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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
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
simultaneous utilization of d-cellobiose, d-glucose, and d-xylose by recombinant corynebacterium glutamicum under oxygen-deprived conditions.corynebacterium glutamicum r was metabolically engineered to broaden its sugar utilization range to d-xylose and d-cellobiose contained in lignocellulose hydrolysates. the resultant recombinants expressed escherichia coli xyla and xylb genes, encoding d-xylose isomerase and xylulokinase, respectively, for d-xylose utilization and expressed c. glutamicum r bglf317a and bgla genes, encoding phosphoenolpyruvate:carbohydrate phosphotransferase system (pts) beta-glucoside-specific enzyme iibca compon ...200818810427
transcriptional regulation of corynebacterium glutamicum methionine biosynthesis genes in response to methionine supplementation under oxygen deprivation.expression at the mrna level of six methionine biosynthesis genes in corynebacterium glutamicum cells under oxygen-deprived conditions was repressed by supplementation of medium with methionine. the repression was not observed in a mutant deficient in the tetr-type transcriptional repressor mcbr. analysis of transcriptional start sites of the methionine biosynthesis genes confirmed that mcbr binding motifs exist in the promoter regions of all genes repressed by methionine supplementation. furthe ...200818800184
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
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
an efficient succinic acid production process in a metabolically engineered corynebacterium glutamicum strain.a corynebacterium glutamicum strain (deltaldha-pcra717) that overexpresses the pyc gene encoding pyruvate carboxylase while simultaneously exhibiting a disrupted ldha gene encoding l-lactate dehydrogenase was investigated in detail for succinic acid production. succinic acid was shown to be efficiently produced at high-cell density under oxygen deprivation with intermittent addition of sodium bicarbonate and glucose. succinic acid concentration reached 1.24 m (146 g l(-1)) within 46 h. the yield ...200818777022
metabolic engineering for bioproduction of sugar alcohols.sugar alcohols find applications in pharmaceuticals, oral and personal care products, and as intermediates in chemical synthesis. while industrial-scale production of these compounds has generally involved catalytic hydrogenation of sugars, microbial-based processes receive increasing attention. the past few years have seen a variety of interesting metabolic engineering efforts to improve the capabilities of bacteria and yeasts to overproduce xylitol, mannitol, and sorbitol. examples include het ...200818760354
heterologous ectoine production in escherichia coli: by-passing the metabolic bottle-neck.transcription of the ectoine biosynthesis genes ecta, ectb and ectc from marinococcus halophilus in recombinant escherichia coli dh5alpha is probably initiated from three individual sigma70/sigmaa-dependent promoter sequences, upstream of each gene. consequently, mrna-fragments containing the single genes and combinations of the genes ecta and ectb or ectb and ectc, respectively, could be detected by northern blot analysis. under the control of its own regulatory promoter region (ectup) a seemin ...200818759971
production of 2-methyl-1-butanol in engineered escherichia coli.recent progress has been made in the production of higher alcohols by harnessing the power of natural amino acid biosynthetic pathways. here, we describe the first strain of escherichia coli developed to produce the higher alcohol and potential new biofuel 2-methyl-1-butanol (2mb). to accomplish this, we explored the biodiversity of enzymes catalyzing key parts of the isoleucine biosynthetic pathway, finding that ahas ii (ilvgm) from salmonella typhimurium and threonine deaminase (ilva) from cor ...200818758769
engineering of a glycerol utilization pathway for amino acid production by corynebacterium glutamicum.the amino acid-producing organism corynebacterium glutamicum cannot utilize glycerol, a stoichiometric by-product of biodiesel production. by heterologous expression of escherichia coli glycerol utilization genes, c. glutamicum was engineered to grow on glycerol. while expression of the e. coli genes for glycerol kinase (glpk) and glycerol 3-phosphate dehydrogenase (glpd) was sufficient for growth on glycerol as the sole carbon and energy source, additional expression of the aquaglyceroporin gen ...200818757581
[phage resistance of corynebacterium crenatum conferred by the restriction and modification system cgli].in order to prevent phage contamination in amino acid fermentation, we introduced the restriction and modification system cgli gene complex into corynebacterium crenatum and studied their phage-resistance. the cgli gene complex was amplified from corynebacterium glutamicum by pcr and constructed into pjl23 vector. the recombinant strains were obtained by transformation of the recombinant plasmid pjl23-cgli into c. crenatum. results showed that the recombinant strains possessed strong phage-resis ...200818724694
