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comparative proteomes of corynebacterium glutamicum grown on aromatic compounds revealed novel proteins involved in aromatic degradation and a clear link between aromatic catabolism and gluconeogenesis via fructose-1,6-bisphosphatase.the current study examined the aromatic degradation and central metabolism in corynebacterium glutamicum by proteomic and molecular methods. comparative analysis of proteomes from cells grown on gentisate and on glucose revealed that 30% of the proteins of which their abundance changed were involved in aromatic degradation and central carbon metabolism. similar results were obtained from cells grown on benzoate, 4-cresol, phenol, and resorcinol. results from these experiments revealed that (i) e ...200717880007
altered metabolic flux due to deletion of odha causes l-glutamate overproduction in corynebacterium glutamicum.l-glutamate overproduction in corynebacterium glutamicum, a biotin auxotroph, is induced by biotin limitation or by treatment with certain fatty acid ester surfactants or with penicillin. we have analyzed the relationship between the inductions, 2-oxoglutarate dehydrogenase complex (odhc) activity, and l-glutamate production. here we show that a strain deleted for odha and completely lacking odhc activity produces l-glutamate as efficiently as the induced wild type (27.8 mmol/g [dry weight] of c ...200717158630
detection and identification of bacteria using antibiotic susceptibility and a multi-array electrochemical sensor with pattern recognition.this work proposes the use of amperometric signals generated by a 96-well multi-array dissolved oxygen multi-electrode sensor (dox) coupled with principal component analysis for continuous monitoring, identification and differentiation of bacteria. two types of differentiation mechanisms were tested: (1) direct monitoring of respiratory activity via oxygen consumption and (2) quantification of the effect of three broad-spectrum antibiotics on bacteria growth and respiration over time. five speci ...200717169547
inactivation of corynebacterium glutamicum ncgl0452 and the role of mgta in the biosynthesis of a novel mannosylated glycolipid involved in lipomannan biosynthesis.mycobacterium tuberculosis pimb has been demonstrated to catalyze the addition of a mannose residue from gdp-mannose to a monoacylated phosphatidyl-myo-inositol mannoside (ac(1)pim(1)) to generate ac(1)pim(2). herein, we describe the disruption of its probable orthologue cg-pimb and the chemical analysis of glycolipids and lipoglycans isolated from wild type corynebacterium glutamicum and the c. glutamicum::pimb mutant. following a careful analysis, two related glycolipids, gl-a and gl-x, were f ...200717179146
the phosphotransferase system of corynebacterium glutamicum: features of sugar transport and carbon regulation.in this review, we describe the phosphotransferase system (pts) of corynebacterium glutamicum and discuss genes for putative global carbon regulation associated with the pts. c. glutamicum atcc 13032 has pts genes encoding the general phosphotransferases enzyme i, hpr and four enzyme ii permeases, specific for glucose, fructose, sucrose and one yet unknown substrate. c. gluamicum has a peculiar sugar transport system involving fructose efflux after hydrolyzing sucrose transported via sucrose eii ...200717183210
rama, the transcriptional regulator of acetate metabolism in corynebacterium glutamicum, is subject to negative autoregulation.the rama protein represents a luxr-type transcriptional activator of genes involved in acetate metabolism of corynebacterium glutamicum. here we analyze the expression of the respective rama gene and its regulation. transcription was found to start 71 nucleotides upstream of the translational start codon and to be two- to threefold up-regulated in the presence of acetate in the growth medium. accordingly, about twofold higher amounts of rama were observed in c. glutamicum cells grown on acetate ...200717183211
nitrogen metabolism and nitrogen control in corynebacteria: variations of a common theme.the published genome sequences of corynebacterium diphtheriae, corynebacterium efficiens, corynebacterium glutamicum and corynebacterium jeikeium were screened for genes encoding central components of nitrogen source uptake, nitrogen assimilation and nitrogen control systems. interestingly, the soil-living species c. efficiens and c. glutamicum exhibit a broader spectrum of genes for nitrogen transport and metabolism than the pathogenic species c. diphtheriae and c. jeikeium. the latter are char ...200717183220
ramb, the transcriptional regulator of acetate metabolism in corynebacterium glutamicum, is subject to regulation by rama and ramb.in corynebacterium glutamicum, the transcriptional regulator ramb negatively controls the expression of genes involved in acetate metabolism. here we show that ramb represses its own expression by direct interaction with a 13-bp motif in the ramb promoter region. additionally, ramb expression is subject to carbon source-dependent positive control by rama.200717114251
role of cytochrome bd oxidase from corynebacterium glutamicum in growth and lysine production.corynebacterium glutamicum possesses two terminal oxidases, cytochrome aa3 and cytochrome bd. cytochrome aa3 forms a supercomplex with the cytochrome bc1 complex, which contains an unusual diheme cytochrome c1. both the bc1 -aa3 supercomplex and cytochrome bd transfer reducing equivalents from menaquinol to oxygen; however, they differ in their proton translocation efficiency by a factor of three. here, we analyzed the role of cytochrome bd for growth and lysine production. when cultivated in gl ...200717142369
reduced folate supply as a key to enhanced l-serine production by corynebacterium glutamicum.the amino acid l-serine is required for pharmaceutical purposes, and the availability of a sugar-based microbial process for its production is desirable. however, a number of intracellular utilization routes prevent overproduction of l-serine, with the essential serine hydroxymethyltransferase (shmt) (glya) probably occupying a key position. we found that constructs of corynebacterium glutamicum strains where chromosomal glya expression is dependent on ptac and laciq are unstable, acquiring muta ...200717142381
analysis of subcellular surface structure, function and dynamics.analytics of single biological cells allows quantitative investigation from a structural, functional and dynamical point of view and opens novel possibilities to an unamplified subcellular analysis. in this article, we report on three different experimental methods and their applications to single cellular systems with a subcellular sensitivity down to the single molecule level. first, the subcellular surface structure of living bacteria (corynebacterium glutamicum) was investigated with atomic ...200717082883
topology and mutational analysis of the single emb arabinofuranosyltransferase of corynebacterium glutamicum as a model of emb proteins of mycobacterium tuberculosis.the cell wall mycolyl-arabinogalactan (ag)--peptidoglycan complex is essential in mycobacterial species, such as mycobacterium tuberculosis, and is the target of several antitubercular drugs. for instance, ethambutol (emb) targets ag biosynthesis through inhibition of the arabinofuranosyltransferases mt-emba and mt-embb, as well as the single emb from corynebacterium glutamicum. here, we present for the first time an experimental analysis of the membrane topology of emb. the domain organization ...200717088267
