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functional identification of novel genes involved in the glutathione-independent gentisate pathway in corynebacterium glutamicum.corynebacterium glutamicum used gentisate and 3-hydroxybenzoate as its sole carbon and energy source for growth. by genome-wide data mining, a gene cluster designated ncg12918-ncg12923 was proposed to encode putative proteins involved in gentisate/3-hydroxybenzoate pathway. genes encoding gentisate 1,2-dioxygenase (ncg12920) and fumarylpyruvate hydrolase (ncg12919) were identified by cloning and expression of each gene in escherichia coli. the gene of ncg12918 encoding a hypothetical protein (nc ...200516000747
[glyoxylate cycle is required for the overproduction of glutamate but is not essential for corynebacterium glutamicum growth on glucose].the glyoxylate cycle was hypothesed to be indispensable for glutamate overproduction in coryneform bacteria, for it was thought to fulfill anaplerotic functions and to supply energy during the growth phase. during glutamate overproduction phase, however, it has been noted that the high level of the cycle is detrimental to the glutamate production. in order to clarify the relationship between the glutamate production and the glyoxylate cycle, a chromosomal acea-disrupted mutant of wild-type c. gl ...200516013488
deletion of cg-emb in corynebacterianeae leads to a novel truncated cell wall arabinogalactan, whereas inactivation of cg-ubia results in an arabinan-deficient mutant with a cell wall galactan core.the cell wall of mycobacterium tuberculosis has a complex ultrastructure that consists of mycolic acids connected to peptidoglycan via arabinogalactan (ag) and abbreviated as the magp complex. the magp complex is crucial for the survival and pathogenicity of m. tuberculosis and is the target of several anti-tubercular agents. apart from sharing a similar magp and the availability of the complete genome sequence, corynebacterium glutamicum has proven useful in the study of orthologous m. tubercul ...200516040600
the impact of fluid mechanical stress on corynebacterium glutamicum during continuous cultivation in an agitated bioreactor.the effect of mechanical stresses generated by an extreme agitation intensity or a high aeration rate on growth parameters and cell physiology were studied during continuous cultivation of the gram-positive bacterium corynebacterium glutamicum. it is concluded that variations in agitation, aeration rate, or do2 concentrations down to about 1% of saturation do not damage the bacterial cells or cause a significant change in physiological response, as measured by flow cytometry, even though the cel ...200516049736
altered morphology produced by ftsz expression in corynebacterium glutamicum atcc 13869.corynebacterium glutamicum is a gram-positive bacterium that lacks the cell division ftsa protein and actin-like mreb proteins responsible for determining cylindrical cell shape. when the cell division ftsz gene from c. glutamicum (ftsz(cg)) was cloned in different multicopy plasmids, the resulting constructions could not be introduced into c. glutamicum; it was assumed that elevated levels of ftsz(cg) result in lethality. the presence of a truncated ftsz(cg) and a complete ftsz(cg) under the co ...200516079335
phosphate starvation-inducible gene usha encodes a 5' nucleotidase required for growth of corynebacterium glutamicum on media with nucleotides as the phosphorus source.phosphorus is an essential component of macromolecules, like dna, and central metabolic intermediates, such as sugar phosphates, and bacteria possess enzymes and control mechanisms that provide an optimal supply of phosphorus from the environment. udp-sugar hydrolases and 5' nucleotidases may play roles in signal transduction, as they do in mammals, in nucleotide salvage, as demonstrated for usha of escherichia coli, or in phosphorus metabolism. the corynebacterium glutamicum gene usha was found ...200516085822
key enzymes of the protocatechuate branch of the beta-ketoadipate pathway for aromatic degradation in corynebacterium glutamicum.although the protocatechuate branch of the beta-ketoadipate pathway in gram+ bacteria has been well studied, this branch is less understood in gram+ bacteria. in this study, corynebacterium glutamicum was cultivated with protocatechuate, p-cresol, vanillate and 4-hydroxybenzoate as sole carbon and energy sources for growth. enzymatic assays indicated that growing cells on these aromatic compounds exhibited protocatechuate 3,4-dioxygenase activities. data-mining of the genome of this bacterium re ...200516092756
multiarray sensors with pattern recognition for the detection, classification, and differentiation of bacteria at subspecies and strain levels.this work describes the integration of a fully autonomous electrochemical biosensor with pattern recognition techniques for the detection and classification of bacteria at subspecies and strain level. the system provides a continuous, real-time monitoring of bacteria activity upon exposure to antibiotics. the system utilizes 96-well-type electrodes array (dox-dissolved oxygen sensor) with principal component analysis (pca) for rapid and routine classification of different classes of bacteria and ...200516351141
fluorescent phospholipid analogs as microscopic probes for detection of the mycolic acid-containing layer in corynebacterium glutamicum: detecting alterations in the mycolic acid-containing layer following ethambutol treatment.corynebacterium glutamicum belongs to the mycolic acid-containing actinomycetes, which also include mycobacterium, nocardia, and rhodococcus. the cells of this group possess a cell wall with a thick outer layer composed primarily of mycolic acid, which functions as a permeability barrier. to investigate the mechanism of mycolic acid-containing layer (mycolate layer) formation, we have developed a fluorescence microscopic technique detecting the mycolate layer in situ. the staining specificity of ...200516306684
the clgr protein regulates transcription of the clpp operon in bifidobacterium breve ucc 2003.five clp genes (clpc, clpb, clpp1, clpp2, and clpx), representing chaperone- and protease-encoding genes, were previously identified in bifidobacterium breve ucc 2003. in the present study, we characterize the b. breve ucc 2003 clpp locus, which consists of two paralogous genes, designated clpp1 and clpp2, whose deduced protein products display significant similarity to characterized clpp peptidases. transcriptional analyses showed that the clpp1 and clpp2 genes are transcribed in response to mo ...200516321946
class 1 integrons and tetracycline resistance genes in alcaligenes, arthrobacter, and pseudomonas spp. isolated from pigsties and manured soil.the presence of tetracycline resistance (tc(r)) genes and class i integrons (in-1), and their ability to cotransfer were investigated in tc(r) gram-negative (185 strains) and gram-positive (72 strains) bacteria from danish farmland and pigsties. the isolates belonged to the groups or species escherichia coli, enterobacter spp., arthrobacter spp., alcaligenes spp., pseudomonas spp., and corynebacterium glutamicum. the 257 isolates were screened for in-1. eighty-one of the gram-negative isolates w ...200516332771
new multiple-deletion method for the corynebacterium glutamicum genome, using a mutant lox sequence.due to the difficulty of multiple deletions using the cre/loxp system, a simple, markerless multiple-deletion method based on a cre/mutant lox system combining a right-element (re) mutant lox site with a left-element (le) mutant lox site was employed for large-scale genome rearrangements in corynebacterium glutamicum. eight distinct genomic regions that had been identified previously by comparative analysis of c. glutamicum r and c. glutamicum 13032 genomes were targeted for deletion. by homolog ...200516332837