characterization of developmental colony formation in corynebacterium glutamicum.we report that corynebacterium glutamicum colonies exhibit a developmental transition in culture. when cultured on a routinely used complete medium (cm2b), this bacterium first formed a flat translucent colony. subsequently, some parts of this colony expanded to form small spherical yellow colonies that finally developed into a single large yellow colony. the small flat colony consisted of long thick cells, which were occasionally v or y shaped, while the large yellow colony consisted of short s ...200818696061
distinct roles of two anaplerotic pathways in glutamate production induced by biotin limitation in corynebacterium glutamicum.corynebacterium glutamicum is a biotin auxotrophic bacterium in which glutamate production is induced under biotin-limited conditions. during glutamate production, anaplerotic reactions catalyzed by phosphoenolpyruvate carboxylase (pepc) and a biotin-containing enzyme pyruvate carboxylase (pc) are believed to play an important role in supplying oxaloacetate in the tricarboxylic acid cycle. to understand the distinct roles of pepc and pc on glutamate production by c. glutamicum, we observed gluta ...200818691531
nitrogen control in mycobacterium smegmatis: nitrogen-dependent expression of ammonium transport and assimilation proteins depends on the ompr-type regulator glnr.the effect of nitrogen regulation on the level of transcriptional control has been investigated in a variety of bacteria, such as bacillus subtilis, corynebacterium glutamicum, escherichia coli, and streptomyces coelicolor; however, until now there have been no data for mycobacteria. in this study, we found that the ompr-type regulator protein glnr controls nitrogen-dependent transcription regulation in mycobacterium smegmatis. based on rna hybridization experiments with a wild-type strain and a ...200818689485
partial redundancy in the synthesis of the d-arabinose incorporated in the cell wall arabinan of corynebacterineae.the major cell wall carbohydrate of corynebacterineae is arabinogalactan (ag), a branched polysaccharide that is essential for the physiology of these bacteria. decaprenylphosphoryl-d-arabinose (dpa), the lipid donor of d-arabinofuranosyl residues of ag, is synthesized through a series of unique biosynthetic steps, the last one being the epimerization of decaprenylphosphoryl-beta-d-ribose (dpr) into dpa, which is believed to proceed via a sequential oxidation-reduction mechanism. two proteins fr ...200818667564
identification and characterization of the dicarboxylate uptake system dcct in corynebacterium glutamicum.many bacteria can utilize c(4)-carboxylates as carbon and energy sources. however, corynebacterium glutamicum atcc 13032 is not able to use tricarboxylic acid cycle intermediates such as succinate, fumarate, and l-malate as sole carbon sources. upon prolonged incubation, spontaneous mutants which had gained the ability to grow on succinate, fumarate, and l-malate could be isolated. dna microarray analysis showed higher mrna levels of cg0277, which subsequently was named dcct, in the mutants than ...200818658264
inactivation of cg10062, a cis-3-chloroacrylic acid dehalogenase homologue in corynebacterium glutamicum, by (r)- and (s)-oxirane-2-carboxylate: analysis and implications.( r)- and ( s)-oxirane-2-carboxylate were determined to be active site-directed irreversible inhibitors of the cis-3-chloroacrylic acid dehalogenase ( cis-caad) homologue cg10062 found in corynebacterium glutamicum. kinetic analysis indicates that the ( r) enantiomer binds more tightly and is the more potent inhibitor, likely reflecting more favorable interactions with active site residues. pro-1 is the sole site of covalent modification by the ( r) and ( s) enantiomers. pro-1, arg-70, arg-73, a ...200818646866
response of the central metabolism of corynebacterium glutamicum to different flux burdens.to evaluate the importance of reactions within the central metabolism under different flux burdens the fluxes within the pentose phosphate pathway (ppp), as well as the other reactions of the central metabolism, were intensively analyzed and quantitated. for this purpose, corynebacterium glutamicum was grown with [1-(13)c]glucose to metabolic and isotopic steady state and the fractional enrichments in precursor metabolites (e.g., pentose 5-phosphate) were quantified. matrix calculus was used to ...199718636622
metabolic and physiological studies of corynebacterium glutamicum mutants.the physiology and central carbon metabolism of corynebacterium glutamicum was investigated through the study of specific disruption mutants. mutants deficient in phosphoenolpyruvate carboxylase (ppc) and/or pyruvate kinase (pk) activity were constructed by disrupting the corresponding gene(s) via transconjugation. standard batch fermentations were carried out with these mutants and results were evaluated in the context of intracellular flux analysis. the following were determined. (a) there is ...199718636597