an experimental comparison of respiration measuring techniques in fermenters and shake flasks: exhaust gas analyzer vs. ramos device vs. respirometer.respiration measurement is applied as a universal tool to determine the activity of biological systems. the measurement techniques are difficult to compare, due to the vast variety of devices and analytical procedures commonly in use. they are used in fields as different as microbiology, gene engineering, toxicology, and industrial process monitoring to observe the physiological activity of living systems in environments as diverse as fermenters, shake flasks, lakes and sewage plants. a method i ...200717001475
genes from a dietzia sp. for synthesis of c40 and c50 beta-cyclic carotenoids.dietzia sp. cq4 accumulated the c(40) beta-cyclic carotenoids (canthaxanthin and echinenone) and the c(50) beta-cyclic carotenoid (c.p.450 monoglucoside). a plant-type lycopene beta-cyclase gene crtl was identified for beta-cyclization of the c(40) carotenoids. a carotenoid synthesis gene cluster was identified away from the crtl gene, which contained the crtebi genes for the synthesis of lycopene followed by the lbtabc genes for lycopene elongation and beta-cyclization of the c(50) carotenoids. ...200717008032
one-pot synthesis of genistein from tyrosine by coincubation of genetically engineered escherichia coli and saccharomyces cerevisiae cells.for production of genistein from n-acetylcysteamine-attached p-coumarate (p-coumaroyl-nac) supplemented to the medium, a chalcone synthase (chs) gene from glycyrrhiza echinata, a chalcone isomerase (chi) gene from pueraria lobata, and an isoflavone synthase (ifs) gene from g. echinata were placed under the control of the galactose-inducible gal promoters in pesc vector and were introduced in saccharomyces cerevisiae. when the recombinant yeast cells (0.5 g wet weight) were used as "enzyme bags" ...200716960736
utilization of fermentation waste (corynebacterium glutamicum) for biosorption of reactive black 5 from aqueous solution.a fermentation waste, corynebacterium glutamicum, was successfully employed as a biosorbent for reactive black 5 (rb5) from aqueous solution. this paper initially studied the effect of pretreatment on the biosorption capacity of c. glutamicum toward rb5, using several chemical agents, such as hcl, h(2)so(4), hno(3), naoh, na(2)co(3), cacl(2) and nacl. among these reagents, 0.1m hno(3) gave the maximum enhancement of the rb5 uptake, exhibiting 195mg/g at ph 1 with an initial rb5 concentration of ...200716879915
quantification of cell size distribution as applied to the growth of corynebacterium glutamicum.it is known that the cell size is related to the physiological state of a cell. therefore, cell size distribution directly reflects the average physiological properties of the cell culture. cell size distribution can be enumerated by image analysis, flow cytometry and coulter counter. in this study, image analysis was used to characterize the cell size distribution during the growth of corynebacterium glutamicum and was further analyzed by a distribution function. the parameters of the distribut ...200817008078
corynebacterium glutamicum superoxide dismutase is a manganese-strict non-cambialistic enzyme in vitro.superoxide dismutase (sod) of corynebacterium glutamicum was purified and characterized. the enzyme had a native molecular weight of about 80kda, whereas a monomer with molecular weight of 24kda was found on sds-page suggesting it to be homotetramer. the native sod activity stained gel revealed a unique cytosolic enzyme. supplementing growth media with manganese increased the specific activity significantly, while adding iron did not result in significant difference. no growth perturbation was o ...200816809027
biosorption of methylene blue from aqueous solution using free and polysulfone-immobilized corynebacterium glutamicum: batch and column studies.the amino acid fermentation industry waste, corynebacterium glutamicum, has been found to possess excellent biosorption capacity towards methylene blue (mb). due to practical difficulties in solid-liquid separation and biomass regeneration, c. glutamicum was immobilized in a polysulfone matrix. the ph edge experiments revealed that neutral or alkaline ph values favored mb biosorption. isotherm experiments indicated that c. glutamicum, when in immobilized state, exhibited slightly inferior dye up ...200817664064
structure of a gtp-dependent bacterial pep-carboxykinase from corynebacterium glutamicum.gtp-dependent phosphoenolpyruvate carboxykinase (pck) is the key enzyme that controls the blood glucose level during fasting in higher animals. here we report the first substrate-free structure of a gtp-dependent phosphoenolpyruvate (pep) carboxykinase from a bacterium, corynebacterium glutamicum (cgpck). the protein crystallizes in space group p2(1) with four molecules per asymmetric unit. the 2.3a resolution structure was solved by molecular replacement using the human cytosolic pck (hcpck) st ...200818234538
dissection of ammonium uptake systems in corynebacterium glutamicum: mechanism of action and energetics of amta and amtb.corynebacterium glutamicum has two different amt-type proteins. while amtb has a low substrate affinity and is not saturable up to 3 mm methylammonium, amta has a high substrate affinity and mediates saturable, membrane potential-dependent transport, resulting in a high steady-state accumulation of methylammonium, even in the absence of metabolic trapping.200818245289
corynebacterium glutamicum possesses two seca homologous genes that are essential for viability.seca is a central component of the bacterial sec preprotein translocase. besides the housekeeping seca (seca1), some mostly pathogenic gram-positive bacteria possess an accessory seca (seca2) that is involved in the export of a few substrates only. here we show that neither of the two seca homologous genes present in the genome of the non-pathogenic bacterium corynebacterium glutamicum can be deleted, unless a copy of the respective gene is provided in trans on a plasmid. this finding is in mark ...200818246326
s-adenosylhomocysteine hydrolase from corynebacterium glutamicum: cloning, overexpression, purification, and biochemical characterization.the s-adenosylhomocysteine hydrolase gene (sahase) was cloned from the gram-positive soil bacterium corynebacterium glutamicum (atcc 13032) and sequenced. the sahase gene possesses an open reading frame, which consists of 1,434 nucleotides that encode 478 amino acids. the sahase gene from c. glutamicum was expressed in escherichia coli rosetta cells by inserting the 1,434-bp fragment downstream from the isopropyl-beta-d-thiogalactopyranoside-inducible promoter of the pet28a+ expression vector. t ...200818253021
cell growth and cell division in the rod-shaped actinomycete corynebacterium glutamicum.bacterial cell growth and cell division are highly complicated and diversified biological processes. in most rod-shaped bacteria, actin-like mreb homologues produce helicoidal structures along the cell that support elongation of the lateral cell wall. an exception to this rule is peptidoglycan synthesis in the rod-shaped actinomycete corynebacterium glutamicum, which is mreb-independent. instead, during cell elongation this bacterium synthesizes new cell-wall material at the cell poles whereas t ...200818283557
transcription of corynebacterium glutamicum genes involved in tricarboxylic acid cycle and glyoxylate cycle.transcription of the tricarboxylic acid cycle genes of corynebacterium glutamicum was investigated. northern hybridizations revealed that glta-fkb, odha-orfa, succ-sucd, sdhc-sdha-sdhb-orfb and mdh-orfc were transcribed as polycistronic mrnas of size 1.9, 4.5, 2.5, 4.0 and 1.7 kb, respectively. the acn-acnr-gat gene cluster was transcribed as a mono-, bi- or tricistronic mrna, depending on the carbon source. the 2.9-kb (acn) and 1.5-kb (acnr-gat) mrnas, which were regulated by different promoter ...200818285691