amplified expression of fructose 1,6-bisphosphatase in corynebacterium glutamicum increases in vivo flux through the pentose phosphate pathway and lysine production on different carbon sources.the overexpression of fructose 1,6-bisphosphatase (fbpase) in corynebacterium glutamicum leads to significant improvement of lysine production on different sugars. amplified expression of fbpase via the promoter of the gene encoding elongation factor tu (eftu) increased the lysine yield in the feedback-deregulated lysine-producing strain c. glutamicum lyscfbr by 40% on glucose and 30% on fructose or sucrose. additionally formation of the by-products glycerol and dihydroxyacetone was significantl ...200516332851
e1 enzyme of the pyruvate dehydrogenase complex in corynebacterium glutamicum: molecular analysis of the gene and phylogenetic aspects.the e1p enzyme is an essential part of the pyruvate dehydrogenase complex (pdhc) and catalyzes the oxidative decarboxylation of pyruvate with concomitant acetylation of the e2p enzyme within the complex. we analyzed the corynebacterium glutamicum acee gene, encoding the e1p enzyme, and constructed and characterized an e1p-deficient mutant. sequence analysis of the c. glutamicum acee gene and adjacent regions revealed that acee is not flanked by genes encoding other enzymes of the pdhc. transcrip ...200516109942
identification and characterization of porh, a new cell wall channel of corynebacterium glutamicum.the cell wall of corynebacterium glutamicum contains the cation-selective channel (porin) pora(c.glut) and the anion-selective channel porb(c.glut) for the passage of hydrophilic solutes. lipid bilayer experiments with organic solvent extracts of whole c. glutamicum cells cultivated in minimal medium suggested that also another cation-selective channel-forming protein, named porh(c.glut), is present in c. glutamicum. the protein was purified to homogeneity by fast-protein liquid chromatography a ...200516112217
enhanced glutamic acid production by a h+-atpase-defective mutant of corynebacterium glutamicum.previously we reported that a mutant of corynebacterium glutamicum atcc14067 with reduced h+-atpase activity, f172-8, showed an approximately two times higher specific rate of glucose consumption than the parent, but no glutamic acid productivity under the standard biotin-limited culture conditions, where biotin concentration was set at 5.5 microg/l in the production medium (sekine et al., appl. microbiol. biotechnol., 57, 534-540 (2001)). in this study, various culture conditions were tested to ...200516116273
functional genomics and expression analysis of the corynebacterium glutamicum fpr2-cysixhdnyz gene cluster involved in assimilatory sulphate reduction.corynebacterium glutamicum is a high-gc gram-positive soil bacterium of great biotechnological importance for the production of amino acids. to facilitate the rational design of sulphur amino acid-producing strains, the pathway for assimilatory sulphate reduction providing the necessary reduced sulfur moieties has to be known. although this pathway has been well studied in gram-negative bacteria like escherichia coli and low-gc gram-positives like bacillus subtilis, little is known for the actin ...200516159395
the cgl2612 protein from corynebacterium glutamicum is a drug resistance-related transcriptional repressor: structural and functional analysis of a newly identified transcription factor from genomic dna analysis.the emergence of antibiotic-resistant bacteria often causes serious clinical problems. the tetr family is one of the major transcription factor families that regulate expression of genes involved in bacterial antimicrobial resistance systems. cgl2612 protein is a transcription factor newly identified by genomic dna analysis on corynebacterium glutamicum, which belongs to the mycolic acid-containing actinomycetales, including the well known pathogens corynebacterium diphtheriae and mycobacterium ...200516166084
the arac-type regulator ripa represses aconitase and other iron proteins from corynebacterium under iron limitation and is itself repressed by dtxr.the mrna level of the aconitase gene acn of corynebacterium glutamicum is reduced under iron limitation. here we show that an arac-type regulator, termed ripa for "regulator of iron proteins a," is involved in this type of regulation. a c. glutamicum deltaripa mutant has a 2-fold higher aconitase activity than the wild type under iron limitation, but not under iron excess. comparison of the mrna profiles of the deltaripa mutant and the wild type revealed that the acn mrna level was increased in ...200516179344
functional analysis of all aminotransferase proteins inferred from the genome sequence of corynebacterium glutamicum.twenty putative aminotransferase (at) proteins of corynebacterium glutamicum, or rather pyridoxal-5'-phosphate (plp)-dependent enzymes, were isolated and assayed among others with l-glutamate, l-aspartate, and l-alanine as amino donors and a number of 2-oxo-acids as amino acceptors. one outstanding at identified is alat, which has a broad amino donor specificity utilizing (in the order of preference) l-glutamate > 2-aminobutyrate > l-aspartate with pyruvate as acceptor. another at is avta, which ...200516267288
metabolic engineering of corynebacterium glutamicum for l-serine production.although l-serine proceeds in just three steps from the glycolytic intermediate 3-phosphoglycerate, and as much as 8% of the carbon assimilated from glucose is directed via l-serine formation, previous attempts to obtain a strain producing l-serine from glucose have not been successful. we functionally identified the genes serc and serb from corynebacterium glutamicum, coding for phosphoserine aminotransferase and phosphoserine phosphatase, respectively. the overexpression of these genes, togeth ...200516269752
structure and function of the betaine uptake system betp of corynebacterium glutamicum: strategies to sense osmotic and chill stress.the soil bacterium corynebacterium glutamicum has to cope with frequent fluctuations of the external osmolarity and temperature. the consequences of hyperosmotic and chill stress seem to differ, either causing dehydration of the cytoplasm or leading to impairment of cellular functions due to low temperature. nevertheless, a particular type of regulatory response, namely the accumulation of so-called compatible solutes, is induced under both conditions. compatible solutes are known to stabilize t ...200516645311
structure determination of secondary transport proteins by electron crystallography: two-dimensional crystallization of the betaine uptake system betp.structure determination at high resolution is still a challenge for membrane proteins in general, but in particular for secondary transporters due to their highly dynamic nature. x-ray structures of ten secondary transporters have recently been determined, but a thorough understanding of transport mechanisms necessitates structures at different functional states. electron cryo-microscopy of two-dimensional (2d) crystals offers an alternative to obtain structural information at intermediate resol ...200516645315
engineering of a xylose metabolic pathway in corynebacterium glutamicum.the aerobic microorganism corynebacterium glutamicum was metabolically engineered to broaden its substrate utilization range to include the pentose sugar xylose, which is commonly found in agricultural residues and other lignocellulosic biomass. we demonstrated the functionality of the corynebacterial xylb gene encoding xylulokinase and constructed two recombinant c. glutamicum strains capable of utilizing xylose by cloning the escherichia coli gene xyla encoding xylose isomerase, either alone ( ...200616672486
