr mutant when compared with the wild-type strain. bioinformatic analysis identified the inverted repeat 5'-tagac-n6 ...200515853877
adaptation of corynebacterium glutamicum to ammonium limitation: a global analysis using transcriptome and proteome techniques.theresponse of corynebacterium glutamicum to ammonium limitation was studied by transcriptional and proteome profiling of cells grown in a chemostat. our results show that ammonium-limited growth of c. glutamicum results in a rearrangement of the cellular transport capacity, changes in metabolic pathways for nitrogen assimilation, amino acid biosynthesis, and carbon metabolism, as well as a decreased cell division. since transcription at different growth rates was studied, it was possible to dis ...200515870326
ethambutol, a cell wall inhibitor of mycobacterium tuberculosis, elicits l-glutamate efflux of corynebacterium glutamicum.corynebacterium glutamicum is used for the large-scale production of l-glutamate, but the efflux of this amino acid is poorly understood. this study shows that addition of ethambutol (emb) to growing cultures of c. glutamicum causes l-glutamate efflux at rates of up to 15 nmol min(-1) (mg dry wt)(-1), whereas in the absence of emb, no efflux occurs. emb is used for the treatment of mycobacterium tuberculosis, and at a molecular level it targets a series of arabinosyltransferases (embcab). the si ...200515870446
functional analysis of sigh expression in corynebacterium glutamicum.the sigh gene of corynebacterium glutamicum encodes ecf sigma factor sigmah. the gene apparently plays an important role in other stress responses as well as heat stress response. in this study, we found that deleting the sigh gene made c. glutamicum cells sensitive to the thiol-specific oxidant diamide. in the sigh mutant strain, the activity of thioredoxin reductase markedly decreased, suggesting that the trxb gene encoding thioredoxin reductase is probably under the control of sigmah. the exp ...200515883048
purification and characterization of succinate:menaquinone oxidoreductase from corynebacterium glutamicum.succinate:menaquinone oxidoreductase from corynebacterium glutamicum, a high-g+c, gram-positive bacterium, was purified to homogeneity. the enzyme contained two heme b molecules and three polypeptides with apparent molecular masses of 67, 29 and 23 kda, which corresponded to sdha (flavoprotein), sdhb (iron-sulfur protein), and sdhc (membrane anchor protein), respectively. in non-denaturating polyacrylamide gel electrophoresis, the enzyme migrated as a single band with an apparent molecular mass ...200515883782
characterization of methionine export in corynebacterium glutamicum.corynebacterium glutamicum is known for its effective excretion of amino acids under particular metabolic conditions. concomitant activities of uptake and excretion systems would create an energy-wasting futile cycle; amino acid export systems are therefore tightly regulated. we have used a dna microarray approach to identify genes for membrane proteins which are overexpressed under conditions of elevated cytoplasmic concentrations of methionine. one of these genes was brnf, coding for the large ...200515901702
the crucial role of trehalose and structurally related oligosaccharides in the biosynthesis and transfer of mycolic acids in corynebacterineae.trehalose (alpha-d-glucopyranosyl-alpha'-d-glucopyranoside) is essential for the growth of the human pathogen mycobacterium tuberculosis but not for the viability of the phylogenetically related corynebacteria. to determine the role of trehalose in the physiology of these bacteria, the so-called corynebacterineae, mutant strains of corynebacterium glutamicum unable to synthesize trehalose due to the knock-out of the genes of the three pathways of trehalose biosynthesis, were biochemically analyz ...200515901732
mapping the membrane proteome of corynebacterium glutamicum.in order to avoid the specific problems with intrinsic membrane proteins in proteome analysis, a new procedure was developed which is superior to the classical two-dimensional polyacrylamide gel electrophoresis (2-d page) method in terms of intrinsic membrane proteins. for analysis of the membrane proteome from corynebacterium glutamicum, we replaced the first separation dimension, i.e., the isoelectric focusing step, by anion-exchange chromatography, followed by sodium dodecyl sulfate (sds)-pag ...200515717325
analyses of enzyme ii gene mutants for sugar transport and heterologous expression of fructokinase gene in corynebacterium glutamicum atcc 13032.corynebacterium glutamicum atcc 13032 has four enzyme ii (eii) genes of the phosphotransferase system in its genome encoding transporters for sucrose, glucose, fructose, and an unidentified eii. to analyze the function of these eii genes, they were inactivated via homologous recombination and the resulting mutants characterized for sugar utilization. whereas the sucrose eii was the only transport system for sucrose in c. glutamicum, fructose and glucose were each transported by a second transpor ...200515766777