changes in enzyme activities at the pyruvate node in glutamate-overproducing corynebacterium glutamicum.glutamate is industrially produced by fermentation using corynebacterium glutamicum. the key factor for efficient glutamate production by this microorganism has been considered to be a metabolic change at the 2-oxoglutarate dehydrogenase (odh) branch point caused by a decrease in odh activity under glutamate-overproducing conditions. however, this change would be insufficient because the odh branch is merely the final branch in the glutamate biosynthetic pathway, and efficient glutamate producti ...200818295714
diviva is required for polar growth in the mreb-lacking rod-shaped actinomycete corynebacterium glutamicum.the actinomycete corynebacterium glutamicum grows as rod-shaped cells by zonal peptidoglycan synthesis at the cell poles. in this bacterium, experimental depletion of the polar diviva protein (diviva(cg)) resulted in the inhibition of polar growth; consequently, these cells exhibited a coccoid morphology. this result demonstrated that diviva is required for cell elongation and the acquisition of a rod shape. diviva from streptomyces or mycobacterium localized to the cell poles of diviva(cg)-depl ...200818296522
arnr, a novel transcriptional regulator, represses expression of the narkghji operon in corynebacterium glutamicum.the narkghji operon that comprises putative nitrate/nitrite transporter (nark) and nitrate reductase (narghji) genes is required for the anaerobic growth of corynebacterium glutamicum with nitrate as a terminal electron acceptor. in this study, we identified a gene, arnr, which encodes a transcriptional regulator that represses the expression of the narkghji operon in c. glutamicum cells under aerobic conditions. disruption of arnr induced nitrate reductase activities of c. glutamicum cells and ...200818296524
identification of amino acids and domains required for catalytic activity of dppr synthase, a cell wall biosynthetic enzyme of mycobacterium tuberculosis.decaprenylphosphoryl-d-arabinose (dpa) has been shown to be the donor of the essential d-arabinofuranosyl residues found in the cell wall of mycobacterium tuberculosis. dpa is formed from phosphoribose diphosphate in a four-step process. the first step is the nucleophilic replacement of the diphosphate group with decaprenyl phosphate. this reaction is catalysed by the integral membrane protein 5-phospho-alpha-d-ribose-1-diphosphate : decaprenyl-phosphate 5-phosphoribosyltransferase (dppr synthas ...200818310020
corynebacterium glutamicum sigmae is involved in responses to cell surface stresses and its activity is controlled by the anti-sigma factor csee.in this study, we demonstrate that sigma(e), an alternative sigma factor of corynebacterium glutamicum, is involved in cell surface stresses. cells in which the sige gene was deleted evidenced increased sensitivity to magnesium deficiency, as well as to sds, lysozymes, edta and heat. we utilized physiological analyses to show that the downstream gene, designated csee, encodes an anti-sigma factor. the retarded growth of the csee mutant cells under ordinary growth conditions could be recovered by ...200818310037
disclosure of the mycobacterial outer membrane: cryo-electron tomography and vitreous sections reveal the lipid bilayer structure.the cell walls of mycobacteria form an exceptional permeability barrier, and they are essential for virulence. they contain extractable lipids and long-chain mycolic acids that are covalently linked to peptidoglycan via an arabinogalactan network. the lipids were thought to form an asymmetrical bilayer of considerable thickness, but this could never be proven directly by microscopy or other means. cryo-electron tomography of unperturbed or detergent-treated cells of mycobacterium smegmatis embed ...200818316738
metabolic responses to pyruvate kinase deletion in lysine producing corynebacterium glutamicum.abstract:200818339202
triple transcriptional control of the resuscitation promoting factor 2 (rpf2) gene of corynebacterium glutamicum by the regulators of acetate metabolism rama and ramb and the camp-dependent regulator glxr.the transcriptional regulators rama, ramb and glxr were detected to bind to the promoter region of the resuscitation promoting factor 2 (rpf2) gene involved in growth and culturability of corynebacterium glutamicum. dna-binding sites were identified by bioinformatic analysis and verified by electrophoretic mobility shift assays with purified hexahistidyl-tagged proteins. carbon source-dependent deregulation of rpf2 expression was demonstrated in vivo in rama and ramb mutants and in a c. glutamic ...200818355281
phytate utilization by genetically engineered lysine-producing corynebacterium glutamicum.heterologous expression of a phytase gene (phyc) from bacillus amyloliquefaciens dsm 7 enabled the growth of corynebacterium glutamicum with phytate (myo-inositol-1,2,3,4,5,6-hexakisphosphate) as a new, sole source of phosphorus. phytate was not used as a carbon source. during growth of the phyc-expressing amino acid (l-lysine)-producing strain c. glutamicum atcc 21253 (pwlq2::phyc) with phytate as the source of phosphorus, merely a small, transient accumulation of inorganic phosphate was observ ...200818374441
the laci/galr family transcriptional regulator urir negatively controls uridine utilization of corynebacterium glutamicum by binding to catabolite-responsive element (cre)-like sequences.the cg1547 protein of corynebacterium glutamicum atcc 13032 is a member of the laci/galr family of dna-binding transcriptional regulators. a defined deletion in the cg1547 gene, now designated urir (uridine utilization regulator), resulted in the mutant strain c. glutamicum kb1547. comparison of gene expression levels in c. glutamicum kb1547 and the wild-type strain revealed enhanced expression of the urir operon genes cg1546 (ribokinase), cg1545 (uridine transporter) and cg1543 (uridine-preferr ...200818375800
corynebacterium glutamicum tailored for high-yield l-valine production.we recently engineered the wild type of corynebacterium glutamicum for the growth-decoupled production of l: -valine from glucose by inactivation of the pyruvate dehydrogenase complex and additional overexpression of the ilvbnce genes, encoding the l-valine biosynthetic enzymes acetohydroxyacid synthase, isomeroreductase, and transaminase b. based on the first generation of pyruvate-dehydrogenase-complex-deficient c. glutamicum strains, a second generation of high-yield l-valine producers was co ...200818379776
structural and enzymatic analysis of msha from corynebacterium glutamicum: substrate-assisted catalysis.the glycosyltransferase termed msha catalyzes the transfer of n-acetylglucosamine from udp-n-acetylglucosamine to 1-l-myo-inositol-1-phosphate in the first committed step of mycothiol biosynthesis. the structure of msha from corynebacterium glutamicum was determined both in the absence of substrates and in a complex with udp and 1-l-myo-inositol-1-phosphate. msha belongs to the gt-b structural family whose members have a two-domain structure with both domains exhibiting a rossman-type fold. bind ...200818390549
structural characterization and functional properties of a novel lipomannan variant isolated from a corynebacterium glutamicum pimb' mutant.the genus corynebacterium is part of the phylogenetic group nocardioform actinomycetes, which also includes the genus mycobacterium. members of this phylogenetic group have a characteristic cell envelope structure, which is dominated by complex lipids and amongst these, lipoglycans are of particular interest. the disruption of ncgl2106 in c. glutamicum resulted in a mutant devoid of monoacylated phosphatidyl-myo-inositol dimannoside (ac(1)pim(2)) resulting in the accumulation of ac(1)pim(1) and ...200818421567