high-throughput transposon mutagenesis of corynebacterium glutamicum and construction of a single-gene disruptant mutant library.a simple and high-throughput transposon-mediated mutagenesis system employing two different types of transposons in combination with direct genomic dna amplification and thermal asymmetric interlaced pcr (tail-pcr) was developed. each of the two minitransposons based on is31831 (isl3 family) and tn5 (is4 family) was integrated into the corynebacterium glutamicum r genome. by using blast and perl, transposon insertion locations were automatically identified based on the sequences of tail-pcr prod ...200616672528
application of global analysis techniques to corynebacterium glutamicum: new insights into nitrogen regulation.the regulation of nitrogen metabolism in the amino acid producer corynebacterium glutamicum was subject of research for several decades. while previous studies focused on single enzymes or pathways, the publication of the c. glutamicum genome sequence gave a fresh impetus to research, since a global investigation of metabolism and regulation networks became possible based on these data. this communication summarizes the advances made by different studies, in which global analysis approaches were ...200616698104
expression of alr gene from corynebacterium glutamicum atcc 13032 in escherichia coli and molecular characterization of the recombinant alanine racemase.we constructed the high-expression system of the alr gene from corynebacterium glutamicum atcc 13032 in escherichia coli bl 21 (de3) to characterize the enzymological and structural properties of the gene product, alr. the alr was expressed in the soluble fractions of the cell extract of the e. coli clone and showed alanine racemase activity. the purified alr was a dimer with a molecular mass of 78 kda. the alr required pyridoxal 5'-phosphate (plp) as a coenzyme and contained 2 mol of plp per mo ...200616707184
purification and characterization of fumarase from corynebacterium glutamicum.fumarase (ec 4.2.1.2) from corynebacterium glutamicum (brevibacterium flavum) atcc 14067 was purified to homogeneity. its amino-terminal sequence (residues 1 to 30) corresponded to the sequence (residues 6 to 35) of the deduced product of the fumarase gene of c. glutamicum (genbank accession no. bab98403). the molecular mass of the native enzyme was 200 kda. the protein was a homotetramer, with a 50-kda subunit molecular mass. the homotetrameric and stable properties indicated that the enzyme be ...200616717409
the corynebacterium glutamicum gene pmt encoding a glycosyltransferase related to eukaryotic protein-o-mannosyltransferases is essential for glycosylation of the resuscitation promoting factor (rpf2) and other secreted proteins.two-dimensional gel electrophoresis and immunoassays revealed several proteins of the secretory subproteome of corynebacterium glutamicum to be glycosylated. by genome-wide searches for genes involved in glycosylation, the c. glutamicum gene cg1014 was found to exhibit significant similarity to eukaryotic protein-o-mannosyltransferases (pmts) and to a recently identified orthologue of mycobacterium tuberculosis, rv1002c, which is responsible for protein-o-mannosylation. the putative membrane pro ...200616734784
respirometric 13c flux analysis--part ii: in vivo flux estimation of lysine-producing corynebacterium glutamicum.a novel method for metabolic flux studies of central metabolism which is based on respirometric (13)c flux analysis, i.e., parallel (13)c tracer studies with online co(2) labeling measurements is applied to flux quantification of a lysine-producing mutant of corynebacterium glutamicum. for this purpose, 3 respirometric (13)c labeling experiments with [1-(13)c(1)], [6-(13)c(1)] and [1,6-(13)c(2)] glucose were carried out in parallel. all fluxes comprising the reactions of glycolysis, of tca cycle ...200616750927
heterologous expression and localization of gentisate transporter ncg12922 from corynebacterium glutamicum atcc 13032.ralstonia sp. strain u2 metabolizes naphthalene via gentisate (2,5-dihydroxybenzoate) to central metabolites, but it was found unable to utilize gentisate as growth substrate. a putative gentisate transporter encoded by ncg12922 from corynebacterium glutamicum atcc 13032 was functionally expressed in ralstonia sp. strain u2, converting strain u2 to a gentisate utilizer. after ncg12922 was inserted into plasmid pgfpe with green fluorescence protein gene gfp, the expressed fusion protein ncg12922- ...200616765316
toward the complete membrane proteome: high coverage of integral membrane proteins through transmembrane peptide detection.to attain a comprehensive membrane proteome of two strains of corynebacterium glutamicum (l-lysine-producing and the characterized model strains), both sample pretreatment and analysis methods were optimized. isolated bacterial membranes were digested with trypsin/cyanogen bromide or trypsin/chymotrypsin, and a complementary protein set was identified using the multidimensional protein identification technology (mudpit). besides a distinct number of cytosolic or membrane-associated proteins, the ...200616291997
the cytosolic, cell surface and extracellular proteomes of the biotechnologically important soil bacterium corynebacterium efficiens ys-314 in comparison to those of corynebacterium glutamicum atcc 13032.reference maps of the cytosolic, cell surface and extracellular proteome fractions of the amino acid-producing soil bacterium corynebacterium efficiens ys-314 were established. the analysis window covers a pi range from 3 to 7 along with a molecular mass range from 10 to 130 kda. after second-dimensional separation on sds-page and coomassie staining, computational analysis detected 635 protein spots in the cytosolic proteome fraction, whereas 76 and 102 spots were detected in the cell surface an ...200616302278
protein and proteome phosphorylation stoichiometry analysis by element mass spectrometry.protein phosphorylation stoichiometry was assessed by two analytical strategies. both are based on element mass spectrometry (icpms, inductively coupled plasma mass spectrometry) and simultaneous monitoring of (31)p and (34)s. one strategy employs a combination of 1d gel electrophoresis, in-gel digestion, and final microlc-icpms analysis (microlc = capillary liquid chromatography). the other strategy uses the combination of 1d gel electrophoresis, protein blotting, and imla-icpms (imla = imaging ...200616536437
identification of rama, a novel luxr-type transcriptional regulator of genes involved in acetate metabolism of corynebacterium glutamicum.in corynebacterium glutamicum, the acetate-activating enzymes phosphotransacetylase and acetate kinase and the glyoxylate cycle enzymes isocitrate lyase and malate synthase are coordinately up-regulated in the presence of acetate in the growth medium. this regulation is due to transcriptional control of the respective pta-ack operon and the acea and aceb genes, brought about at least partly by the action of the negative transcriptional regulator ramb. using cell extracts of c. glutamicum and emp ...200616547043
the surface (s)-layer gene cspb of corynebacterium glutamicum is transcriptionally activated by a luxr-type regulator and located on a 6 kb genomic island absent from the type strain atcc 13032.the surface (s)-layer gene region of the gram-positive bacterium corynebacterium glutamicum atcc 14067 was identified on fosmid clones, sequenced and compared with the genome sequence of c. glutamicum atcc 13032, whose cell surface is devoid of an ordered s-layer lattice. a 5.97 kb dna region that is absent from the c. glutamicum atcc 13032 chromosome was identified. this region includes cspb, the structural gene encoding the s-layer protomer ps2, and six additional coding sequences. pcr experim ...200616549657
