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from corynebacterium glutamicum to mycobacterium tuberculosis--towards transfers of gene regulatory networks and integrated data analyses with mycoregnet.year by year, approximately two million people die from tuberculosis, a disease caused by the bacterium mycobacterium tuberculosis. there is a tremendous need for new anti-tuberculosis therapies (antituberculotica) and drugs to cope with the spread of tuberculosis. despite many efforts to obtain a better understanding of m. tuberculosis' pathogenicity and its survival strategy in humans, many questions are still unresolved. among other cellular processes in bacteria, pathogenicity is controlled ...200919494184
siccanin rediscovered as a species-selective succinate dehydrogenase inhibitor.to identify antibiotics targeting to respiratory enzymes, we carried out matrix screening of a structurally varied natural compound library with pseudomonas aeruginosa membrane-bound respiratory enzymes. we identified a succinate dehydrogenase inhibitor, siccanin (ic(50), 0.9 microm), which is a potent antibiotic against some pathogenic fungi like trichophyton mentagrophytes and inhibits their mitochondrial succinate dehydrogenase. we found that siccanin was effective against enzymes from p. aer ...200919505951
engineering of pentose transport in corynebacterium glutamicum to improve simultaneous utilization of mixed sugars.corynebacterium glutamicum strains cra1 and crx2 are able to grow on l-arabinose and d-xylose, respectively, as sole carbon sources. nevertheless, they exhibit the major shortcoming that their sugar consumption appreciably declines at lower concentrations of these substrates. to address this, the c. glutamicum atcc31831 l-arabinose transporter gene, arae, was independently integrated into both strains. unlike its parental strain, resultant cra1-arae was able to aerobically grow at low (3.6 g.l(- ...200919529932
diviva uses an n-terminal conserved region and two coiled-coil domains to localize and sustain the polar growth in corynebacterium glutamicum.corynebacterium glutamicum is a rod-shaped actinomycete with a distinct model of peptidoglycan synthesis during cell elongation, which takes place at the cell poles and is sustained by the essential protein diviva(cg) (c. glutamicum diviva). this protein contains a short conserved n-terminal domain and two coiled-coil regions: cc1 and cc2. domain deletions and chimeric versions of diviva were used to functionally characterize the three domains, and all three were found to be essential for proper ...200919552709
crystallization and preliminary crystallographic analysis of cghle, a homoserine acetyltransferase homologue, from corynebacterium glutamicum.cghle is an enzyme that is encoded by gene cg0961 from corynebacterium glutamicum. the physiological function of cghle is so far unclear. bioinformatic annotations based on sequence homology indicated that cghle may be an acetyl-coa:homoserine acetyl transferase and as such may be involved in methionine biosynthesis, but recent evidence has shown that it is an esterase that catalyzes the hydrolysis of acetyl esters. here, the crystallization of cghle in two orthorhombic crystal forms, a trigonal ...200919153452
enhanced decolorization and biodegradation of textile azo dye scarlet r by using developed microbial consortium-gr.a developed consortium-gr, consisting of proteus vulgaris ncim-2027 (pv) and micrococcus glutamicus ncim-2168 (mg), completely decolorized an azo dye scarlet r under static anoxic condition with an average decolorization rate of 16,666 microg h(-1); which is much faster than that of the pure cultures (pv, 3571 microg h(-1); mg, 2500 microg h(-1)). consortium-gr gave best decolorization performance with nearly complete mineralization of scarlet r (over 90% toc and cod reduction) within 3h, much s ...200919157864
pathway identification combining metabolic flux and functional genomics analyses: acetate and propionate activation by corynebacterium glutamicum.corynebacterium glutamicum can utilize acetic acid and propionic acid for growth and amino acid production. growth on acetate as sole carbon source requires acetate activation by acetate kinase (ak) and phosphotransacetylase (pta), encoded in the pta-ack operon. genetic and enzymatic studies showed that these enzymes also catalyze propionate activation and were required for growth on propionate as sole carbon source. however, when glucose was present as a co-substrate strain lacking the ak-pta p ...200919162097
roles of maltodextrin and glycogen phosphorylases in maltose utilization and glycogen metabolism in corynebacterium glutamicum.corynebacterium glutamicum transiently accumulates large amounts of glycogen, when cultivated on glucose and other sugars as a source of carbon and energy. apart from the debranching enzyme glgx, which is required for the formation of maltodextrins from glycogen, alpha-glucan phosphorylases were assumed to be involved in glycogen degradation, forming alpha-glucose 1-phosphate from glycogen and from maltodextrins. we show here that c. glutamicum in fact possesses two alpha-glucan phosphorylases, ...200919202084
microarray studies reveal a 'differential response' to moderate or severe heat shock of the hrca- and hspr-dependent systems in corynebacterium glutamicum.genome-wide transcription profile analysis of the heat-shocked wild-type strain under moderate (40 degrees c) and severe heat stress (50 degrees c) revealed that a large number of genes are differentially expressed after heat shock. of these, 358 genes were upregulated and 420 were downregulated in response to moderate heat shock (40 degrees c) in corynebacterium glutamicum. our results confirmed the hrca/controlling inverted repeat of chaperone expression (circe)-dependent and hspr/hspr-associa ...200919202085
molecular mechanism of sugr-mediated sugar-dependent expression of the ldha gene encoding l-lactate dehydrogenase in corynebacterium glutamicum.this paper reports on the transcriptional regulation mechanism of the corynebacterium glutamicum ldha gene encoding l: -lactate dehydrogenase responsible for production of l: -lactate. dna affinity purification allowed us to identify sugr, a global repressor of genes involved in sugar uptake and glycolysis, as a protein binding to the ldha promoter region. whereas ldha gene expression and ldha promoter activity were completely repressed during growth of wild-type cells in the absence of sugar, n ...200919221735
expression and localization of the corynebacterium glutamicum ncgl1221 protein encoding an l-glutamic acid exporter.corynebacterium glutamicum strains are used for the fermentative production of l-glutamate. biotin limitation and addition of fatty acid ester surfactants can induce l-glutamic acid secretion. however, the mechanism of l-glutamate secretion remains unclear. it was recently reported that the ncgl1221 protein, a mechanosensitive channel homolog, was considered to be functional as an important l-glutamate exporter. however, the structure of the ncgl1221 protein has not been studied recently. in thi ...200919233628
formation and metabolism of methylmalonyl coenzyme a in corynebacterium glutamicum.genome sequence information suggests that b(12)-dependent mutases are present in a number of bacteria, including members of the suborder corynebacterineae like mycobacterium tuberculosis and corynebacterium glutamicum. we here functionally identify a methylmalonyl coenzyme a (coa) mutase in c. glutamicum that is retained in all of the members of the suborder corynebacterineae and is encoded by ncgl1471, ncgl1472, and ncgl1470. in addition, we observe the presence of methylmalonate in c. glutamic ...200919233926