from the characterization of the four serine/threonine protein kinases (pkna/b/g/l) of corynebacterium glutamicum toward the role of pkna and pknb in cell division.corynebacterium glutamicum contains four serine/threonine protein kinases (stpks) named pkna, pknb, pkng, and pknl. here we present the first biochemical and comparative analysis of all four c. glutamicum stpks and investigate their potential role in cell shape control and peptidoglycan synthesis during cell division. in vitro assays demonstrated that, except for pkng, all stpks exhibited autokinase activity. we provide evidence that activation of pkng is part of a phosphorylation cascade mechan ...200818442973
identification of a novel alpha(1-->6) mannopyranosyltransferase mptb from corynebacterium glutamicum by deletion of a conserved gene, ncgl1505, affords a lipomannan- and lipoarabinomannan-deficient mutant.mycobacterium tuberculosis and corynebacterium glutamicum share a similar cell wall structure and orthologous enzymes involved in cell wall assembly. herein, we have studied c. glutamicum ncgl1505, the orthologue of putative glycosyltransferases rv1459c from m. tuberculosis and msmeg3120 from mycobacterium smegmatis. deletion of ncgl1505 resulted in the absence of lipomannan (cg-lm-a), lipoarabinomannan (cg-lam) and a multi-mannosylated polymer (cg-lm-b) based on a 1,2-di-o-c(16)/c(18:1)-(alpha- ...200818452585
disruption of metf increased l-lysine production by methylophilus methylotrophus from methanol.methionine auxotrophic mutants of methylophilus methylotrophus as1 expressing a mutant form of dapa (dapa24) encoding a dihydrodipicolinate synthase desensitized from feedback inhibition by l-lysine, and mutated lyse (lyse24) encoding the l-lysine exporter from corynebacterium glutamicum 2256, produced higher amounts of l-lysine from methanol as sole carbon source than did other amino acid auxotrophic mutants. especially, the m. methylotrophus 102 strain, carrying both dapa24 and lyse24, produce ...200818460806
a putative alpha-helical porin from corynebacterium glutamicum.the cell wall of corynebacterium glutamicum contains a mycolic acid layer, which is a protective nonpolar barrier similar to the outer membrane of gram-negative bacteria. the exchange of material across this barrier requires porins. porin b (porb) is one of them. recombinant porb has been produced in escherichia coli, purified, crystallized and analyzed by x-ray diffraction, yielding 16 independent molecular structures in four different crystal forms at resolutions up to 1.8 a. all 16 molecules ...200818462756
construction of heat-inducible expression vector of corynebacterium glutamicum and c. ammoniagenes: fusion of lambda operator with promoters isolated from c. ammoniagenes.the heat-inducible expression vectors for corynebacterium glutamicum and c. ammoniagenes were constructed by using the lambdaol1 and the cryptic promoters, cj1 and cj4 that express genes constitutively in c. ammoniagenes.. although the promoters were isolated from c. ammoniagenes, cj1 and cj4 were also active in c. glutamicum. to construct vectors, the ol1 from the lambdapl promoter was isolated and fused to the cj1 and cj4 promoters by recombinant pcr. the resulting artificial promoters, cj1o a ...200818467855
effect of increased glutamate availability on l-ornithine production in corynebacterium glutamicum.glutamate availability in the argf-argr-probdelta strain of corynebacterium glutamicum was increased by addition of glutamate to the cell or inactivation of the phosphoenolpyruvate carboxykinase activity and simultaneous overexpression of the pyruvate carboxylase activity to assess its effect on lornithine production. when glutamate was increased in an lornithine- producing strain, the production of l-ornithine was not changed. this unexpected result indicated that the intracellular concentratio ...200818467864
population heterogeneity in corynebacterium glutamicum atcc 13032 caused by prophage cgp3.the genome of corynebacterium glutamicum type strain atcc 13032 (accession number bx927147) contains three prophages, cgp1, cgp2, and cgp3. we recently observed that many genes within the cgp3 prophage region have increased mrna levels in a dtxr deletion mutant that lacks the master regulator of iron homeostasis (j. wennerhold and m. bott, j. bacteriol. 188:2907-2918, 2006). here, we provide evidence that this effect is due to the increased induction of the prophage cgp3 in the dtxr mutant, poss ...200818487330
regulation of nitrogen metabolism in mycobacterium tuberculosis: a comparison with mechanisms in corynebacterium glutamicum and streptomyces coelicolor.the mechanisms governing the regulation of nitrogen metabolism in corynebacterium glutamicum and streptomyces coelicolor have been extensively studied. these actinomycetales are closely related to the mycobacterium genus and may therefore serve as a models to elucidate the cascade of nitrogen signalling in other mycobacteria. some factors involved in nitrogen metabolism in mycobacterium tuberculosis have been described, including glutamine synthetase and its adenylyltransferase, but not much dat ...200818493948
impact of pulsed electric fields on corynebacterium glutamicum cell membrane permeabilization.the permeability barrier of the microbial cell envelope for substrates and products often causes very low reaction rates of whole cells. therefore, it is of interest to develop an effective method to reduce this permeability barrier in order to increase product yields. utilisation of pulse electric fields may improve amino acid release from corynebacterium glutamicum by up to several orders of magnitude. in particular pulsed electric fields may change the cell/membrane's dielectric properties an ...200818499054
molecular mass sorting of proteome using hollow fiber flow field-flow fractionation for proteomics.hollow fiber flow field-flow fractionation (hf flfff) has been demonstrated as a tool for pre-fractionating proteomes by differences in molecular mass (mr), where the resulting protein fractions are subsequently digested and analyzed by shotgun proteomics using two-dimensional liquid chromatography-electrospray ionization-tandem mass spectrometry (2d-lc-esi-ms/ms). hf flfff is a separation device capable of fractionating proteins or cells by hydrodynamic radius, and protein fraction can be readi ...200818541480
corynebacterium glutamicum contains 3-deoxy-d-arabino-heptulosonate 7-phosphate synthases that display novel biochemical features.3-deoxy-d-arabino-heptulosonate 7-phosphate (dahp) synthase (ec 2.5.1.54) catalyzes the first step of the shikimate pathway that finally leads to the biosynthesis of aromatic amino acids phenylalanine (phe), tryptophan (trp), and tyrosine (tyr). in corynebacterium glutamicum atcc 13032, two chromosomal genes, ncgl0950 (arof) and ncgl2098 (arog), were located that encode two putative dahp synthases. the deletion of ncgl2098 resulted in the loss of the ability of c. glutamicum res167 (a restrictio ...200818621870
identification of a gene encoding a transporter essential for utilization of c4 dicarboxylates in corynebacterium glutamicum.the corynebacterium glutamicum r genome contains a total of eight genes encoding proteins with sequence similarity to c4-dicarboxylate transporters identified from other bacteria. three of the genes encode proteins within the dicarboxylate/amino acid:cation symporter (daacs) family, another three encode proteins within the tripartite atp-independent periplasmic transporter family, and two encode proteins within the divalent anion:na+ symporter (dass) family. we observed that a mutant strain defi ...200818586971