oxygen limitation is a pitfall during screening for industrial strains.oxygen supply is a key parameter in aerobic fermentation processes like the industrial production of amino acids. although the oxygen transfer rate (otr; or the volumetric oxygen transfer coefficient k(l)a) is routinely analyzed by engineers during stirred tank fermentations, it is often not taken into account by biologists conducting screening experiments in shake flasks. to show the importance of knowing how to avoid oxygen transfer limitations during primary screenings, corynebacterium glutam ...200616575561
[cloning, sequence analysis and expression of n-acetylglutamate kinase gene in corynebacterium crenatum].n-acetylglutamate kinase (ec 2.7.2.8;nagk) genes from wild-type corynebacterium crenatum as 1.542 and a l-arginine-producing mutant c. crenatum 971.1 were cloned and sequenced. analysis of argb sequences revealed that only one orf existed, which used atg as the initiation codon and coded a peptide of 317 amino acids with a calculated molecular weight of 33.6kda. only one nucleotide difference was found in the structure gene and the difference did not cause a change of amino acid by comparison of ...200616579472
the dtxr regulon of corynebacterium glutamicum.previous studies with corynebacterium diphtheriae and mycobacterium species revealed that the transcriptional regulator dtxr and its ortholog ider play a central role in the control of iron metabolism. in the present work, we used genome-based approaches to determine the dtxr regulon of corynebacterium glutamicum, a nonpathogenic relative of c. diphtheriae. first, global gene expression of a dtxr deletion mutant was compared with that of the wild type using dna microarrays. second, we used a com ...200616585752
identification of a novel arabinofuranosyltransferase (afta) involved in cell wall arabinan biosynthesis in mycobacterium tuberculosis.the cell wall mycolyl-arabinogalactan-peptidoglycan complex is essential in mycobacterial species, such as mycobacterium tuberculosis, and is the target of several anti-tubercular drugs. for instance, ethambutol targets arabinogalactan biosynthesis through inhibition of the arabinofuranosyltransferases mt-emba and mt-embb. following a detailed bioinformatics analysis of genes surrounding the conserved emb locus, we present the identification and characterization of a novel arabinofuranosyltransf ...200616595677
ammonium toxicity in bacteria.although an excellent nitrogen source for most bacteria, ammonium was-in analogy to plant and animal systems-assumed be detrimental to bacteria when present in high concentrations. in this study, we examined the effect of molar ammonium concentrations on different model bacteria, namely, corynebacterium glutamicum, escherichia coli, and bacillus subtilis. the studied bacteria are highly resistant to ammonium. when growth was impaired upon addition of molar (nh4)2so4 concentrations, this was not ...200616604417
on-line optimization of glutamate production based on balanced metabolic control by rq.in glutamate fermentations by corynebacterium glutamicum, higher glutamate concentration could be achieved by constantly controlling dissolved oxygen concentration (do) at a lower level; however, by-product lactate also severely accumulated. the results of analyzing activities changes of the two key enzymes, glutamate and lactate dehydrogenases involved with the fermentation, and the entire metabolic network flux analysis showed that the lactate overproduction was because the metabolic flux in t ...200616614826
metabolic engineering of escherichia coli and corynebacterium glutamicum for biotechnological production of organic acids and amino acids.industrial microorganisms have been developed as biocatalysts to provide new or to optimize existing processes for the biotechnological production of chemicals from renewable plant biomass. rational strain development by metabolic engineering is crucial to successful processes, and is based on efficient genetic tools and detailed knowledge of metabolic pathways and their regulation. this review summarizes recent advances in metabolic engineering of the industrial model bacteria escherichia coli ...200616617034
gene expression of corynebacterium glutamicum in response to the conditions inducing glutamate overproduction.the ultimate aim is to elucidate the molecular mechanisms for glutamate overproduction by corynebacterium glutamicum.200616620205
metabolic pathway analysis for rational design of l-methionine production by escherichia coli and corynebacterium glutamicum.metabolic pathway analysis was carried out to predict the metabolic potential of corynebacterium glutamicum and escherichia coli for the production of l-methionine. based on detailed stoichiometric models for these organisms, this allowed the calculation of the theoretically optimal methionine yield and related metabolic fluxes for various scenarios involving different mutants and process conditions. the theoretical optimal methionine yield on the substrates glucose, sulfate and ammonia for the ...200616621639
comparisons of potentials for l-lysine production among different corynebacterium glutamicum strains.corynebacterium glutamicum is an industrially important organism that is most widely used for the production of various amino acids. a defined l-lysine-producing mutant was generated by introduction of the lysc mutation (t311i) into each of six representative c. glutamicum strains. the resulting six isogenic mutants were compared for l-lysine production under traditional 30 degrees c conditions and industrially more advantageous 40 degrees c conditions. it was found that there were significant d ...200616636474
metabolic activity of corynebacterium glutamicum grown on l: -lactic acid under stress.respiration measurement in shake flasks is introduced as a new method to characterize the metabolic activity of microorganisms during and after stress exposure. the major advantage of the new method is the possibility to determine the metabolic activity independent of manual sampling without the necessity to change the culture vessel or the cultivation medium. this excludes stress factors, which may be induced by transferring the microorganisms to plates or respirometers. the negative influence, ...200616642330
cloning, expression, purification and preliminary crystallographic characterization of a shikimate dehydrogenase from corynebacterium glutamicum.the shikimate dehydrogenase from corynebacterium glutamicum has been cloned into an escherichia coli expression vector, overexpressed and purified. native crystals were obtained by the vapour-diffusion technique using 2-methyl-2,4-pentanediol as a precipitant. the crystals belong to the centred monoclinic space group c2, with unit-cell parameters a = 118.77, b = 63.17, c = 35.67 angstroms, beta = 92.26 degrees (at 100 k), and diffract to 1.64 angstroms on a synchrotron x-ray source. the asymmetr ...200616820680
mutation-induced metabolite pool alterations in corynebacterium glutamicum: towards the identification of nitrogen control signals.the influence of glutamate dehydrogenase activity on nitrogen regulation in corynebacterium glutamicum was investigated. as shown by rna hybridization experiments deletion of the gdh gene results in a rearrangement of nitrogen metabolism. even when sufficiently supplied with nitrogen sources, a gdh deletion strain showed the typical nitrogen starvation response of c. glutamicum. these changes in transcription correlate with distinct alterations of intracellular metabolite pattern. metabolite ana ...200616822574
