Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
a universal framework for 13c metabolic flux analysis.a general methodology is presented for the modeling, simulation, design, evaluation, and statistical analysis of (13)c-labeling experiments for metabolic flux analysis. the universal software framework 13c-flux was implemented to support all steps of this process. guided by the example of anaplerotic flux determination in corynebacterium glutamicum, the technical details of the model setup, experimental design, and data evaluation are discussed. it is shown how the network structure, the input s ...200111461148
study of mycoloyl transferase transport across the cell envelope of corynebacterium glutamicum.ps1 is a major exported protein of corynebacterium glutamicum homologous to mycobacterial antigen 85. it is largely associated with the mycolic acid-containing cell wall and acts as a mycoloyl transferase. the transport of ps1 to the cell wall is slow and occurs through two energetically distinct steps: the first one, which includes processing by signal peptidase, is rapid and inhibited by sodium azide or carbonyl cyanide m-chlorophenylhydrazone. this step is probably associated with translocati ...200111470353
lipoamide dehydrogenase from corynebacterium glutamicum: molecular and physiological analysis of the lpd gene and characterization of the enzyme.lipoamide dehydrogenase (lpd) is an essential component of the pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase complexes, both playing a crucial role within the central metabolism of aerobic organisms. using oligonucleotides designed according to conserved regions of lpd amino acid sequences from several organisms, the lpd gene from corynebacterium glutamicum was identified and subsequently subcloned. the cloned lpd gene expressed in c. glutamicum cells harbouring the gene on a plasmid s ...200111495999
the physiological effects and metabolic alterations caused by the expression of rhizobium etli pyruvate carboxylase in escherichia coli.oxaloacetate (oaa) plays an important role in the tricarboxylic acid cycle and for the biosynthesis of a variety of cellular compounds. some microorganisms, such as rhizobium etli and corynebacterium glutamicum, are able to synthesize oaa during growth on glucose via either of the enzymes pyruvate carboxylase (pyc) or phosphoenolpyruvate carboxylase (ppc). other microorganisms, including escherichia coli, synthesize oaa during growth on glucose only via ppc because they lack pyc. in this study w ...200111499929
detailed biosynthetic pathway to decaprenoxanthin diglucoside in corynebacterium glutamicum and identification of novel intermediates.carotenogenic mutants of corynebacterium glutamicum were analyzed for their carotenoid content. mutant mv10 accumulated the same carotenoids as the wild-type, decaprenoxanthin, decaprenoxanthin monoglucoside, and (2r,6r,2'r,6'r)-decaprenoxanthin di-(beta-d)-glucoside, but in three-fold higher amounts. in addition, decaprenoxanthin diglucoside fatty acid esters and the intermediates nonaprene, 2-(3-methyl-2-butenyl)-epsilon,psi-carotene, and sarcinene, 2,2'-bis(3-methyl-2-butenyl)-epsilon,epsilon ...200111511870
l-threonine export: use of peptides to identify a new translocator from corynebacterium glutamicum.bacterial mechanisms for the uptake of peptides and their hydrolysis to amino acids are known in great detail, whereas much less is known about the fates of the peptide-derived amino acids. we show that the addition of l-threonine-containing di- or tripeptides results in reduction of the growth of corynebacterium glutamicum, with concomitant high intracellular accumulation of l-threonine to up to 130 mm. using transposon mutagenesis and isolation of mutants with increased thr peptide sensitivity ...200111514515
single and double overexpression of c(4)-cycle genes had differential effects on the pattern of endogenous enzymes, attenuation of photorespiration and on contents of uv protectants in transgenic potato and tobacco plants.to improve the efficiency of co(2) fixation in c(3) photosynthesis, c(4)-cycle genes were overexpressed in potato and tobacco plants either individually or in combination. overexpression of the phosphoenolpyruvate carboxylase (pepc) gene (ppc) from corynebacterium glutamicum (cppc) or from potato (stppc, deprived of the phosphorylation site) in potato resulted in a 3-6-fold induction of endogenous cytosolic nadp malic enzyme (me) and an increase in the activities of nad-me (3-fold), nadp isocitr ...200111520867
cloning, sequencing, and functional analysis of three glycosyltransferases involved in the biosynthesis of the inner core region of klebsiella pneumoniae lipopolysaccharide.the genes encoding the 3-deoxy-d-manno-oct-2-ulosonic acid (kdo) transferase (waaa) and heptosyltransferases i (waac) and ii (waaf) in klebsiella pneumoniae were cloned from a dna library by functional complementation of corresponding escherichia coli and salmonella enterica mutants. sequence analyses revealed extensive homologies of the deduced proteins to their counterparts in other enterobacteriaceae. however, differences were evident with regard to the chromosomal organization of the genes. ...200111521078
the cell division genes ftsq and ftsz, but not the three downstream open reading frames yfih, orf5 and orf6, are essential for growth and viability in brevibacterium lactofermentum atcc 13869.the three orfs (yfih, orf5 and orf6) located downstream of the cell division genes ftsq and ftsz in brevibacterium lactofermentum were disrupted by single homologous recombination events between internal fragments of the corresponding genes and the chromosomal sequences. the phenotypes of the disrupted mutants were similar to that of the wild type, suggesting that these genes are dispensable for growth and viability. however, using different plasmid constructs, it was not possible to obtain disr ...200111523774
the involvement of cd14 in the activation of human monocytes by peptidoglycan monomers.cell-wall components of gram-positive and gram-negative bacteria induce the production of cytokines in human peripheral blood mononuclear cells. these cytokines are the main mediators of local or systemic inflammatory reaction that can contribute to the development of innate immunity.200111545252
regulation of aromatic amino acid biosynthesis in gamma-proteobacteria.computational comparative techniques were applied to analysis of the aromatic amino acid regulons in gamma-proteobacteria. this resulted in characterization of the trpr and tyrr regulons in the genomes of yersinia pestis, haemophilus influenzae, vibrio cholerae and other bacteria and identification of new members of the phhr regulon in the genome of pseudomonas aeruginosa. candidate attenuators were constructed for all studied genomes, including the trpba operon of the very distantly related bac ...200111545272
identification of two mycobacterium avium subspecies paratuberculosis gene products differentially recognised by sera from rabbits immunised with live mycobacteria but not heat-killed mycobacteria.the investigation of environmentally regulated proteins has led to a better understanding of host-pathogen interactions and identified novel vaccine candidate antigens for several bacterial pathogens. in an effort to identify such proteins in mycobacterium avium subsp. paratuberculosis (m. paratuberculosis), a genomic expression library was differentially screened with sera from rabbits that had been immunised with live m. paratuberculosis (alpha-live) as well as sera from rabbits immunised with ...200111549181