evolution of metal(loid) binding sites in transcriptional regulators.expression of the genes for resistance to heavy metals and metalloids is transcriptionally regulated by the toxic ions themselves. members of the arsr/smtb family of small metalloregulatory proteins respond to transition metals, heavy metals, and metalloids, including as(iii), sb(iii), cd(ii), pb(ii), zn(ii), co(ii), and ni(ii). these homodimeric repressors bind to dna in the absence of inducing metal(loid) ion and dissociate from the dna when inducer is bound. the regulatory sites are often thr ...200818591244
the cgl1281-encoding putative transporter of the cation diffusion facilitator family is responsible for alkali-tolerance in corynebacterium glutamicum.mutants of corynebacterium glutamicum that were unable to grow under mild alkaline ph conditions were isolated by mutagenesis. strain al-43 exhibiting the highest sensitivity to alkaline ph among the mutants was selected and used to clone a dna fragment that could complement the phenotype. sequencing and subcloning of the cloned 4.0-kb ecori dna fragment showed that the cgl1281 gene was responsible for the complementation. the deduced amino acid sequence of cgl1281 was found to show significant ...200818592219
insights into the structural basis of substrate recognition by histidinol-phosphate aminotransferase from corynebacterium glutamicum.histidinol-phosphate aminotransferase (hisc) is a pyridoxal 5'-phosphate-dependent enzyme that catalyzes the reversible transamination reaction between histidinol phosphate (his-p) and 2-oxoglutarate (o-glu). the crystal structures of apo histidinol-phosphate aminotransferase from corynebacterium glutamicum, of the internal plp aldimine adduct and of a pyridoxamine 5-phosphate-enzyme complex were determined at resolutions of 2.2, 2.1 and 1.8 a, respectively. residues important for substrate spec ...200818560156
analysis of 13c labeling enrichment in microbial culture applying metabolic tracer experiments using gas chromatography-combustion-isotope ratio mass spectrometry.the applicability of gas chromatography-combustion-isotope ratio mass spectrometry (gc-c-irms) for the quantification of 13c enrichment of proteinogenic amino acids in metabolic tracer experiments was evaluated. measurement of the 13c enrichment of proteinogenic amino acids from cell hydrolyzates of corynebacterium glutamicum growing on different mixtures containing between 0.5 and 10% [1-13c]glucose shows the significance of kinetic isotope effects in metabolic flux studies at low degree of lab ...200818565321
1.6 angstroms structure of an nad+-dependent quinate dehydrogenase from corynebacterium glutamicum.to date, three different functional classes of bacterial shikimate/quinate dehydrogenases have been identified and are referred to as aroe, sdh-l and ydib. the enzyme aroe and the catalytically much slower sdh-l clearly prefer nadp+/nadph as the cosubstrate and are specific for (dehydro-)shikimate, whereas in ydib the differences in affinity for nadp+/nadph versus nad+/nadh as well as for (dehydro-)shikimate versus (dehydro-)quinate are marginal. these three subclasses have a similar three-dimen ...200818566515
direct visualization of the outer membrane of mycobacteria and corynebacteria in their native state.the cell envelope of mycobacteria, which include the causative agents of tuberculosis and leprosy, is crucial for their success as pathogens. despite a continued strong emphasis on identifying the multiple chemical components of this envelope, it has proven difficult to combine its components into a comprehensive structural model, primarily because the available ultrastructural data rely on conventional electron microscopy embedding and sectioning, which are known to induce artifacts. the existe ...200818567661
group 2 sigma factor sigb of corynebacterium glutamicum positively regulates glucose metabolism under conditions of oxygen deprivation.the sigb gene of corynebacterium glutamicum encodes a group 2 sigma factor of rna polymerase. under conditions of oxygen deprivation, the sigb gene is upregulated and cells exhibit high productivity of organic acids as a result of an elevated glucose consumption rate. using dna microarray and quantitative reverse transcription-pcr (rt-pcr) analyses, we found that sigb disruption led to reduced transcript levels of genes involved in the metabolism of glucose into organic acids. this in turn resul ...200818567683
the glxr regulon of the amino acid producer corynebacterium glutamicum: in silico and in vitro detection of dna binding sites of a global transcription regulator.the glxr (cg0350) gene of corynebacterium glutamicum atcc 13032 encodes a dna-binding transcription regulator of the crp/fnr protein family. five genomic dna regions known to be bound by glxr provided the seed information for dna binding site discovery by expectation maximization and gibbs sampling approaches. the detection of additional motifs in the genome sequence of c. glutamicum was performed with a position weight matrix and a profile hidden markov model, both deduced from the initial moti ...200818573287
characterization of mutations induced by n-methyl-n'-nitro-n-nitrosoguanidine in an industrial corynebacterium glutamicum strain.mutations induced by classical whole-cell mutagenesis using n-methyl-n'-nitro-n-nitrosoguanidine (ntg) were determined for all genes of pathways from glucose to l-lysine in an industrial l-lysine producer of corynebacterium glutamicum. a total of 50 mutations with a genome-wide distribution were identified and characterized for mutational types and mutagenic specificities. those mutations were all point mutations with single-base substitutions and no deletions, frame shifts, and insertions were ...200818037338
regulation of l-lactate utilization by the fadr-type regulator lldr of corynebacterium glutamicum.corynebacterium glutamicum can grow on l-lactate as a sole carbon and energy source. the ncgl2816-lldd operon encoding a putative transporter (ncgl2816) and a quinone-dependent l-lactate dehydrogenase (lldd) is required for l-lactate utilization. dna affinity chromatography revealed that the fadr-type regulator lldr (encoded by ncgl2814) binds to the upstream region of ncgl2816-lldd. overexpression of lldr resulted in strongly reduced ncgl2816-lldd mrna levels and strongly reduced lldd activity, ...200818039772
microbial production of l -glutamate and l -glutamine by recombinant corynebacterium glutamicum harboring vitreoscilla hemoglobin gene vgb.vitreoscilla hemoglobin (vhb) gene vgb equipped with a native promoter pvgb or a tac promoter ptac was introduced into corynebacterium glutamicum atcc14067, respectively. ptac was proven to be more suitable for expressing vhb protein in higher concentration in both escherichia coli and c. glutamicum strains compared with the native vgb promoter pvgb. vhb-expressing c. glutamicum exhibited higher oxygen uptake rate and enhanced cell growth. recombinant c. glutamicum harboring vgb gene equipped wi ...200818040683
competition of reactive red 4, reactive orange 16 and basic blue 3 during biosorption of reactive blue 4 by polysulfone-immobilized corynebacterium glutamicum.competition of reactive red 4 (rr4), reactive orange 16 (ro16) and basic blue 3 (bb3) during biosorption of reactive blue 4 (rb4) by polysulfone-immobilized protonated corynebacterium glutamicum (pipc) was investigated in batch and column mode of operations. through potentiometric titrations, and with the aid of proton-binding model, carboxyl, phosphonate and amine were identified as functional groups of pipc, with apparent pk(a) values of 3.47+/-0.05, 7.08+/-0.07 and 9.90+/-0.05 mmol/g, respect ...200817913354
