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comparisons of potentials for l-lysine production among different corynebacterium glutamicum strains.corynebacterium glutamicum is an industrially important organism that is most widely used for the production of various amino acids. a defined l-lysine-producing mutant was generated by introduction of the lysc mutation (t311i) into each of six representative c. glutamicum strains. the resulting six isogenic mutants were compared for l-lysine production under traditional 30 degrees c conditions and industrially more advantageous 40 degrees c conditions. it was found that there were significant d ...200616636474
metabolic activity of corynebacterium glutamicum grown on l: -lactic acid under stress.respiration measurement in shake flasks is introduced as a new method to characterize the metabolic activity of microorganisms during and after stress exposure. the major advantage of the new method is the possibility to determine the metabolic activity independent of manual sampling without the necessity to change the culture vessel or the cultivation medium. this excludes stress factors, which may be induced by transferring the microorganisms to plates or respirometers. the negative influence, ...200616642330
enhancement of biomolecule transport by electroporation: a review of theory and practical application to transformation of corynebacterium glutamicum.selective and reversible permeabilization of the cell wall permeability barrier is the focus for many biotechnological applications. in this article, the basic principles for reversible membrane permeabilization, based on biological, chemical, and physical methods are reviewed. emphasis is given to electroporation (electropermeabilization) which tends to be the most popular method for membrane permeabilization and for introduction of foreign molecules into the cells. the applications of this met ...200616224791
the iclr-type transcriptional repressor ltbr regulates the expression of leucine and tryptophan biosynthesis genes in the amino acid producer corynebacterium glutamicum.the transcriptional regulator cg1486 of corynebacterium glutamicum atcc 13032 is a member of the iclr protein family and belongs to the conserved set of regulatory proteins in corynebacteria. a defined deletion in the cg1486 gene, now designated ltbr (leucine and tryptophan biosynthesis regulator), led to the mutant strain c. glutamicum ib1486. according to whole-genome expression analysis by dna microarray hybridizations, transcription of the leub and leucd genes encoding enzymes of the leucine ...200717259312
urea transport in bacteria: acid acclimation by gastric helicobacter spp.urea transporters in bacteria are relatively rare. there are three classes, the abc transporters such as those expressed by cyanobacteria and corynebacterium glutamicum, the yut protein expressed by yersinia spp and the urei expressed by gastric helicobacter spp. this review focuses largely on the urei proton-gated channel that is part of the acid acclimation mechanism essential for gastric colonization by the latter. urei is a six-transmembrane polytopic integral membrane protein, n and c termi ...200717264989
effect of elevated dissolved carbon dioxide concentrations on growth of corynebacterium glutamicum on d-glucose and l-lactate.the effect of increased dissolved carbon dioxide concentrations on growth of corynebacterium glutamicum was studied with continuous turbidostatic cultures. the carbon sources were either l-lactate or d-glucose. to increase the dissolved carbon dioxide concentration the carbon dioxide partial pressure of the inlet gas stream pco2,in was increased stepwise from 0.0003 bar (air) up to 0.79 bar, while the oxygen partial pressure of the inlet gas stream was kept constant at 0.21 bar. for each resulti ...200717275119
effect of lignocellulose-derived inhibitors on growth of and ethanol production by growth-arrested corynebacterium glutamicum r.in cellulosic ethanol production, pretreatment of a biomass to facilitate enzymatic hydrolysis inevitably yields fermentation inhibitors such as organic acids, furans, and phenols. with representative inhibitors included in the medium at various concentrations, individually or in various combinations, ethanol production by corynebacterium glutamicum r under growth-arrested conditions was investigated. in the presence of various inhibitors, the 62 to 100% ethanol productivity retained by the c. g ...200717277203
metabolic flux estimation--a self-adaptive evolutionary algorithm with singular value decomposition.metabolic flux analysis is important for metabolic system regulation and intracellular pathway identification. a popular approach for intracellular flux estimation involves using 13c tracer experiments to label states that can be measured by nuclear magnetic resonance spectrometry or gas chromatography mass spectrometry. however, the bilinear balance equations derived from 13c tracer experiments and the noisy measurements require a nonlinear optimization approach to obtain the optimal solution. ...200717277420
crystallization and preliminary crystallographic analysis of dtsr1, a carboxyltransferase subunit of acetyl-coa carboxylase from corynebacterium glutamicum.dtsr1, a carboxyltransferase subunit of acetyl-coa carboxylase derived from corynebacterium glutamicum, was crystallized by the sitting-drop vapour-diffusion method using polyethylene glycol 6000 as a precipitant. the crystal belongs to the trigonal system with space group r32 and contains three subunits in the asymmetric unit. a molecular-replacement solution was found using the structure of transcarboxylase 12s from propionibacterium shermanii as a search model.200717277455
in vitro analysis of the two-component system mtrb-mtra from corynebacterium glutamicum.the two-component system mtrba is involved in the osmostress response of corynebacterium glutamicum. mtrb was reconstituted in a functionally active form in liposomes and showed autophosphorylation and phosphatase activity. in proteoliposomes, mtrb activity was stimulated by monovalent cations used by many osmosensors for the detection of hypertonicity. although mtrb was activated by monovalent cations, they lead in vitro to a general stabilization of histidine kinases and do not represent the s ...200717293417
the deor-type regulator sugr represses expression of ptsg in corynebacterium glutamicum.corynebacterium glutamicum grows on a variety of carbohydrates and organic acids. uptake of the preferred carbon source glucose via the phosphoenolpyruvate-dependent phosphotransferase system (pts) is reduced during coutilization of glucose with acetate, sucrose, or fructose compared to growth on glucose as the sole carbon source. here we show that the deor-type regulator sugr (ncgl1856) represses expression of ptsg, which encodes the glucose-specific pts enzyme ii. overexpression of sugr result ...200717293426
l-valine production with pyruvate dehydrogenase complex-deficient corynebacterium glutamicum.corynebacterium glutamicum was engineered for the production of l-valine from glucose by deletion of the acee gene encoding the e1p enzyme of the pyruvate dehydrogenase complex and additional overexpression of the ilvbnce genes encoding the l-valine biosynthetic enzymes acetohydroxyacid synthase, isomeroreductase, and transaminase b. in the absence of cellular growth, c. glutamicum deltaacee showed a relatively high intracellular concentration of pyruvate (25.9 mm) and produced significant amoun ...200717293513