gene lmrb of corynebacterium glutamicum confers efflux-mediated resistance to lincomycin.the lmrb gene of corynebacterium glutamicum, which confers specific resistance to lincosamides, such as lincomycin and clindamycin, was isolated. c. glutamicum cells, carrying the lmrb gene in a multicopy plasmid, showed increased resistance to lincomycin with a mic of 230 microg/ml, which is a 9-fold increase compared to that of the wild type. the lmrb-disrupted mutant became sensitive to the compound. no difference in sensitivity to erythromycin, penicillin g, tetracycline, chloramphenicol, sp ...200111561719
characterization of the phosphoenolpyruvate carboxykinase gene from corynebacterium glutamicum and significance of the enzyme for growth and amino acid production.corynebacterium glutamicum possesses phosphoenolpyruvate (pep) carboxykinase, oxaloacetate decarboxylase and malic enzyme, all three in principle being able to catalyze the first step in gluconeogenesis. to investigate the role of pep carboxykinase for growth and amino acid production, the respective pck gene was isolated, characterized and used for construction and analysis of mutants and overexpressing strains. sequence analysis of the pck gene predicts a polypeptide of 610 amino acids showing ...200111565516
the osmoreactive betaine carrier betp from corynebacterium glutamicum is a sensor for cytoplasmic k+.the isolated glycine betaine uptake carrier betp from corynebacterium glutamicum was reconstituted in escherichia coli phospholipid liposomes and its response to osmotic stress studied. the transport activity of betp, which was previously shown to comprise both osmosensory and osmoregulatory functions, was used to identify the nature of the physicochemical stimulus related to hyperosmotic stress. putative factors modulating transport activity in response to osmotic stress were dissected. these i ...200111574473
cytochrome c oxidase contains an extra charged amino acid cluster in a new type of respiratory chain in the amino-acid-producing gram-positive bacterium corynebacterium glutamicum.the membranes from corynebacterium glutamicum cells contain a hydrophobic di-haem c protein as the cytochrome c subunit of the new type of cytochrome bc complex (complex iii in the respiratory chain) encoded by the qcrcab operon [sone, n., nagata, k., kojima, h., tajima, j., kodera, y., kanamaru, t., noguchi, s. & sakamoto, j. (2001). biochim biophys acta 1503, 279-290]. to characterize complex iv, cytochrome c oxidase and its structural genes were isolated. the oxidase is of the cytochrome aa(3 ...200111577165
purification and characterization of l-2,3-butanediol dehydrogenase of brevibacterium saccharolyticum c-1012 expressed in escherichia coli.the l-2,3-butanediol dehydrogenase produced in e. coli jm109/plbd2-ctc was purified by 5 steps. the molecular mass of this enzyme was estimated at 110 kda and the subunit was measured to be 30 kda. the l-bdh had some differences from the bdhs from other sources in substrate specificity, pi value, ph stability, effects of divalent cations, and organic acids.200111577733
a novel hydrophobic diheme c-type cytochrome. purification from corynebacterium glutamicum and analysis of the qcrcba operon encoding three subunit proteins of a putative cytochrome reductase complex.electrophoresis of a corynebacterium glutamicum membrane preparation in the presence of sodium dodecyl sulfate, followed by staining for peroxidase activity (heme staining), showed only one band at about 28 kda. this 28 kda protein was purified from c. glutamicum membranes by chromatography in the presence of decylglucoside using deae-toyopearl and hydroxylapatite columns, as the sole c-type cytochrome in the bacterium. the cytochrome showed an alpha band at 551 nm, and its e(m, 7) was about 210 ...200111115640
serine 187 is a crucial residue for allosteric regulation of corynebacterium glutamicum 3-deoxy-d-arabino-heptulosonate-7-phosphate synthase.corynebacterium glutamicum 3-deoxy-d-arabino-heptulosonate-7-phosphate (dahp) synthase is sensitive to feedback inhibition by tyrosine. one feedback-insensitive mutant was obtained by in vitro chemical mutagenesis and the mutation was identified as a c-->g mutation at nucleotide 560 causing a ser(187) to cys(187) substitution. replacing ser(187) with cysteine, tyrosine or phenylalanine by site-directed mutagenesis not only reduced the enzymatic activity but also relieved its feedback inhibition ...200111150666
multiplicity of ammonium uptake systems in corynebacterium glutamicum: role of amt and amtb.in corynebacterium glutamicum, a gram-positive soil bacterium widely used in the industrial production of amino acids, two genes encoding (putative) ammonium uptake carriers have been described. the isolation of amt was the first report of the sequence of a gene encoding a bacterial ammonium uptake system combined with the characterization of the corresponding protein. recently, a second amt gene, amtb, with so far unknown function, was isolated. the isolation of this gene and the suggestion of ...200111160807
the low-molecular-mass subunit of the cell wall channel of the gram-positive corynebacterium glutamicum. immunological localization, cloning and sequencing of its gene pora.the 5-kda protein pora of the gram-positive bacterium corynebacterium glutamicum is the subunit of the cell wall channel. antibodies raised against pora specifically detected the protein on the cell surface. pora was sequenced using edman degradation and a gas phase sequencer. the primary sequence was used to create degenerate oligonucleotide primers. the gene of the channel-forming protein and its flanking regions were obtained by pcr followed by inverse pcr. the gene pora comprises 138 bp and ...200111168383
stereochemical applications of the expression of the l-2,3-butanediol dehydrogenase gene in escherichia coli.the l-2,3-butanediol dehydrogenase (l-bdh) gene of brevibacterium saccharolyticum was strongly expressed in escherichia coli using the tac promoter. however, the stereospecificity of the resulting l-bdh was reduced. the region upstream of the meso-bdh gene of klebsiella pneumoniae was also involved in the expression of the b. saccharolyticum gene. however, in this case, the resulting l-bdh exhibited more stable stereospecificity. a stereospecificity recognition region was located within the rear ...200111169050
metabolic consequences of altered phosphoenolpyruvate carboxykinase activity in corynebacterium glutamicum reveal anaplerotic regulation mechanisms in vivo.corynebacterium glutamicum possesses high in vivo activity of the gluconeogenic phosphoenolpyruvate carboxykinase (pepck) during growth on glucose, resulting together with anaplerotic carboxylation reactions in a pep/pyruvate/oxaloacetate substrate cycle. the present study investigated the changes in intracellular fluxes and metabolite concentrations that are caused by altered pepck activity in l-lysine-producing c. glutamicum mh20-22b, applying a recently developed (13)c labeling-based strategy ...200111676569
cloning and transcriptional characterization of two sigma factor genes, siga and sigb, from brevibacterium flavum.using a dna fragment containing the principal sigma factor gene hrdb of streptomyces aureofaciens, we identified two sigma70-like genes in a library of brevibacterium flavum. sequence analysis of the complete genes revealed two orfs coding for gene products of 498 and 331 amino acid residues, which showed the greatest similarity to siga and sigb sigma factors from brevibacterium lactofermentum. we designated them similarly siga and sigb. transcription of b. flavum siga and sigb has been investig ...200111683358
l-glutamate production by lysozyme-sensitive corynebacterium glutamicum ltsa mutant strains.a non-pathogenic species of coryneform bacteria, corynebacterium glutamicum, was originally isolated as an l-glutamate producing bacterium and is now used for fermentative production of various amino acids. a mutation in the c. glutamicum ltsa gene caused susceptibility to lysozyme, temperature-sensitive growth, and l-glutamate production.200111696248
