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heat shock proteome analysis of wild-type corynebacterium glutamicum atcc 13032 and a spontaneous mutant lacking groel1, a dispensable chaperone.proteome analysis of corynebacterium glutamicum atcc 13032 showed that levels of several proteins increased drastically in response to heat shock. these proteins were identified as dnak, groel1, groel2, clpb, grpe, and poxb, and their heat response was in agreement with previous transcriptomic results. a major heat-induced protein was absent in the proteome of strain 13032b of c. glutamicum, used for genome sequencing in germany, compared with the wild-type atcc 13032 strain. the missing protein ...200515659666
pyruvate:quinone oxidoreductase from corynebacterium glutamicum: purification and biochemical characterization.pyruvate:quinone oxidoreductase catalyzes the oxidative decarboxylation of pyruvate to acetate and co2 with a quinone as the physiological electron acceptor. so far, this enzyme activity has been found only in escherichia coli. using 2,6-dichloroindophenol as an artificial electron acceptor, we detected pyruvate:quinone oxidoreductase activity in cell extracts of the amino acid producer corynebacterium glutamicum. the activity was highest (0.055 +/- 0.005 u/mg of protein) in cells grown on compl ...200515659664
isolation and characterization of a native composite transposon, tn14751, carrying 17.4 kilobases of corynebacterium glutamicum chromosomal dna.a native composite transposon was isolated from corynebacterium glutamicum atcc 14751. this transposon comprises two functional copies of a corynebacterial is31831-like insertion sequence organized as converging terminal inverted repeats. this novel 20.3-kb element, tn14751, carries 17.4 kb of c. glutamicum chromosomal dna containing various genes, including genes involved in purine biosynthesis but not genes related to bacterial warfare, such as genes encoding mediators of antibiotic resistance ...200515640215
feedback-resistant acetohydroxy acid synthase increases valine production in corynebacterium glutamicum.acetohydroxy acid synthase (ahas), which catalyzes the key reactions in the biosynthesis pathways of branched-chain amino acids (valine, isoleucine, and leucine), is regulated by the end products of these pathways. the whole corynebacterium glutamicum ilvbnc operon, coding for acetohydroxy acid synthase (ilvbn) and aceto hydroxy acid isomeroreductase (ilvc), was cloned in the newly constructed escherichia coli-c. glutamicum shuttle vector pecka (5.4 kb, km(r)). by using site-directed mutagenesis ...200515640189
a novel gnd mutation leading to increased l-lysine production in corynebacterium glutamicum.toward more efficient l-lysine production, we have been challenging genome-based strain breeding by the approach of assembling only relevant mutations in a single wild-type background. following the creation of a new l-lysine producer corynebacterium glutamicum ahp-3 that carried three useful mutations (lysc311, hom59, and pyc458) on the relevant downstream pathways, we shifted our target to the pentose phosphate pathway. comparative genomic analysis for the pathway between a classically derived ...200515621447
dynamics of glutamate synthesis and excretion fluxes in batch and continuous cultures of temperature-triggered corynebacterium glutamicum.corynebacterium glutamicum 2262 strain, when triggered for glutamate excretion, experiences a rapid decrease in growth rate and increase in glutamate efflux. in order to gain a better quantitative understanding of the factors controlling the metabolic transition, the fermentation dynamics was investigated for a temperature-sensitive strain cultivated in batch and glucose-limited continuous cultures. for non-excreting cells at 33 degrees c, increasing the growth rate resulted in strong increases ...200415614534
resistance of corynebacterial strains to infection and lysis by corynephage bfk 20.defence mechanisms of the corynebacterial strains against corynephage bfk 20, which causes lysis of brevibacterium flavum ccm 251.200515610431
activity regulation of the betaine transporter betp of corynebacterium glutamicum in response to osmotic compensation.as a response to hyperosmotic stress bacterial cells accumulate compatible solutes by synthesis or by uptake. beside the instant activation of uptake systems after an osmotic upshift, transport systems show also a second, equally important type of regulation. in order to adapt the pool size of compatible solutes in the cytoplasm to the actual extent of osmotic stress, cells down-regulate solute uptake when the initial osmotic stress is compensated. here we describe the role of the betaine transp ...200415581860
metabolic fluxes in corynebacterium glutamicum during lysine production with sucrose as carbon source.metabolic fluxes in the central metabolism were determined for lysine-producing corynebacterium glutamicum atcc 21526 with sucrose as a carbon source, providing an insight into molasses-based industrial production processes with this organism. for this purpose, 13c metabolic flux analysis with parallel studies on [1-(13c)fru]sucrose, [1-(13c)glc]sucrose, and [13c6fru]sucrose was carried out. c. glutamicum directed 27.4% of sucrose toward extracellular lysine. the strain exhibited a relatively hi ...200415574927
cometabolism of a nongrowth substrate: l-serine utilization by corynebacterium glutamicum.despite its key position in central metabolism, l-serine does not support the growth of corynebacterium glutamicum. nevertheless, during growth on glucose, l-serine is consumed at rates up to 19.4 +/- 4.0 nmol min(-1) (mg [dry weight])(-1), resulting in the complete consumption of 100 mm l-serine in the presence of 100 mm glucose and an increased growth yield of about 20%. use of 13c-labeled l-serine and analysis of cellularly derived metabolites by nuclear magnetic resonance spectroscopy reveal ...200415574911
effect of nadh dehydrogenase-disruption and over-expression on respiration-related metabolism in corynebacterium glutamicum ky9714.the function of type ii nadh dehydrogenase (ndh-2) in gram-positive corynebacterium glutamicum was investigated by preparing strains with ndh, the ndh-2 gene, disrupted and over-expressed. although disruption showed no growth defects on glucose minimum medium, the growth rate of the over-expressed strain was lower compared with its parent, c. glutamicum ky9714. ndh-disruption and over-expression did not lead to a large change in the respiratory chain and energetics, including the cytochrome comp ...200415558275
production of l-2,3-butanediol by a new pathway constructed in escherichia coli.a metabolic pathway for l-2,3-butanediol (bd) as the main product has not yet been found. to rectify this situation, we attempted to produce l-bd from diacetyl (da) by producing simultaneous expression of diacetyl reductase (dar) and l-2,3-butanediol dehydrogenase (bdh) using transgenic bacteria, escherichia coli jm109/pbud-comb.200415548307
crp of streptomyces coelicolor is the third transcription factor of the large crp-fnr superfamily able to bind camp.the chromosomal inactivation of the unique transcription factor of streptomyces coelicolor that displays a cyclic-nucleotide-binding domain, crp(sco), led to a germination-defective phenotype similar to the mutant of the adenylate cyclase gene (cya) unable to produce camp. by means of camp affinity chromatography we demonstrate the specific camp-binding ability of crp(sco), which definitely demonstrate that a cya/camp/crp system is used to trigger germination in s. coelicolor. however, electromo ...200415541386