the reductase that catalyzes mycolic motif synthesis is required for efficient attachment of mycolic acids to arabinogalactan.mycolic acids are essential components of the cell walls of bacteria belonging to the suborder corynebacterineae, including the important human pathogens mycobacterium tuberculosis and mycobacterium leprae. mycolic acid biosynthesis is complex and the target of several frontline antimycobacterial drugs. the condensation of two fatty acids to form a 2-alkyl-3-keto mycolate precursor and the subsequent reduction of this precursor represent two key and highly conserved steps in this pathway. althou ...200717308303
scale-up from shake flasks to fermenters in batch and continuous mode with corynebacterium glutamicum on lactic acid based on oxygen transfer and ph.scale-up from shake flasks to fermenters has been hampered by the lack of knowledge concerning the influence of operating conditions on mass transfer, hydromechanics, and power input. however, in recent years the properties of shake flasks have been described with empirical models. a practical scale-up strategy for everyday use is introduced for the scale-up of aerobic cultures from shake flasks to fermenters in batch and continuous mode. the strategy is based on empirical correlations of the vo ...200717318907
genome-wide investigation of aromatic acid transporters in corynebacterium glutamicum.genome-wide data mining indicated that six genes (ncgl1031, ncgl2302, ncgl2325, ncgl2326, ncgl2922 and ncgl2953) encoding putative transport proteins are involved in uptake of various aromatic compounds that are further degraded through the beta-ketoadipate, gentisate and resorcinol pathways in corynebacterium glutamicum. the gentisate (genk/ncgl2922) and vanillate (vank/ncgl2302) transporters have been identified previously. in this study, physiological functions of the remaining four putative ...200717322206
effect of pyruvate dehydrogenase complex deficiency on l-lysine production with corynebacterium glutamicum.intracellular precursor supply is a critical factor for amino acid productivity of corynebacterium glutamicum. to test for the effect of improved pyruvate availability on l-lysine production, we deleted the acee gene encoding the e1p enzyme of the pyruvate dehydrogenase complex (pdhc) in the l-lysine-producer c. glutamicum dm1729 and characterised the resulting strain dm1729-bb1 for growth and l-lysine production. compared to the host strain, c. glutamicum dm1729-bb1 showed no pdhc activity, was ...200717333167
anaerobic growth of corynebacterium glutamicum using nitrate as a terminal electron acceptor.corynebacterium glutamicum, a gram-positive soil bacterium, has been regarded as an aerobe because its growth by fermentative catabolism or by anaerobic respiration has, to this date, not been demonstrated. in this study, we report on the anaerobic growth of c. glutamicum in the presence of nitrate as a terminal electron acceptor. c. glutamicum strains r and atcc13032 consumed nitrate and excreted nitrite during growth under anaerobic, but not aerobic, conditions. this was attributed to the pres ...200717347820
structural insight into concerted inhibition of alpha 2 beta 2-type aspartate kinase from corynebacterium glutamicum.aspartate kinase (ak) catalyzes the first step of the biosynthesis of the aspartic acid family amino acids, and is regulated via feedback inhibition by end-products including thr and lys. to elucidate the mechanism of this inhibition, we determined the crystal structure of the regulatory subunit of ak from corynebacterium glutamicum at 1.58 a resolution in the thr-binding form, the first crystal structure of the regulatory subunit of alpha(2)beta(2)-type ak. the regulatory subunit contains two a ...200717350037
improving lysine production by corynebacterium glutamicum through dna microarray-based identification of novel target genes.for the biotechnological production of l: -lysine, mainly strains of corynebacterium glutamicum are used, which have been obtained by classical mutagenesis and screening or selection or by metabolic engineering. gene targets for the amplification and deregulation of the lysine biosynthesis pathway, for the improvement of carbon precursor supply and of nicotinamide adenine dinucleotide phosphate (reduced form) (nadph) regeneration, are known. to identify novel target genes to improve lysine produ ...200717364200
comparative analysis of the corynebacterium glutamicum group and complete genome sequence of strain r.the complete genome sequence of corynebacterium glutamicum strain r was determined to allow its comparative analysis with other corynebacteria. the biology of corynebacteria was explored by refining the definition of the subset of genes that constitutes the corynebacterial core as well as those characteristic of saprophytic and pathogenic ecological niches. in addition, the relative scarcity of corynebacterial sigma factors and the plasticity of their two-component system machinery reflect their ...200717379713
glycogen formation in corynebacterium glutamicum and role of adp-glucose pyrophosphorylase.glycogen is generally assumed to serve as a major reserve polysaccharide in bacteria. in this work, glycogen accumulation in the amino acid producer corynebacterium glutamicum was characterized, expression of the c. glutamicum glgc gene, encoding the key enzyme in glycogen synthesis, adp-glucose (adp-glc) pyrophosphorylase, was analysed, and the relevance of this enzyme for growth, survival, amino acid production and osmoprotection was investigated. c. glutamicum cells grown in medium containing ...200717379737
anaerobic growth and potential for amino acid production by nitrate respiration in corynebacterium glutamicum.oxygen limitation is a crucial problem in amino acid fermentation by corynebacterium glutamicum. toward this subject, our study was initiated by analysis of the oxygen-requiring properties of c. glutamicum, generally regarded as a strict aerobe. this organism formed colonies on agar plates up to relatively low oxygen concentrations (0.5% o(2)), while no visible colonies were formed in the absence of o(2). however, in the presence of nitrate (no3-), the organism exhibited limited growth anaerobic ...200717380327
[regulation of methionine/cysteine biosynthesis in corynebacterium glutamicum and related genomes].methionine is an essential amino acid and the universal n-terminal amino acid of proteins. the biosynthesis of methionine is extensively studied in various organisms that could be used in biotechnological production of methionine. transcriptional regulation of the methionine synthesis in the corynebacterium glutamicum genome is well studied. the mcbr protein is a transcriptional regulator of methionine/cysteine biosynthesis genes. the operon structures for members of the mcbr regulon also were p ...200717380901
identification of a novel arabinofuranosyltransferase aftb involved in a terminal step of cell wall arabinan biosynthesis in corynebacterianeae, such as corynebacterium glutamicum and mycobacterium tuberculosis.arabinofuranosyltransferase enzymes, such as emba, embb, and afta, play pivotal roles in the biosynthesis of arabinogalactan, and the anti-tuberculosis agent ethambutol (emb) targets arabinogalactan biosynthesis through inhibition of mt-emba and mt-embb. herein, we describe the identification and characterization of a novel arabinofuranosyltransferase, now termed aftb (rv3805c), which is essential in mycobacterium tuberculosis. deletion of its orthologue ncgl2780 in the closely related species c ...200717387176