glutamate synthase of corynebacterium glutamicum is not essential for glutamate synthesis and is regulated by the nitrogen status.the corynebacterium glutamicum gltb and gltd genes, encoding the large (alpha) and small (beta) subunit of glutamate synthase (gogat), were investigated in this study. using rt-pcr, a common transcript of gltb and gltd was shown. reporter gene assays and northern hybridization experiments revealed that transcription of this operon depends on nitrogen starvation. the expression of gltbd is under control of the global repressor protein amtr as demonstrated by gel shift experiments and analysis of ...200111700347
purification and characterization of an enzyme from mycobacterium sp. pyr-1, with nitroreductase activity and an n-terminal sequence similar to lipoamide dehydrogenase.mycobacterium sp. pyr-1 produces an enzyme with nitroreductase activity that reduces 1-nitropyrene and 4-nitrobenzoic acid to the corresponding aromatic amines. this enzyme was constitutive and required nadh; and its activity was enhanced by fad. it was inhibited by antimycin a, dicumarol, and o-iodosobenzoic acid; and it was inactivated by ammonium sulfate precipitation. after purification to homogeneity, the protein produced a single band on native and sds-polyacrylamide gels and had a single ...200111702081
construction of a xylanase-producing strain of brevibacterium lactofermentum by stable integration of an engineered xysa gene from streptomyces halstedii jm8.a xylanolytic strain of brevibacterium lactofermentum containing the streptomyces halstedii his-tagged xysa gene was generated. the new strain contains dna derived from s. halstedii, expresses xylanolytic activity, and was obtained by an integrative process mediated by a conjugative plasmid targeted to a dispensable chromosomal region located downstream from the essential cell division gene ftsz. the his-tagged xys1 enzyme was constitutively expressed under the control of the kan promoter from t ...200111722888
nadh dehydrogenase of corynebacterium glutamicum. purification of an nadh dehydrogenase ii homolog able to oxidize nadph.nadph oxidase activity, in addition to nadh oxidase activity, has been shown to be present in the respiratory chain of corynebacterium glutamicum. in this study, we tried to purify nadph oxidase and nadh dehydrogenase activities from the membranes of c. glutamicum. both the enzyme activities were simultaneously purified in the same fraction, and the purified enzyme was shown to be a single polypeptide of 55 kda. the n-terminal sequence of the enzyme was consistent with the sequence deduced from ...200111731134
identification of a novel gene involved in stable maintenance of plasmid pga1 from corynebacterium glutamicum.the cryptic plasmid pga1 (4.8 kb) from corynebacterium glutamicum, replicating in the rolling-circle mode, has been reported to contain four open reading frames longer than 200 bp (orfa/per, orfa2, orfb, orfc/rep). here we present another pga1 gene, orfe (174 bp), located in the region downstream of the per-orfa2 gene cluster. the orfe is transcribed into two rna species in a direction opposite to that of the per-orfa2 rna. introduction of orfe in trans into the cells harboring the pga1 derivati ...200111735365
the ptsi gene encoding enzyme i of the phosphotransferase system of corynebacterium glutamicum.the phosphoenolpyruvate:carbohydrate phosphotransferase system (pts) is widespread among bacteria where it mediates carbohydrate uptake and often serves in carbon control. here we present cloning and analysis of the monocistronic ptsi gene of corynebacterium glutamicum r, which encodes pts enzyme i (ei). ei catalyzes the first reaction of pts and the reported ptsi was shown to complement the corresponding defect in escherichia coli. the deduced 59.2-kda ei of 564 amino acids shares more than 50% ...200111741338
nitrogen and carbon regulation of glutamine synthetase and glutamate synthase in corynebacterium glutamicum atcc 13032.the effect of nitrogen and carbon status on the regulation of glutamine synthetase (gs) and glutamate synthase (gogat) were investigated in corynebacterium glutamicum 13032. under carbon-sufficient, nitrogen-limiting conditions, gs and gogat activities were five- and seven-fold higher, respectively, and transcription of the corresponding genes (glna and gltbd) was similarly induced. gs activity was also induced in complete medium with added glucose, while gogat activity was unaffected. under car ...200111750828
l-glutamate efflux with corynebacterium glutamicum: why is penicillin treatment or tween addition doing the same? 200111200230
a corynebacterium glutamicum mutant with a defined deletion within the rplk gene is impaired in (p)ppgpp accumulation upon amino acid starvation.the rplk gene of corynebacterium glutamicum atcc13032 comprises 438 nucleotides and encodes a protein of 145 amino acids with a molecular mass of 15.3 kda. the amino acid sequence revealed extensive similarities to the large ribosomal subunit protein l11 from several gram-positive and gram-negative bacteria. the c. glutamicum rplk gene is located downstream of sece, representing part of the protein export apparatus, and of nusg, encoding a transcription antiterminator protein. the rplk gene is f ...200111238976
sequence analysis of the aminoacylase-1 family. a new proposed signature for metalloexopeptidases.the amino acid sequence analysis of the human and porcine aminoacylases-1, the carboxypeptidase s precursor from saccharomyces cerevisiae, the succinyl-diaminopimelate desuccinylase from escherichia coli, haemophilus influenzae and corynebacterium glutamicum, the acetylornithine deacetylase from escherichia coli and dictyostelium discoideum and the carboxypeptidase g(2) precursor from pseudomonas strain, using the basic local alignment search tool (blast) and the position-specific iterated blast ...200111250542
modeling and experimental design for metabolic flux analysis of lysine-producing corynebacteria by mass spectrometry.experimental design of (13)c-tracer studies for metabolic flux analysis with mass spectrometric determination of labeling patterns was performed for the central metabolism of corynebacterium glutamicum comprising various flux scenarios. ratio measurement of mass isotopomer pools of corynebacterium products lysine, alanine, and trehalose is sufficient to quantify the flux partitioning ratios (i) between glycolysis and pentose phosphate pathways (phi(ppp)), (ii) between the split pathways in the l ...200111289793
application of maldi-tof ms to lysine-producing corynebacterium glutamicum: a novel approach for metabolic flux analysis.in the present work, a novel comprehensive approach of (13)c-tracer studies with labeling measurements by maldi-tof ms, and metabolite balancing was developed to elucidate key fluxes in the central metabolism of lysine producing corynebacterium glutamicum during batch culture. maldi-tof ms methods established allow the direct quantification of labeling patterns of low molecular mass corynebacterium products from 1 microl of diluted culture supernatant. a mathematical model of the central coryneb ...200111298764
organization and transcriptional analysis of a six-gene cluster around the rplk-rpla operon of corynebacterium glutamicum encoding the ribosomal proteins l11 and l1.a cluster of six genes, trna(trp)-sece-nusg-rplk-rpla-pkwr, was cloned and sequenced from a corynebacterium glutamicum cosmid library and shown to be contiguous in the c. glutamicum genome. these genes encode a tryptophanyl trna, the protein translocase component sece, the antiterminator protein nusg, and the ribosomal proteins l11 and l1 in addition to pkwr, a putative regulatory protein of the laci-galr family. s1 nuclease mapping analysis revealed that nusg and rplk are expressed as separate ...200111319098