scanning the corynebacterium glutamicum r genome for high-efficiency secretion signal sequences.systematic screening of secretion proteins using an approach based on the completely sequenced genome of corynebacterium glutamicum r revealed 405 candidate signal peptides, 108 of which were able to heterologously secrete an active-form alpha-amylase derived from geobacillus stearothermophilus. these comprised 90 general secretory (sec)-type, 10 twin-arginine translocator (tat)-type and eight sec-type with presumptive lipobox peptides. only sec- and tat-type signals directed high-efficiency sec ...200919246745
molecular basis of transport and regulation in the na(+)/betaine symporter betp.osmoregulated transporters sense intracellular osmotic pressure and respond to hyperosmotic stress by accumulation of osmolytes to restore normal hydration levels. here we report the determination of the x-ray structure of a member of the family of betaine/choline/carnitine transporters, the na(+)-coupled symporter betp from corynebacterium glutamicum, which is a highly effective osmoregulated uptake system for glycine betaine. glycine betaine is bound in a tryptophan box occluded from both side ...200919262666
regulation of corynebacterium glutamicum heat shock response by the extracytoplasmic-function sigma factor sigh and transcriptional regulators hspr and hrca.heat shock response in corynebacterium glutamicum was characterized by whole-genome expression analysis using a dna microarray. it was indicated that heat shock response of c. glutamicum included not only upregulation of heat shock protein (hsp) genes encoding molecular chaperones and atp-dependent proteases, but it also increased and decreased expression of more than 300 genes related to disparate physiological functions. an extracytoplasmic-function sigma factor, sigh, was upregulated by heat ...200919270092
potassium transport in corynebacterium glutamicum is facilitated by the putative channel protein cglk, which is essential for ph homeostasis and growth at acidic ph.we studied the requirement for potassium and for potassium transport activity for the biotechnologically important bacterium corynebacterium glutamicum, which is used for large-scale production of amino acids. different from many other bacteria, at alkaline or neutral ph, c. glutamicum is able to grow without the addition of potassium, resulting in very low cytoplasmic potassium concentrations. in contrast, at acidic ph, the ability for growth was found to depend on the presence of k+. for the f ...200919270097
arsenate reductase, mycothiol, and mycoredoxin concert thiol/disulfide exchange.we identified the first enzymes that use mycothiol and mycoredoxin in a thiol/disulfide redox cascade. the enzymes are two arsenate reductases from corynebacterium glutamicum (cg_arsc1 and cg_arsc2), which play a key role in the defense against arsenate. in vivo knockouts showed that the genes for cg_arsc1 and cg_arsc2 and those of the enzymes of the mycothiol biosynthesis pathway confer arsenate resistance. with steady-state kinetics, arsenite analysis, and theoretical reactivity analysis, we u ...200919286650
de novo biosynthesis of vanillin in fission yeast (schizosaccharomyces pombe) and baker's yeast (saccharomyces cerevisiae).vanillin is one of the world's most important flavor compounds, with a global market of 180 million dollars. natural vanillin is derived from the cured seed pods of the vanilla orchid (vanilla planifolia), but most of the world's vanillin is synthesized from petrochemicals or wood pulp lignins. we have established a true de novo biosynthetic pathway for vanillin production from glucose in schizosaccharomyces pombe, also known as fission yeast or african beer yeast, as well as in baker's yeast, s ...200919286778
exopolyphosphatases ppx1 and ppx2 from corynebacterium glutamicum.corynebacterium glutamicum accumulates up to 300 mm of inorganic polyphosphate (polyp) in the cytosol or in granules. the gene products of cg0488 (ppx1) and cg1115 (ppx2) were shown to be active as exopolyphosphatases (ppx), as overexpression of either gene resulted in higher exopolyphosphatase activities in crude extracts and deletion of either gene with lower activities than those of the wild-type strain. ppx1 and ppx2 from c. glutamicum share only 25% identical amino acids and belong to diffe ...200919304823
structure of thermotoga maritima tm0439: implications for the mechanism of bacterial gntr transcription regulators with zn2+-binding fcd domains.the gntr superfamily of dimeric transcription factors, with more than 6200 members encoded in bacterial genomes, are characterized by n-terminal winged-helix dna-binding domains and diverse c-terminal regulatory domains which provide a basis for the classification of the constituent families. the largest of these families, fadr, contains nearly 3000 proteins with all-alpha-helical regulatory domains classified into two related pfam families: fadr_c and fcd. only two crystal structures of fadr-fa ...200919307717
osmosensing and osmosignaling in corynebacterium glutamicum.the gram-positive soil bacterium corynebacterium glutamicum is used in microbial biotechnology for the large-scale production of amino acids, e.g., l: -glutamate and l: -lysine. we have studied the response of this organism to hyperosmotic challenge at the level of both transcription and protein activity. two systems responding to hyperosmotic stress in c. glutamicum are reviewed here, the two component system mtrab and the glycine-betaine uptake system betp. the osmosensory two-component system ...200919308662
the two-phase partitioning system--a powerful technique to purify integral membrane proteins of corynebacterium glutamicum for quantitative shotgun analysis.we established a single consecutive strategy which assigned the most comprehensive number of integral membrane proteins from gram-positive bacteria to date. for this purpose, we adapted a biphasic partitioning system for the biotechnologically intensively used corynebacterium glutamicum and proved for the first time that such a system is well suited for quantitative comparison. 297 integral membrane proteins were identified by our integrated approach, which depletes stringently cytosolic protein ...200919322788
dual production of poly(3-hydroxybutyrate) and glutamate using variable biotin concentrations in corynebacterium glutamicum.we previously synthesized poly(3-hydroxybutyrate) [p(3hb)] in recombinant corynebacterium glutamicum, a prominent producer of amino acids. in this study, a two-step cultivation was established for the dual production of glutamate and p(3hb) due to the differences in the optimal concentration of biotin. glutamate was extracellularly produced first under the biotin-limited condition of 0.3 microg/l. production was then shifted to p(3hb) by addition of biotin to a total concentration of 9 microg/l. ...200919332300
regulation of ldh expression during biotin-limited growth of corynebacterium glutamicum.corynebacterium glutamicum is a biotin-auxotrophic bacterium and some strains efficiently produce glutamic acid under biotin-limiting conditions. in an effort to understand c. glutamicum metabolism under biotin limitation, growth of the type strain atcc 13032 was investigated in batch cultures and a time-course analysis was performed. a transient excretion of organic acids was observed and we focused our attention on lactate synthesis. lactate synthesis was due to the ldh-encoded l-lactate dehyd ...200919332837
identification and functional analysis of the gene cluster for l-arabinose utilization in corynebacterium glutamicum.corynebacterium glutamicum atcc 31831 grew on l-arabinose as the sole carbon source at a specific growth rate that was twice that on d-glucose. the gene cluster responsible for l-arabinose utilization comprised a six-cistron transcriptional unit with a total length of 7.8 kb. three l-arabinose-catabolizing genes, araa (encoding l-arabinose isomerase), arab (l-ribulokinase), and arad (l-ribulose-5-phosphate 4-epimerase), comprised the arabda operon, upstream of which three other genes, arar (laci ...200919346355