ethanol catabolism in corynebacterium glutamicum.corynebacterium glutamicum grows on a variety of carbohydrates and organic acids as single or combined sources of carbon and energy. here we show the ability of c. glutamicum to grow on ethanol with growth rates up to 0.24 h(-1) and biomass yields up to 0.47 g dry weight (g ethanol)(-1). mutants of c. glutamicum deficient in phosphotransacetylase (pta), isocitrate lyase (icl) and malate synthase (ms) were unable to grow on ethanol, indicating that acetate activation and the glyoxylate cycle are ...200817693703
a new approach to study the decolorization of complex reactive dye bath effluent by biosorption technique.this work focused on the development of a practical biosorbent for the decolorization of textile effluents. the fermentation waste, corynebacterium glutamicum biomass, when decarboxylated and immobilized in polysulfone matrix performed well in decolorization of simulated reactive dye bath effluent comprised of four different reactive dyes and other auxiliary chemicals. the regeneration of polysulfone-immobilized c. glutamicum was successful with the aid of 0.01 m naoh as the eluant, which enable ...200818060770
production of chryseobacterium proteolyticum protein-glutaminase using the twin-arginine translocation pathway in corynebacterium glutamicum.the protein glutaminase (pg) secreted by the gram-negative bacterium chryseobacterium proteolyticum can deamidate glutaminyl residues in several substrate proteins, including insoluble wheat glutens. this enzyme therefore has potential application in the food industry. we assessed the possibility to produce pg containing a pro-domain in corynebacterium glutamicum which we have successfully used for production of several kinds of proteins at industrial-scale. when it was targeted to the general p ...200818064454
genetic and biochemical characterization of a 4-hydroxybenzoate hydroxylase from corynebacterium glutamicum.corynebacterium glutamicum uses 4-hydroxybenzoic acid (4hba) as sole carbon source for growth. previous studies showed that 4hba was taken up into cells via pcak, and the aromatic ring was cleaved via protocatechuate 3,4-dioxygenase. in this study, the gene poba ( cg ) (ncgl1032) involved in the conversion of 4hba into 3,4-dihydroxybenzoate (protocatechuate) was identified, and the gene product poba (cg) was characterized as a 4hba 3-hydroxylase, which is a homodimer of poba(cg). the poba (cg) i ...200818071645
divs, a novel sos-inducible cell-division suppressor in corynebacterium glutamicum.dna damage-induced sos response elicits the induction of cell-division suppressor as well as dna repair genes. in gram-positive bacteria, cell-division suppressor genes, so far characterized from bacillus subtilis (ynea) and mycobacterium tuberculosis (rv2719c), share limited homology, but are both located in the vicinity of lexa on their respective genomes. using this proximity to lexa, corynebacterium glutamicum r divs (cgr1759) was identified as an sos-inducible cell-division suppressor in th ...200818086211
chromosomally encoded small antisense rna in corynebacterium glutamicum.the first observation of chromosomally encoded small antisense rna in corynebacterium glutamicum is reported. transcription oriented in the reverse direction to the transcription of the genes cg1934 and cg1935 was demonstrated within the chromosomal cg1934-cg1935 intergenic region. the transcription was found to be increased after heat shock. the transcriptional start point of this rna designated arna was localized 21 bp upstream of the cg1935 translational start point by primer extension analys ...200818093135
regulation of the expression of phosphoenolpyruvate: carbohydrate phosphotransferase system (pts) genes in corynebacterium glutamicum r.the phosphoenolpyruvate : carbohydrate phosphotransferase system (pts) catalyses the transport of carbohydrates by coupling carbohydrate translocation and phosphorylation. in corynebacterium glutamicum r, the genes ptsh and ptsi encode general components of the pts, and genes ptsf, ptss and ptsg each encode fructose-, sucrose- and glucose-specific components of the pts, respectively. in this study, we examined the mrna levels of the pts genes in the presence or absence of pts sugars. glucose ele ...200818174145
nmr structure of protein cgl2762 from corynebacterium glutamicum implicated in dna transposition reveals a helix-turn-helix motif attached to a flexibly disordered leucine zipper. 200818175328
analysis of a new mannosyltransferase required for the synthesis of phosphatidylinositol mannosides and lipoarbinomannan reveals two lipomannan pools in corynebacterineae.the cell walls of the corynebacterineae, which includes the important human pathogen mycobacterium tuberculosis, contain two major lipopolysaccharides, lipoarabinomannan (lam) and lipomannan (lm). lam is assembled on a subpool of phosphatidylinositol mannosides (pims), whereas the identity of the lm lipid anchor is less well characterized. in this study we have identified a new gene (rv2188c in m. tuberculosis and ncgl2106 in corynebacterium glutamicum) that encodes a mannosyltransferase involve ...200818178556
regulation of expression of general components of the phosphoenolpyruvate: carbohydrate phosphotransferase system (pts) by the global regulator sugr in corynebacterium glutamicum.the phosphoenolpyruvate: carbohydrate phosphotransferase system (pts) catalyzes transport of carbohydrates by coupling carbohydrate translocation and phosphorylation. enzyme i and hpr, encoded in ptsi and ptsh, respectively, are cytoplasmic proteins commonly used for transport of variety of pts sugars. in this study, we investigated the role of sugr on the expression of the ptsi and ptsh which increases in the presence of pts sugars in corynebacterium glutamicum. disruption of sugr resulted in t ...200818183389
production of d-lactic acid by corynebacterium glutamicum under oxygen deprivation.in mineral salts medium under oxygen deprivation, corynebacterium glutamicum exhibits high productivity of l-lactic acid accompanied with succinic and acetic acids. in taking advantage of this elevated productivity, c. glutamicum was genetically modified to produce d-lactic acid. the modification involved expression of fermentative d-lactate dehydrogenase (d-ldh)-encoding genes from escherichia coli and lactobacillus delbrueckii in l-lactate dehydrogenase (l-ldh)-encoding ldha-null c. glutamicum ...200818188553
secretion of streptomyces mobaraensis pro-transglutaminase by coryneform bacteria.we previously reported on the secretion of streptomyces mobaraensis transglutaminase by corynebacterium glutamicum atcc13869 (formerly classified as brevibacterium lactofermentum). in the present work, we investigated whether any other coryneform bacteria showed higher productivity than c. glutamicum atcc13869. we found that most coryneform species secreted pro-transglutaminase efficiently. moreover, we confirmed that corynebacterium ammoniagenes atcc6872 produced about 2.5 g/l pro-transglutamin ...200818219481
influence of l-isoleucine and pantothenate auxotrophy for l-valine formation in corynebacterium glutamicum revisited by metabolome analyses.the effect of different amounts of supplemented l-isoleucine and pantothenate has been analysed with the auxotrophic strain corynebacterium glutamicum deltailva deltapanb, showing that the final biomass concentration of this preliminary l-valine production strain can be controlled by the amount of added l-isoleucine. one gramme cell dry weight is formed from 48 micromol l-isoleucine. different amounts of available pantothenate affect the intracellular pyruvate concentration. by limiting pantothe ...200818224342