development and validation of corynebacterium dna microarrays.we have developed dna microarray techniques for studying corynebacterium glutamicum. a set of 52 c. glutamicum genes encoding enzymes from primary metabolism was amplified by pcr and printed in triplicate onto glass slides. total rna was extracted from cells harvested during the exponential-growth and lysine production phases of a c. glutamicum fermentation. fluorescently labeled cdnas were prepared by reverse transcription using random hexamer primers and hybridized to the microarrays. to estab ...200111319117
pyruvate carboxylase is a major bottleneck for glutamate and lysine production by corynebacterium glutamicum.corynebacterium glutamicum possesses both phosphoenolpyruvate carboxylase (pepcx) and pyruvate carboxylase (pcx) as anaplerotic enzymes for growth on carbohydrates. to analyze the significance of pcx for the amino acid production by this organism, the wild-type pyc gene, encoding pcx, was used for the construction of defined pyc-inactive and pyc-overexpressing strains and the glutamate, lysine and threonine production capabilities of these recombinant strains of c. glutamicum were tested in comp ...200111321586
h+-atpase defect in corynebacterium glutamicum abolishes glutamic acid production with enhancement of glucose consumption rate.a mutant of corynebacterim glutamicum ('brevibacterium flayum') atcc14067 with a reduced h+-atpase activity, f172-8, was obtained as a spontaneous neomycin-resistant mutant. the atpase activity of strain f172-8 was reduced to about 25% of that of the parental strain. strain f172-8 was cultured in a glutamic-acid fermentation medium containing 100 g/l of glucose using ajar fermentor. it was found that glucose consumption per cell during the exponential phase was higher by 70% in the mutant than i ...200111762601
heterologous expression of cyanophycin synthetase and cyanophycin synthesis in the industrial relevant bacteria corynebacterium glutamicum and ralstonia eutropha and in pseudomonas putida. 200111777412
metabolic redirection of carbon flow toward isoleucine by expressing a catabolic threonine dehydratase in a threonine-overproducing corynebacterium glutamicum.carbon destined for lysine synthesis in corynebacterium glutamicum atcc 21799 can be diverted toward threonine by overexpression of genes encoding a feedback-insensitive homoserine dehydrogenase (hom(dr)) and homoserine kinase (thrb). we studied the effects of introducing two different threonine dehydratase genes into this threonine-producing system to gauge their effects on isoleucine production. co-expression of hom(dr), thrb, and ilva, which encodes a native threonine dehydratase, caused isol ...200111778876
expression of the genes coding for the xylanase xys1 and the cellulase cel1 from the straw-decomposing streptomyces halstedii jm8 cloned into the amino-acid producer brevibacterium lactofermentum atcc13869.the xylanase ( xysa) and the cellulase ( cela1) genes from streptomyces halstedii jm8 were cloned into escherichia coli/ brevibacterium lactofermentum shuttle vectors and successfully expressed in both hosts when placed downstream from the kanamycin resistance promoter (pkan) from tn 5 but not when under the control of their own promoters. xylanase was secreted into the culture media of b. lactofermentum by removal of the same leader peptide as is removed in s. halstedii. the main difference bet ...200111797049
metabolic engineering for l-lysine production by corynebacterium glutamicum.corynebacterium glutamicum has been used since several decades for the large-scale production of amino acids, esp. l-glutamate and l-lysine. after initial successes of random mutagenesis and screening approaches, further strain improvements now require a much more rational design, i.e. metabolic engineering. not only recombinant dna technology but also mathematical modelling of metabolism as well as metabolic flux analysis represent important metabolic engineering tools. this review covers as st ...200111816814
a high-resolution reference map for cytoplasmic and membrane-associated proteins of corynebacterium glutamicum.we present a high-resolution reference map for soluble proteins obtained from corynebacterium glutamicum cells grown in glucose minimal medium. the analysis window covers the pl range from 4-6 and the molecular mass range from 5-100 kda. using overlapping narrow immobilized ph gradients for isoelectric focusing, 970 protein spots were detected after second-dimensional separation on sds-polyacrylamide gels and colloidal coomassie-staining. by tryptic peptide mass fingerprinting 169 protein spots ...200111824608
sensing nitrogen limitation in corynebacterium glutamicum: the role of glnk and glnd.a novel nitrogen control system regulating the transcription of genes expressed in response to nitrogen starvation in corynebacterium glutamicum was identified by us recently. in this communication, we also show that the nitrogen regulation cascade in c. glutamicum functions by a new mechanism, although components highly similar to sensor and signal transmitter proteins of escherichia coli are used, namely uridylyltransferase and a pii-type glnk protein. the genes encoding these key components o ...200111886559
osmosensing and osmoregulatory compatible solute accumulation by bacteria.bacteria inhabit natural and artificial environments with diverse and fluctuating osmolalities, salinities and temperatures. many maintain cytoplasmic hydration, growth and survival most effectively by accumulating kosmotropic organic solutes (compatible solutes) when medium osmolality is high or temperature is low (above freezing). they release these solutes into their environment when the medium osmolality drops. solutes accumulate either by synthesis or by transport from the extracellular med ...200111913457
l-methionine degradation potentialities of cheese-ripening microorganisms.volatile sulphur compounds are major flavouring compounds in many traditional fermented foods including cheeses. these compounds are products of the catabolism of l-methionine by cheese-ripening microorganisms. the diversity of l-methionine degradation by such microorganisms, however, remains to be characterized. the objective of this work was to compare the capacities to produce volatile sulphur compounds by five yeasts, geotrichum candidum, yarrowia lipolytica, kluyveromyces lactis, debaryomyc ...200111928962
effect of capsule circulation velocity on production of l-lysine by encapsulated corynebacterium glutamicum in an airlift bioreactor.the effect of capsule circulation velocity and volumetric oxygen transfer coefficient on the production of l-lysine by encapsulated corynebacterium glutamicum in an airlift bioreactor has been evaluated. a larger oxygen supply in the airlift bioreactor caused a more than 58% increase in l-lysine productivity compared to that in a shaking flask incubator. the quantity of l-lysine produced during 5 h of cultivation in the airlift bioreactor was suggested to increase with increasing circulation vel ...200116232951
triggering mechanism of l-glutamate overproduction by dtsr1 in coryneform bacteria.the mechanism of l-glutamate-overproduction by corynebacterium glutamicum, a biotin auxotroph, is very unique and interesting. l-glutamate overproduction by this bacterium is induced by biotin-limitation and suppressed by an excess of biotin. addition of a surfactant or penicillin is also induces l-glutamate overproduction even under excess biotin. after the development of general molecular biological tools such as cloning vectors and dna transfer techniques, genes encoding biosynthetic enzymes ...200216233348