characterization of compatible solute transporter multiplicity in corynebacterium glutamicum.the soil bacterium corynebacterium glutamicum is efficiently protected against hyperosmotic stress by a high redundancy of uptake systems and biosynthesis pathways for compatible solutes. we have previously identified and analyzed four osmoregulated uptake systems for betaine, ectoine, and proline. because of overlapping substrate specificities, it is not possible to quantify their individual contribution to the stress response in wild-type cells. using a set of strains in which only one uptake ...200717390131
sampling for metabolome analysis of microorganisms.in the present work we investigated the most commonly applied methods used for sampling of microorganisms in the field of metabolomics in order to unravel potential sources of error previously ignored but of utmost importance for accurate metabolome analysis. to broaden the significance of our study, we investigated different gram-negative and gram-positive bacteria, i.e., bacillus subtilis, corynebacterium glutamicum, escherichia coli, gluconobacter oxydans, pseudomonas putida, and zymononas mo ...200717411014
crystal structures and site-directed mutagenesis of a mycothiol-dependent enzyme reveal a novel folding and molecular basis for mycothiol-mediated maleylpyruvate isomerization.mycothiol (msh) is the major low molecular mass thiols in many gram-positive bacteria such as mycobacterium tuberculosis and corynebacterium glutamicum. the physiological roles of msh are believed to be equivalent to those of gsh in gram-negative bacteria, but current knowledge of msh is limited to detoxification of alkalating chemicals and protection from host cell defense/killing systems. recently, an msh-dependent maleylpyruvate isomerase (mdmpi) was discovered from c. glutamicum, and this is ...200717428791
innovative metabolic pathway design for efficient l-glutamate production by suppressing co2 emission.in the pathway of l-glutamic acid (l-glu) biosynthesis in corynebacterium glutamicum, 1 mol of l-glu is synthesized from 1 mol of glucose at a cost of 1 mol of carbon dioxide (co(2)), with a maximum theoretical yield of 81.7% by weight. we have designed an innovative pathway for efficient l-glu production employing phosphoketolase (pkt) to bypass the co(2)-releasing pyruvate dehydrogenase reaction, thereby increasing the maximum theoretical yield of l-glu from glucose to up to 98.0% by weight (1 ...200717434430
[cloning, sequence analysis and expression of anthranilate synthetase gene in corynebacterium pekinense].anthranilate synthetase (ec4.1.3.27;as) genes from wild-type corynebacterium pekinense as1.299 and its mutant pd-67 were cloned and sequenced. analysis of pcr fragments revealed that three orfs existed, which corresponded to trpl, trpe and trpg gene, respectively. six bases changes that resulted in the changes of five amino acids were found in the trpe structural gene of c. pekinense pd-67 and a single-base change that resulted in an amino acid substitution was found in the trpg structural gene ...200717436623
glutamate production by corynebacterium glutamicum: dependence on the oxoglutarate dehydrogenase inhibitor protein odhi and protein kinase pkng.we recently showed that the activity of the 2-oxoglutarate dehydrogenase complex (odhc) in corynebacterium glutamicum is controlled by a novel regulatory mechanism that involves a 15-kda protein called odhi and serine/threonine protein kinase g (pkng). in its unphosphorylated state, odhi binds to the e1 subunit (odha) of odhc and, thereby, inhibits its activity. inhibition is relieved by phosphorylation of odhi at threonine-14 by pkng under conditions requiring high odhc activity. in this work, ...200717437098
comparative analysis of twin-arginine (tat)-dependent protein secretion of a heterologous model protein (gfp) in three different gram-positive bacteria.in contrast to the general protein secretion (sec) system, the twin-arginine translocation (tat) export pathway allows the translocation of proteins across the bacterial plasma membrane in a fully folded conformation. due to this feature, the tat pathway provides an attractive alternative to the secretory production of heterologous proteins via the sec system. in this study, the potential for tat-dependent heterologous protein secretion was compared in the three gram-positive bacteria staphyloco ...200717453196
the key role of the mycolic acid content in the functionality of the cell wall permeability barrier in corynebacterineae.recently, it has been shown that trehalose and mycolic acids are essential for the growth of mycobacterium tuberculosis, the causative agent of tuberculosis, and mycobacterium smegmatis, and important but not indispensable to the survival of corynebacterium glutamicum. therefore, to investigate the function of mycolic acids in both the permeability of the cell wall to small nutrients and antibiotics, and the excretion of amino acids by c. glutamicum, a trehalose-deficient mutant of the l-lysine ...200717464056
the two carboxylases of corynebacterium glutamicum essential for fatty acid and mycolic acid synthesis.the suborder corynebacterianeae comprises bacteria like mycobacterium tuberculosis and corynebacterium glutamicum, and these bacteria contain in addition to the linear fatty acids, unique alpha-branched beta-hydroxy fatty acids, called mycolic acids. whereas acetyl-coenzyme a (coa) carboxylase activity is required to provide malonyl-coa for fatty acid synthesis, a new type of carboxylase is apparently additionally present in these bacteria. it activates the alpha-carbon of a linear fatty acid by ...200717483212
the extracytoplasmic function-type sigma factor sigm of corynebacterium glutamicum atcc 13032 is involved in transcription of disulfide stress-related genes.the gene for the extracytoplasmic function (ecf) sigma factor sigm was deleted from the chromosome of the gram-positive soil bacterium corynebacterium glutamicum to elucidate the role of the sigm protein in the regulation of gene expression. comparative dna microarray hybridizations of the c. glutamicum wild type and sigm-deficient mutant c. glutamicum dn1 revealed 23 genes with enhanced expression in the sigm-proficient strain, encoding functions in the assembly of iron-sulfur clusters (suf ope ...200717483229
farr, a putative regulator of amino acid metabolism in corynebacterium glutamicum.with the publication of the corynebacterium glutamicum genome sequence, a global characterization of genes controlled by functionally uncharacterized transcriptional regulators became possible. we used dna microarrays in combination with gel retardation experiments to study gene regulation by farr, a hutc/farr-type regulator of the gntr family. based on our results, farr seems to be involved in the regulation of amino acid biosynthesis in c. glutamicum. especially, transcript levels of the arg c ...200717483938