efficient production of (2s)-flavanones by escherichia coli containing an artificial biosynthetic gene cluster.for the fermentative production of plant-specific flavanones (naringenin, pinocembrin) by escherichia coli, a plasmid was constructed which carried an artificial biosynthetic gene cluster, including pal encoding a phenylalanine ammonia-lyase from a yeast, scccl encoding a cinnamate/coumarate:coa ligase from the actinomycete streptomyces coelicolor a3(2), chs encoding a chalcone synthase from a licorice plant and chi encoding a chalcone isomerase from the pueraria plant. the recombinant e. coli c ...200515770480
comparative study of flux redistribution of metabolic pathway in glutamate production by two coryneform bacteria.in amino acid production by coryneform bacteria, study on relationship between change in enzyme activities and production of a target amino acid is important. in glutamate production, kawahara et al. discovered that the effect of decrease in 2-oxoglutamate dehydrogenase complex (odhc) on glutamate production is essential (kawahara et al., biosci. biotechnol. biochem. 61(7) (1997) 1109). significant reduction of the odhc activity was observed in the cells under the several glutamate-productive co ...200515781416
in vivo quantification of intracellular amino acids and intermediates of the methionine pathway in corynebacterium glutamicum. 200515802143
characterization of ltsa from rhodococcus erythropolis, an enzyme with glutamine amidotransferase activity.the nocardioform actinomycete rhodococcus erythropolis has a characteristic cell wall structure. the cell wall is composed of arabinogalactan and mycolic acid and is highly resistant to the cell wall-lytic activity of lysozyme (muramidase). in order to improve the isolation of recombinant proteins from r. erythropolis host cells (n. nakashima and t. tamura, biotechnol. bioeng. 86:136-148, 2004), we isolated two mutants, l-65 and l-88, which are susceptible to lysozyme treatment. the lysozyme sen ...200515805504
theoretical aspects of 13c metabolic flux analysis with sole quantification of carbon dioxide labeling.the potential of using sole respirometric co2 labeling measurement for 13c metabolic flux analysis was investigated by metabolic simulations. for this purpose a model was created, considering all co2 forming and consuming reactions in the central catabolic and anabolic pathways. to facilitate the interpretation of the simulation results, the underlying metabolic network was parameterized by physiologically meaningful flux parameters such as flux partitioning ratios at metabolic branch points and ...200515833440
rational design of a corynebacterium glutamicum pantothenate production strain and its characterization by metabolic flux analysis and genome-wide transcriptional profiling.a "second-generation" production strain was derived from a corynebacterium glutamicum pantothenate producer by rational design to assess its potential to synthesize and accumulate the vitamin pantothenate by batch cultivation. the new pantothenate production strain carries a deletion of the ilva gene to abolish isoleucine synthesis, the promoter down-mutation p-ilvem3 to attenuate ilve gene expression and thereby increase ketoisovalerate availability, and two compatible plasmids to overexpress t ...200515933028
e1 enzyme of the pyruvate dehydrogenase complex in corynebacterium glutamicum: molecular analysis of the gene and phylogenetic aspects.the e1p enzyme is an essential part of the pyruvate dehydrogenase complex (pdhc) and catalyzes the oxidative decarboxylation of pyruvate with concomitant acetylation of the e2p enzyme within the complex. we analyzed the corynebacterium glutamicum acee gene, encoding the e1p enzyme, and constructed and characterized an e1p-deficient mutant. sequence analysis of the c. glutamicum acee gene and adjacent regions revealed that acee is not flanked by genes encoding other enzymes of the pdhc. transcrip ...200516109942
dna microarray analysis of the nitrogen starvation response of corynebacterium glutamicum.nitrogen is an essential component of nearly all of the complex macromolecules in a bacterial cell, e.g. proteins, nucleic acids, and cell wall components. accordingly, most prokaryotes have developed elaborate control mechanisms to provide an optimal supply of nitrogen for cellular metabolism and to cope with situations of nitrogen limitation. in this communication, a global analysis of the corynebacterium glutamicum nitrogen starvation response by transcriptional profiling using dna microarray ...200515935503
the individual and common repertoire of dna-binding transcriptional regulators of corynebacterium glutamicum, corynebacterium efficiens, corynebacterium diphtheriae and corynebacterium jeikeium deduced from the complete genome sequences.the genus corynebacterium includes gram-positive microorganisms of great biotechnologically importance, such as corynebacterium glutamicum and corynebacterium efficiens, as well as serious human pathogens, such as corynebacterium diphtheriae and corynebacterium jeikeium. although genome sequences of the respective species have been determined recently, the knowledge about the repertoire of transcriptional regulators and the architecture of global regulatory networks is scarce. here, we apply a c ...200515938759
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