[analysis on integration sites of transposon-insertion mutant by transposon rescue].in order to define the chromosomal locus of the transposon integration in a mutant of corynebacterium glutamicum, transposon rescue experiments were performed. by isolating parts of the transposon together with adjacent parts of the bacterial chromosome and subsequent sequencing of the adjacent parts, the mutant was found to have three transposon integrations, one just in front of the citrate synthase gene glta, the other two in hitherto unknown open reading frames designated orfa and orfb. the ...200212557374
[site-directed construction of in-frame deletion mutants of corynebacterium glutamicum].this study is focused on corynebacterium glutamicum, an important producer in amino-acids industry, by the protocol with construction of the in-frame deletion fragments of targeting genes, application of dna recombination technique and so on. we achieved successfully the defined deletion mutants in frame of the single gene or double genes. the in-frame deletion mutants are subsequently analyzed and confirmed by polymerase chain reaction and sequencing.200212557553
bacterial amino acid transport proteins: occurrence, functions, and significance for biotechnological applications.transport processes play a pivotal role in cellular metabolism, e.g. for the uptake of nutrients or the excretion of metabolic waste products. moreover, they are also important in biotechnological processes such as the production of various amino acids by the use of microorganisms. the focus of this review is on bacterial amino acid transport systems, in particular those of corynebacterium glutamicum and escherichia coli, with respect to their function and biotechnological significance.200211935175
[serological affinity of some species of nonpathogenic corynebacteria].serological peculiarities of the species strains corynebacterium glutamicum, c. ammoniagenes, c. vitaeruminis, c. variabilis and strain of corynebacterium sp. (brevibacterium stationis) ucm ac-719 have been investigated with the help of immunoenzyme analysis elisa with the use of mice immune serum, specific to c. ammoniagenes ucm ac-732t, c. vitaeruminis ucm ac-718t, c. variabilis ucm ac-717t, c. glutamicum ucm ac-733 and corynebacterium sp. ucm ac-719. it has been established that the species o ...200211944349
nitrogen assimilation in corynebacterium diphtheriae: pathways and regulatory cascades.genes encoding proteins for ammonium uptake, assimilation, and the nitrogen regulatory system in corynebacterium diphtheriae were studied on basis of homology searches using corynebacterium glutamicum genes as query sequences. regulation of transcription of these genes in response to nitrogen starvation was analyzed by rna hybridization experiments and knock-out mutants were generated to verify the function of distinct genes. in this communication, we were able to identify the key components of ...200211959451
linking central metabolism with increased pathway flux: l-valine accumulation by corynebacterium glutamicum.mutants of corynebacterium glutamicum were made and enzymatically characterized to clone ilvd and ilve, which encode dihydroxy acid dehydratase and transaminase b, respectively. these genes of the branched-chain amino acid synthesis were overexpressed together with ilvbn (which encodes acetohydroxy acid synthase) and ilvc (which encodes isomeroreductase) in the wild type, which does not excrete l-valine, to result in an accumulation of this amino acid to a concentration of 42 mm. since l-valine ...200211976094
identification of two prpdbc gene clusters in corynebacterium glutamicum and their involvement in propionate degradation via the 2-methylcitrate cycle.genome sequencing revealed that the corynebacterium glutamicum genome contained, besides glta, two additional citrate synthase homologous genes (prpc) located in two different prpdbc gene clusters, which were designated prpd1b1c1 and prpd2b2c2. the coding regions of the two gene clusters as well as the predicted gene products showed sequence identities of about 70 to 80%. significant sequence similarities were found also to the prpbcde operons of escherichia coli and salmonella enterica, which a ...200211976302
intraspecific diversity of brevibacterium linens, corynebacterium glutamicum and rhodococcus erythropolis based on partial 16s rdna sequence analysis and fourier-transform infrared (ft-ir) spectroscopy.the intraspecific diversity of 31 strains of brevibacterium linens, 27 strains of corynebacterium glutamicum and 29 strains of rhodococcus erythropolis was determined by partial 16s rdna sequence analysis and fourier-transform infrared (ft-ir) spectroscopy. as a prerequisite for the analyses, 27 strains derived from culture collections which had carried invalid or wrong species designations were reclassified in accordance with polyphasic taxonomical data. ft-ir spectroscopy proved to be a rapid ...200211988527
charting and unzipping the surface layer of corynebacterium glutamicum with the atomic force microscope.bacterial surface layers (s-layers) are extracellular protein networks that act as molecular sieves and protect a large variety of archaea and bacteria from hostile environments. atomic force microscopy (afm) was used to asses the s-layer of coryne-bacterium glutamicum formed of ps2 proteins that assemble into hexameric complexes within a hexagonal lattice. native and trypsin-treated s-layers were studied. using the afm stylus as a nanodissector, native arrays that adsorbed to mica as double lay ...200211994150
evidence for a partial redundancy of the fibronectin-binding proteins for the transfer of mycoloyl residues onto the cell wall arabinogalactan termini of mycobacterium tuberculosis.mycobacterium tuberculosis produces a series of major secreted proteins, the fibronectin-binding proteins (fbps), also known as the antigen 85 complex, that are believed to play an essential role in the pathogenesis of tuberculosis through their mycoloyltransferase activity required for maintaining the integrity of the bacterial cell envelope. four different fbp genes are found in the genome of m. tuberculosis, but the reason for the existence of these fbps sharing the same substrate specificity ...200212010501
flexibility of the metabolism of corynebacterium glutamicum 2262, a glutamic acid-producing bacterium, in response to temperature upshocks.in order to test the temperature sensitivity of glutamate production metabolism, several temperature shifts, from 33 to 37, 38, 39, 40 or 41 degrees c, were applied to the temperature-sensitive strain, corynebacterium glutamicum 2262, cultivated in a 24-h fed-batch process. whereas glucose was entirely dedicated to biomass synthesis when cells were grown at 33 degrees c, applying temperature upshocks, whatever their range, triggered a redistribution of the carbon utilisation between glutamate, b ...200212032806
influence of glucose, fructose and sucrose as carbon sources on kinetics and stoichiometry of lysine production by corynebacterium glutamicum.batch cultivations of l-lysine-producing corynebacterium glutamicum atcc 21253 were carried out on the different carbon sources, glucose, sucrose and fructose. the time profiles of substrate and product concentrations were evaluated to compare kinetics and stoichiometry of lysine production. the lysine yield (mol c/mol c) on glucose was 8% higher than on sucrose and 30% higher than on fructose. the highest final biomass concentration of 5.0 g/l was obtained on glucose, whereas fructose and sucro ...200212032807