integration of e. coli arog-phea tandem genes into corynebacterium glutamicum tyra locus and its effect on l-phenylalanine biosynthesis.to study the effect of integration of tandem arog-phea genes into the tyra locus of corynebacterium glutamicum (c. glutamicum) on the production of l-phenylalanine.200415534933
molecular identification of the urea uptake system and transcriptional analysis of urea transporter- and urease-encoding genes in corynebacterium glutamicum.the molecular identification of the corynebacterium glutamicum urea uptake system is described. this abc-type transporter is encoded by the urtabcde operon, which is transcribed in response to nitrogen limitation. expression of the urt genes is regulated by the global nitrogen regulator amtr, and an amtr deletion strain showed constitutive expression of the urtabcde genes. the amtr repressor protein also controls transcription of the urease-encoding ureabcefgd genes in c. glutamicum. the ure gen ...200415516578
identification of acnr, a tetr-type repressor of the aconitase gene acn in corynebacterium glutamicum.in corynebacterium glutamicum, the activity of aconitase is 2.5-4-fold higher on propionate, citrate, or acetate than on glucose. here we show that this variation is caused by transcriptional regulation. in search for putative regulators, a gene (acnr) encoding a tetr-type transcriptional regulator was found to be encoded immediately downstream of the aconitase gene (acn) in c. glutamicum. deletion of the acnr gene led to a 5-fold increased acn-mrna level and a 5-fold increased aconitase activit ...200515494411
comprehensive analysis of metabolites in corynebacterium glutamicum by gas chromatography/mass spectrometry.an analytical method based on gas chromatography/mass spectrometry was developed for metabolome investigation of corynebacterium glutamicum. for the first time a fast method for metabolic screening that can be automated is described for this organism. more than 1000 compounds could be detected per experiment, ca. 330 of those showed a peak area significantly above background. out of these 164 compounds were identified so far, representing derivatives of 121 different metabolites, which were quan ...200415493881
metabolic network simulation using logical loop algorithm and jacobian matrix.a novel method to accomplish efficient numerical simulation of metabolic networks for flux analysis was developed. the only inputs required are the set of stoichiometric balances and the atom mapping matrices of all components of the reaction network. the latter are used to automatically calculate isotopomer mapping matrices. using the symbolic toolbox of matlab the analytical solution of the stoichiometric balance equation system, isotopomer balances and the analytical jacobian matrix of the to ...200415491855
the glycosylated cell surface protein rpf2, containing a resuscitation-promoting factor motif, is involved in intercellular communication of corynebacterium glutamicum.the genome of corynebacterium glutamicum atcc 13032 contains two genes, rpf1 and rpf2, encoding proteins with similarities to the essential resuscitation-promoting factor (rpf) of micrococcus luteus. both the rpf1 (20.4 kda) and rpf2 (40.3 kda) proteins share the so-called rpf motif, a highly conserved protein domain of approximately 70 amino acids, which is also present in rpf-like proteins of other gram-positive bacteria with a high g+c content of the chromosomal dna. purification of the c. gl ...200415480574
effect of cysteine on methionine production by a regulatory mutant of corynebacterium lilium.the production of methionine by submerged fermentation using a mutant strain of corynebacterium lilium was studied to determine suitable conditions for obtaining high productivity. the mutant strain resistant to the methionine analogues ethionine, norleucine, methionine sulfoxide and methionine methylsulfonium chloride produced 2.34 g l(-1) of methionine in minimal medium containing glucose as carbon source. the effect of cysteine on methionine production in a 15 l bioreactor was studied by supp ...200515474928
deletion of the genes encoding the mtra-mtrb two-component system of corynebacterium glutamicum has a strong influence on cell morphology, antibiotics susceptibility and expression of genes involved in osmoprotection.the mtrab two-component signal transduction system is highly conserved in sequence and genomic organization in mycobacterium and corynebacterium species, but its function is completely unknown. here, the role of mtrab was studied with c. glutamicum as model organism. in contrast to m. tuberculosis, it was possible to delete the mtrab genes in c. glutamicum. the mutant cells showed a radically different cell morphology and were more sensitive to penicillin, vancomycin and lysozyme but more resist ...200415469514
detection of low levels of listeria monocytogenes cells by using a fiber-optic immunosensor.biosensor technology has a great potential to meet the need for sensitive and nearly real-time microbial detection from foods. an antibody-based fiber-optic biosensor to detect low levels of listeria monocytogenes cells following an enrichment step was developed. the principle of the sensor is a sandwich immunoassay where a rabbit polyclonal antibody was first immobilized on polystyrene fiber waveguides through a biotin-streptavidin reaction to capture listeria cells on the fiber. capture of cel ...200415466560
regulation of glnk activity: modification, membrane sequestration and proteolysis as regulatory principles in the network of nitrogen control in corynebacterium glutamicum.p(ii)-type signal transduction proteins play a central role in nitrogen regulation in many bacteria. in response to the intracellular nitrogen status, these proteins are rendered in their function and interaction with other proteins by modification/demodification events, e.g. by phosphorylation or uridylylation. in this study, we show that glnk, the only p(ii)-type protein in corynebacterium glutamicum, is adenylylated in response to nitrogen starvation and deadenylylated when the nitrogen suppl ...200415458411
metabolic analysis of corynebacterium glutamicum during lactate and succinate productions under oxygen deprivation conditions.lactate and succinate were produced from glucose by corynebacterium glutamicum under oxygen deprivation conditions without growth. addition of bicarbonate to the reaction mixture led not only to a 3.6-fold increase in succinate production rate, but also to a 2.3- and 2.5-fold increase, respectively, of the rates of lactate production and glucose consumption, compared to the control. furthermore, when small amounts of pyruvate were added to the reaction mixture, acid production rates and the gluc ...200415383716
roles of pyruvate kinase and malic enzyme in corynebacterium glutamicum for growth on carbon sources requiring gluconeogenesis.in many bacteria, pyruvate kinase serves a well-defined function in glycolysis, catalyzing an atp-generating reaction. however, its role during growth on carbon sources requiring glucoeneogenesis is less well investigated. we analyzed a defined pyruvate kinase gene (pyk) deletion mutant of corynebacterium glutamicum, which is unable to grow on ribose as sole carbon source. unexpectedly, the pyk deletion mutant was also unable to grow on acetate or citrate as sole carbon sources unless low amount ...200415375646
comparative genomics identified two conserved dna modules in a corynebacterial plasmid family present in clinical isolates of the opportunistic human pathogen corynebacterium jeikeium.investigation of 62 clinical isolates of the opportunistic human pathogen corynebacterium jeikeium revealed that 17 possessed plasmids ranging in size from 7.6 to 14.9 kb. the plasmids formed four groups on dna restriction analysis. the complete nucleotide sequence of a representative from each group (pk43, pk64, pcj84, and pb85766) was subsequently determined. additionally, two plasmids (pco455 and pco420) were shown to be derivatives of pk43 and pk64 carrying insertion sequences of the is3 fam ...200415336488