repeatability of peptide identifications in shotgun proteome analysis employing off-line two-dimensional chromatographic separations and ion-trap ms.the repeatability of peptide identifications in shotgun proteome analyses employing strong cation-exchange-xion-pair rp hplc hyphenated to esi ms/ms was compared to an alternative scheme, comprising high-ph rp chromatography combined with low-ph ion-pair rp chromatography. equivalent results were obtained with both methods in proteome analysis of corynebacterium glutamicum. from a total number of 1350 to 1850 peptides identified in triplicate analyses of five consecutive fractions chosen from th ...200919360783
dynamic and structural characterization of a bacterial fha protein reveals a new autoinhibition mechanism.the odhi protein is key regulator of the tca cycle in corynebacterium glutamicum. this highly conserved protein is found in gc rich gram-positive bacteria (e.g., the pathogenic mycobacterium tuberculosis). the unphosphorylated form of odhi inhibits the odha protein, a key enzyme of the tca cycle, whereas the phosphorylated form is inactive. odhi is predicted to be mainly a single fha domain, a module that mediates protein-protein interaction through binding of phosphothreonine peptides, with a d ...200919368890
genetic makeup of the corynebacterium glutamicum lexa regulon deduced from comparative transcriptomics and in vitro dna band shift assays.the lexa gene of corynebacterium glutamicum atcc 13032 was deleted to create the mutant strain c. glutamicum nj2114, which has an elongated cell morphology and an increased doubling time. to characterize the sos regulon in c. glutamicum, the transcriptomes of nj2114 and a dna-damage-induced wild-type strain were compared with that of a wild-type control using dna microarray hybridization. the expression data were combined with bioinformatic pattern searches for lexa binding sites, leading to the ...200919372162
ecofriendly degradation of sulfonated diazo dye c.i. reactive green 19a using micrococcus glutamicus ncim-2168.micrococcus glutamicus ncim-2168 exhibited complete decolorization and degradation of c.i. reactive green 19a (an initial concentration of 50 mg l(-1)) within 42 h at temperature 37 degrees c and ph 8, under static condition. extent of mineralization was determined with total organic carbon (toc) and chemical oxygen demand (cod) measurement, showing a satisfactory reduction of toc (72%) and cod (66%) within 42 h. enzyme studies shows involvement of oxidoreductive enzymes in decolorization/degrad ...200919375909
citrate utilization by corynebacterium glutamicum is controlled by the citab two-component system through positive regulation of the citrate transport genes cith and tctcba.in this work, the molecular basis of aerobic citrate utilization by the gram-positive bacterium corynebacterium glutamicum was studied. genome analysis revealed the presence of two putative citrate transport systems. the permease encoded by cith belongs to the citrate-mg(2+):h(+)/citrate-ca(2+):h(+) symporter family, whereas the permease encoded by the tctcba operon is a member of the tripartite tricarboxylate transporter family. the expression of cith or tctcba in escherichia coli enabled this ...200919376865
regulation of expression of genes involved in quinate and shikimate utilization in corynebacterium glutamicum.the utilization of the hydroaromatic compounds quinate and shikimate by corynebacterium glutamicum was investigated. c. glutamicum grew well with either quinate or shikimate as the sole carbon source. the disruption of qsud, encoding quinate/shikimate dehydrogenase, completely suppressed growth with either substrate but did not affect growth with glucose, indicating that the enzyme encoded by qsud catalyzes the first step of the catabolism of quinate/shikimate but is not involved in the shikimat ...200919376919
the cmar gene of corynebacterium ammoniagenes performs a novel regulatory role in the metabolism of sulfur-containing amino acids.a novel regulatory gene, which performs an essential function in sulfur metabolism, has been identified in corynebacterium ammoniagenes and was designated cmar (cysteine and methionine regulator in c. ammoniagenes). the cmar-disrupted strain (deltacmar) lost the ability to grow on minimal medium, and was identified as a methionine and cysteine double auxotroph. the mutant strain proved unable to convert cysteine to methionine (and vice versa), and lost the ability to assimilate and reduce sulfat ...200919383689
a game with many players: control of gdh transcription in corynebacterium glutamicum.glutamate dehydrogenase is a central enzyme connecting nitrogen and carbon metabolism via its precursors ammonium and oxoglutarate and its product glutamate. in corynebacterium glutamicum glutamate dehydrogenase is especially important, since it is a key enzyme for the biotechnological production of the flavour enhancer l-glutamate. in this study, the regulation of gdh transcription was investigated. while originally described as a constitutively expressed gene, we could show that gdh transcript ...200919394370
characterization of the corynebacterium glutamicum deltapimb' deltamgta double deletion mutant and the role of mycobacterium tuberculosis orthologues rv2188c and rv0557 in glycolipid biosynthesis.in this study, utilizing a corynebacterium glutamicum deltapimb' deltamgta double deletion mutant, we unequivocally assign the in vivo functions of rv2188c as an ac(1)pim(1):mannosyltransferase (originally termed pimb'(mt) [mycobacterium tuberculosis pimb']) and rv0557 as a glcagroac(2):mannosyltransferase (originally termed pimb(mt)), which we have reassigned as pimb(mt) and mgta(mt), respectively, in mycobacterium tuberculosis.200919395496
productivity of cyclohexanone oxidation of the recombinant corynebacterium glutamicum expressing chnb of acinetobacter calcoaceticus.the biocatalytic efficiency of recombinant corynebacterium glutamicum expressing the chnb gene encoding cyclohexanone monooxygenase (chmo) of acinetobacter calcoaceticus ncimb 9871 was investigated. optimization of an expression system and induction conditions enabled the recombinant biocatalyst to produce chmo to a specific activity of ca. 0.5 u mg(-1) protein. tight control of feeding of an energy source (i.e., glucose) and dissolved oxygen tension during fed-batch culture-based biotransformat ...200919397940
gluconate as suitable potential reduction supplier in corynebacterium glutamicum: cloning and expression of gntp and gntk in escherichia coli.corynebacterium glutamicum is widely used in the industrial production of amino acids. we have found that this bacterium grows exponentially on a mineral medium supplemented with gluconate. gluconate permease and gluconokinase are expressed in an inducible form and, 6-phosphogluconate dehydrogenase, although constitutively expressed, shows a 3-fold higher specific level in gluconate grown cells than those grown in fructose under similar conditions. interestingly, these activities are lower than ...200919399347
regulation of quinone oxidoreductase by the redox-sensing transcriptional regulator qorr in corynebacterium glutamicum.corynebacterium glutamicum cgr_1435 (cg1552) encodes a protein of the duf24 protein family, which is a novel family of transcriptional regulators. cgr1435 (qorr) is a negative regulator of cgr_1436 (qor2), which is located upstream of cgr_1435 (qorr) in the opposite orientation, and its structural gene. qorr binds to the intergenic region between qor2 and qorr to repress their expression, which is induced by the thiol-specific oxidant diamide. the dna-binding activity of qorr is impaired by oxid ...200919403527