augmentation of nkt and nk cell-mediated cytotoxicity by peptidoglycan monomer linked with zinc.peptidoglycan monomer (pgm), which was originally prepared by biosynthesis from culture fluids of penicillin-treated brevibacterium divaricatum, is an immunostimulator, the activities of which might be improved by addition of zinc (zn) to the basic molecule.200212061425
export of l-isoleucine from corynebacterium glutamicum: a two-gene-encoded member of a new translocator family.bacteria possess amino acid export systems, and corynebacterium glutamicum excretes l-isoleucine in a process dependent on the proton motive force. in order to identify the system responsible for l-isoleucine export, we have used transposon mutagenesis to isolate mutants of c. glutamicum sensitive to the peptide isoleucyl-isoleucine. in one such mutant, strong peptide sensitivity resulted from insertion into a gene designated brnf encoding a hydrophobic protein predicted to possess seven transme ...200212081967
l-glutamic acid production in a continuous stirred tank bioreactor using coimmobilized bio-catalyst using a fluorosensor.the production of l-glutamic acid has been studied using coimmobilized whole cells of pseudomonas reptilivora and micrococcus glutamicus in a two litre tokyo rikakikai fermentor using glucose as selected production medium. the process was carried out at an optimum temperature of 32 degree celsius and a ph of 7.2. the progress of the reaction was recorded using dr. ingold fluorosensor. the effect of initial substrate concentration, speed of agitation, volume ofcalcium alginate beads and aeration ...200212085657
identification of glya (encoding serine hydroxymethyltransferase) and its use together with the exporter thre to increase l-threonine accumulation by corynebacterium glutamicum.l-threonine can be made by the amino acid-producing bacterium corynebacterium glutamicum. however, in the course of this process, some of the l-threonine is degraded to glycine. we detected an aldole cleavage activity of l-threonine in crude extracts with an activity of 2.2 nmol min(-1) (mg of protein)(-1). in order to discover the molecular reason for this activity, we cloned glya, encoding serine hydroxymethyltransferase (shmt). by using affinity-tagged glya, shmt was isolated and its substrat ...200212089010
influence of threonine exporters on threonine production in escherichia coli.threonine production in escherichia coli threonine producer strains is enhanced by overexpression of the e. coli rhtb and rhtc genes or by heterologous overexpression of the gene encoding the corynebacterium glutamicum threonine excretion carrier, thre. both e. coli genes give rise to a threonine-resistant phenotype when overexpressed, and they decrease the accumulation of radioactive metabolites derived from [(14)c] l-threonine. the evidence presented supports the conclusion that both rhtb and ...200212111147
genome-wide transcription profiling of corynebacterium glutamicum after heat shock and during growth on acetate and glucose.to monitor the global gene expression of corynebacterium glutamicum we established two formats of dna-arrays on nylon membranes. we produced an ordered dna-array of pcr fragments from a shotgun library of c. glutamicum representing a threefold coverage of the genome. with this format we studied genome-wide transcriptional changes after heat shock. sequence and subsequent blast analysis of pcr fragments with elevated expression after heat shock revealed pcr fragments harboring genes that encode s ...200212141991
corynebacterium efficiens sp. nov., a glutamic-acid-producing species from soil and vegetables.three glutamic-acid-producing coryneform strains were isolated from soil and vegetable samples. chemotaxonomic investigations indicated that these strains belonged to the genus corynebacterium. phylogenetic studies, based on 16s rdna analysis, demonstrated that the three strains formed a distinct cluster within the genus corynebacterium and that their nearest relatives were corynebacterium glutamicum and corynebacterium callunae, also known as glutamic-acid-producing species. the data from 16s r ...200212148616
transcriptome analysis of acetate metabolism in corynebacterium glutamicum using a newly developed metabolic array.following the determination of the whole-genome sequence of corynebacterium glutamicum, we have developed a dna array to extensively investigate gene expression and regulation relevant to carbon metabolism. for this purpose, a total of 120 c. glutamicum genes, including those in central metabolism and amino acid biosyntheses, were amplified by pcr and printed onto glass slides. the resulting array, designated a "metabolic array", was used for hybridization with fluorescently labeled cdna probes ...200212162556
plasmid-borne macrolide resistance in micrococcus luteus.a plasmid designated pmec2 which confers resistance to erythromycin, other macrolides, and lincomycin was detected in micrococcus luteus strain maw843 isolated from human skin. curing of this approximately 4.2 kb plasmid from the host organism resulted in erythromycin sensitivity of the strain. introduction of pmec2 into a different m. luteus strain conferred erythromycin resistance upon this strain. macrolide resistance in m. luteus maw843 was an inducible trait. induction occurred at subinhibi ...200212177341
antibacterial activity in four marine crustacean decapods.a search for antibacterial activity in different body-parts of pandalus borealis (northern shrimp), pagurus bernhardus (hermit crab), hyas araneus (spider crab) and paralithodes camtschatica (king crab) was conducted. dried samples were extracted with 60% (v/v) acetonitrile, containing 0.1% (v/v) trifluoroacetic acid, and further extracted and concentrated on c18 cartridges. eluates from the solid phase extraction were tested for antibacterial, lysozyme and haemolytic activity. antibacterial act ...200212194450
the alanine racemase gene alr is an alternative to antibiotic resistance genes in cloning systems for industrial corynebacterium glutamicum strains.the potential of the alanine racemase gene alr from corynebacterium glutamicum atcc 13032 to substitute for antibiotic resistance determinants in cloning systems has been investigated. the alr gene was identified by a pcr technique and its nucleotide sequence was determined. the deduced protein revealed the highest amino acid sequence similarity to the alr protein from mycobacterium smegmatis with 45% identical and 58% similar amino acids. a defined alr deletion mutant of c. glutamicum displayed ...200212204559
optimisation of a culture medium containing fish silage for l-lysine production by corynebacterium glutamicum.in a first step the effects of 10 components of a culture medium designed for l-lysine production were evaluated with a 2(10-6) factorial design. among them, glucose, fish silage, and ammonium sulphate showed a significant effect. in a second step, an orthogonal-central composite experimental design and response surface methodology was performed with five from the 10 initial compounds. the determination coefficient (r2) of the fitted second-order model was 0.990. l-lysine production with the opt ...200212227548
efficient electrotransformation of corynebacterium diphtheriae with a mini-replicon derived from the corynebacterium glutamicum plasmid pga1.efficient transformation of the human pathogen corynebacterium diphtheriae was achieved with novel cloning vectors consisting of a mini-replicon from the cryptic c. glutamicum plasmid pga1 as well as of the aph(3')-iia or teta(z ) antibiotic resistance genes. plasmid-containing transformants of c. diphtheriae were recovered at frequencies ranging from 1.3 x 10(5) to 4.8 x 10(6) colony forming units (cfu)/microg of plasmid dna. vector dna was directly transferred from escherichia coli into c. dip ...200212232668