an on-line physiological state recognition system for the lysine fermentation process based on a metabolic reaction model.a metabolic reaction model was developed for the lysine fermentation process by corynebacterium glutamicum aj-3462 to estimate the physiological state of the cells-that is, the growth and production activity, and the flux distribution of metabolites-from on-line measurable rates only. first, the extended kalman filter was applied to eliminate noise in the measured rates. then, using the metabolic reaction model, the lysine production rate and flux distribution were calculated. the estimation res ...199718636455
bidirectional reaction steps in metabolic networks: ii. flux estimation and statistical analysis.metabolic carbon labelling experiments enable a large amount of extracellular fluxes and intracellular carbon isotope enrichments to be measured. since the relation between the measured quantities and the unknown intracellular metabolic fluxes is given by bilinear balance equations, flux determination from this data set requires the numerical solution of a nonlinear inverse problem. to this end, a general algorithm for flux estimation from metabolic carbon labelling experiments based on the leas ...199718636450
development and application of a membrane cyclone reactor for in vivo nmr spectroscopy with high microbial cell densities.a new bioreactor system has been developed for in vivo nmr spectroscopy of microorganisms under defined physiological conditions. this cyclone reactor with an integrated nmr flow cell is continuously operated in the magnet of a 400-mhz wide-bore nmr spectrometer system. the residence times of medium and cells are decoupled by a circulation-integrated cross-flow microfiltration module to achieve higher cell densities as compared to continuous fermentations without cell retention (increase in cell ...199618629829
biosynthesis of mycobacterial arabinogalactan: identification of a novel alpha(1-->3) arabinofuranosyltransferase.the cell wall mycolyl-arabinogalactan-peptidoglycan complex is essential in mycobacterial species, such as mycobacterium tuberculosis and is the target of several antitubercular drugs. for instance, ethambutol targets arabinogalactan biosynthesis through inhibition of the arabinofuranosyltransferases mt-emba and mt-embb. a bioinformatics approach identified putative integral membrane proteins, msmeg2785 in mycobacterium smegmatis, rv2673 in mycobacterium tuberculosis and ncgl1822 in corynebacter ...200818627460
reaction engineering analysis of l-lysine transport by corynebacterium glutamicum.to identify potential l-lysine export limitations by corynebacterium glutamicum in the l-lysine production process, the excretion of l-lysine was studied in continuous and fed-batch operated stirred tank reactors. a structured biochemical model of the l-lysine excretion mechanism was used to determine the activity of the export carrier and to calculate a cell-specific concentration of the export carrier. for the biochemical characterization of this specific carrier concentration a standardized l ...199618627086
water reuse in the l-lysine fermentation process.l-lysine is produced commercially by fermentation. as is typical for fermentation processes, a large amount of liquid waste is generated. to minimize the waste, which is mostly the broth effluent from the cation exchange column used for l-lysine recovery, we investigated a strategy of recycling a large fraction of this broth effluent to the subsequent fermentation. this was done on a labscale process with corynebacterium glutamicum atcc 21253 as the l-lysine-producing organism. broth effluent fr ...199618623586
determination of the fluxes in the central metabolism of corynebacterium glutamicum by nuclear magnetic resonance spectroscopy combined with metabolite balancing.to determine the in vivo fluxes of the central metabolism we have developed a comprehensive approach exclusively based on the fundamental enzyme reactions known to be present, the fate of the carbon atoms of individual reactions, and the metabolite balance of the culture. no information on the energy balance is required, nor information on enzyme activities, or the directionalities of reactions. our approach combines the power of (1)h-detected (13)c nuclear magnetic resonance spectroscopy to fol ...199618623562
fermentation and recovery of glutamic acid from palm waste hydrolysate by ion-exchange resin column.glutamic acid produced from palm waste hydrolysate by fermentation with brevibacterium lactofermentum atcc 13869 is produced with a remarkably high yield compared with that produced from pure glucose as a carbon source. the produce yield is 70 g/l with glucose, wherease, when palm waste hydrolysate is the fermentation medium in the same bioreactor under same conditions, it is 88 g/l. the higher yield may be attributed to the fact that this organism has the ability to convert sugars other than on ...199518623521