the identification of enzyme targets for the optimization of a valine producing corynebacterium glutamicum strain using a kinetic model.the enzyme targets for the rational optimization of a corynebacterium glutamicum strain constructed for valine production are identified by analyzing the control of flux in the valine/leucine pathway. the control analysis is based on measurements of the intracellular metabolite concentrations and on a kinetic model of the reactions in the investigated pathway. data-driven and model-based methods are used and evaluated against each other. the approach taken gives a quantitative evaluation of the ...200919405093
double deletion of dtsr1 and pyc induce efficient l: -glutamate overproduction in corynebacterium glutamicum.corynebacterium glutamicum strains are used for the fermentative production of l-glutamate. five c. glutamicum deletion mutants were isolated by two rounds of selection for homologous recombination and identified by southern blot analysis. the growth, glucose consumption and glutamate production of the mutants were analyzed and compared with the wild-type atcc 13032 strain. double disruption of dtsr1 (encoding a subunit of acetyl-coa carboxylase complex) and pyc (encoding pyruvate carboxylase) c ...200919408028
regulative interactions of the osmosensing c-terminal domain in the trimeric glycine betaine transporter betp from corynebacterium glutamicum.activation of the osmoregulated trimeric betaine transporter betp from corynebacterium glutamicum was shown to depend mainly on the correct folding and integrity of its 55 amino acid long, partly alpha-helical c-terminal domain. reorientation of the three c-terminal domains in the betp trimer indicates different lipid-protein and protein-protein interactions of the c-terminal domain during osmoregulation. a regulation mechanism is suggested where this domain switches the transporter from the ina ...200919426128
the ldha gene, encoding fermentative l-lactate dehydrogenase of corynebacterium glutamicum, is under the control of positive feedback regulation mediated by lldr.corynebacterium glutamicum ldha encodes l-lactate dehydrogenase, a key enzyme that couples l-lactate production to reoxidation of nadh formed during glycolysis. we previously showed that in the absence of sugar, sugr binds to the ldha promoter region, thereby repressing ldha expression. in this study we show that lldr is another protein that binds to the ldha promoter region, thus regulating ldha expression. lldr has hitherto been characterized as an l-lactate-responsive transcriptional represso ...200919429617
development of novel cell surface display in corynebacterium glutamicum using porin.we have developed a novel cell surface display in corynebacterium glutamicum using porin proteins as anchor proteins. porins are localized at c. glutamicum mycolic acid layer and exist as a hexamer. we used alpha-amylase from streptococcus bovis 148 (amya) as a model protein to be displayed on the c. glutamicum cell surface. amya was fused to the c terminus of the porins porb, porc, or porh. expression vectors using fused proteins under the control of the cspb promoter were constructed and intro ...200919430772
a cell-based screening system for detection of inhibitors toward mycobacterial cell wall core.mycobacterium tuberculosis and nonpathogenic bacteria, corynebacterium glutamicum, possess a common and unusual cell wall architecture. a cell-based screening system was designed to identify novel compounds interacting with the synthesis, assembly or regulation of the m. tuberculosis cell wall. c. glutamicum was tested in a paired medium assay in 96-well plates with natural product extracts and pure chemical compounds in the presence and absence of the osmotic stabilizer, sorbitol and some ions. ...200919444301
an emergent self-organizing map based analysis pipeline for comparative metabolome studies.modern high-throughput techniques allow for the identification and quantification of hundreds of metabolites ofa biological system which cover central parts of the metabolome. due to the amount and complexity of obtained data there is an increasing need for the development of appropriate computational interpretation methods. a novel data analysis pipeline designed for high-throughput determined metabolomic data is presented. the combination of principal component analysis (pca) with emergent sel ...200920109147
metabolic flux estimation using particle swarm optimization with penalty function.metabolic flux estimation through 13c trace experiment is crucial for quantifying the intracellular metabolic fluxes. in fact, it corresponds to a constrained optimization problem that minimizes a weighted distance between measured and simulated results. in this paper, we propose particle swarm optimization (pso) with penalty function to solve 13c-based metabolic flux estimation problem. the stoichiometric constraints are transformed to an unconstrained one, by penalizing the constraints and bui ...200920077391
functional genomics of ph homeostasis in corynebacterium glutamicum revealed novel links between ph response, oxidative stress, iron homeostasis and methionine synthesis.the maintenance of internal ph in bacterial cells is challenged by natural stress conditions, during host infection or in biotechnological production processes. comprehensive transcriptomic and proteomic analyses has been conducted in several bacterial model systems, yet questions remain as to the mechanisms of ph homeostasis.200920025733
flux design: in silico design of cell factories based on correlation of pathway fluxes to desired properties.the identification of genetic target genes is a key step for rational engineering of production strains towards bio-based chemicals, fuels or therapeutics. this is often a difficult task, because superior production performance typically requires a combination of multiple targets, whereby the complex metabolic networks complicate straightforward identification. recent attempts towards target prediction mainly focus on the prediction of gene deletion targets and therefore can cover only a part of ...200920035624
elucidation of genes relevant to the microaerobic growth of corynebacterium glutamicum.mutagenized cell libraries of corynebacterium glutamicum were screened for mutants that lost the ability to grow under low oxygen concentrations. the resulting high-oxygen-requiring mutants were used to clone wild-type dna fragments that could complement the phenotype. sequencing and subcloning analyses identified six genes, cgl0807, cgl1102, cgl0600, cgl1427, cgl2857, and cgl2859, as the genes responsible for complementation. some of these genes showed cross-complementation of the mutants in ox ...200919966452
microbial production host selection for converting second-generation feedstocks into bioproducts.increasingly lignocellulosic biomass hydrolysates are used as the feedstock for industrial fermentations. these biomass hydrolysates are complex mixtures of different fermentable sugars, but also inhibitors and salts that affect the performance of the microbial production host. the performance of six industrially relevant microorganisms, i.e. two bacteria (escherichia coli and corynebacterium glutamicum), two yeasts (saccharomyces cerevisiae and pichia stipitis) and two fungi (aspergillus niger ...200919958560
ramb is an activator of the pyruvate dehydrogenase complex subunit e1p gene in corynebacterium glutamicum.in corynebacterium glutamicum, the transcriptional regulator ramb negatively controls the expression of genes involved in acetate metabolism. here we show that during growth in media containing glucose and in complex medium without glucose ramb activates expression of the acee gene, encoding the e1p subunit of the pyruvate dehydrogenase complex. thus, ramb functions both as repressor and as activator in c. glutamicum.200917890844