temperature-sensitive cloning vector for corynebacterium glutamicum.we constructed a temperature-sensitive form of the corynebacterium glutamicum atcc13869 cryptic plasmid, pbl1. the c. glutamicum/escherichia coli shuttle vector psfk6, which is composed of pbl1 and the e. coli cloning vector pk1, was mutagenized in vitro by treatment with hydroxylamine, and introduced into c. glutamicum cells. a mutant plasmid, which was stably maintained at 25 degrees c but not at 34 degrees c, was isolated from the cells. sequencing the plasmid, which was named p48k, revealed ...200616828161
respirometric 13c flux analysis, part i: design, construction and validation of a novel multiple reactor system using on-line membrane inlet mass spectrometry.a novel method for (13)c flux analysis based on on-line co(2) labeling measurements is presented. this so-called respirometric (13)c flux analysis requires multiple parallel (13)c labeling experiments using differently labeled tracer substrates. in part i of the work, a membrane-inlet mass spectrometry-based measurement system with 6 parallel reactors with each 12 ml liquid volume and associated experimental and computational methods for the respirometric (13)c data acquisition and evaluation ar ...200616844397
morphological changes and proteome response of corynebacterium glutamicum to a partial depletion of ftsi.in corynebacterium glutamicum, as in many gram-positive bacteria, the cell division gene ftsi is located at the beginning of the dcw cluster, which comprises cell division- and cell wall-related genes. transcriptional analysis of the cluster revealed that ftsi is transcribed as part of a polycistronic mrna, which includes at least mraz, mraw, ftsl, ftsi and mure, from a promoter that is located upstream of mraz. ftsi appears also to be expressed from a minor promoter that is located in the inter ...200616849811
[effect of synthetic surfactants on some biological properties of non-pathogenic species of the genus corynebacterium].the influence of cationic, anionic and non-ionic synthetic surfactants on some biological properties of different representatives of the following species corynebacterium glutamicum, corynebacterium ammoniagenes, corynebacterium vitaeruminis, corynebacterium variabile and strain corynebacterium sp. (brevibacterium stationis) ukm as-719 has been investigated. it has been shown that the action of surfactants is accompanied by the change of cell morphology and loss of ability for gram-staining, as ...200616869145
enhancement of l-lysine production in methylotroph methylophilus methylotrophus by introducing a mutant lyse exporter.the obligate methylotroph methylophilus methylotrophus as1 expressing a mutant form of dapa (dapa24) encoding a dihydrodipicolinate synthase desensitized from feedback inhibition by l-lysine could secrete l-lysine into the medium, but also maintained a high concentration of intracellular l-lysine. to improve the yield from excretion, we attempted to introduce an l-lysine/l-arginine exporter (lyse) from corynebacterium glutamicum 2256 into m. methylotrophus. we were unable to stably transform m. ...200616870294
monitoring and modeling of the reaction dynamics in the valine/leucine synthesis pathway in corynebacterium glutamicum.the intracellular concentrations of the valine and leucine pathway intermediates in a corynebacterium glutamicum strain were measured during a transient state. the data were obtained by performing a glucose stimulus-response experiment with the use of a rapid sampling device and advanced mass spectrometry. the glucose stimulus resulted in a 3-fold increase in the intracellular pyruvate concentration within less than a second, demonstrating the very fast interactions in metabolic networks. the sa ...200616889382
arabinan-deficient mutants of corynebacterium glutamicum and the consequent flux in decaprenylmonophosphoryl-d-arabinose metabolism.the arabinogalactan (ag) of corynebacterianeae is a critical macromolecule that tethers mycolic acids to peptidoglycan, thus forming a highly impermeable cell wall matrix termed the mycolyl-arabinogalactan peptidoglycan complex (magp). the front line anti-tuberculosis drug, ethambutol (emb), targets the mycobacterium tuberculosis and corynebacterium glutamicum arabinofuranosyltransferase mt-emba, mt-embb and cg-emb enzymes, respectively, which are responsible for the biosynthesis of the arabinan ...200616891347
random mutagenesis in corynebacterium glutamicum atcc 13032 using an is6100-based transposon vector identified the last unknown gene in the histidine biosynthesis pathway.corynebacterium glutamicum, a gram-positive bacterium of the class actinobacteria, is an industrially relevant producer of amino acids. several methods for the targeted genetic manipulation of this organism and rational strain improvement have been developed. an efficient transposon mutagenesis system for the completely sequenced type strain atcc 13032 would significantly advance functional genome analysis in this bacterium.200616901339
siderophore-mediated iron transport in bacillus subtilis and corynebacterium glutamicum.hexadentate bacillibactin is the siderophore of bacillus subtilis and is structurally similar to the better known enterobactin of gram-negative bacteria such as escherichia coli. although both are triscatecholamide trilactones, the structural differences of these two siderophores result in opposite metal chiralities, different affinity for ferric ion, and dissimilar iron transport behaviors. bacillibactin was first reported as isolated from corynebacterium glutamicum and called corynebactin. how ...200616912897
proteomics of corynebacterium glutamicum: essential industrial bacterium. 200616929678
markov chain monte carlo algorithm based metabolic flux distribution analysis on corynebacterium glutamicum.metabolic flux analysis via a (13)c tracer experiment has been achieved using a monte carlo method with the assumption of system noise as gaussian noise. however, an unbiased flux analysis requires the estimation of fluxes and metabolites jointly without the restriction on the assumption of gaussian noise. the flux distributions under such a framework can be freely obtained with various system noise and uncertainty models.200616940326
a leuc mutation leading to increased l-lysine production and rel-independent global expression changes in corynebacterium glutamicum.we previously found by transcriptome analysis that global induction of amino acid biosynthetic genes occurs in a classically derived industrial l-lysine producer, corynebacterium glutamicum b-6. based on this stringent-like transcriptional profile in strain b-6, we analyzed the relevant mutations from among those identified in the genome of the strain, with special attention to the genes that are involved in amino acid biosynthesis and metabolism. among these mutations, a gly-456-->asp mutation ...200616944136
global gene expression during stringent response in corynebacterium glutamicum in presence and absence of the rel gene encoding (p)ppgpp synthase.the stringent response is the initial reaction of microorganisms to nutritional stress. during stringent response the small nucleotides (p)ppgpp act as global regulators and reprogram bacterial transcription. in this work, the genetic network controlled by the stringent response was characterized in the amino acid-producing corynebacterium glutamicum.200616961923