corynebacterium glutamicum contains 3-deoxy-d-arabino-heptulosonate 7-phosphate synthases that display novel biochemical features.3-deoxy-d-arabino-heptulosonate 7-phosphate (dahp) synthase (ec 2.5.1.54) catalyzes the first step of the shikimate pathway that finally leads to the biosynthesis of aromatic amino acids phenylalanine (phe), tryptophan (trp), and tyrosine (tyr). in corynebacterium glutamicum atcc 13032, two chromosomal genes, ncgl0950 (arof) and ncgl2098 (arog), were located that encode two putative dahp synthases. the deletion of ncgl2098 resulted in the loss of the ability of c. glutamicum res167 (a restrictio ...200818621870
metabolic monitoring by using the rate of change of nad(p)h fluorescene.the amino acid fermentation by corynebacterium glutamicum was monitored with an new technique that uses the first derivative of the nad(p)h fluorescene signal. the rate of change of nad(p)h pools is indicative of intracellular redox balance variations that correspond to metabolic changes. the profile of this signal showed several characteristics that coincided with major metabolic events during fermentation. we show here that the derivative fluorescence signal can accurately estimate points of t ...199418618779
metabolic flux distributions in corynebacterium glutamicum during growth and lysine overproduction.the two main contributions of this are the solidification of corynebacterium glutamicum biochemistry guided by bioreaction network analysis, and the determination of bansal metabolic flux distributions during growth and lysine synthesis. employed methodology makes use of stoichiometrically based mass balances to determine flux distributions in the c. glutamicum metabolic network. presented are a brief description of the methodology, a through literature review of glutamic acid bacteria biochemis ...199318609599
effect of reducing agents in an aerobic amino acid fermentation.this study focuses on the effects of the reducing agents, dithiothreitol (dtt) and glutathione (gsh), on amino acid production in aerobically growing corynebacterium glutamicum. the problem of reducing agent addition affecting the dissolved oxygen level was solved by positioning the culture at a high dissolved oxygen level and feeding the reducing agent into the fermentor. we show that it is possible to lower the redox potential even in a highly aerobic environment. the addition of dtt to the fe ...199218601189
metabolic characterization of a l-lysine-producing strain by continuous culture.continuous culture experiments with the l-producer, corynebacterium glutamicum, were carried out to characterize the effect of specific growth rate on fermentation yields, specific rates, productivities, and fluxes through the primary metabolism. the specific productivity of l-lysine exhibited a maximum with respect to specific growth rate, with an initial growth-associated behavior up to specific growth rates of about 0.1 h(-1), and a constant specific productivity for specific growth rates in ...199218600983
utility of culture redox potential for identifying metabolic state changes in amino acid fermentation.we investigated the relationship of dissolved oxygen and culture redox potential (crp) on amino acid production. corynebacterium glutamicum atcc 14296 was used for all experiments. the fermentation can be divided into a growth phase and a production phase. our results indicate that in order to get higher amino acid production, a lower oxygen supply during the exponential phase is favored. a higher oxygen supply rate appears to be necessary during the production phase. culture redox potential (cr ...199118600868
genome sequence of the lytic bacteriophage p1201 from corynebacterium glutamicum nchu 87078: evolutionary relationships to phages from corynebacterineae.p1201 is a lytic corynephage of corynebacterium glutamicum nchu 87078. its genome consists of a linear double-stranded dna molecule of 70,579 base pairs, with 3'-protruding cohesive ends of ten nucleotides. we have identified 69 putative open reading frames, including three apparent genes (thymidylate synthase, terminase, and rnr alpha subunit genes) that are interrupted by an intein. protein-splicing activities of these inteins were demonstrated in escherichia coli. three structural proteins in ...200818599103
characterization of cg10062 from corynebacterium glutamicum: implications for the evolution of cis-3-chloroacrylic acid dehalogenase activity in the tautomerase superfamily.a 149-amino acid protein designated cg10062 is encoded by a gene from corynebacterium glutamicum. the physiological function of cg10062 is unknown, and the gene encoding this protein has no obvious genomic context. sequence analysis links cg10062 to the cis-3-chloroacrylic acid dehalogenase ( cis-caad) family, one of the five known families of the tautomerase superfamily. the characterized tautomerase superfamily members have two distinctive characteristics: a beta-alpha-beta structure motif and ...200818598055
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
the cgl1281-encoding putative transporter of the cation diffusion facilitator family is responsible for alkali-tolerance in corynebacterium glutamicum.mutants of corynebacterium glutamicum that were unable to grow under mild alkaline ph conditions were isolated by mutagenesis. strain al-43 exhibiting the highest sensitivity to alkaline ph among the mutants was selected and used to clone a dna fragment that could complement the phenotype. sequencing and subcloning of the cloned 4.0-kb ecori dna fragment showed that the cgl1281 gene was responsible for the complementation. the deduced amino acid sequence of cgl1281 was found to show significant ...200818592219