activity of exporters of escherichia coli in corynebacterium glutamicum, and their use to increase l-threonine production.l-threonine is an important biotechnological product and corynebacterium glutamicum is able to synthesize and accumulate this amino acid to high intracellular levels. we here use four exporters of escherichia coli and show that three of them operate in c. glutamicum, with rhta and rhtc being the most effective. whereas rhta was unspecific, resulting in l-homoserine together with l-threonine excretion, this was not the case with rhtc. expression of rhtc reduced the intracellular l-threonine conce ...200918594129
surface modification of corynebacterium glutamicum for enhanced reactive red 4 biosorption.this study reports the possibility of enhancing the reactive dye biosorption capacity of corynebacterium glutamicum via its cross-linking with polyethylenimine (pei). the amine groups in the cell wall of c. glutamicum were found to electrostatically interact with reactive dye anions. thus, cross-linking the biomass with pei enhanced the primary and secondary amine groups, thereby increased the biosorption of reactive dye. the ph edge experiments revealed that acidic conditions, due to protonatio ...200918782665
a genomic view on nitrogen metabolism and nitrogen control in mycobacteria.knowledge about nitrogen metabolism and control in the genus mycobacterium is sparse, especially compared to the state of knowledge in related actinomycetes like streptomyces coelicolor or the close relative corynebacterium glutamicum. therefore, we screened the published genome sequences of mycobacterium smegmatis, mycobacterium tuberculosis, mycobacterium bovis, mycobacterium avium ssp. paratuberculosis and mycobacterium leprae for genes encoding proteins for uptake of nitrogen sources, nitrog ...200918824837
effect of odha overexpression and odha antisense rna expression on tween-40-triggered glutamate production by corynebacterium glutamicum.recent studies have suggested that a decrease in the specific activity of the 2-oxoglutarate dehydrogenase complex (odhc) is important for glutamate overproduction by corynebacterium glutamicum. to further investigate the role of the odha gene and its product in this process, we constructed the recombinant strains of c. glutamicum in which the expression of the odha and its product could be controlled by odha overexpression and odha antisense rna expression. we examined changes in glutamate prod ...200918923827
characterization of a new 2.4-kb plasmid of corynebacterium casei and development of stable corynebacterial cloning vector.a new plasmid pcase1 was isolated from gram-positive corynebacterium casei jcm 12072. it comprised a 2.4-kb nucleotide sequence with three orfs, two of which were indispensable for autonomous replication in corynebacterium glutamicum. homology search identified these two orfs as repa and repb, areas coding proteins involved in plasmid replication. repa sequence showed high similarity to theta-replicating escherichia coli cole2-p9 plasmids and even higher similarity to plasmids derived from gram- ...200918936936
in silico genome-scale reconstruction and validation of the corynebacterium glutamicum metabolic network.a genome-scale metabolic model of the gram-positive bacteria corynebacterium glutamicum atcc 13032 was constructed comprising 446 reactions and 411 metabolites, based on the annotated genome and available biochemical information. the network was analyzed using constraint based methods. the model was extensively validated against published flux data, and flux distribution values were found to correlate well between simulations and experiments. the split pathway of the lysine synthesis pathway of ...200918985611
direct production of cadaverine from soluble starch using corynebacterium glutamicum coexpressing alpha-amylase and lysine decarboxylase.here, we demonstrated the one-step production of cadaverine from starch using a corynebacterium glutamicum strain coexpressing streptococcus bovis 148 alpha-amylase (amya) and escherichia coli k-12 lysine decarboxylase (cada). we constructed the e. coli-c. glutamicum shuttle vector, which produces cada under the control of the high constitutive expression (hce) promoter, and transformed this vector into c. glutamicum css secreting amya. the engineered c. glutamicum expressed both cada and amya, ...200918989633
crystal structure of the caseinolytic protease gene regulator, a transcriptional activator in actinomycetes.human pathogens of the genera corynebacterium and mycobacterium possess the transcriptional activator clgr (clp gene regulator) which in corynebacterium glutamicum has been shown to regulate the expression of the clpcp protease genes. clgr specifically binds to pseudo-palindromic operator regions upstream of clpc and clpp1p2. here, we present the first crystal structure of a clgr protein from c. glutamicum. the structure was determined from two different crystal forms to resolutions of 1.75 and ...200919019826
identification and characterization of a bacterial transport system for the uptake of pyruvate, propionate, and acetate in corynebacterium glutamicum.the metabolism of monocarboxylic acids is of central importance for bacteria in their natural habitat as well as during biotechnological production. although biosynthesis and degradation are well understood, the transport of such compounds is still a matter of discussion. here we present the identification and characterization of a new transport system in corynebacterium glutamicum with high affinity for acetate and propionate and with lower affinity for pyruvate. biochemical analysis of this mo ...200919028892
characterization of crustins from the hemocytes of the spider crab, hyas araneus, and the red king crab, paralithodes camtschaticus.crustins are distributed across the decapods and are believed to play a significant part in the humoral defense system of their host. in this study, two crustin isoforms from hyas araneus hemocytes were purified and tested for antimicrobial activity against selected microorganisms. they show both antibacterial and antifungal activity, with highest activity against the gram-positive bacteria corynebacterium glutamicum. sequencing of the transcripts showed them to have a mature peptide of 90 amino ...200919041340
a combination of metabolome and transcriptome analyses reveals new targets of the corynebacterium glutamicum nitrogen regulator amtr.the effects of a deletion of the amtr gene, encoding the master regulator of nitrogen control in corynebacterium glutamicum, were investigated by metabolome and transcriptome analyses. compared to the wild type, different metabolite patterns were observed in respect to glycolysis, pentose phosphate pathway, citric acid cycle, and most amino acid pools. not all of these alterations could be attributed to changes at the level of mrna and must be caused by posttranscriptional regulatory processes. ...200919041910
dual transcriptional control of the acetaldehyde dehydrogenase gene ald of corynebacterium glutamicum by rama and ramb.corynebacterium glutamicum has been shown to grow with ethanol as the sole or as additional carbon and energy source and accordingly, to possess both alcohol dehydrogenase and acetaldehyde dehydrogenase (aldh) activities, which are responsible for the two-step ethanol oxidation to acetate. here we identify and functionally analyze the c. glutamicum aldh gene (cg3096, ald), its expression and its regulation. directed inactivation of the chromosomal ald gene led to the absence of detectable aldh a ...200919041911