lcop, an osmoregulated betaine/ectoine uptake system from corynebacterium glutamicum.in corynebacterium glutamicum, four uptake systems for compatible solutes have been characterized so far. dhpe (deltabetpdeltaputpdeltapropdeltaectp), a derivative of the c. glutamicum type strain atcc 13032 carrying deletions in the corresponding genes, still showed a low betaine uptake rate of 1.4 nmol/(min mg cdm). genome analyses revealed the presence of a putative carrier, named low capacity osmoregulated permease (lcop), which shows similarities to compatible solute transporters of the bet ...200415327991
acyl-coa carboxylases (accd2 and accd3), together with a unique polyketide synthase (cg-pks), are key to mycolic acid biosynthesis in corynebacterianeae such as corynebacterium glutamicum and mycobacterium tuberculosis.the corynebacterianeae such as corynebacterium glutamicum and mycobacterium tuberculosis possess several unique and structurally diverse lipids, including the genus-specific mycolic acids. although the function of a number of genes involved in fatty acid and mycolic acid biosynthesis is known, information relevant to the initial steps within these biosynthetic pathways is relatively sparse. interestingly, the genomes of corynebacterianeae possess a high number of accd genes, whose gene products ...200415308633
genomewide expression analysis in amino acid-producing bacteria using dna microarrays.dna microarray technology has become an important research tool for biotechnology and microbiology. it is now possible to characterize genetic diversity and gene expression in a genomewide manner. dna microarrays have been applied extensively to study the biology of many bacteria including escherichia coli, but only recently have they been developed for the gram-positive corynebacterium glutamicum. both bacteria are widely used for biotechnological amino acid production. in this article, in addi ...200415304751
classification of hyper-variable corynebacterium glutamicum surface-layer proteins by sequence analyses and atomic force microscopy.the structural s-layer proteins of 28 different corynebacterium glutamicum isolates have been analyzed systematically. treatment of whole c. glutamicum cells with detergents resulted in the isolation of s-layer proteins with different apparent molecular masses, ranging in size from 55 to 66 kda. the s-layer genes analyzed were characterized by coding regions ranging from 1,473 to 1,533 nucleotides coding for s-layer proteins with a size of 490-510 amino acids. using pcr techniques, the correspon ...200415288952
betp of corynebacterium glutamicum, a transporter with three different functions: betaine transport, osmosensing, and osmoregulation.in order to circumvent deleterious effects of hypo- and hyperosmotic conditions in its environment, corynebacterium glutamicum has developed a number of mechanisms to counteract osmotic stress. the first response to an osmotic upshift is the activation of uptake mechanisms for the compatible solutes betaine, proline, or ectoine, namely betp, ectp, prop, lcop and putp. betp, the most important uptake system responds to osmotic stress by regulation at the level of both protein activity and gene ex ...200415282171
purification and characterization of o-acetylserine sulfhydrylase of corynebacterium glutamicum.we highly purified o-acetylserine sulfhydrylase from the glutamate-producing bacterium corynebacterium glutamicum. the molecular mass of the purified enzyme was 34,500 as determined by sds-polyacrylamide gel electrophoresis, and 70,800 as determined by gel filtration chromatography. it had an apparent km of 7.0 mm for o-acetylserine and a vmax of 435 micromol min-1 (mg x protein)-1. this is the first report of the cysteine biosynthetic enzyme of c. glutamicum in purified form.200415277766
identification of the anabaena sp. strain pcc7120 cyanophycin synthetase as suitable enzyme for production of cyanophycin in gram-negative bacteria like pseudomonas putida and ralstonia eutropha.the cyanophycin synthetase gene cpha1 encoding the major cyanophycin synthetase (cpha) of anabaena sp. strain pcc7120 was expressed in escherichia coli conferring so far the highest specific cpha activity to e. coli (6.7 nmol arginine per min and mg protein). cpha1 and cpha genes of synechocystis sp. strains pcc6803 and pcc6308 and synechococcus strain ma19 were also expressed in wild types and polyhydroxyalkanoate-negative (pha) mutants of pseudomonas putida and ralstonia eutropha. recombinant ...200415244482
osmotic stress response: quantification of cell maintenance and metabolic fluxes in a lysine-overproducing strain of corynebacterium glutamicum.osmotic stress diminishes cell productivity and may cause cell inactivation in industrial fermentations. the quantification of metabolic changes under such conditions is fundamental for understanding and describing microbial behavior during bioprocesses. we quantified the gradual changes that take place when a lysine-overproducing strain of corynebacterium glutamicum is grown in continuous culture with saline gradients at different dilution rates. the use of compatible solutes depended on enviro ...200415240305
impact of heterologous expression of escherichia coli udp-glucose pyrophosphorylase on trehalose and glycogen synthesis in corynebacterium glutamicum.trehalose is a disaccharide with a wide range of applications in the food industry. we recently proposed a strategy for trehalose production based on improved strains of the gram-positive bacterium corynebacterium glutamicum. this microorganism synthesizes trehalose through two major pathways, otsba and treyz, by using udp-glucose and adp-glucose, respectively, as the glucosyl donors. in this paper we describe improvement of the udp-glucose supply through heterologous expression in c. glutamicum ...200415240254
transcriptional analysis of the groes-groel1, groel2, and dnak genes in corynebacterium glutamicum: characterization of heat shock-induced promoters.the appropriate conditions to switch on the heat shock promoters in corynebacterium glutamicum were defined by northern blot analysis. transcriptional patterns were characterized for the groel2 gene and the groes-groel1 and dnak operons. transcriptional start points of these genes were determined by primer extension analysis, allowing the identification of circe and hair boxes close to the -10 and -35 regions of the promoters. the presence of both circe and hair sequences within a single promote ...200415231814
three-dimensional models and structure analysis of corynemycolyltransferases in corynebacterium glutamicum and corynebacterium efficiens.the corynemycolyltransferase proteins were identified from corynebacterium glutamicum and corynebacterium efficiens genomes using computational tools available in the public domain. three-dimensional models were constructed for corynemycolyltransferases based on the crystal structures of related mycolyltransferases in mycobacterium tuberculosis using the comparative modeling methods. the corynemycolyltransferases share overall an alpha/beta-fold characteristic of the mycolyltransferases despite ...200415225990
inhibitor-associated transposition events in corynebacterium glutamicum.in up to 100% of all bacteria grown in the presence of initially inhibitory concentrations of five diverse inhibitors, an extra copy of the resident insertion element is 31831 was found in specific chromosomal regions, the sites of which apparently depended on the inhibitor used. thus, in nine out of nine independently isolated cyanide-associated transpositions, the acquired copy was located within an orf encoding a protein related to the hypothetical but conserved protein yeih of escherichia co ...200415221457