biosorption of reactive black 5 by corynebacterium glutamicum biomass immobilized in alginate and polysulfone matrices.corynebacterium glutamicum, a lysine fermentation industry waste, showed promise for the removal of reactive black 5 (rb5). due to practical difficulties in solid-liquid separation, the free biomass was immobilized in two polymer matrices: calcium alginate and polysulfone. initially, the optimization of biomass loading in polymeric beads and bead dosage were examined. of the different combinations examined, 4% (with bead dosage of 2 g per 40 ml) and 14% (with bead dosage of 1 g per 40 ml) in the ...200717490706
target genes and dna-binding sites of the response regulator phor from corynebacterium glutamicum.the two-component signal transduction system phors of corynebacterium glutamicum is involved in the phosphate (p(i)) starvation response. to analyze the binding of unphosphorylated and phosphorylated phor to the promoters of phosphate starvation-inducible (psi) genes, this response regulator and the kinase domain of its cognate sensor, phos (mbp-phosdelta1-246), were overproduced and purified. mbp-phosdelta1-246 showed constitutive autophosphorylation activity, and a rapid phosphoryl group trans ...200717496102
expression of glf z.m. increases d-mannitol formation in whole cell biotransformation with resting cells of corynebacterium glutamicum.a recombinant oxidation/reduction cycle for the conversion of d-fructose to d-mannitol was established in resting cells of corynebacterium glutamicum. whole cells were used as biocatalysts, supplied with 250 mm sodium formate and 500 mm d-fructose at ph 6.5. the mannitol dehydrogenase gene (mdh) from leuconostoc pseudomesenteroides was overexpressed in strain c. glutamicum atcc 13032. to ensure sufficient cofactor [nicotinamide adenine dinucleotide (reduced form, nadh)] supply, the fdh gene enco ...200717503033
mutations of the corynebacterium glutamicum ncgl1221 gene, encoding a mechanosensitive channel homolog, induce l-glutamic acid production.corynebacterium glutamicum is a biotin auxotroph that secretes l-glutamic acid in response to biotin limitation; this process is employed in industrial l-glutamic acid production. fatty acid ester surfactants and penicillin also induce l-glutamic acid secretion, even in the presence of biotin. however, the mechanism of l-glutamic acid secretion remains unclear. it was recently reported that disruption of odha, encoding a subunit of the 2-oxoglutarate dehydrogenase complex, resulted in l-glutamic ...200717513583
gene expression analysis of corynebacterium glutamicum subjected to long-term lactic acid adaptation.corynebacteria form an important part of the red smear cheese microbial surface consortium. to gain a better understanding of molecular adaptation due to low ph induced by lactose fermentation, the global gene expression profile of corynebacterium glutamicum adapted to ph 5.7 with lactic acid under continuous growth in a chemostat was characterized by dna microarray analysis. expression of a total of 116 genes was increased and that of 90 genes was decreased compared to ph 7.5 without lactic aci ...200717526706
ncgl2620 encodes a class ii polyphosphate kinase in corynebacterium glutamicum.corynebacterium glutamicum is able to accumulate up to 600 mm cytosolic phosphorus in the form of polyphosphate (poly p). granular poly p (volutin) can make up to 37% of the internal cell volume. this bacterium lacks the classic enzyme of poly p synthesis, class i polyphosphate kinase (ppk1), but it possesses two genes, ppk2a (corresponds to ncgl0880) and ppk2b (corresponds to ncgl2620), for putative class ii (ppk2) ppks. deletion of ppk2b decreased ppk activity and cellular poly p content, whil ...200717545325
[construction of corynebacterium glutamicum/e. coli shuttle promoter-probe vector].based on the replication origins of the c. glutamicum pxz10145 and the escherichia coli cole1 plasmid, a novel corynebacterium glutamicum/escherichia coli shuttle vector pak6 was constructed. this vector was able to replicate in c. glutamicum and e. coli. plasmid pak6 carried multiple cloning site useful for gene cloning, kanamysin- and ampicillin-resistance-encoding gene. furtherly based on the shuttle vector pak6, a promoter-probe vector was developed for the isolation of promoter elements fro ...200717552218
the impact of phb accumulation on l-glutamate production by recombinant corynebacterium glutamicum.corynebacterium glutamicum, a gram-positive soil bacterium, has been used extensively for the industrial production of l-glutamate and other amino acids. in this study, an escherichia coli-c. glutamicum shuttle expression plasmid harboring polyhydroxybutyrate (phb) synthesis genes, phbcab from ralstonia eutropha, was constructed under the ptrc promoter. c. glutamicum harboring this plasmid accumulated 3-13% phb with a weight average molecular mass of 125,400 and a polydispersity of 11.3 when gro ...200717555841
characterization of citrate utilization in corynebacterium glutamicum by transcriptome and proteome analysis.corynebacterium glutamicum grows aerobically on a variety of carbohydrates and organic acids as single or combined sources of carbon and energy. to characterize the citrate utilization in c. glutamicum on a genomewide scale, a comparative analysis was carried out by combining transcriptome and proteome analysis. in cells grown on citrate, transcriptome analysis revealed highest expression changes for two different citrate-uptake systems encoded by citm and tctcba, whereas genes encoding uptake s ...200717559405
active site geometry of glucose-1-phosphate uridylyltransferase.glucose-1-phosphate uridylyltransferase, or ugpase, catalyzes the production of udp-glucose from glucose-1-phosphate and utp. because of the biological role of udp-glucose in glycogen synthesis and in the formation of glycolipids, glycoproteins, and proteoglycans, the enzyme is widespread in nature. recently this laboratory reported the three-dimensional structure of ugpase from escherichia coli. while the initial x-ray analysis revealed the overall fold of the enzyme, details concerning its act ...200717567737
a proteome analysis of corynebacterium glutamicum after exposure to the herbicide 2,4-dichlorophenoxy acetic acid (2,4-d).the herbicide 2,4-dichlorophenoxy acetic acid (2,4-d) induces a wide spectrum of toxic responses in living organisms. in this study, we analyzed the stress-induced responses of corynebacterium glutamicum cells on protein level upon treatment with 2,4-d. for this, growing c. glutamicum cells were exposed to sublethal concentrations of 2,4-d, and changes of the gene expression profiles in comparison to non-exposed organisms were analyzed by two-dimensional gel electrophoresis and mass spectrometry ...200717568655
parallel analysis of antimicrobial activities in microbial community by sscp based on ce.conventional antimicrobial activity analyses such as the broth dilution method and disk diffusion test are considerably demanding processes for new antimicrobial agent discovery and sensitive diagnosis of infectious diseases. here, we developed a new antimicrobial activity analysis system using ce-based sscp (ce-sscp) combined with 16s rrna gene-specific pcr (pcr/ce-sscp). using this method, the population change in the microbial community in response to specific antimicrobial agents could be qu ...200717577886