involvement of the luxr-type transcriptional regulator rama in regulation of expression of the gapa gene, encoding glyceraldehyde-3-phosphate dehydrogenase of corynebacterium glutamicum.sugr, rama, glxr, gntr1, and a marr-type transcriptional regulator bind to the promoter region of the gapa gene encoding glyceraldehyde-3-phosphate dehydrogenase (gapdh), essential for glycolysis in corynebacterium glutamicum. we previously showed that sugr, a transcriptional repressor of phosphotransferase system genes for the sugar transport system, is involved in the downregulation of gapa expression in the absence of sugar. in this study, the role of rama in the expression of the gapa gene w ...200919047347
acetohydroxyacid synthase, a novel target for improvement of l-lysine production by corynebacterium glutamicum.the influence of acetohydroxy acid synthase (ahas) on l-lysine production by corynebacterium glutamicum was investigated. an ahas with a deleted c-terminal domain in the regulatory subunit ilvn was engineered by truncating the ilvn gene. compared to the wild-type ahas, the newly constructed enzyme showed altered kinetic properties, i.e., (i) an about twofold-lower k(m) for the substrate pyruvate and an about fourfold-lower v(max); (ii) a slightly increased k(m) for the substrate alpha-ketobutyra ...200919047397
the whca gene plays a negative role in oxidative stress response of corynebacterium glutamicum.in this study, we analyzed the whca gene from corynebacterium glutamicum, which codes for a homologue of the whib-family of proteins. deletion of the gene did not affect the growth of the mutant cells, indicating that the whca gene was not essential under ordinary growth conditions. however, cells overexpressing the protein not only showed retarded growth as compared with the wild-type or the deltawhca mutant cells but also showed increased sensitivity to a variety of oxidants, such as diamide, ...200919016879
metabolic quenching of corynebacterium glutamicum: efficiency of methods and impact of cold shock.representative and valid cytoplasmic concentrations are essential for ensuring the significance of results in the field of metabolome analysis. one of the most crucial points in this respect is the sampling itself. a rapid and sudden stopping of the metabolism on a timescale that is much faster than the conversion rates of investigated metabolites is worthwhile. this can be achieved by applying of cold methanol quenching combined with reproducible, fast, and automated sampling. unfortunately, qu ...200919050933
myo-inositol facilitators iolt1 and iolt2 enhance d-mannitol formation from d-fructose in corynebacterium glutamicum.reduction of d-fructose to d-mannitol by whole-cell biotransformation with recombinant resting cells of corynebacterium glutamicum atcc13032 requires the coexpression of mdh and fdh, which encode mannitol and formate dehydrogenases, respectively. however, d-mannitol formation is limited by the uptake of d-fructose in its unphosphorylated form, because additional expression of the sugar facilitator from zymomonas mobilis resulted in a significantly increased productivity. here we identified simil ...200919054080
maturing dynamics of surface microflora in fontina pdo cheese studied by culture-dependent and -independent methods.to study the evolution of rind microbial communities in fontina pdo cheese.200919054234
effect of ph on the binding mechanisms in biosorption of reactive orange 16 by corynebacterium glutamicum.binding mechanisms of reactive orange 16 (ro 16) by the protonated waste biomass of corynebacterium glutamicum were investigated. the solution ph was found to strongly influence the uptake of ro 16 by c. glutamicum. the biosorption of the dye was reversible at ph <7 but irreversible under basic ph conditions. at acidic ph, the electrostatic interaction was found to be a major binding mechanism. the maximum sorption capacities of the biomass were evaluated to be 156.6+/-6.2 and 64.0+/-2.4 mg/g at ...200919062035
a 2d reversed-phase x ion-pair reversed-phase hplc-maldi tof/tof-ms approach for shotgun proteome analysis.the separation of complex peptide mixtures in shotgun proteome analysis using a 2d separation scheme encompassing reversed-phase x ion-pair reversed-phase (ip-rp) liquid chromatography coupled online to electrospray ion trap mass spectrometry (ms) has been shown earlier to be superior in terms of separation efficiency and technical robustness compared to the classically used separation scheme encompassing strong cation exchange x ip-rp-chromatography in shotgun proteome analysis. in the present ...200919066860
identification of new secreted proteins and secretion of heterologous amylase by c. glutamicum.in this study, secreted corynebacterium glutamicum proteins were investigated by two-dimensional gel electrophoresis. around 100 spots observed in the ph range 4.5-5.5 had molecular masses that varied from 10 to 50 kda. upon n-terminal amino acid sequence analysis by edman degradation, two of them were hits to two hypothetical proteins encoded by cgr_1176 and cgr_2070 on c. glutamicum r genome, respectively. active-form alpha-amylase derived from geobacillus stearothermophilus was successfully s ...200919066885
tatabc overexpression improves corynebacterium glutamicum tat-dependent protein secretion.the twin-arginine translocation (tat) pathway in corynebacterium glutamicum has been described previously. the minimal functional tat system in c. glutamicum required tata and tatc but did not require tatb, although this component was required for maximal efficiency of tat-dependent secretion. we previously demonstrated that chryseobacterium proteolyticum pro-protein glutaminase (pro-pg) and streptomyces mobaraensis pro-transglutaminase (pro-tg) could be secreted via the tat pathway in c. glutam ...200919074606
l-valine production during growth of pyruvate dehydrogenase complex-deficient corynebacterium glutamicum in the presence of ethanol or by inactivation of the transcriptional regulator sugr.pyruvate dehydrogenase complex-deficient strains of corynebacterium glutamicum produce l-valine from glucose only after depletion of the acetate required for growth. here we show that inactivation of the deor-type transcriptional regulator sugr or replacement of acetate by ethanol already in course of the growth phase results in efficient l-valine production.200919088318
complex expression control of the corynebacterium glutamicum aconitase gene: identification of rama as a third transcriptional regulator besides acnr and ripa.expression of the aconitase gene acn of corynebacterium glutamicum was previously shown to be repressed by the tetr-type regulator acnr in response to a yet unknown stimulus and by the arac-type regulator ripa in response to iron limitation. here we have identified a third transcriptional regulator of aconitase, rama. the rama protein was enriched by dna affinity chromatography with the acn promoter region from protein extracts of acetate-grown cells but not or only weakly from extracts of gluco ...200919095019
elastase digests: new ammunition for shotgun membrane proteomics.despite many advances in membrane proteomics during the last decade the fundamental problem of accessing the transmembrane regions itself has only been addressed to some extent. the present study establishes a method for the nano-lc-based analysis of complex membrane proteomes on the basis of a methanolic porcine pancreatic elastase digest to increase transmembrane coverage. halobacterium salinarium purple and corynebacterium glutamicum membranes were successfully analyzed by using the new proto ...200919116210