biochemical and molecular characterization of a ring fission dioxygenase with the ability to oxidize (substituted) salicylate(s) from pseudaminobacter salicylatoxidans.the gene coding for a dioxygenase with the ability to cleave salicylate by a direct ring fission mechanism to 2-oxohepta-3,5-dienedioic acid was cloned from pseudaminobacter salicylatoxidans strain bn12. the deduced amino acid sequence encoded a protein with a molecular mass of 41,176 da, which showed 28 and 31% sequence identity, respectively, to a gentisate 1,2-dioxygenase from pseudomonas alcaligenes ncimb 9867 and a 1-hydroxy-2-naphthoate 1,2-dioxygenase from nocardioides sp. kp7. the highes ...200415220336
metabolic network analysis of lysine producing corynebacterium glutamicum at a miniaturized scale.we present a straightforward approach comprising (13)c tracer experiments at 200-microl volume in 96-well microtiter plates with on-line measurement of dissolved oxygen for quantitative high-throughput metabolic network analysis at a miniaturized scale. this method was successfully applied for cultivation and (13)c metabolic flux analysis of two mutants of lysine producing corynebacterium glutamicum (atcc 13287 and atcc 21543). microtiter-plate cultivations showed excellent accordance in kinetic ...200415211482
functional identification of the gene locus (ncg12319 and characterization of catechol 1,2-dioxygenase in corynebacterium glutamicum.corynebacterium glutamicum assimilated phenol, benzoate, 4-hydroxybenzoate p-cresol and 3,4-dihydroxybenzoate. ring cleavage was by catechol 1,2-dioxygenase when phenol or benzoate was used and by protocatechuate 3,4-dioxygenase when the others were used as substrate. the locus ncg12319 of its genome was cloned and expressed in escherichia coli. enzyme assays showed that ncg12319 encodes a catechol 1,2-dioxygenase. this catechol 1,2-dioxygenase was purified and accepted catechol, 3-, or 4-methyl ...200415168857
streptomyces lividans and brevibacterium lactofermentum as heterologous hosts for the production of x22 xylanase from aspergillus nidulans.the aspergillus nidulans gene xlna coding for the fungal xylanase x22 has been cloned and expressed in two heterologous bacterial hosts: streptomyces lividans and brevibacterium lactofermentum. streptomyces strains yielded 10 units/ml of xylanase when the protein was produced with its own signal peptide, and 19 units/ml when its signal peptide was replaced by the one for xylanase xys1 from streptomyces halstedii. b. lactofermentum was also able to produce xylanase x22, affording 6 units/ml upon ...200415168093
evolutionary process of amino acid biosynthesis in corynebacterium at the whole genome level.corynebacterium glutamicum, which is the closest relative of corynebacterium efficiens, is widely used for the large scale production of many kinds of amino acids, particularly glutamic acid and lysine, by fermentation. corynebacterium diphtheriae, which is well known as a human pathogen, is also closely related to these two species of corynebacteria, but it lacks such productivity of amino acids. it is an important and interesting question to ask how those closely related bacterial species have ...200415163767
high level expression of streptomyces mobaraensis transglutaminase in corynebacterium glutamicum using a chimeric pro-region from streptomyces cinnamoneus transglutaminase.we previously observed secretion of native-type streptomyces mobaraensis transglutaminase (mtgase) in corynebacterium glutamicum by co-expressing the subtilisin-like protease sam-p45 from s. albogriseolus which processes the pro-region. in the present study, we have used a chimeric pro-region consisting of s. mobaraensis and streptomyces cinnamoneus transglutaminases for the production of mtgase in c. glutamicum. as a result, secretion of mtgase using the chimeric pro-region is increased compare ...200415163512
evidence for an arginine exporter encoded by ygga (argo) that is regulated by the lysr-type transcriptional regulator argp in escherichia coli.the anonymous open reading frame ygga of escherichia coli was identified in this study as a gene that is under the transcriptional control of argp (previously called icia), which encodes a lysr-type transcriptional regulator protein. strains with null mutations in either ygga or argp were supersensitive to the arginine analog canavanine, and ygga-lac expression in vivo exhibited argp(+)-dependent induction by arginine. lysine supplementation phenocopied the argp null mutation in that it virtuall ...200415150242
identification and characterization of glxr, a gene involved in regulation of glyoxylate bypass in corynebacterium glutamicum.a corynebacterial clone, previously isolated by scoring repression of laczya fused to the aceb promoter of corynebacterium glutamicum, was analyzed further. in the clone, an open reading frame designated glxr, consisting of 681 nucleotides and encoding a 24,957-da protein, was found. the molecular mass of a native glxr protein was estimated by gel filtration column chromatography to be 44,000 da, suggesting that the protein formed dimers. the predicted amino acid sequence contained both cyclic a ...200415150232
utilization of creatinine as an alternative nitrogen source in corynebacterium glutamicum.in order to utilize different nitrogen sources and to survive situations of nitrogen limitation, microorganisms have developed several mechanisms to adapt their metabolism to changes in the nitrogen supply. in this communication, the use of creatinine as an alternative nitrogen source in corynebacterium glutamicum, the identification of a membrane protein involved in creatinine uptake, the transcriptional regulation of the corresponding gene, and expression regulation of the gene encoding the cr ...200415148566
the c-terminal domain of the betaine carrier betp of corynebacterium glutamicum is directly involved in sensing k+ as an osmotic stimulus.the glycine betaine carrier betp of corynebacterium glutamicum was recently shown to function both as an osmosensor and as an osmoregulator in proteoliposomes by sensing changes in the internal k(+) concentration as a measure of hyperosmotic stress. in vivo analysis of mutants carrying deletions at the c-terminal extension of betp indicated that this domain participates in osmostress-dependent activity regulation. to address the question, whether a putative k(+) sensor is located within the c-te ...200415134432
glutamate as an inhibitor of phosphoenolpyruvate carboxylase activity in corynebacterium glutamicum.the glutamate-producing bacterium, corynebacterium glutamicum is known to possess two anaplerotic enzymes: pyruvate carboxylase (pc) and phosphoenolpyruvate carboxylase (pepc). in vitro, this latter enzyme appeared to be inhibited by different glutamic acid salts, whereas ammonium-glutamate had no influence on pc activity. to investigate the in vivo relevance of pepc activity inhibition, the intracellular concentration of glutamate was determined throughout the glutamate-producing process. the i ...200415133716
heterologous expression of lactose- and galactose-utilizing pathways from lactic acid bacteria in corynebacterium glutamicum for production of lysine in whey.the genetic determinants for lactose utilization from lactobacillus delbrueckii subsp. bulgaricus atcc 11842 and galactose utilization from lactococcus lactis subsp. cremoris mg 1363 were heterologously expressed in the lysine-overproducing strain corynebacterium glutamicum atcc 21253. the c. glutamicum strains expressing the lactose permease and beta-galactosidase genes of l. delbrueckii subsp. bulgaricus exhibited beta-galactosidase activity in excess of 1000 miller units/ml of cells and were ...200415128544