evolution of metal(loid) binding sites in transcriptional regulators.expression of the genes for resistance to heavy metals and metalloids is transcriptionally regulated by the toxic ions themselves. members of the arsr/smtb family of small metalloregulatory proteins respond to transition metals, heavy metals, and metalloids, including as(iii), sb(iii), cd(ii), pb(ii), zn(ii), co(ii), and ni(ii). these homodimeric repressors bind to dna in the absence of inducing metal(loid) ion and dissociate from the dna when inducer is bound. the regulatory sites are often thr ...200818591244
identification of a gene encoding a transporter essential for utilization of c4 dicarboxylates in corynebacterium glutamicum.the corynebacterium glutamicum r genome contains a total of eight genes encoding proteins with sequence similarity to c4-dicarboxylate transporters identified from other bacteria. three of the genes encode proteins within the dicarboxylate/amino acid:cation symporter (daacs) family, another three encode proteins within the tripartite atp-independent periplasmic transporter family, and two encode proteins within the divalent anion:na+ symporter (dass) family. we observed that a mutant strain defi ...200818586971
simultaneous measurements of oxygen diffusion coefficients and solubilities in fermentation media with polarographic oxygen electrodes.a membrane-covered oxygen electrode was used to measure oxygen diffusion coefficients and solubilities in aqueous glucose solutions and various fermentation media following a newly developed methodology. the fermentation media studied were tryptic soy broth and those for fermentations of penicillium chrysogenum, saccharomyces cerevisiae, and micrococcus glutamicus. the experimental results of oxygen diffusion coefficients and solubilities in glucose solutions were in good accord with the literat ...198818584707
in situ global method for measurement of oxygen demand and mass transfer.two aerobic microorganisms, saccharomycopsis lipolytica and brevibacterium lactofermentum, have been used in a study of mass transfer and oxygen uptake from a global perspective, using a closed gas system. oxygen concentrations in the gas and liquid were followed using oxygen electrodes; the results allowed for easy calculation of in situ oxygen transport. the cell yields on oxygen for s. lipolytica and b. lactofermentum were 1.01 and 1.53 g/g, respectively. the mass transfer coefficient was est ...199818576018
the glxr regulon of the amino acid producer corynebacterium glutamicum: in silico and in vitro detection of dna binding sites of a global transcription regulator.the glxr (cg0350) gene of corynebacterium glutamicum atcc 13032 encodes a dna-binding transcription regulator of the crp/fnr protein family. five genomic dna regions known to be bound by glxr provided the seed information for dna binding site discovery by expectation maximization and gibbs sampling approaches. the detection of additional motifs in the genome sequence of c. glutamicum was performed with a position weight matrix and a profile hidden markov model, both deduced from the initial moti ...200818573287
group 2 sigma factor sigb of corynebacterium glutamicum positively regulates glucose metabolism under conditions of oxygen deprivation.the sigb gene of corynebacterium glutamicum encodes a group 2 sigma factor of rna polymerase. under conditions of oxygen deprivation, the sigb gene is upregulated and cells exhibit high productivity of organic acids as a result of an elevated glucose consumption rate. using dna microarray and quantitative reverse transcription-pcr (rt-pcr) analyses, we found that sigb disruption led to reduced transcript levels of genes involved in the metabolism of glucose into organic acids. this in turn resul ...200818567683
direct visualization of the outer membrane of mycobacteria and corynebacteria in their native state.the cell envelope of mycobacteria, which include the causative agents of tuberculosis and leprosy, is crucial for their success as pathogens. despite a continued strong emphasis on identifying the multiple chemical components of this envelope, it has proven difficult to combine its components into a comprehensive structural model, primarily because the available ultrastructural data rely on conventional electron microscopy embedding and sectioning, which are known to induce artifacts. the existe ...200818567661
1.6 angstroms structure of an nad+-dependent quinate dehydrogenase from corynebacterium glutamicum.to date, three different functional classes of bacterial shikimate/quinate dehydrogenases have been identified and are referred to as aroe, sdh-l and ydib. the enzyme aroe and the catalytically much slower sdh-l clearly prefer nadp+/nadph as the cosubstrate and are specific for (dehydro-)shikimate, whereas in ydib the differences in affinity for nadp+/nadph versus nad+/nadh as well as for (dehydro-)shikimate versus (dehydro-)quinate are marginal. these three subclasses have a similar three-dimen ...200818566515