characterization of the laci-type transcriptional repressor rbsr controlling ribose transport in corynebacterium glutamicum atcc 13032.the gene products of the rbsracbd (rbs) operon of c. glutamicum (cg1410-cg1414) encode a ribose-specific atp-binding cassette (abc) transport system and its corresponding regulatory protein (rbsr). deletion of the structural genes rbsacbd prohibited ribose uptake. deletion of the regulatory gene rbsr resulted in an increased mrna level of the whole operon. analysis of the promoter region of the rbs operon by electrophoretic mobility shift assays identified a catabolite-responsive element (cre)-l ...200919118356
metabolic engineering of the l-valine biosynthesis pathway in corynebacterium glutamicum using promoter activity modulation.the previously constructed strain corynebacterium glutamicumilvnm13 with acetohydroxy acid synthase, resistant to inhibition by all three branched-chain amino acids (l-valine, l-isoleucine and l-leucine), was used as a basis to develop a new type of valine producer by genetic engineering. the main strategy was to modulate expression of the genes involved in the biosynthesis of branched-chain amino acids. the activity of the promoters p-ilvd (dihydroxyacid dehydratase) and p-ilve (transaminase) w ...200919121344
the serine hydroxymethyltransferase gene glya in corynebacterium glutamicum is controlled by glyr.serine hydroxymethyltransferase (shmt) occupies a central position in one-carbon metabolism, and we here study its regulation in corynebacterium glutamicum. enzyme quantifications revealed an about 3-fold increase of shmt activity during exponential growth with a further increase at the onset of the stationary phase. the shmt encoding glya gene was shown to be transcribed as a monocistronic mrna, and its transcriptional start site was determined. using dna affinity chromatography the regulator g ...200919124047
reengineering of a corynebacterium glutamicum l-arginine and l-citrulline producer.toward the creation of a robust and efficient producer of l-arginine and l-citrulline (arginine/citrulline), we have performed reengineering of a corynebacterium glutamicum strain by using genetic information of three classical producers. sequence analysis of their arg operons identified three point mutations (argr123, argg92(up), and argg45) in one producer and one point mutation (argb26 or argb31) in each of the other two producers. reconstitution of the former three mutations or of each argb ...200919139237
reliable transfer of transcriptional gene regulatory networks between taxonomically related organisms.transcriptional regulation of gene activity is essential for any living organism. transcription factors therefore recognize specific binding sites within the dna to regulate the expression of particular target genes. the genome-scale reconstruction of the emerging regulatory networks is important for biotechnology and human medicine but cost-intensive, time-consuming, and impossible to perform for any species separately. by using bioinformatics methods one can partially transfer networks from we ...200919146695
recombinant glutamine synthetase (gs) from c. glutamicum existed as both hexamers & dedocamers and c-terminal his-tag enhanced inclusion bodies formation in e. coli.in order to investigate the effect of his-tag on glutamine synthetase (gs, ec 6.3.1.2) from corynebacterium glutamicum, recombinant escherichia coli strains overexpressing gsim, hgsim (gs fused with n-terminal his-tag), gsimh (gs fused with c-terminal his-tag), and hgsimh (gs fused with n-terminal & c-terminal his-tags) were constructed, respectively. under similar expression conditions, gsim and hgsim were partially solubly expressed; no soluble gsimh and hgsimh were observed, based on the resu ...200919148777
[cloning, expression and sequence analysis of ds i gene in corynebacterium pekinense as1.299 and pd-67].3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (ec 2.5.1.54;ds) is the key enzyme in tryptophan synthesis pathway. cloning ds i gene from corynebacterium pekinense and expression of ds i gene might facilitate testing the existence and function of ds i in corynebacterium pekinense.200819149161
response of the cytoplasmic and membrane proteome of corynebacterium glutamicum atcc 13032 to ph changes.c. glutamicum has traditionally been grown in neutral-ph media for amino acid production, but in a previous article we reported that this microorganism is a moderate alkaliphile since it grows optimally at ph 7.0-9.0, as shown in fermentor studies under tightly controlled ph conditions. we determined the best ph values to study differential expression of several genes after acidic or basic ph conditions (ph 6.0 for acidic expression and ph 9.0 for alkaline expression). thus, it was interesting t ...200819091079
scrb (cg2927) is a sucrose-6-phosphate hydrolase essential for sucrose utilization by corynebacterium glutamicum.corynebacterium glutamicum can grow on a variety of carbohydrates from which glucose, fructose and sucrose are taken up and phosphorylated by the phosphoenolpyruvate-dependent phosphotransferase system (pts). here, we show that cg2927 (scrb) encodes sucrose-6-phosphate hydrolase. the purified his-tagged protein hydrolyzed sucrose-6-phosphate and sucrose, but not sucrose-6'-phosphate. the km value for sucrose was 190 mm while the km for sucrose-6-phosphate was much lower, 0.04 mm. sucrose-6-phosp ...200819054097
regulation of glutamate metabolism by protein kinases in mycobacteria.protein kinase g of mycobacterium tuberculosis has been implicated in virulence and in regulation of glutamate metabolism. here we show that this kinase undergoes a pattern of autophosphorylation that is distinct from that of other m. tuberculosis protein kinases characterized to date and we identify gara as a substrate for phosphorylation by pkng. autophosphorylation of pkng has little effect on kinase activity but promotes binding to gara, an interaction that is also detected in living mycobac ...200819019160
physiological response of corynebacterium glutamicum to oxidative stress induced by deletion of the transcriptional repressor mcbr.in the present work the metabolic response of corynebacterium glutamicum to deletion of the global transcriptional regulator mcbr, which controls, e.g. the expression of enzymes of l-methionine and l-cysteine biosynthesis and sulfur assimilation, was studied. several oxidative stress proteins were significantly upregulated among about 40 proteins in response to deletion of mcbr. linked to this oxidative stress, the mutant exhibited a 50 % reduced growth rate, a 30 % reduced glucose uptake rate a ...200819047758
methionine uptake in corynebacterium glutamicum by metqni and by metps, a novel methionine and alanine importer of the nss neurotransmitter transporter family.the soil bacterium corynebacterium glutamicum is a model organism in amino acid biotechnology. here we present the identification of two different l-methionine uptake systems including the first characterization of a bacterial secondary methionine carrier. the primary carrier metqni is a high affinity abc-type transporter specific for l-methionine. its expression is under the control of the transcription factor mcbr, the global regulator of sulfur metabolism in c. glutamicum. besides metqni, a n ...200818991398
enhanced valine production in corynebacterium glutamicum with defective h+-atpase and c-terminal truncated acetohydroxyacid synthase.we have reported increased glutamate production by a mutant of corynebacterium glutamicum atcc14067 (strain f172-8) with reduced h(+)-atpase activity under biotin-limiting culture conditions (aoki et al. biosci. biotechnol. biochem., 69, 1466-1472 (2005)). in the present study, we examined valine production by an h(+)-atpase-defective mutant of c. glutamicum. using the double-crossover chromosome replacement technique, we constructed a newly defined h(+)-atpase-defective mutant from atcc13032. a ...200818997402