ramb, a novel transcriptional regulator of genes involved in acetate metabolism of corynebacterium glutamicum.the adaptation of corynebacterium glutamicum to acetate as a carbon and energy source involves transcriptional regulation of the pta-ack operon coding for the acetate-activating enzymes phosphotransacetylase and acetate kinase and of the acea and aceb genes coding for the glyoxylate cycle enzymes isocitrate lyase and malate synthase, respectively. deletion and mutation analysis of the respective promoter regions led to the identification of highly conserved 13-bp motifs (aa/gaactttgcaaa) as cis- ...200415090522
production of a novel polygalacturonic acid bioflocculant rea-11 by corynebacterium glutamicum.the production of a novel polygalacturonic acid bioflocculant rea-11 from a newly isolated strain, corynebacterium glutamicum cctcc m201005, was investigated. sucrose was chosen as a carbon source for rea-11 production. complex nitrogen sources containing urea and an organic nitrogen compound enhanced both bacterial growth and rea-11 production, among which urea plus corn steep liquor was shown to be the most efficient combination. a cost-effective medium for rea-11 production mainly comprised 1 ...200415081493
cation specificity of osmosensing by the betaine carrier betp of corynebacterium glutamicum.the na(+)/betaine carrier betp from corynebacterium glutamicum was purified and reconstituted in escherichia coli phospholipid liposomes and its osmosensory properties were studied with respect to the cation specificity of osmotic activation. to dissect the influence of the co-substrate na(+) on the energetics of uptake from its possible role as a putative trigger of osmolality-dependent betp activation, the internal na(+) concentration was varied without changing deltapna(+). studying betaine u ...200415063732
characterization and chromosomal organization of the murd-murc-ftsq region of corynebacterium glutamicum atcc 13869.the sequence of a 4.6-kb region of dna from corynebacterium glutamicum atcc 13869 lying upstream from the ftsq-ftsz region has been determined. the region contains four genes with high similarity to the murd, ftsw, murg, and murc genes from different microorganisms. the products of these mur genes probably catalyse several steps in the formation of the precursors for peptidoglycan synthesis in c. glutamicum, whereas ftsw might play also a role in the stabilisation of the ftsz ring during cell di ...200415059630
cloning of the o-acetylhomoserine sulfhydrylase gene from the ruminal bacterium selenomonas ruminantium hd4.the o-acetylhomoserine sulfhydrylase (oahs) gene was cloned from a selenomonas ruminantium hd4 lambda zap ii genomic library by degenerative probe hybridization and complementation. sequence analysis revealed an 869-bp orf with a g + c content of 53%. the orf had significant homology with enzymes involved in homocysteine biosynthesis. a curablastn homology search showed that the orf has 63% nucleotide identity with the oahs of bacillus stearothermophilus, corynebacterium glutamicum, and acremoni ...200415057458
lead biosorption by waste biomass of corynebacterium glutamicum generated from lysine fermentation process.biomass waste, mainly corynebacterium glutamicum, is generated from large-scale lysine fermentation process. in this study, protonated c. glutamicum biomass was evaluated as a biosorbent for the removal of lead from synthetic wastewater. as pb2+ were bound to the biomass, the solution ph deceased, indicating that protons in the biomass were exchanged with lead ions. the corynebacterium biomass bound pb2+ at up to 2.74 mmol g(-1) at ph 5, where lead does not precipitate. compared with other bioso ...200415055771
clpc and clpp1p2 gene expression in corynebacterium glutamicum is controlled by a regulatory network involving the transcriptional regulators clgr and hspr as well as the ecf sigma factor sigmah.the atp-dependent protease clp plays important roles in the cell's protein quality control system and in the regulation of cellular processes. in corynebacterium glutamicum, the levels of the proteolytic subunits clpp1 and clpp2 as well as of the corresponding mrnas were drastically increased upon deletion of the clpc gene, coding for a clp atpase subunit. we identified a regulatory protein, designated clgr, binding to a common palindromic sequence motif in front of clpp1p2 as well as of clpc. d ...200415049827
projection structure and oligomeric state of the osmoregulated sodium/glycine betaine symporter betp of corynebacterium glutamicum.the high-affinity glycine betaine uptake system betp, an osmosensing and osmoregulated sodium-coupled symporter from corynebacterium glutamicum, was overexpressed in escherichia coli with an n-terminal strepii-tag, solubilized in beta-dodecylmaltoside and purified by streptactin affinity chromatography. analytical ultracentrifugation indicated that betp forms trimers in detergent solution. detergent-solubilized betp can be reconstituted into proteoliposomes without loss of function, suggesting t ...200415046983
a systematic method to identify genomic islands and its applications in analyzing the genomes of corynebacterium glutamicum and vibrio vulnificus cmcp6 chromosome i.some genomic islands contain horizontally transferred genes, which play critical roles in altering the genotypes and phenotypes of organisms, and horizontal gene transfer has been recognized as a universal event throughout bacterial evolution. a windowless method to display the distribution of genomic gc content, the cumulative gc profile, is proposed to identify genomic islands in genomes whose complete genome sequences are available. two new indices are proposed to assess the codon usage bias ...200415033867
impact of the cold shock phenomenon on quantification of intracellular metabolites in bacteria.in the present work the effect of quenching on quantification of intracellular metabolites in corynebacterium glutamicum was investigated. c. glutamicum showed a high sensitivity to cold shock. quenching of the cells by -50 degrees c buffered methanol prior to cell separation and extraction led to drastically reduced concentrations for free intracellular amino acids compared to those for nonquenched filtration. as demonstrated for glutamate and glutamine, this was clearly due to a more than 90% ...200415033521
in-depth profiling of lysine-producing corynebacterium glutamicum by combined analysis of the transcriptome, metabolome, and fluxome.an in-depth analysis of the intracellular metabolite concentrations, metabolic fluxes, and gene expression (metabolome, fluxome, and transcriptome, respectively) of lysine-producing corynebacterium glutamicum atcc 13287 was performed at different stages of batch culture and revealed distinct phases of growth and lysine production. for this purpose, 13c flux analysis with gas chromatography-mass spectrometry-labeling measurement of free intracellular amino acids, metabolite balancing, and isotopo ...200414996808
serial flux mapping of corynebacterium glutamicum during fed-batch l-lysine production using the sensor reactor approach.using our recently developed sensor reactor approach, lysine-producing, nongrowing corynebacterium glutamicum mh20-22b cells were subjected to serial (13)c-labeling experiments for flux analysis during the leucine-limited fed-batch production phase in a 300-l bioreactor. based on two-dimensional (2d) nuclear magnetic resonance (nmr) measurements of (13)c-labeling patterns of cytoplasmic free metabolites, metabolic flux distributions in the central metabolism were successfully determined. focusin ...200414760690