a high-throughput method for microbial metabolome analysis using gas chromatography/mass spectrometry.an analytical high-throughput method based on gas chromatography/mass spectrometry (gc/ms) was developed for fast metabolome investigation. by parallelization and partial automation the time needed for the preanalytical steps could be reduced. in addition a strong decrease of the relative standard deviation of metabolite concentrations from independent samples on the same microtiter plate from 25 to 13% was achieved. between different plates the relative standard deviation is comparable to the o ...200717585867
investigation of central carbon metabolism and the 2-methylcitrate cycle in corynebacterium glutamicum by metabolic profiling using gas chromatography-mass spectrometry.the 2-methylcitrate cycle as the primary way to metabolize propionate was investigated using metabolic profiling. for this purpose, a fast harvesting procedure was applied in which cells growing in liquid minimal medium were harvested by a short centrifugation and freeze-dried. subsequently, gas chromatography-mass spectrometry of polar extracts derivatized by mstfa was employed for metabolite characterization. routinely more than 300 different peaks were obtained in the chromatograms, and 74 su ...200717586079
study on roles of anaplerotic pathways in glutamate overproduction of corynebacterium glutamicum by metabolic flux analysis.corynebacterium glutamicum has several anaplerotic pathways (anaplerosis), which are essential for the productions of amino acids, such as lysine and glutamate. it is still not clear how flux changes in anaplerotic pathways happen when glutamate production is induced by triggers, such as biotin depletion and the addition of the detergent material, tween 40. in this study, we quantitatively analyzed which anaplerotic pathway flux most markedly changes the glutamate overproduction induced by tween ...200717587457
expression of corynebacterium glutamicum glycolytic genes varies with carbon source and growth phase.a basic pattern of gene expression and of relative expression levels during different growth phases was obtained for corynebacterium glutamicum r grown on different carbon sources. the gapa-pgk-tpi-ppc gene cluster was transcribed as a mono- or polycistronic mrna, depending on the growth phase. the 1.4 kb (gapa) and 2.3 kb (pgk-tip) mrnas were expressed in the early through late exponential phases, whereas the 3.7 kb (gapa-pgk-tpi) and 5.4 kb (pgk-tpi-ppc) mrnas were only detected in the mid-exp ...200717600063
the glgx gene product of corynebacterium glutamicum is required for glycogen degradation and for fast adaptation to hyperosmotic stress.corynebacterium glutamicum cells growing in medium containing sugars accumulate glycogen in the early exponential-growth phase, and start to degrade this polymer at entry into the stationary phase. in a first attempt to investigate glycogen degradation, the c. glutamicum glgx gene, which encodes a protein with 46 % identity to the isoamylase-type debranching enzyme of escherichia coli, was analysed, expressed and inactivated. the purified c. glutamicum gene product showed debranching activity to ...200717600065
characteristics of methionine production by an engineered corynebacterium glutamicum strain.a methionine-producing strain was derived from a lysine-producing corynebacterium glutamicum through a process of genetic manipulation in order to assess its potential to synthesize and accumulate methionine during growth. the strain carries a deregulated hom gene (hom(fbr)) to abolish feedback inhibition of homoserine dehydrogenase by threonine and a deletion of the thrb gene (delta thrb) to abolish threonine synthesis. the constructed c. glutamicum mh20-22b/hom(fbr)/delta thrb strain accumulat ...200717604670
isolation of a new insertion sequence, is13655, and its application to corynebacterium glutamicum genome mutagenesis.a new functional corynebacterium glutamicum insertion sequence (is) element, is13655, was isolated using a suicide vector. the is element was 1,293 bp in size and contained 26-bp imperfect inverted repeats (irs) and 3-bp target site duplication as direct repeats (drs). is13655 harbored two orfs with high similarity to the transposase of is1206, an is3 family element. is13655 revealed relatively high transposition efficiency, with low target site selectivity along the corynebacterium glutamicum r ...200717617717
cell envelope fluidity modification for an effective glutamate excretion in corynebacterium glutamicum 2262.1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (tma-dph) was used to assess the cell envelope fluidity of corynebacterium glutamicum 2262 during a temperature-triggered glutamate producing process. because the fluorescence lifetime of tma-dph was shown to be constant all over the process, fluorescence anisotropy can be considered as a good index of cell envelope fluidity. when the temperature of the fed-batch culture was increased from 33 to 39 degrees c to induce glutamate excretion, t ...200717619186
metabolic flux engineering of l-lysine production in corynebacterium glutamicum--over expression and modification of g6p dehydrogenase.in the present work, metabolic flux engineering of corynebacterium glutamicum was carried out to increase lysine production. the strategy focused on engineering of the pentose phosphate pathway (ppp) flux by different genetic modifications. over expression of the zwf gene, encoding g6p dehydrogenase, in the feedback-deregulated lysine-producing strain c. glutamicum atcc 13032 lysc(fbr) resulted in increased lysine production on different carbon sources including the two major industrial sugars, ...200717624457
transcriptionally regulated adha gene encodes alcohol dehydrogenase required for ethanol and n-propanol utilization in corynebacterium glutamicum r.corynebacterium glutamicum r adha gene encodes a homodimeric, nad-dependent, 345 amino acid residue alcohol dehydrogenase with two zinc ions per subunit. chromosomal inactivation of the adha gene rendered the strain incapable of growth on either ethanol or n-propanol as the sole carbon source. rna hybridization analysis revealed that adha transcription was not only induced by these two substrates, but it was also subject to glucose catabolite repression. accordingly, both induction of adha activ ...200717646983
osmosensing properties of the histidine protein kinase mtrb from corynebacterium glutamicum.the mtrb-mtra two component system of corynebacterium glutamicum was recently shown to be in involved in the osmostress response as well as cell wall metabolism. to address the question of whether the histidine protein kinase mtrb is an osmosensor, the kinase was purified and reconstituted into liposomes in a functionally active form. the activity regulation was investigated by varying systematically physicochemical parameters, which are putative stimuli that could be used by the bacterial cell ...200717650500
the three tricarboxylate synthase activities of corynebacterium glutamicum and increase of l-lysine synthesis.corynebacterium glutamicum owns a citrate synthase and two methylcitrate synthases. characterization of the isolated enzymes showed that the two methylcitrate synthases have comparable catalytic efficiency, k (cat)/k (m), as the citrate synthase with acetyl-coa as substrate, although these enzymes are only synthesized during growth on propionate-containing media. thus, the methylcitrate synthases have a relaxed substrate specifity, as also demonstrated by their activity with butyryl-coa, whereas ...200717653710