genetic characterization of the resorcinol catabolic pathway in corynebacterium glutamicum.corynebacterium glutamicum grew on resorcinol as a sole source of carbon and energy. by genome-wide data mining, two gene clusters, designated ncgl1110-ncgl1113 and ncgl2950-ncgl2953, were proposed to encode putative proteins involved in resorcinol catabolism. deletion of the ncgl2950-ncgl2953 gene cluster did not result in any observable phenotype changes. disruption and complementation of each gene at ncgl1110-ncgl1113, ncgl2951, and ncgl2952 indicated that these genes were involved in resorci ...200616963551
determination of soluble and granular inorganic polyphosphate in corynebacterium glutamicum.corynebacterium glutamicum forms inorganic polyphosphate (poly p) that may occur as soluble (cytosolic) poly p and/or as volutin granules. a suitable method for monitoring soluble and granular poly p in c. glutamicum was developed and applied to c. glutamicum cells cultivated under different growth conditions. under phosphate-limiting conditions, c. glutamicum did not accumulate poly p, but it rebuilt its poly p storages when phosphate became available. the poly p content of c. glutamicum growin ...200616977467
characterization of myo-inositol utilization by corynebacterium glutamicum: the stimulon, identification of transporters, and influence on l-lysine formation.although numerous bacteria possess genes annotated iol in their genomes, there have been very few studies on the possibly associated myo-inositol metabolism and its significance for the cell. we found that corynebacterium glutamicum utilizes myo-inositol as a carbon and energy source, enabling proliferation with a high maximum rate of 0.35 h-1. whole-genome dna microarray analysis revealed that 31 genes respond to myo-inositol utilization, with 21 of them being localized in two clusters of >14 k ...200616997948
functional analysis of the twin-arginine translocation pathway in corynebacterium glutamicum atcc 13869.compared to those of other gram-positive bacteria, the genetic structure of the corynebacterium glutamicum tat system is unique in that it contains the tate gene in addition to tata, tatb, and tatc. the tate homologue has been detected only in the genomes of gram-negative enterobacteria. to assess the function of the c. glutamicum tat pathway, we cloned the tata, tatb, tatc, and tate genes from c. glutamicum atcc 13869 and constructed mutants carrying deletions of each tat gene or of both the ta ...200616997984
analysis of optimal phenotypic space using elementary modes as applied to corynebacterium glutamicum.quantification of the metabolic network of an organism offers insights into possible ways of developing mutant strain for better productivity of an extracellular metabolite. the first step in this quantification is the enumeration of stoichiometries of all reactions occurring in a metabolic network. the structural details of the network in combination with experimentally observed accumulation rates of external metabolites can yield flux distribution at steady state. one such methodology for quan ...200617038164
production system for biodegradable polyester polyhydroxybutyrate by corynebacterium glutamicum.a biosynthetic pathway for poly(3-hydroxybutyrate) [p(3hb)] production by corynebacterium glutamicum was developed by introducing the phbcab operon derived from ralstonia eutropha. p(3hb) synthase activity was detected in this recombinant c. glutamicum carrying a cell surface protein gene promoter. intracellular p(3hb) was microscopically observed as inclusion granules and its content was calculated to be 22.5% (w/w) with a number average molecular weight of 2.1x10(5) and a polydispersity of 1.6 ...200617046539
two-chamber afm: probing membrane proteins separating two aqueous compartments.biological membranes compartmentalize and define physical borders of cells. they are crowded with membrane proteins that fulfill diverse crucial functions. about one-third of all genes in organisms code for, and the majority of drugs target, membrane proteins. to combine structure and function analysis of membrane proteins, we designed a two-chamber atomic force microscopy (afm) setup that allows investigation of membranes spanned over nanowells, therefore separating two aqueous chambers. we ima ...200617060909
corynebacterium glutamicum as a model bacterium for the bioremediation of arsenic.arsenic is an extremely toxic metalloid that, when present in high concentrations, severely threatens the biota and human health. arsenic contamination of soil, water, and air is a global growing environmental problem due to leaching from geological formations, the burning of fossil fuels, wastes generated by the gold mining industry present in uncontrolled landfills, and improper agriculture or medical uses. unlike organic contaminants, which are degraded into harmless chemical species, metals ...200617061211
evidence for activator and repressor functions of the response regulator mtra from corynebacterium glutamicum.previous analysis of a corynebacterium glutamicum delta mtrab mutant showed that the mtrab two-component signal transduction system influences the expression of genes involved in cell wall metabolism or osmoregulation, but it remained unknown whether this influence is direct or indirect. in order to identify the direct target genes of the response regulator mtra, chromatin immunoprecipitation as a genome-wide approach and dna affinity chromatography as a gene-specific approach were used. the res ...200617064374
crystallization and initial crystallographic characterization of the corynebacterium glutamicum nitrilotriacetate monooxygenase component a.safety and environmental concerns have recently dictated the proper disposal of nitrilotriacetate (nta). biodegradation of nta is initiated by nta monooxygenase, which is composed of two proteins: component a and component b. the nta monooxygenase component a protein from corynebacterium glutamicum was crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium sulfate as the precipitant. x-ray diffraction data were collected to a maximum resolution of 2.5 a on a sync ...200617077499
disruption of malate:quinone oxidoreductase increases l-lysine production by corynebacterium glutamicum.genomic analysis of a classically derived l-lysine-producing mutant, corynebacterium glutamicum b-6, identified a nonsense mutation in the mqo gene, which encodes malate:quinone oxidoreductase (mqo). the effect of mqo disruption on l-lysine production was investigated in a defined l-lysine producer, c. glutamicum ahp-3, showing approximately 18% increased production. to explore the underlying mechanisms of the increase, the mqo-disrupted strain was analyzed from the viewpoints of redox balance, ...200617090916
multiple gene duplication and rapid evolution in the groel gene: functional implications.the chaperonins, groel and groes, are present ubiquitously and provide a paradigm in the understanding of assisted protein folding. due to its essentiality of function, groel exhibits high sequence conservation across species. complete genome sequencing has shown the occurrence of duplicate or multiple copies of groel genes in bacteria such as mycobacterium tuberculosis and corynebacterium glutamicum. monophyly of each bacterial clade in the phylogenetic tree generated for the groel protein sugg ...200617103057
characterization of a unique mutant lyse gene, originating from corynebacterium glutamicum, encoding a product that induces l-lysine production in methylophilus methylotrophus.lyse24 is an allele of lyse encoding an l-lysine exporter of corynebacterium glutamicum. the mutant gene is able to induce l-lysine production in methylophilus methylotrophus. although lyse24 has a mutation in the middle of lyse that results in chain termination, the entire lyse locus, including the region downstream of the short open reading frame, is necessary for l-lysine production. we propose that separate polypeptides are synthesized from the lyse24 locus due to reinitiation of translation ...200617151474