mutational analysis of feedback inhibition and catalytic sites of prephenate dehydratase from corynebacterium glutamicum.prephenate dehydratase is a key regulatory enzyme in the phenylalanine-specific pathway of corynebacterium glutamicum. pcr-based random mutagenesis and functional complementation were used to screen for m-fluorophenylalanine ( mfp)-resistant mutants. comparison of the amino acid sequence of the mutant prephenate dehydratases indicated that ser-99 plays a role in the feedback regulation of the enzyme. when ser-99 of the wild-type enzyme was replaced by met, the specific activity of the mutant enz ...200414749915
properties and applications of microbial transglutaminase.some properties and applications of the transglutaminase (tgase) referred to as microbial tgase (mtgase), derived from a variant of streptomyces mobaraensis (formerly classified as streptoverticillium mobaraense), are described. mtgase cross-linked most food proteins, such as caseins, soybean globulins, gluten, actin, myosins, and egg proteins, as efficiently as mammalian tgases by forming an epsilon-(gamma-glutamyl)lysine bond. however, unlike many other tgases, mtgase is calcium-independent an ...200414740191
overproduction of trehalose: heterologous expression of escherichia coli trehalose-6-phosphate synthase and trehalose-6-phosphate phosphatase in corynebacterium glutamicum.trehalose is a disaccharide with potential applications in the biotechnology and food industries. we propose a method for industrial production of trehalose, based on improved strains of corynebacterium glutamicum. this paper describes the heterologous expression of escherichia coli trehalose-synthesizing enzymes trehalose-6-phosphate synthase (otsa) and trehalose-6-phosphate phosphatase (otsb) in c. glutamicum, as well as its impact on the trehalose biosynthetic rate and metabolic-flux distribu ...200414711665
comparative metabolic flux analysis of lysine-producing corynebacterium glutamicum cultured on glucose or fructose.a comprehensive approach to (13)c tracer studies, labeling measurements by gas chromatography-mass spectrometry, metabolite balancing, and isotopomer modeling, was applied for comparative metabolic network analysis of lysine-producing corynebacterium glutamicum on glucose or fructose. significantly reduced yields of lysine and biomass and enhanced formation of dihydroxyacetone, glycerol, and lactate in comparison to those for glucose resulted on fructose. metabolic flux analysis revealed drastic ...200414711646
characterization of the cryptic plasmid pcc1 from corynebacterium callunae and its use for vector construction.the complete nucleotide sequence of the cryptic plasmid pcc1 from corynebacterium callunae (4109 bp) was determined. dna sequence analysis revealed five open reading frames longer than 200 bp. one of the deduced polypeptides showed homology with the rep proteins encoded by plasmids of the pij101/pjv1 family of plasmids replicating by the rolling-circle (rc) mechanism. within this plasmid family, the rep protein of pcc1 showed the highest degree of similarity to the rep proteins of corynebacteria ...200414711530
importance of mycoloyltransferases on the physiology of corynebacterium glutamicum.mycoloyltransferases (myts) play an essential role in the biogenesis of the cell envelope of members of the corynebacterineae, a group of bacteria that includes the mycobacteria and corynebacteria. while the existence of several functional myt genes has been demonstrated in both mycobacteria and corynebacteria (cmyt), the disruption of any of these genes has at best generated cell-wall-defective but always viable strains. to investigate the importance of myts on the physiology of members of the ...200414702399
a polyketide synthase catalyzes the last condensation step of mycolic acid biosynthesis in mycobacteria and related organisms.mycolic acids are major and specific constituents of the cell envelope of corynebacterineae, a suborder of bacterial species including several important human pathogens such as mycobacterium tuberculosis, mycobacterium leprae, or corynebacterium diphtheriae. these long-chain fatty acids are involved in the unusual architecture and impermeability of the cell envelope of these bacteria. the condensase, the enzyme responsible for the final condensation step in mycolic acid biosynthesis, has remaine ...200414695899
dynamic calibration and dissolved gas analysis using membrane inlet mass spectrometry for the quantification of cell respiration.a membrane inlet mass spectrometer connected to a miniaturized reactor was applied for dynamic dissolved gas analysis. cell samples were taken from 7 ml shake flask cultures of corynebacterium glutamicum atcc 13032, and transferred to the 12 ml miniaturized reactor. there, oxygen uptake and carbon dioxide and its mass isotopomer production rates were determined using a new experimental procedure and applying nonlinear model equations. a novel dynamic method for the calibration of the membrane in ...200314673819
involvement of diviva in the morphology of the rod-shaped actinomycete brevibacterium lactofermentum.in brevibacterium lactofermentum, as in many gram-positive bacteria, a diviva gene is located downstream from the dcw cluster of cell-division- and cell-wall-related genes. this gene (diviva(bl)) is mostly expressed during exponential growth, and the protein encoded, diviva(bl,) bears some sequence similarity to antigen 84 (ag84) from mycobacteria and was detected with monoclonal antibodies against ag84. disruption experiments using an internal fragment of the diviva(bl) gene or a disrupted divi ...200314663085
development of a corynebacterium glutamicum dna microarray and validation by genome-wide expression profiling during growth with propionate as carbon source.a dna microarray was developed to analyse global gene expression of the amino acid-producing bacterium corynebacterium glutamicum. pcr products representing 93.4% of the predicted c. glutamicum genes were prepared and spotted in quadruplicate onto 3-aminopropyltrimethoxysilane-coated glass slides. the applicability of the c. glutamicum dna microarray was demonstrated by co-hybridisation with fluorescently labelled cdna probes. analysis of the technical variance revealed that c. glutamicum genes ...200314651867
a corynebacterium glutamicum rnha recg double mutant showing lysozyme-sensitivity, temperature-sensitive growth, and uv-sensitivity.corynebacterium glutamicum mutant ky9707 was originally isolated for lysozyme-sensitivity, and showed temperature-sensitive growth. two dna fragments from a wild-type c. glutamicum chromosomal library suppressed the temperature-sensitivity of ky9707. these clones also rescued the lysozyme-sensitivity of ky9707, although partially. one of them encodes a protein of 382 amino acid residues, the n-terminal domain of which was homologous to rnase hi. this gene suppressed the temperature-sensitive gro ...200314646202
ammonium assimilation and nitrogen control in corynebacterium glutamicum and its relatives: an example for new regulatory mechanisms in actinomycetes.nitrogen is an essential component of nearly all complex macromolecules in a bacterial cell, such as proteins, nucleic acids and cell wall components. accordingly, most prokaryotes have developed elaborate control mechanisms to provide an optimal supply of nitrogen for cellular metabolism and to cope with situations of nitrogen limitation. in this review, recent advances in our knowledge of ammonium uptake, its assimilation, and related regulatory systems in corynebacterium glutamicum, a gram-po ...200314638415