in vivo labeling with stable isotopes as a tool for the identification of unidentified peaks in the metabolome analysis of corynebacterium glutamicum by gc/ms.of the hyphenated techniques used for metabolic profiling of cell and tissue extracts, gc/ms is in some ways advantageous as it allows the simultaneous fingerprinting of chemically very different metabolites, and the electron impact mass spectra recorded in many cases lead to unambiguous identification of the compounds. however, prior to chromatography, the hydrophilic substances of the cell extracts have to be converted to vaporizable derivatives, the mass spectra of which often are not known o ...200717655507
plasmid vectors for testing in vivo promoter activities in corynebacterium glutamicum and rhodococcus erythropolis.novel shuttle promoter-probe vectors replicating in escherichia coli, corynebacterium glutamicum, and rhodococcus erythropolis were constructed on the basis of the c. glutamicum plasmid pcg1. the vectors carry reporter genes coding for fluorescent proteins, which allow the measurement of promoter activities in vivo. the promoter-probe vector ppre11 contains the rsgfp reporter gene, coding for a variant of green fluorescent protein (gfp) with a red-shifted excitation maximum. to ensure efficient ...200717657537
transcriptional profiling of corynebacterium glutamicum metabolism during organic acid production under oxygen deprivation conditions.a transcriptional profiling of the metabolism of corynebacterium glutamicum under oxygen deprivation conditions is reported. it was observed that the glucose consumption rate per cell when c. glutamicum cells were incubated under oxygen deprivation conditions was higher than that achieved by cells incubated under aerobic growth conditions. furthermore, dna microarray and quantitative rt-pcr analyses revealed that the genes of several key enzymes of the glycolytic and organic acid production path ...200717660414
structural characterization of a partially arabinosylated lipoarabinomannan variant isolated from a corynebacterium glutamicum ubia mutant.arabinan polysaccharide side-chains are present in both mycobacterium tuberculosis and corynebacterium glutamicum in the heteropolysaccharide arabinogalactan (ag), and in m. tuberculosis in the lipoglycan lipoarabinomannan (lam). this study shows by quantitative sugar and glycosyl linkage analysis that c. glutamicum possesses a much smaller lam version, cg-lam, characterized by single t-araf residues linked to the alpha(1-->6)-linked mannan backbone. maldi-tof ms showed an average molecular mass ...200717660426
identification of an alpha(1-->6) mannopyranosyltransferase (mpta), involved in corynebacterium glutamicum lipomanann biosynthesis, and identification of its orthologue in mycobacterium tuberculosis.corynebacterium glutamicum and mycobacterium tuberculosis share a similar cell wall architecture, and the availability of their genome sequences has enabled the utilization of c. glutamicum as a model for the identification and study of, otherwise essential, mycobacterial genes involved in lipomannan (lm) and lipoarabinomannan (lam) biosynthesis. we selected the putative glycosyltransferase-rv2174 from m. tuberculosis and deleted its orthologue ncgl2093 from c. glutamicum. this resulted in the f ...200717714444
corynebacterium diphtheriae: identification and characterization of a channel-forming protein in the cell wall.the cell wall fraction of the gram-positive, nontoxic corynebacterium diphtheriae strain c8r(-) tox- (=atcc 11913) contained a channel-forming protein, as judged from reconstitution experiments with artificial lipid bilayer experiments. the channel-forming protein was present in detergent-treated cell walls and in extracts of whole cells obtained using organic solvents. the protein had an apparent molecular mass of about 66 kda as determined on tricine-containing sodium dodecyl sulfate-polyacryl ...200717720794
offering surprises: tca cycle regulation in corynebacterium glutamicum.corynebacterium glutamicum, a gram-positive soil bacterium, is used for the production of l-glutamate and l-lysine, both of which are derived from intermediates of the tricarboxylic acid (tca) cycle. recent studies have revealed that this amphibolic pathway is subject to complex regulation not only at the transcriptional level, but also at the post-transcriptional level. the latter involves serine/threonine protein kinase g and its target protein odhi. depending on its phosphorylation state, odh ...200717764950
the structures of transcription factor cgl2947 from corynebacterium glutamicum in two crystal forms: a novel homodimer assembling and the implication for effector-binding mode.among the transcription factors, the helix-turn-helix (hth) gntr family comprised of fadr, hutc, mocr, ytra, arar, and plma subfamilies regulates the most varied biological processes. generally, proteins belonging to this family contain an n-terminal dna-binding domain and a c-terminal effector-binding/oligomerization domain. the members of the ytra subfamily are much shorter than other members of this family, with chain lengths of 120-130 residues with about 50 residues located in the c-termina ...200717766384
a comparative proteomic approach to understand the adaptations of an h+ -atpase-defective mutant of corynebacterium glutamicum atcc14067 to energy deficiencies.f172-8, an h(+)-atpase-defective mutant of the glutamic acid-producing bacterium corynebacterium glutamicum atcc 14067, exhibits enhanced rates of glucose consumption and respiration compared to the parental strain when cultured in a biotin-rich medium with glucose as the carbon source. we conducted a comparative proteomic analysis to clarify the mechanism by which the enhanced glucose metabolism in this mutant is established using a proteome reference map for strain atcc 14067. a comparison of ...200717849411
characterization of hmw-pbps from the rod-shaped actinomycete corynebacterium glutamicum: peptidoglycan synthesis in cells lacking actin-like cytoskeletal structures.analysis of the complete genome sequence of corynebacterium glutamicum indicated that, in addition to ftsi, there are eight proteins with sequence motifs that are strongly conserved in penicillin binding proteins (pbps): four genes that code for high-molecular-weight (hmw)-pbps (pbp1a, pbp1b, pbp2a and pbp2b), two genes encoding low-molecular-weight pbps (pbp4 and pbp4b) and two probable beta-lactamases (pbp5 and pbp6). here, the function of the four hmw-pbps in c. glutamicum was investigated us ...200717877698
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
high cell density cultivation of recombinant yeasts and bacteria under non-pressurized and pressurized conditions in stirred tank bioreactors.this study demonstrates the applicability of pressurized stirred tank bioreactors for oxygen transfer enhancement in aerobic cultivation processes. the specific power input and the reactor pressure was employed as process variable. as model organism escherichia coli, arxula adeninivorans, saccharomyces cerevisiae and corynebacterium glutamicum were cultivated to high cell densities. by applying specific power inputs of approx. 48kwm(-3) the oxygen transfer rate of a e. coli culture in the non-pr ...200717681630