transcriptional regulation of catabolic pathways for aromatic compounds in corynebacterium glutamicum.corynebacterium glutamicum is a gram-positive soil microorganism able to utilize a large variety of aromatic compounds as the sole carbon source. the corresponding catabolic routes are associated with multiple ring-fission dioxygenases and among other channeling reactions, include the gentisate pathway, the protocatechuate and catechol branches of the beta-ketoadipate pathway and two potential hydroxyquinol pathways. genes encoding the enzymatic machinery for the bioconversion of aromatic compou ...200617183485
precise metabolic flux analysis of coryneform bacteria by gas chromatography-mass spectrometry and verification by nuclear magnetic resonance.precise metabolic flux analysis (mfa) by gas chromatography-mass spectrometry (gc-ms) and computer calculation was performed, and the consistency of the estimated results was verified by independently performed nuclear magnetic resonance (nmr) analysis. the precise estimation of flux by the integration method of the mass isotopomer signal, defined as the coefficient of variance (cv) of multiple determination, was investigated, and the results estimated using different data sets with the same mag ...200617189168
secrets of soil survival revealed by the genome sequence of arthrobacter aurescens tc1.arthrobacter sp. strains are among the most frequently isolated, indigenous, aerobic bacterial genera found in soils. member of the genus are metabolically and ecologically diverse and have the ability to survive in environmentally harsh conditions for extended periods of time. the genome of arthrobacter aurescens strain tc1, which was originally isolated from soil at an atrazine spill site, is composed of a single 4,597,686 basepair (bp) circular chromosome and two circular plasmids, ptc1 and p ...200617194220
a clean route for preparation of cdte nanocrystals and their conjugation with bacterium.the thiol-capped cdte nanocrystals were obtained by a clean chemical approach with hydrazine hydrate. in alkaline aqueous solution, hydrazine hydrate reduced commercial tellurium to be active reactant, and further reduced to negative bivalent telluride for the preparation of cdte nanocrystals. the resulting cdte nanocrystals were characterized by uv-vis absorption spectra, photoluminescence spectra, x-ray diffraction, and high-resolution transmission electron microscopy. the synthesized cdte nan ...200617256331
quantification of s-adenosyl methionine in microbial cell extracts.a sensitive method for quantification of s-adenosyl methionine (sam) in microbial cell extracts was developed and applied to corynebacterium glutamicum. the method is based on sam being completely hydrolyzed into (18)o-homoserine when extracted in boiling h(2) (18)o and thus can be clearly distinguished by gc-ms analysis from naturally labeled homoserine present in the cell extract. additional quantification of the total homoserine pool, representing both sam and homoserine, via hplc allows sepa ...200616369687
towards bacterial strains overproducing l-tryptophan and other aromatics by metabolic engineering.the aromatic amino acids, l-tryptophan, l-phenylalanine, and l-tyrosine, can be manufactured by bacterial fermentation. until recently, production efficiency of classical aromatic amino-acid-producing mutants had not yet reached a high level enough to make the fermentation method the most economic. with the introduction of recombinant dna technology, it has become possible to apply more rational approaches to strain improvement. many recent activities in this metabolic engineering have led to se ...200616374633
characterization and use of catabolite-repressed promoters from gluconate genes in corynebacterium glutamicum.the genes involved in gluconate catabolism (gntp and gntk) in corynebacterium glutamicum are scattered in the chromosome, and no regulatory genes are apparently associated with them, in contrast with the organization of the gnt operon in escherichia coli and bacillus subtilis. in c. glutamicum, gntp and gntk are essential genes when gluconate is the only carbon and energy source. both genes contain upstream regulatory regions consisting of a typical promoter and a hypothetical cyclic amp (camp) ...200616385030
accumulation of homolanthionine and activation of a novel pathway for isoleucine biosynthesis in corynebacterium glutamicum mcbr deletion strains.in the present work, the metabolic consequences of the deletion of the methionine and cysteine biosynthesis repressor protein (mcbr) in corynebacterium glutamicum, which releases almost all enzymes of methionine biosynthesis and sulfate assimilation from transcriptional regulation (d. a. rey, a. pühler, and j. kalinowski, j. biotechnol. 103:51-65, 2003), were studied. c. glutamicum atcc 13032 deltamcbr showed no overproduction of methionine. metabolome analysis revealed drastic accumulation of a ...200616385051
two-component systems of corynebacterium glutamicum: deletion analysis and involvement of the phos-phor system in the phosphate starvation response.corynebacterium glutamicum contains genes for 13 two-component signal transduction systems. in order to test for their essentiality and involvement in the adaptive response to phosphate (pi) starvation, a set of 12 deletion mutants was constructed. one of the mutants was specifically impaired in its ability to grow under pi limitation, and therefore the genes lacking in this strain were named phos (encoding the sensor kinase) and phor (encoding the response regulator). dna microarray analyses wi ...200616385062
transcriptional analysis of the f0f1 atpase operon of corynebacterium glutamicum atcc 13032 reveals strong induction by alkaline ph.corynebacterium glutamicum, a soil gram-positive bacterium used for industrial amino acid production, was found to grow optimally at ph 7.0-9.0 when incubated in 5 litre fermenters under ph-controlled conditions. the highest biomass was accumulated at ph 9.0. growth still occurred at ph 9.5 but at a reduced rate. the expression of the ph-regulated f0 f1 atpase operon (containing the eight genes atpbefhagdc) was induced at alkaline ph. a 7.5 kb transcript, corresponding to the eight-gene operon, ...200616385111
emerging corynebacterium glutamicum systems biology.corynebacterium glutamicum is widely used for the biotechnological production of amino acids. amino acid producing strains have been improved classically by mutagenesis and screening as well as in a rational manner using recombinant dna technology. metabolic flux analysis may be viewed as the first systems approach to c. glutamicum physiology since it combines isotope labeling data with metabolic network models of the biosynthetic and central metabolic pathways. however, only the complete genome ...200616406159
secretion of human epidermal growth factor by corynebacterium glutamicum.to examine the secretion of human epidermal growth factor (hegf) by corynebacterium glutamicum.200616411922
substrate-free structure of a monomeric nadp isocitrate dehydrogenase: an open conformation phylogenetic relationship of isocitrate dehydrogenase.both monomeric and dimeric nadp+-dependent isocitrate dehydrogenase (idh) belong to the metal-dependent beta-decarboxylating dehydrogenase family and catalyze the oxidative decarboxylation from 2r,3s-isocitrate to yield 2-oxoglutarate, co2, and nadph. it is important to solve the structures of idhs from various species to correlate with its function and evolutionary significance. so far, only two crystal structures of substrate/cofactor-bound (isocitrate/nadp) nadp+-dependent monomeric idh from ...200616416443