isolation and characterization of buta, a secondary glycine betaine transport system operating in tetragenococcus halophila.through functional complementation of an escherichia coli mutant defective in glycine betaine uptake, we identified a single-component glycine betaine transporter from tetragenococcus halophila, a moderate halophilic lactic acid bacterium. dna sequence analysis characterized the buta protein as a member of the betaine choline carnitine transporter (bcct) family, that includes a variety of previously characterized compatible solute transporters such as opud from bacillus subtilis, ectp and betp f ...200314629018
identification of an anion-specific channel in the cell wall of the gram-positive bacterium corynebacterium glutamicum.a cation-selective channel (porin), designated pora, facilitates the passage of hydrophilic solutes across the cell wall of the mycolic acid-containing actinomycete corynebacterium glutamicum. biochemical and electrophysiological investigations of the cell wall of the mutant strain revealed the presence of an alternative channel-forming protein. this porin was purified to homogeneity and studied in lipid bilayer membranes. it forms small anion-selective channels with a diameter of about 1.4 nm a ...200314622416
the genome stability in corynebacterium species due to lack of the recombinational repair system.corynebacterium species are members of gram-positive bacteria closely related to mycobacterium species, both of which are classified into the same taxonomic order actinomycetales. recently, three corynebacteria, corynebacterium efficiens, corynebacterium glutamicum, and corynebacterium diphtheriae have been sequenced independently. we found that the order of orthologous genes in these species has been highly conserved though it has been disrupted in mycobacterium species. this synteny suggests t ...200314604803
expression, purification, and characterization of a bacterial gtp-dependent pep carboxykinase.the corynebacterium glutamicum (c. glutamicum) phosphoenolpyruvate carboxykinase (pck) gene (pcka) was cloned into an escherichia coli expression vector with a glutathione s-transferase (gst) tag. this recombinant dna can produce highly overexpressed tagged protein in soluble form. this is the first report of the production of c. glutamicum pck overexpressed in e. coli. the gst-fused pck was purified using the glutathione-sepharose 4b affinity column and the gst tag was removed in one-step. this ...200314550651
effects of the changes in enzyme activities on metabolic flux redistribution around the 2-oxoglutarate branch in glutamate production by corynebacterium glutamicum.an experimental method for metabolic control analysis (mca) was applied to the investigation of a metabolic network of glutamate production by corynebacterium glutamicum. a metabolic reaction (mr) model was constructed and used for flux distribution analysis (mfa). the flux distribution at a key branch point, 2-oxoglutarate, was investigated in detail. activities of isocitrate dehydrogenase (icdh), glutamate dehydrogenase (gdh), and 2-oxoglutarate dehydrogenase complex (odhc) around this the bra ...200314505173
development of a rapid 1-h fluorescence-based cytotoxicity assay for listeria species.listeria monocytogenes is cytotoxic to the lymphocyte-origin hybridoma ped-2e9 cell line. the relative cytotoxicity can be calculated by assaying the release of alkaline phosphatase (alp) from the infected cell line. in this study, a fluorogenic substrate (4-methylumbelliferyl phosphate, mup) was used to quantify the alp activity. the assay is 3.5-fold more sensitive than the colorimetric-based assay and requires only 1 h to differentiate virulent from avirulent strains. in addition to various l ...200314499993
screening method for microorganisms accumulating metabolites and its use in the isolation of micrococcus glutamicus. 196013840150
function of corynebacterium glutamicum promoters in escherichia coli, streptomyces lividans, and bacillus subtilis.the function of seven promoters from corynebacterium glutamicum, p-hom, p-leua, p-per, p-aes1, p-aes2, p-45, and p-104, was analyzed in a heterologous background. dna fragments carrying the promoters were cloned into shuttle promoter-probe vectors replicating in escherichia coli and c. glutamicum (pet2), streptomyces lividans (pgl7011) and bacillus subtilis (prb394). with the exception of p-hom, p-leua and p-104 in b. subtilis, all promoters were found to be active in all species. non-radioactiv ...200312948649
promoters of corynebacterium glutamicum.regulation of gene expression in corynebacterium glutamicum represents an important issue since this gram-positive bacterium is a notable industrial amino acid producer. transcription initiation, beginning by binding of rna polymerase to the promoter dna sequence, is one of the main points at which bacterial gene expression is regulated. more than 50 transcriptional promoters have so far been experimentally localized in c. glutamicum. most of them are assumed to be promoters of vegetative genes ...200312948648
the mobile element is1207 of brevibacterium lactofermentum atcc21086: isolation and use in the construction of tn5531, a versatile transposon for insertional mutagenesis of corynebacterium glutamicum.is1207 is the insertion most frequently found among the spontaneous mutations that abolish the activity of an escherichia coli phage lambda ci gene integrated in the corynebacterium brevibacterium lactofermentum atcc21086 genome. we examined the transposition of transposon-like structures composed of a selective kanamycin resistance gene (aph3), and one or two is1207 sequences. one of these, the tn5531 transposon, transposed efficiently in corynebacterium glutamicum. a replicative and a non-repl ...200312948647
tools for genetic engineering in the amino acid-producing bacterium corynebacterium glutamicum.during the last decades, the gram-positive soil bacterium corynebacterium glutamicum has been shown to be a very versatile microorganism for the large-scale fermentative production of l-amino acids. up to now, a vast amount of techniques and tools for genetic engineering and amplification of relevant structural genes have been developed. the objectives of this study are to summarize the published literature on tools for genetic engineering in c. glutamicum and to focus on new sophisticated and h ...200312948646
genome-wide expression analysis in corynebacterium glutamicum using dna microarrays.dna microarray technology has become an important research tool for microbiology and biotechnology as it allows for comprehensive dna and rna analyses to characterize genetic diversity and gene expression in a genome-wide manner. dna microarrays have been applied extensively to study the biology of many bacteria including mycobacterium tuberculosis, but only recently have they been used for the related high-gc gram-positive corynebacterium glutamicum, which is widely used for biotechnological am ...200312948645
metabolic network analysis during fed-batch cultivation of corynebacterium glutamicum for pantothenic acid production: first quantitative data and analysis of by-product formation.a first generation genetically modified strain of corynebacterium glutamicum has been assessed for its potential to synthesise and accumulate the vitamin pantothenic acid in the medium using fed-batch cultivation technology, with biomass concentration controlled by isoleucine limitation. kinetic analysis of specific rates throughout the process has been used to model carbon flux through both central metabolism and the specific pathways involved in product formation. flux towards pantothenic acid ...200312948644
ketopantoate reductase activity is only encoded by ilvc in corynebacterium glutamicum.ketopantoate reductase catalyzes the second step of the pantothenate pathway after ketoisovalerate, common intermediate in valine, leucine and pantothenate biosynthesis. we show here that the corynebacterium glutamicum ilvc gene is able to complement a ketopantoate reductase deficient escherichia coli mutant. thus ilvc, encoding acetohydroxyacid isomeroreductase, involved in the common pathway for branched-chained amino acids, also exhibits ketopantoate reductase activity. enzymatic activity was ...200312948643