co-ordinated regulation of gluconate catabolism and glucose uptake in corynebacterium glutamicum by two functionally equivalent transcriptional regulators, gntr1 and gntr2.corynebacterium glutamicum is a gram-positive soil bacterium that prefers the simultaneous catabolism of different carbon sources rather than their sequential utilization. this type of metabolism requires an adaptation of the utilization rates to the overall metabolic capacity. here we show how two functionally redundant gntr-type transcriptional regulators, designated gntr1 and gntr2, co-ordinately regulate gluconate catabolism and glucose uptake. gntr1 and gntr2 strongly repress the genes enco ...200818047570
engineering of an l-arabinose metabolic pathway in corynebacterium glutamicum.corynebacterium glutamicum was metabolically engineered to broaden its substrate utilization range to include the pentose sugar l-arabinose, a product of the degradation of lignocellulosic biomass. the resultant cra1 recombinant strain expressed the escherichia coli genes araa, arab, and arad encoding l-arabinose isomerase, l-ribulokinase, and l-ribulose-5-phosphate 4-epimerase, respectively, under the control of a constitutive promoter. unlike the wild-type strain, cra1 was able to grow on mine ...200817965859
regulatory properties and interaction of the c- and n-terminal domains of betp, an osmoregulated betaine transporter from corynebacterium glutamicum.the glycine betaine carrier betp from corynebacterium glutamicum responds to changes in external osmolality by regulation of its transport activity, and the c-terminal domain was previously identified to be involved in this process. here we investigate the structural requirements of the c-terminal domain for osmoregulation as well as interacting domains that are relevant for intramolecular signal transduction in response to osmotic stress. for this purpose, we applied a proline scanning approach ...200818950194
characterization of cg10062 from corynebacterium glutamicum: implications for the evolution of cis-3-chloroacrylic acid dehalogenase activity in the tautomerase superfamily.a 149-amino acid protein designated cg10062 is encoded by a gene from corynebacterium glutamicum. the physiological function of cg10062 is unknown, and the gene encoding this protein has no obvious genomic context. sequence analysis links cg10062 to the cis-3-chloroacrylic acid dehalogenase ( cis-caad) family, one of the five known families of the tautomerase superfamily. the characterized tautomerase superfamily members have two distinctive characteristics: a beta-alpha-beta structure motif and ...200818598055
genome sequence of the lytic bacteriophage p1201 from corynebacterium glutamicum nchu 87078: evolutionary relationships to phages from corynebacterineae.p1201 is a lytic corynephage of corynebacterium glutamicum nchu 87078. its genome consists of a linear double-stranded dna molecule of 70,579 base pairs, with 3'-protruding cohesive ends of ten nucleotides. we have identified 69 putative open reading frames, including three apparent genes (thymidylate synthase, terminase, and rnr alpha subunit genes) that are interrupted by an intein. protein-splicing activities of these inteins were demonstrated in escherichia coli. three structural proteins in ...200818599103
a proteome analysis of the cadmium and mercury response in corynebacterium glutamicum.cadmium and mercury are well-known toxic heavy metals, but the basis of their toxicity is not well understood. in this study, we analyzed the cellular response of corynebacterium glutamicum to sublethal concentrations of cadmium and mercury ions using 2-de and ms. mercury induced the over-expression of 13 c. glutamicum proteins, whereas 35 proteins were induced, and 8 proteins were repressed, respectively, under cadmium stress. the principal response to these metals was protection against oxidat ...200818972541
the murc ligase essential for peptidoglycan biosynthesis is regulated by the serine/threonine protein kinase pkna in corynebacterium glutamicum.the mur ligases play an essential role in the biosynthesis of bacterial cell-wall peptidoglycan and thus represent attractive targets for the design of novel antibacterials. these enzymes catalyze the stepwise formation of the peptide moiety of the peptidoglycan disaccharide peptide monomer unit. murc is responsible of the addition of the first residue (l-alanine) onto the nucleotide precursor udp-murnac. phosphorylation of proteins by ser/thr protein kinases has recently emerged as a major phys ...200818974047
regulation of glutamate metabolism by protein kinases in mycobacteria.protein kinase g of mycobacterium tuberculosis has been implicated in virulence and in regulation of glutamate metabolism. here we show that this kinase undergoes a pattern of autophosphorylation that is distinct from that of other m. tuberculosis protein kinases characterized to date and we identify gara as a substrate for phosphorylation by pkng. autophosphorylation of pkng has little effect on kinase activity but promotes binding to gara, an interaction that is also detected in living mycobac ...200819019160
structural and functional characterization of the lldr from corynebacterium glutamicum: a transcriptional repressor involved in l-lactate and sugar utilization.lldr (cgl2915) from corynebacterium glutamicum is a transcription factor belonging to the gntr family, which is typically involved in the regulation of oxidized substrates associated with amino acid metabolism. in the present study, the crystal structure of lldr was determined at 2.05-a resolution. the structure consists of n- and c-domains similar to those of fadr, but with distinct domain orientations. lldr and fadr dimers achieve similar structures by domain swapping, which was first observed ...200818988622
methionine uptake in corynebacterium glutamicum by metqni and by metps, a novel methionine and alanine importer of the nss neurotransmitter transporter family.the soil bacterium corynebacterium glutamicum is a model organism in amino acid biotechnology. here we present the identification of two different l-methionine uptake systems including the first characterization of a bacterial secondary methionine carrier. the primary carrier metqni is a high affinity abc-type transporter specific for l-methionine. its expression is under the control of the transcription factor mcbr, the global regulator of sulfur metabolism in c. glutamicum. besides metqni, a n ...200818991398
enhanced valine production in corynebacterium glutamicum with defective h+-atpase and c-terminal truncated acetohydroxyacid synthase.we have reported increased glutamate production by a mutant of corynebacterium glutamicum atcc14067 (strain f172-8) with reduced h(+)-atpase activity under biotin-limiting culture conditions (aoki et al. biosci. biotechnol. biochem., 69, 1466-1472 (2005)). in the present study, we examined valine production by an h(+)-atpase-defective mutant of c. glutamicum. using the double-crossover chromosome replacement technique, we constructed a newly defined h(+)-atpase-defective mutant from atcc13032. a ...200818997402
scrb (cg2927) is a sucrose-6-phosphate hydrolase essential for sucrose utilization by corynebacterium glutamicum.corynebacterium glutamicum can grow on a variety of carbohydrates from which glucose, fructose and sucrose are taken up and phosphorylated by the phosphoenolpyruvate-dependent phosphotransferase system (pts). here, we show that cg2927 (scrb) encodes sucrose-6-phosphate hydrolase. the purified his-tagged protein hydrolyzed sucrose-6-phosphate and sucrose, but not sucrose-6'-phosphate. the km value for sucrose was 190 mm while the km for sucrose-6-phosphate was much lower, 0.04 mm. sucrose-6-phosp ...200819054097
response of the cytoplasmic and membrane proteome of corynebacterium glutamicum atcc 13032 to ph changes.c. glutamicum has traditionally been grown in neutral-ph media for amino acid production, but in a previous article we reported that this microorganism is a moderate alkaliphile since it grows optimally at ph 7.0-9.0, as shown in fermentor studies under tightly controlled ph conditions. we determined the best ph values to study differential expression of several genes after acidic or basic ph conditions (ph 6.0 for acidic expression and ph 9.0 for alkaline expression). thus, it was interesting t ...200819091079