structural and functional characterization of the lldr from corynebacterium glutamicum: a transcriptional repressor involved in l-lactate and sugar utilization.lldr (cgl2915) from corynebacterium glutamicum is a transcription factor belonging to the gntr family, which is typically involved in the regulation of oxidized substrates associated with amino acid metabolism. in the present study, the crystal structure of lldr was determined at 2.05-a resolution. the structure consists of n- and c-domains similar to those of fadr, but with distinct domain orientations. lldr and fadr dimers achieve similar structures by domain swapping, which was first observed ...200818988622
regulatory properties and interaction of the c- and n-terminal domains of betp, an osmoregulated betaine transporter from corynebacterium glutamicum.the glycine betaine carrier betp from corynebacterium glutamicum responds to changes in external osmolality by regulation of its transport activity, and the c-terminal domain was previously identified to be involved in this process. here we investigate the structural requirements of the c-terminal domain for osmoregulation as well as interacting domains that are relevant for intramolecular signal transduction in response to osmotic stress. for this purpose, we applied a proline scanning approach ...200818950194
a proteome analysis of the cadmium and mercury response in corynebacterium glutamicum.cadmium and mercury are well-known toxic heavy metals, but the basis of their toxicity is not well understood. in this study, we analyzed the cellular response of corynebacterium glutamicum to sublethal concentrations of cadmium and mercury ions using 2-de and ms. mercury induced the over-expression of 13 c. glutamicum proteins, whereas 35 proteins were induced, and 8 proteins were repressed, respectively, under cadmium stress. the principal response to these metals was protection against oxidat ...200818972541
the murc ligase essential for peptidoglycan biosynthesis is regulated by the serine/threonine protein kinase pkna in corynebacterium glutamicum.the mur ligases play an essential role in the biosynthesis of bacterial cell-wall peptidoglycan and thus represent attractive targets for the design of novel antibacterials. these enzymes catalyze the stepwise formation of the peptide moiety of the peptidoglycan disaccharide peptide monomer unit. murc is responsible of the addition of the first residue (l-alanine) onto the nucleotide precursor udp-murnac. phosphorylation of proteins by ser/thr protein kinases has recently emerged as a major phys ...200818974047
characterization and crystal structure of lysine insensitive corynebacterium glutamicum dihydrodipicolinate synthase (cdhdps) protein.the lysine insensitive corynebacterium glutamicum dihydrodipicolinate synthase enzyme (cdhdps) was recently successfully introduced into maize plants to enhance the level of lysine in the grain. to better understand lysine insensitivity of the cdhdps, we expressed, purified, kinetically characterized the protein, and solved its x-ray crystal structure. the cdhdps enzyme has a fold and overall structure that is highly similar to other dhdps proteins. a noteworthy feature of the active site is the ...200818930704
deletion of cgr_1596 and cgr_2070, encoding nlpc/p60 proteins, causes a defect in cell separation in corynebacterium glutamicum r.in previous work, random genome deletion mutants of corynebacterium glutamicum r were generated using the insertion sequence (is) element is31831 and the cre/loxp excision system. one of these mutants, c. glutamicum strain rd41, resulting from the deletion of a 10.1-kb genomic region (deltacgr_1595 through cgr_1604) from the wt strain, showed cell elongation, and several lines appeared on the cell surface (bamboo shape). the morphological changes were suppressed by overexpression of cgr_1596. si ...200818931118
metabolic function of corynebacterium glutamicum aminotransferases alat and avta and impact on l-valine production.aminotransferases (ats) interacting with l-alanine are the least studied bacterial ats. whereas alat converts pyruvate to l-alanine in a glutamate-dependent reaction, avta is able to convert pyruvate to l-alanine in an l-valine-dependent manner. we show here that the wild type of corynebacterium glutamicum with a deletion of either of the corresponding genes does not exhibit an explicit growth deficiency. however, a double mutant was auxotrophic for l-alanine, showing that both ats can provide l ...200818931286
effect of carbon source availability and growth phase on expression of corynebacterium glutamicum genes involved in the tricarboxylic acid cycle and glyoxylate bypass.the effect of different carbon sources on the expression of tricarboxylic acid (tca) cycle genes, along with glyoxylate bypass genes, in corynebacterium glutamicum was determined. all tca cycle genes were coordinately expressed in medium containing acetate. growth in the presence of acetate gave rise to abundant expression of most tca cycle genes, with the level of glta transcript being the highest. however, when the cells entered the stationary phase triggered by acetate exhaustion, all genes w ...200818832313
the global repressor sugr controls expression of genes of glycolysis and of the l-lactate dehydrogenase ldha in corynebacterium glutamicum.the transcriptional regulator sugr from corynebacterium glutamicum represses genes of the phosphoenolpyruvate-dependent phosphotransferase system (pts). growth experiments revealed that the overexpression of sugr not only perturbed the growth of c. glutamicum on the pts sugars glucose, fructose, and sucrose but also led to a significant growth inhibition on ribose, which is not taken up via the pts. chromatin immunoprecipitation combined with dna microarray analysis and gel retardation experimen ...200818849435
different binding mechanisms in biosorption of reactive dyes according to their reactivity.various binding mechanisms for the uptake of reactive dyes by the protonated waste biomass of corynebacterium glutamicum were investigated. as model reactive dyes, reactive blue 4 (rb 4), reactive orange 16 (ro 16) and reactive yellow 2 (ry 2) were used in this study. the solution ph strongly influenced the sorption capacity and the binding mechanisms of reactive dyes by c. glutamicum. at acidic ph, the electrostatic interaction was found to be a major binding mechanism. the maximum uptakes of r ...200818851867
the dual transcriptional regulator cysr in corynebacterium glutamicum atcc 13032 controls a subset of genes of the mcbr regulon in response to the availability of sulphide acceptor molecules.regulation of sulphur metabolism in corynebacterium glutamicum atcc 13032 has been studied intensively in the last few years, due to its industrial as well as scientific importance. previously, the gene cg0156 was shown to belong to the regulon of mcbr, a global transcriptional repressor of sulphur metabolism in c. glutamicum. this gene encodes a putative rok-type regulator, a paralogue of the activator of sulphonate utilisation, ssur. therefore, it is an interesting candidate for study to furth ...200818854009
expression of the gapa gene encoding glyceraldehyde-3-phosphate dehydrogenase of corynebacterium glutamicum is regulated by the global regulator sugr.regulation of expression of the gapa gene encoding glyceraldehyde-3-phosphate dehydrogenase essential for glycolysis in corynebacterium glutamicum was studied. we applied dna affinity beads to isolate proteins binding to the promoter region of the gapa gene and obtained sugr, which has been shown to be a repressor of pts genes involved in sugar transport system. the results of electrophoretic mobility shift assays revealed that sugr specifically bound to the gapa promoter and the consensus seque ...200818791709
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