characterisation of the enzyme activities involved in the valine biosynthetic pathway in a valine-producing strain of corynebacterium glutamicum.the enzyme activities of the valine biosynthetic pathway and their regulation have been studied in the valine-producing strain, corynebacterium glutamicum 13032deltailvapjc1ilvbncd. in this micro-organism, this pathway might involve up to five enzyme activities: acetohydroxy acid synthase (ahas), acetohydroxy acid isomeroreductase (ahair), dihydroxyacid dehydratase and transaminases b and c. for each enzyme, kinetic parameters (optimal temperature, optimal ph and affinity for substrates) were de ...200312948642
genome-based analysis of biosynthetic aminotransferase genes of corynebacterium glutamicum.due to broad and overlapping substrate specificities, aminotransferases remain the last uncharacterized enzymes from most amino acid biosynthetic pathways in corynebacterium glutamicum. we report here a complete description of all aminotransferases participating in the biosynthesis of the branched-chain amino acids and phenylalanine in c. glutamicum. we used methods of profile analysis on the newly available genome sequence to systematically search for and characterize members of the four known ...200312948641
genome-wide analysis of the l-methionine biosynthetic pathway in corynebacterium glutamicum by targeted gene deletion and homologous complementation.the genome sequence of corynebacterium glutamicum, a gram-positive soil bacterium widely used as an amino acid producer, was analyzed by a similarity-based approach to elucidate the pathway for the biosynthesis of l-methionine. the functions of candidate orfs were derived by gene deletion and, if necessary, by homologous complementation of suitable mutants. of nine candidate orfs (four of which were known previously), seven orfs (cg0754 (metx), cg0755 (mety), cg1290 (mete), cg1702 (meth), cg2383 ...200312948640
identification and characterization of the last two unknown genes, dapc and dapf, in the succinylase branch of the l-lysine biosynthesis of corynebacterium glutamicum.the inspection of the complete genome sequence of corynebacterium glutamicum atcc 13032 led to the identification of dapc and dapf, the last two unknown genes of the succinylase branch of the l-lysine biosynthesis. the deduced dapf protein of c. glutamicum is characterized by a two-domain structure and a conserved diaminopimelate (dap) epimerase signature. overexpression of dapf resulted in an 8-fold increase of the specific epimerase activity. a defined deletion in the dapf gene led to a reduce ...200312948639
metabolic phenotype of phosphoglucose isomerase mutants of corynebacterium glutamicum.a series of experiments reported in the literature using fluxomics as an efficient functional genomics tool revealed that the l-lysine production of the corynebacterium glutamicum strain mh20-22b correlates with the extent of intracellular nadph supply. some alternative metabolic engineering strategies to increase intracellular nadph supply in the c. glutamicum strain dsm5715 were considered and finally the redirection of carbon flux through the pentose phosphate pathway with two nadph generatin ...200312948638
instability of glutamate production by corynebacterium glutamicum 2262 in continuous culture using the temperature-triggered process.kinetics and physiology of corynebacterium glutamicum 2262 cultured for extended periods in continuous mode were investigated at 33, 39 and 41 degrees c. at 33 degrees c no glutamate production occurred whatever the dilution rates tested (ranging between 0.05 and 0.5 h(-1)). when the continuous culture was performed at 39 degrees c and d=0.05 h(-1), the glutamate was actively produced, while the activities of 2-oxoglutarate dehydrogenase complex (odhc) and pyruvate dehydrogenase (pdh) were, resp ...200312948637
industrial production of amino acids by coryneform bacteria.in the 1950s corynebacterium glutamicum was found to be a very efficient producer of l-glutamic acid. since this time biotechnological processes with bacteria of the species corynebacterium developed to be among the most important in terms of tonnage and economical value. l-glutamic acid and l-lysine are bulk products nowadays. l-valine, l-isoleucine, l-threonine, l-aspartic acid and l-alanine are among other amino acids produced by corynebacteria. applications range from feed to food and pharma ...200312948636
the respiratory chain of corynebacterium glutamicum.corynebacterium glutamicum is an aerobic bacterium that requires oxygen as exogenous electron acceptor for respiration. recent molecular and biochemical analyses together with information obtained from the genome sequence showed that c. glutamicum possesses a branched electron transport chain to oxygen with some remarkable features. reducing equivalents obtained by the oxidation of various substrates are transferred to menaquinone via at least eight different dehydrogenases, i.e. nadh dehydrogen ...200312948635
lysine synthesis control in corynebacterium glutamicum rc 115 in mixed substrate (glucose-acetate) medium.the effect of acetate as a glucose co-substrate on growth, lysine synthesis and experimental lysine yield from carbon substrates by corynebacterium glutamicum rc 115 was investigated. it was found that low amounts of acetate, injected with a glucose-acetate pulse into the steady-state continuous culture in bioreactor, caused a slight decrease in the specific rates of glucose uptake and bacterial growth, but a significant increase in the cell specific rate of lysine synthesis and an increase in l ...200312948634
acetate metabolism and its regulation in corynebacterium glutamicum.the amino acid producing corynebacterium glutamicum grows aerobically on a variety of carbohydrates and organic acids as single or combined sources of carbon and energy. among the substrates metabolized are glucose and acetate which both can also serve as substrates for amino acid production. based on biochemical, genetic and regulatory studies and on quantitative determination of metabolic fluxes during utilization of acetate and/or glucose, this review summarizes the present knowledge on the d ...200312948633
impact of osmotic stress on volume regulation, cytoplasmic solute composition and lysine production in corynebacterium glutamicum mh20-22b.the response of the l-lysine producing corynebacterium glutamicum strain mh20-22b to osmotic stress was studied in batch cultures. to mimic the conditions during a fermentation process the long term adaptation of cells subjected to a constant osmotic stress between 1.0 and 2.5 osm was investigated. cytoplasmic water content and volume of c. glutamicum cells were found to depend on growth phase, extent of osmotic stress and availability of betaine. the maximal cytoplasmic volumes, which were high ...200312948632
osmotic stress, glucose transport capacity and consequences for glutamate overproduction in corynebacterium glutamicum.glucose uptake by corynebacterium glutamicum is predominantly assured by a mannose phosphotransferase system (pts) with a high affinity for glucose (km=0.35 mm). mutants selected for their resistance to 2-deoxyglucose (2dg) and lacking detectable pep-dependent glucose-transporting activity, retained the capacity to grow on media in which glucose was the only carbon and energy source, albeit at significantly diminished rates, due to the presence of a low affinity (ks=11 mm) non-pts uptake system. ...200312948631
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