influence of membrane composition on osmosensing by the betaine carrier betp from corynebacterium glutamicum.the glycine betaine carrier betp from corynebacterium glutamicum was recently shown to function as both an osmosensor and osmoregulator in proteoliposomes made from escherichia coli phospholipids by sensing changes in the internal k+ concentration as a measure of hyperosmotic stress (rübenhagen, r., morbach, s., and krämer, r. (2001) embo j. 20, 5412-5420). furthermore, evidence was provided that a stretch of 25 amino acids of the c-terminal domain of betp is critically involved in k+ sensing. t ...200616421104
changes in composition and content of mycolic acids in glutamate-overproducing corynebacterium glutamicum.overproduction of glutamate by corynebacterium glutamicum is induced by biotin limitation or by the supplementation of specific detergents, sublethal amounts of penicillin, or cerulenin. but, it remains unclear why these different treatments, which have different sites of primary action, produce similar effects. in this study, it was found that the cellular content of mycolic acids--characteristic constituents of corynebacterineae that are synthesized from fatty acids and form a cell surface lay ...200616428817
functional analysis of l-serine o-acetyltransferase from corynebacterium glutamicum.we report here the function of l-serine o-acetyltransferase (sat) from the glutamic acid-producing bacterium corynebacterium glutamicum. based on the genome sequence of c. glutamicum and the nh(2)-terminal amino-acid sequence, the gene encoding sat (cyse) was cloned and expressed in c. glutamicum. deletion analysis of the 5'-noncoding region showed a putative -10 region ((-27)ttaagt(-22) or (-26)taagtc(-21)) and a possible ribosome-binding site ((-12)aga(-10)) just upstream from the start codon. ...200616436075
pyruvate:quinone oxidoreductase in corynebacterium glutamicum: molecular analysis of the pqo gene, significance of the enzyme, and phylogenetic aspects.corynebacterium glutamicum recently has been shown to possess pyruvate:quinone oxidoreductase (pqo), catalyzing the oxidative decarboxylation of pyruvate to acetate and co2 with a quinone as the electron acceptor. here, we analyze the expression of the c. glutamicum pqo gene, investigate the relevance of the pqo enzyme for growth and amino acid production, and perform phylogenetic studies. expression analyses revealed that transcription of pqo is initiated 45 bp upstream of the translational sta ...200616452416
the dtxr protein acting as dual transcriptional regulator directs a global regulatory network involved in iron metabolism of corynebacterium glutamicum.the knowledge about complete bacterial genome sequences opens the way to reconstruct the qualitative topology and global connectivity of transcriptional regulatory networks. since iron is essential for a variety of cellular processes but also poses problems in biological systems due to its high toxicity, bacteria have evolved complex transcriptional regulatory networks to achieve an effective iron homeostasis. here, we apply a combination of transcriptomics, bioinformatics, in vitro assays, and ...200616469103
the gene ncgl2918 encodes a novel maleylpyruvate isomerase that needs mycothiol as cofactor and links mycothiol biosynthesis and gentisate assimilation in corynebacterium glutamicum.data mining of the corynebacterium glutamicum genome identified 4 genes analogous to the msha, mshb, mshc, and mshd genes that are involved in biosynthesis of mycothiol in mycobacterium tuberculosis and mycobacterium smegmatis. individual deletion of these genes was carried out in this study. mutants mshc- and mshd- lost the ability to produce mycothiol, but mutant mshb- produced mycothiol as the wild type did. the phenotypes of mutants mshc- and mshd- were the same as the wild type when grown i ...200616481315
utilization of soluble starch by a recombinant corynebacterium glutamicum strain: growth and lysine production.corynebacterium glutamicum, well known for the industrial production of amino acids, grows aerobically on a variety of mono- and disaccharides and on alcohols and organic acids as single or combined sources of carbon and energy. members of the genera corynebacterium and brevibacterium were here tested for their ability to use the homopolysaccharide starch as a substrate for growth. none of the 24 type strains tested showed growth on or degradation of this substrate, indicating that none of the s ...200616488498
transcriptome analysis reveals global expression changes in an industrial l-lysine producer of corynebacterium glutamicum.toward the elucidation of advanced mechanisms of l-lysine production by corynebacterium glutamicum, a highly developed industrial strain b-6 was analyzed from the viewpoint of gene expression. northern blot analysis showed that the lysc gene encoding aspartokinase, the key enzyme of l-lysine biosynthesis, was up-regulated by several folds in strain b-6, while no repression mechanism exists in l-lysine biosynthesis of this bacterium. to analyze the underlying mechanisms of the up-regulation, we c ...200616495679
a genome-based approach to create a minimally mutated corynebacterium glutamicum strain for efficient l-lysine production.based on the progress in genomics, we have developed a novel approach that employs genomic information to generate an efficient amino acid producer. a comparative genomic analysis of an industrial l-lysine producer with its natural ancestor identified a variety of mutations in genes associated with l-lysine biosynthesis. among these mutations, we identified two mutations in the relevant terminal pathways as key mutations for l-lysine production, and three mutations in central metabolism that res ...200616506038
protein cleavage strategies for an improved analysis of the membrane proteome.membrane proteins still remain elusive in proteomic studies. this is in part due to the distribution of the amino acids lysine and arginine, which are less frequent in integral membrane proteins and almost absent in transmembrane helices. as these amino acids are cleavage targets for the commonly used protease trypsin, alternative cleavage conditions, which should improve membrane protein analysis, were tested by in silico digestion for the three organisms saccharomyces cerevisiae, halobacterium ...200616512920
metabolic engineering of corynebacterium glutamicum for trehalose overproduction: role of the treyz trehalose biosynthetic pathway.trehalose has many potential applications in biotechnology and the food industry due to its protective effect against environmental stress. our work explores microbiological production methods based on the capacity of corynebacterium glutamicum to excrete trehalose. we address here raising trehalose productivity through homologous overexpression of maltooligosyltrehalose synthase and the maltooligosyltrehalose trehalohydrolase genes. in addition, heterologous expression of the udp-glucose pyroph ...200616517642
corynebacterial protein kinase g controls 2-oxoglutarate dehydrogenase activity via the phosphorylation status of the odhi protein.a novel regulatory mechanism for control of the ubiquitous 2-oxoglutarate dehydrogenase complex (odh), a key enzyme of the tricarboxylic acid cycle, was discovered in the actinomycete corynebacterium glutamicum, a close relative of important human pathogens like corynebacterium diphtheriae and mycobacterium tuberculosis. based on the finding that a c. glutamicum mutant lacking serine/threonine protein kinase g (pkng) was impaired in glutamine utilization, proteome comparisons led to the identifi ...200616522631
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