characterization of riboflavin (vitamin b2) transport proteins from bacillus subtilis and corynebacterium glutamicum.riboflavin (vitamin b(2)) is the direct precursor of the flavin cofactors flavin mononucleotide and flavin adenine dinucleotide, essential components of cellular biochemistry. in this work we investigated the unrelated proteins ypaa from bacillus subtilis and pnux from corynebacterium glutamicum for a role in riboflavin uptake. based on the regulation of the corresponding genes by a riboswitch mechanism, both proteins have been predicted to be involved in flavin metabolism. moreover, their prima ...200717693491
osmolality, temperature, and membrane lipid composition modulate the activity of betaine transporter betp in corynebacterium glutamicum.the gram-positive soil bacterium corynebacterium glutamicum, a major amino acid-producing microorganism in biotechnology, is equipped with several osmoregulated uptake systems for compatible solutes, which is relevant for the physiological response to osmotic stress. the most significant carrier, betp, is instantly activated in response to an increasing cytoplasmic k(+) concentration. importantly, it is also activated by chill stress independent of osmotic stress. we show that the activation of ...200717693504
the alcohol dehydrogenase gene adha in corynebacterium glutamicum is subject to carbon catabolite repression.corynebacterium glutamicum has recently been shown to grow on ethanol as a carbon and energy source and to possess high alcohol dehydrogenase (adh) activity when growing on this substrate and low adh activity when growing on ethanol plus glucose or glucose alone. here we identify the c. glutamicum adh gene (adha), analyze its transcriptional organization, and investigate the relevance of the transcriptional regulators of acetate metabolism rama and ramb for adha expression. sequence analysis of ...200717693518
direct production of l-lysine from raw corn starch by corynebacterium glutamicum secreting streptococcus bovis alpha-amylase using cspb promoter and signal sequence.corynebacterium glutamicum is an important microorganism in the industrial production of amino acids. we engineered a strain of c. glutamicum that secretes alpha-amylase from streptococcus bovis 148 (amya) for the efficient utilization of raw starch. among the promoters and signal sequences tested, those of cspb from c. glutamicum possessed the highest expression level. the fusion gene was introduced into the homoserine dehydrogenase gene locus on the chromosome by homologous recombination. l-ly ...200717891388
metabolic engineering of corynebacterium glutamicum for cadaverine fermentation.cadaverine, the expected raw material of polyamides, is produced by decarboxylation of l-lysine. if we could produce cadaverine from the cheapest sugar, and as a renewable resource, it would be an effective solution against global warming, but there has been no attempt to produce cadaverine from glucose by fermentation. we focused on corynebacterium glutamicum, whose l-lysine fermentation ability is superior, and constructed a metabolically engineered c. glutamicum in which the l-homoserine dehy ...200717895539
analyses of the acetate-producing pathways in corynebacterium glutamicum under oxygen-deprived conditions.corynebacterium glutamicum r efficiently produces valuable chemicals from glucose under oxygen-deprived conditions. in an effort to reduce acetate as a byproduct, acetate productivity of several mutant-disrupted genes encoding possible key enzymes for acetate formation was determined. disruption of the acee gene that encodes the e1 enzyme of the pyruvate dehydrogenase complex resulted in almost complete elimination of acetate formation under oxygen-deprived conditions, implying that acetate synt ...200717909785
the role of lipids and salts in two-dimensional crystallization of the glycine-betaine transporter betp from corynebacterium glutamicum.the osmoregulated and chill-sensitive glycine-betaine transporter (betp) from corynebacterium glutamicum was reconstituted into lipids to form two-dimensional (2d) crystals. the sensitivity of betp partly bases on its interaction with lipids. here we demonstrate that lipids and salts influence crystal morphology and crystallinity of a c-terminally truncated betp. the salt type and concentration during crystallization determined whether crystals grew in the form of planar-tubes, sheets or vesicle ...200717981051
coryneregnet 4.0 - a reference database for corynebacterial gene regulatory networks.detailed information on dna-binding transcription factors (the key players in the regulation of gene expression) and on transcriptional regulatory interactions of microorganisms deduced from literature-derived knowledge, computer predictions and global dna microarray hybridization experiments, has opened the way for the genome-wide analysis of transcriptional regulatory networks. the large-scale reconstruction of these networks allows the in silico analysis of cell behavior in response to changi ...200717986320
a 2-step cooking method of searing and hot water pasteurization to maximize the safety of refrigerated, vacuum packaged, chicken breast meat.americans consume almost 40 kg per capita of chicken each year. increasing consumption of chicken surpassed pork in 1982 and beef in 1992. the objectives of this study were to examine the effectiveness of a novel, 2-step cooking method of grilling, slicing, vacuum packaging, and hot water pasteurization to inhibit the growth of listeria monocytogenes in chicken breast meat. because this study required the use of pilot plant scale pasteurization equipment, listeria innocua m1, a nonpathogen with ...200717995778
the deor-type transcriptional regulator sugr acts as a repressor for genes encoding the phosphoenolpyruvate:sugar phosphotransferase system (pts) in corynebacterium glutamicum.the major uptake system responsible for the transport of fructose, glucose, and sucrose in corynebacterium glutamicum atcc 13032 is the phosphoenolpyruvate:sugar phosphotransferase system (pts). the genes encoding pts components, namely ptsi, ptsh, and ptsf belong to the fructose-pts gene cluster, whereas ptsg and ptss are located in two separate regions of the c. glutamicum genome. due to the localization within and adjacent to the fructose-pts gene cluster, two genes coding for deor-type trans ...200718005413
expression, purification, crystallization and initial crystallographic characterization of the p-hydroxybenzoate hydroxylase from corynebacterium glutamicum.p-hydroxybenzoate hydroxylase (phbh) is an fad-dependent monooxygenase that catalyzes the hydroxylation of p-hydroxybenzoate (pohb) to 3,4-dihydroxybenzoate in an nadph-dependent reaction and plays an important role in the biodegradation of aromatic compounds. phbh from corynebacterium glutamicum was crystallized using the hanging-drop vapour-diffusion method in the presence of nah(2)po(4) and k(2)hpo(4) as precipitants. x-ray diffraction data were collected to a maximum resolution of 2.5 a on a ...200718007046
corynecenter - an online resource for the integrated analysis of corynebacterial genome and transcriptome data.the introduction of high-throughput genome sequencing and post-genome analysis technologies, e.g. dna microarray approaches, has created the potential to unravel and scrutinize complex gene-regulatory networks on a large scale. the discovery of transcriptional regulatory interactions has become a major topic in modern functional genomics.200718034885