carbon flux analysis in a pantothenate overproducing corynebacterium glutamicum strain.carbon flux analysis during a pseudo-stationary phase of metabolite accumulation in a genetically engineered strain of corynebacterium glutamicum, containing plasmids leading to over-expression of the ilvbncd and panbc operons, has identified the basic metabolic constraints governing the potential of this bacterium to produce pantothenate. carbon flux converging on pyruvate (75% of glucose uptake) is controlled by anabolic precursor requirements and nadph demand provoking high carbon loss as co2 ...200212241042
influence of adjuvant-active peptidoglycan monomer on specific t cell responses in mice.peptidoglycan monomer (pgm) originating from brevibacterium divaricatum is a non-toxic, non-pyrogenic, water-soluble immunostimulator. it potentiates humoral immune response to ovalbumin (ova) in mice upregulating both immunoglobulin (igg) 1 and igg2a antibody subclasses. this study concerns the influence of pgm on t cell activation and cytokine networks in response to ova. ova-specific proliferative response as well as interferon-gamma (ifn-gamma) and interleukin-4 (il-4) secretion in lymph nod ...200212297400
the 27.8-kb r-plasmid ptet3 from corynebacterium glutamicum encodes the aminoglycoside adenyltransferase gene cassette aada9 and the regulated tetracycline efflux system tet 33 flanked by active copies of the widespread insertion sequence is6100.we determined the complete nucleotide sequence of the 27.8-kb r-plasmid ptet3 from corynebacterium glutamicum lp-6 which encodes streptomycin, spectinomycin, and tetracycline resistance. the antibiotic resistance determinant of ptet3 comprises an inti1-like gene, which was truncated by the insertion sequence is6100, and the novel aminoglycoside adenyltransferase gene cassette aada9. the deduced aada9 protein showed 61% identity and 71% similarity to aada6 of integron in51 from pseudomonas aerugi ...200212383729
effect of pyruvate carboxylase overexpression on the physiology of corynebacterium glutamicum.pyruvate carboxylase was recently sequenced in corynebacterium glutamicum and shown to play an important role of anaplerosis in the central carbon metabolism and amino acid synthesis of these bacteria. in this study we investigate the effect of the overexpression of the gene for pyruvate carboxylase (pyc) on the physiology of c. glutamicum atcc 21253 and atcc 21799 grown on defined media with two different carbon sources, glucose and lactate. in general, the physiological effects of pyc overexpr ...200212406733
atypical location of double-strand origin of replication (nic site) on the plasmid pga1 from corynebacterium glutamicum.the double-strand origin of replication (dso) of the rolling-circle-replicating (rc) plasmid pga1 from corynebacterium glutamicum was analyzed using the runoff dna synthesis assay. the site- and strand-specific breakage of double-stranded plasmid dna, representing the nic site of dso, was localized precisely within the sequence 5'-ctgg decreases at-3' in the distal part of the pga1 rep gene. this location of dso differs from the dso positions found on other rc plasmids and is in agreement with t ...200212422507
characterization of a novel plasmid pxz608 from corynebacterium glutamicum.the complete nucleotide sequence of a novel cryptic plasmid pxz608 from corynebacterium glutamicum 227 was determined. pxz608 was 5949 bp with six open reading frames (orf1-6). the predicted orf1 gene product was homologous to replication proteins of rolling circle replication plasmids. the conserved single- and double-stranded origins of rolling circle replication were found, and interestingly, the two origins were both located on orf1, which indicated that the rep protein encoded by orf1 could ...200212423755
s-layer protein transport across the cell wall of corynebacterium glutamicum: in vivo kinetics and energy requirements.corynebacteria are gram-positive bacteria with a very peculiar cell envelope structure as it is constituted of an inner membrane and an outer membrane-like structure. protein secretion in corynebacterium glutamicum was studied in vivo, using the s-layer protein ps2 as a model. we show that different variants of ps2 protein are exported through the whole cell envelope with a half-life ranging between 2 and 4 min, by a two-step mechanism. the first step, which is over after about 1.5 min, is atp- ...200212445648
purification, characterization and identification of cysteine desulfhydrase of corynebacterium glutamicum, and its relationship to cysteine production.we highly purified the enzyme having l-cysteine desulfhydrase activity from corynebacterium glutamicum. according to its partial amino acid sequence, the enzyme was identified as the aecd gene product, a c-s lyase with alpha, beta-elimination activity [i. rossol and a. pühler (1992) j. bacteriol. 174, 2968-2977]. to produce l-cysteine in c. glutamicum, the escherichia coli-altered cyse gene encoding met256ile mutant serine acetyltransferase, which is desensitized to feedback inhibition by l-cyst ...200212445652
expression of genes of lipid synthesis and altered lipid composition modulates l-glutamate efflux of corynebacterium glutamicum.l-glutamate is made with corynebacterium glutamicum on a scale of more than 106 tons/year. nevertheless, formation of this amino acid is enigmatic and there is very limited molecular information available to unravel the apparently complex conditions leading to l-glutamate efflux. here, we report the isolation and overexpression of the genes involved in lipid synthesis: acp, fadd 15, cma, cls, pgsa2, cdsa, gpsa, and plsc, and the inactivation of cma and cls. in addition, the consequences for phos ...200211831479
corynebacterium glutamicum utilizes both transsulfuration and direct sulfhydrylation pathways for methionine biosynthesis.a direct sulfhydrylation pathway for methionine biosynthesis in corynebacterium glutamicum was found. the pathway was catalyzed by mety encoding o-acetylhomoserine sulfhydrylase. the gene mety, located immediately upstream of meta, was found to encode a protein of 437 amino acids with a deduced molecular mass of 46,751 da. in accordance with dna and protein sequence data, the introduction of mety into c. glutamicum resulted in the accumulation of a 47-kda protein in the cells and a 30-fold incre ...200211844756
a novel methodology employing corynebacterium glutamicum genome information to generate a new l-lysine-producing mutant.classical whole-cell mutagenesis has achieved great success in development of many industrial fermentation strains, but has the serious disadvantage of accumulation of uncharacterized secondary mutations that are detrimental to their performance. in the post-genomic era, a novel methodology which avoids this drawback presents itself. this "genome-based strain reconstruction" involves identifying mutations by comparative genomic analysis, defining mutations beneficial for production, and assembli ...200211876415
strategy to sequence the genome of corynebacterium glutamicum atcc 13032: use of a cosmid and a bacterial artificial chromosome library.the initial strategy of the corynebacterium glutamicum genome project was to sequence overlapping inserts of an ordered cosmid library. high-density colony grids of approximately 28 genome equivalents were used for the identification of overlapping clones by southern hybridization. altogether 18 contiguous genomic segments comprising 95 overlapping cosmids were assembled. systematic shotgun sequencing of the assembled cosmid set revealed that only 2.84 mb (86.6%) of the c. glutamicum genome were ...200211879709