inactivation of cg10062, a cis-3-chloroacrylic acid dehalogenase homologue in corynebacterium glutamicum, by (r)- and (s)-oxirane-2-carboxylate: analysis and implications.( r)- and ( s)-oxirane-2-carboxylate were determined to be active site-directed irreversible inhibitors of the cis-3-chloroacrylic acid dehalogenase ( cis-caad) homologue cg10062 found in corynebacterium glutamicum. kinetic analysis indicates that the ( r) enantiomer binds more tightly and is the more potent inhibitor, likely reflecting more favorable interactions with active site residues. pro-1 is the sole site of covalent modification by the ( r) and ( s) enantiomers. pro-1, arg-70, arg-73, a ...200818646866
identification and characterization of the dicarboxylate uptake system dcct in corynebacterium glutamicum.many bacteria can utilize c(4)-carboxylates as carbon and energy sources. however, corynebacterium glutamicum atcc 13032 is not able to use tricarboxylic acid cycle intermediates such as succinate, fumarate, and l-malate as sole carbon sources. upon prolonged incubation, spontaneous mutants which had gained the ability to grow on succinate, fumarate, and l-malate could be isolated. dna microarray analysis showed higher mrna levels of cg0277, which subsequently was named dcct, in the mutants than ...200818658264
partial redundancy in the synthesis of the d-arabinose incorporated in the cell wall arabinan of corynebacterineae.the major cell wall carbohydrate of corynebacterineae is arabinogalactan (ag), a branched polysaccharide that is essential for the physiology of these bacteria. decaprenylphosphoryl-d-arabinose (dpa), the lipid donor of d-arabinofuranosyl residues of ag, is synthesized through a series of unique biosynthetic steps, the last one being the epimerization of decaprenylphosphoryl-beta-d-ribose (dpr) into dpa, which is believed to proceed via a sequential oxidation-reduction mechanism. two proteins fr ...200818667564
nitrogen control in mycobacterium smegmatis: nitrogen-dependent expression of ammonium transport and assimilation proteins depends on the ompr-type regulator glnr.the effect of nitrogen regulation on the level of transcriptional control has been investigated in a variety of bacteria, such as bacillus subtilis, corynebacterium glutamicum, escherichia coli, and streptomyces coelicolor; however, until now there have been no data for mycobacteria. in this study, we found that the ompr-type regulator protein glnr controls nitrogen-dependent transcription regulation in mycobacterium smegmatis. based on rna hybridization experiments with a wild-type strain and a ...200818689485
distinct roles of two anaplerotic pathways in glutamate production induced by biotin limitation in corynebacterium glutamicum.corynebacterium glutamicum is a biotin auxotrophic bacterium in which glutamate production is induced under biotin-limited conditions. during glutamate production, anaplerotic reactions catalyzed by phosphoenolpyruvate carboxylase (pepc) and a biotin-containing enzyme pyruvate carboxylase (pc) are believed to play an important role in supplying oxaloacetate in the tricarboxylic acid cycle. to understand the distinct roles of pepc and pc on glutamate production by c. glutamicum, we observed gluta ...200818691531
characterization of developmental colony formation in corynebacterium glutamicum.we report that corynebacterium glutamicum colonies exhibit a developmental transition in culture. when cultured on a routinely used complete medium (cm2b), this bacterium first formed a flat translucent colony. subsequently, some parts of this colony expanded to form small spherical yellow colonies that finally developed into a single large yellow colony. the small flat colony consisted of long thick cells, which were occasionally v or y shaped, while the large yellow colony consisted of short s ...200818696061
[phage resistance of corynebacterium crenatum conferred by the restriction and modification system cgli].in order to prevent phage contamination in amino acid fermentation, we introduced the restriction and modification system cgli gene complex into corynebacterium crenatum and studied their phage-resistance. the cgli gene complex was amplified from corynebacterium glutamicum by pcr and constructed into pjl23 vector. the recombinant strains were obtained by transformation of the recombinant plasmid pjl23-cgli into c. crenatum. results showed that the recombinant strains possessed strong phage-resis ...200818724694
engineering of a glycerol utilization pathway for amino acid production by corynebacterium glutamicum.the amino acid-producing organism corynebacterium glutamicum cannot utilize glycerol, a stoichiometric by-product of biodiesel production. by heterologous expression of escherichia coli glycerol utilization genes, c. glutamicum was engineered to grow on glycerol. while expression of the e. coli genes for glycerol kinase (glpk) and glycerol 3-phosphate dehydrogenase (glpd) was sufficient for growth on glycerol as the sole carbon and energy source, additional expression of the aquaglyceroporin gen ...200818757581
production of 2-methyl-1-butanol in engineered escherichia coli.recent progress has been made in the production of higher alcohols by harnessing the power of natural amino acid biosynthetic pathways. here, we describe the first strain of escherichia coli developed to produce the higher alcohol and potential new biofuel 2-methyl-1-butanol (2mb). to accomplish this, we explored the biodiversity of enzymes catalyzing key parts of the isoleucine biosynthetic pathway, finding that ahas ii (ilvgm) from salmonella typhimurium and threonine deaminase (ilva) from cor ...200818758769
heterologous ectoine production in escherichia coli: by-passing the metabolic bottle-neck.transcription of the ectoine biosynthesis genes ecta, ectb and ectc from marinococcus halophilus in recombinant escherichia coli dh5alpha is probably initiated from three individual sigma70/sigmaa-dependent promoter sequences, upstream of each gene. consequently, mrna-fragments containing the single genes and combinations of the genes ecta and ectb or ectb and ectc, respectively, could be detected by northern blot analysis. under the control of its own regulatory promoter region (ectup) a seemin ...200818759971
metabolic engineering for bioproduction of sugar alcohols.sugar alcohols find applications in pharmaceuticals, oral and personal care products, and as intermediates in chemical synthesis. while industrial-scale production of these compounds has generally involved catalytic hydrogenation of sugars, microbial-based processes receive increasing attention. the past few years have seen a variety of interesting metabolic engineering efforts to improve the capabilities of bacteria and yeasts to overproduce xylitol, mannitol, and sorbitol. examples include het ...200818760354
an efficient succinic acid production process in a metabolically engineered corynebacterium glutamicum strain.a corynebacterium glutamicum strain (deltaldha-pcra717) that overexpresses the pyc gene encoding pyruvate carboxylase while simultaneously exhibiting a disrupted ldha gene encoding l-lactate dehydrogenase was investigated in detail for succinic acid production. succinic acid was shown to be efficiently produced at high-cell density under oxygen deprivation with intermittent addition of sodium bicarbonate and glucose. succinic acid concentration reached 1.24 m (146 g l(-1)) within 46 h. the yield ...200818777022
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