biochemical analysis on the parallel pathways of methionine biosynthesis in corynebacterium glutamicum.two alternative pathways for methionine biosynthesis are known in corynebacterium glutamicum: one involving transsulfuration (mediated by metb and metc) and the other involving direct sulthydrylation (mediated by mety). in this study, metb (cystathionine gamma-synthase) and mety (o-acetylhomoserine sulfhydrylase) from c. glutamicum were purified to homogeneity and the biochemical parameters were compared to assess the functional and evolutionary importance of each pathway. the molecular masses o ...200718050920
expression analysis of the csp-like genes from corynebacterium glutamicum encoding homologs of the escherichia coli major cold-shock protein cspa.three csp-like genes were identified in the corynebacterium glutamicum genome and designated cspa, cspb, and cspa2. the genes cspa and cspa2 encode proteins, comprising of 67 amino acid residues, respectively. they share 83% identity with each other. identity of those proteins with escherichia coli csp proteins was near 50%. the cspb gene encodes a protein composed of 127 amino acids, which has 40% and 35% sequence identity with cspa and cspa2, respectively, especially at its n-terminal region. ...200718051605
nitrogen control in corynebacterium glutamicum: proteins, mechanisms, signals.in order to utilize different nitrogen sources and to survive in a situation of nitrogen limitation, microorganisms have developed sophisticated mechanisms to adapt their metabolism to a changing nitrogen supply. in this communication, the recent knowledge of nitrogen regulation in the amino acid producer corynebacterium glutamicum is summarized. the core adaptations of c. glutamicum to nitrogen limitation on the level of transcription are controlled by the global regulator amtr. further compone ...200718051748
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
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
understanding the roadmap of metabolism by pathway analysis.the theoretical investigation of the structure of metabolic systems has recently attracted increasing interest. in this chapter, the basic concepts of metabolic pathway analysis are described and various applications are outlined. in particular, the concepts of nullspace and elementary flux modes are explained. the presentation is illustrated by a simple example from tyrosine metabolism and a system describing lysine production in corynebacterium glutamicum. the latter system gives rise to 37 el ...200717035688
the alternative sigma factor sigb of corynebacterium glutamicum modulates global gene expression during transition from exponential growth to stationary phase.corynebacterium glutamicum is a gram-positive soil bacterium widely used for the industrial production of amino acids. there is great interest in the examination of the molecular mechanism of transcription control. one of these control mechanisms are sigma factors. c. glutamicum atcc 13032 has seven putative sigma factor-encoding genes, including siga and sigb. the siga gene encodes the essential primary sigma factor of c. glutamicum and is responsible for promoter recognition of house-keeping g ...200717204139
expression of the escherichia coli pntab genes encoding a membrane-bound transhydrogenase in corynebacterium glutamicum improves l-lysine formation.a critical factor in the biotechnological production of l: -lysine with corynebacterium glutamicum is the sufficient supply of nadph. the membrane-integral nicotinamide nucleotide transhydrogenase pntab of escherichia coli can use the electrochemical proton gradient across the cytoplasmic membrane to drive the reduction of nadp(+) via the oxidation of nadh. as c. glutamicum does not possess such an enzyme, we expressed the e. coli pntab genes in the genetically defined c. glutamicum lysine-produ ...200717216441
production of l-lysine from starch by corynebacterium glutamicum displaying alpha-amylase on its cell surface.we engineered a corynebacterium glutamicum strain displaying alpha-amylase from streptococcus bovis 148 (amya) on its cell surface to produce amino acids directly from starch. we used pgsa from bacillus subtilis as an anchor protein, and the n-terminus of alpha-amylase was fused to the pgsa. the genes of the fusion protein were integrated into the homoserine dehydrogenase gene locus on the chromosome by homologous recombination. l-lysine fermentation was carried out using c. glutamicum displayin ...200717216452
random segment deletion based on is31831 and cre/loxp excision system in corynebacterium glutamicum.a simple and random genome deletion method combining insertion sequence (is) element is31831 and the cre/loxp excision system generated 42 corynebacterium glutamicum mutants (0.2-186 kb). a total of 393.6 kb (11.9% of c. glutamicum r genome) coding for 331 genes was confirmed to be nonessential under standard laboratory conditions. the deletion strains, generated using only two vectors, varied not only in their lengths but also the location of the deletion along the c. glutamicum r genome. by co ...200717221197
evaluation of two proteomics technologies used to screen the membrane proteomes of wild-type corynebacterium glutamicum and an l-lysine-producing strain.the membrane proteomes of a wild-type corynebacterium glutamicum and an l-lysine-producing strain were quantitatively analyzed by two complementary proteomics techniques -- anion exchange chromatography aiec/sds-page and 16bac-page/sds-page -- and the results were compared. although both techniques allow for the fast screening of differences in protein abundance, aiec/sds-page was superior to 16bac-page/sds-page with respect to protein separation, it was more suitable for relative protein quanti ...200717221235
the transcriptional regulatory network of the amino acid producer corynebacterium glutamicum.the complete nucleotide sequence of the corynebacterium glutamicum atcc 13032 genome was previously determined and allowed the reliable prediction of 3002 protein-coding genes within this genome. using computational methods, we have defined 158 genes, which form the minimal repertoire for proteins that presumably act as transcriptional regulators of gene expression. most of these regulatory proteins have a direct role as dna-binding transcriptional regulator, while others either have less well-d ...200717227685
coryneregnet 3.0--an interactive systems biology platform for the analysis of gene regulatory networks in corynebacteria and escherichia coli.coryneregnet is an ontology-based data warehouse for the reconstruction and visualization of transcriptional regulatory interactions in prokaryotes. to extend the biological content of coryneregnet, we added comprehensive data on transcriptional regulations in the model organism escherichia coli k-12, originally deposited in the international reference database regulondb. the enhanced web interface of coryneregnet offers several types of search options. the results of a search are displayed in a ...200717229482
a proteomic study of corynebacterium glutamicum aaa+ protease ftsh.the influence of the membrane-bound aaa+ protease ftsh on membrane and cytoplasmic proteins of corynebacterium glutamicum was investigated in this study. for the analysis of the membrane fraction, anion exchange chromatography was combined with sds-page, while the cytoplasmic protein fraction was studied by conventional two-dimensional gel electrophoresis.200717254330
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