priming and activation of mouse macrophages by trehalose 6,6'-dicorynomycolate vesicles from corynebacterium glutamicum.vesicles consisting of pure trehalose dicorynomycolate (tdcm), the corynebacterial analog of the most studied mycobacterial glycolipid 'cord factor', were isolated from corynebacterium glutamicum cells by mild detergent treatment; these induced in vivo a macrophage priming similar to that obtained with mycobacterial-derived trehalose dimycolate. in vitro, both tdcm and bacterial lipopolysaccharide (lps) induced in macrophages the production of nitric oxide (no) and tumor necrosis factor-alpha (t ...200211821236
genealogy profiling through strain improvement by using metabolic network analysis: metabolic flux genealogy of several generations of lysine-producing corynebacteria.a comprehensive approach of metabolite balancing, (13)c tracer studies, gas chromatography-mass spectrometry, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and isotopomer modeling was applied for comparative metabolic network analysis of a genealogy of five successive generations of lysine-producing corynebacterium glutamicum. the five strains examined (c. glutamicum atcc 13032, 13287, 21253, 21526, and 21543) were previously obtained by random mutagenesis and sel ...200212450803
3-phosphoglycerate dehydrogenase from corynebacterium glutamicum: the c-terminal domain is not essential for activity but is required for inhibition by l-serine.the sera gene of corynebacterium glutamicum coding for 3-phosphoglycerate dehydrogenase (pgdh) was isolated and functionally characterized. it encodes a polypeptide of 530 aminoacyl residues (aa), which is substantially longer than the corresponding escherichia coli polypeptide of 410 aa. the difference is largely due to an additional stretch of aa in the carboxy- (c)-terminal part of the polypeptide. overexpression of sera in c. glutamicum results in a 16-fold increase in specific pgdh activity ...200212466884
optimization of l-phenylalanine production of corynebacterium glutamicum under product feedback inhibition by elevated oxygen transfer rate.production feedback inhibition both on cell growth and on product formation of phenylalanine fermentation might be alleviated by elevated oxygen supply. batch fermentations by a high phenylalanine producing strain corynebacterium glutamicum ccrc 18335 at various initial phenylalanine concentrations (p(0)) ranging from 0 to 20 g/l and different oxygen transfer rate coefficients (k(l)a) ranging from 23 to 76 h(-1) were studied. the fermentation parameters with respect to p(0) were strongly depende ...200211753919
changes of pentose phosphate pathway flux in vivo in corynebacterium glutamicum during leucine-limited batch cultivation as determined from intracellular metabolite concentration measurements.corynebacterium glutamicum is an important organism for the industrial production of amino acids such as lysine. in the present study time-dependent changes in the oxidative pentose phosphate pathway activity, an important site of nadph regeneration in c. glutamicum, are investigated, whereby intracellular metabolite concentrations and specific enzyme activities in two isogenic leucine auxotrophic strains differing only in the regulation of their aspartate kinases were compared. after leucine li ...200212646324
disparity between changes in mrna abundance and enzyme activity in corynebacterium glutamicum: implications for dna microarray analysis.the relationship between changes in mrna abundance and enzyme activity was determined for three genes over a span of nearly 3 h during amino acid production in corynebacterium glutamicum. gene expression changes during c. glutamicum fermentations were examined by complementary dna (cdna) microarrays and by a second method for quantitating rna levels, competitive reverse transcriptase-pcr (rt-pcr). the results obtained independently by both methods were compared and found to be in agreement, thus ...200312658516
glts, the sodium-coupled l-glutamate uptake system of corynebacterium glutamicum: identification of the corresponding gene and impact on l-glutamate production.a screening procedure was established to identify corynebacterium glutamicum transposon mutants with an altered l-glutamate excretion behaviour. by this microtiter plate-based approach seven non- or less excreting c. glutamicum strains and two hyper-excreters were found. the subsequently carried out molecular analysis of a hyper-producing clone led to the identification of the glts gene, which codes for the sodium-coupled secondary l-glutamate uptake system in c. glutamicum. characterization of ...200312664155
control of rep gene expression in plasmid pga1 from corynebacterium glutamicum.the cryptic multicopy plasmid pga1 (4,826 bp) from corynebacterium glutamicum lp-6 belongs to the fifth group of rolling-circle-replicating plasmids. a determinant, which negatively controls pga1 replication, was localized in the leader region of the rep gene coding for the initiator of plasmid replication. this region, when cloned into the compatible vector pec6, was found to cause decrease of segregational stability of the pga1 derivative pkg48. a promoter and a single transcriptional start si ...200312670963
global expression profiling and physiological characterization of corynebacterium glutamicum grown in the presence of l-valine.addition of l-valine (50 to 200 mm) to glucose minimal medium had no effect on the growth of wild-type corynebacterium glutamicum atcc 13032 but inhibited the growth of the derived valine production strain val1 [13032 deltailva deltapanbc(pjc1ilvbncd)] in a concentration-dependent manner. in order to explore this strain-specific valine effect, genomewide expression profiling was performed using dna microarrays, which showed that valine caused an increased ilvbn mrna level in val1 but not in the ...200312732517
production of native-type streptoverticillium mobaraense transglutaminase in corynebacterium glutamicum.we previously observed secretion of active-form transglutaminase in corynebacterium glutamicum by coexpressing the subtilisin-like protease sam-p45 from streptomyces albogriseolus to process the prodomain. however, the n-terminal amino acid sequence of the transglutaminase differed from that of the native streptoverticillium mobaraense enzyme. in the present work we have used site-directed mutagenesis to generate an optimal sam-p45 cleavage site in the c-terminal region of the prodomain. as a re ...200312732581
identification and functional analysis of six mycolyltransferase genes of corynebacterium glutamicum atcc 13032: the genes cop1, cmt1, and cmt2 can replace each other in the synthesis of trehalose dicorynomycolate, a component of the mycolic acid layer of the cell envelope.by data mining in the sequence of the corynebacterium glutamicum atcc 13032 genome, six putative mycolyltransferase genes were identified that code for proteins with similarity to the n-terminal domain of the mycolic acid transferase ps1 of the related c. glutamicum strain atcc 17965. the genes identified were designated cop1, cmt1, cmt2, cmt3, cmt4, and cmt5 ( cmt from corynebacterium mycolyl transferases). cop1 encodes a protein of 657 amino acids, which is larger than the proteins encoded by ...200312740729
the corynebacterium glutamicum genome: features and impacts on biotechnological processes.corynebacterium glutamicum has played a principal role in the progress of the amino acid fermentation industry. the complete genome sequence of the representative wild-type strain of c. glutamicum, atcc 13032, has been determined and analyzed to improve our understanding of the molecular biology and physiology of this organism, and to advance the development of more efficient production strains. genome annotation has helped in elucidation of the gene repertoire defining a desired pathway, which ...200312743753
Refresh
firstprev
12345678910...
nextlast
Displaying items 501 - 600 of 2194