analysis of 13c labeling enrichment in microbial culture applying metabolic tracer experiments using gas chromatography-combustion-isotope ratio mass spectrometry.the applicability of gas chromatography-combustion-isotope ratio mass spectrometry (gc-c-irms) for the quantification of 13c enrichment of proteinogenic amino acids in metabolic tracer experiments was evaluated. measurement of the 13c enrichment of proteinogenic amino acids from cell hydrolyzates of corynebacterium glutamicum growing on different mixtures containing between 0.5 and 10% [1-13c]glucose shows the significance of kinetic isotope effects in metabolic flux studies at low degree of lab ...200818565321
insights into the structural basis of substrate recognition by histidinol-phosphate aminotransferase from corynebacterium glutamicum.histidinol-phosphate aminotransferase (hisc) is a pyridoxal 5'-phosphate-dependent enzyme that catalyzes the reversible transamination reaction between histidinol phosphate (his-p) and 2-oxoglutarate (o-glu). the crystal structures of apo histidinol-phosphate aminotransferase from corynebacterium glutamicum, of the internal plp aldimine adduct and of a pyridoxamine 5-phosphate-enzyme complex were determined at resolutions of 2.2, 2.1 and 1.8 a, respectively. residues important for substrate spec ...200818560156
control of nitrate concentration in fermentations of corynebacterium glutamicum.a nitrate control system has been devised for the maintenance of stable nitrate concentrations throughout fed-batch fermentations of corynebacterium glutamicum. the feedback control system was based on the use of a nitrate-ion-selective electrode to directly monitor the nitrate levels in the fermentor and an automatic controller to activate a nitrate feed pump. the electrode which was used for controlling the nitrate level was stable through-out the fermentation period. the apparent maximum spec ...198618555376
continuous glutamate production using an immobilized whole-cell system.for the purpose of saving the energy and raw materials required in glutamate fermentation, an immobilized whole-cell system was prepared and its performance in a continuous reactor system was evaluated. corynebacterium glutamicum (a mutant strain of atcc 13058) whole cell was immobilized in k-carrageenan matrix and the gel structure was strengthened by treatment with a hardening agent. the effective diffusivities of carrageenan gel for glucose and oxygen were found to decrease significantly with ...198218546125
molecular mass sorting of proteome using hollow fiber flow field-flow fractionation for proteomics.hollow fiber flow field-flow fractionation (hf flfff) has been demonstrated as a tool for pre-fractionating proteomes by differences in molecular mass (mr), where the resulting protein fractions are subsequently digested and analyzed by shotgun proteomics using two-dimensional liquid chromatography-electrospray ionization-tandem mass spectrometry (2d-lc-esi-ms/ms). hf flfff is a separation device capable of fractionating proteins or cells by hydrodynamic radius, and protein fraction can be readi ...200818541480
impact of pulsed electric fields on corynebacterium glutamicum cell membrane permeabilization.the permeability barrier of the microbial cell envelope for substrates and products often causes very low reaction rates of whole cells. therefore, it is of interest to develop an effective method to reduce this permeability barrier in order to increase product yields. utilisation of pulse electric fields may improve amino acid release from corynebacterium glutamicum by up to several orders of magnitude. in particular pulsed electric fields may change the cell/membrane's dielectric properties an ...200818499054
regulation of nitrogen metabolism in mycobacterium tuberculosis: a comparison with mechanisms in corynebacterium glutamicum and streptomyces coelicolor.the mechanisms governing the regulation of nitrogen metabolism in corynebacterium glutamicum and streptomyces coelicolor have been extensively studied. these actinomycetales are closely related to the mycobacterium genus and may therefore serve as a models to elucidate the cascade of nitrogen signalling in other mycobacteria. some factors involved in nitrogen metabolism in mycobacterium tuberculosis have been described, including glutamine synthetase and its adenylyltransferase, but not much dat ...200818493948
population heterogeneity in corynebacterium glutamicum atcc 13032 caused by prophage cgp3.the genome of corynebacterium glutamicum type strain atcc 13032 (accession number bx927147) contains three prophages, cgp1, cgp2, and cgp3. we recently observed that many genes within the cgp3 prophage region have increased mrna levels in a dtxr deletion mutant that lacks the master regulator of iron homeostasis (j. wennerhold and m. bott, j. bacteriol. 188:2907-2918, 2006). here, we provide evidence that this effect is due to the increased induction of the prophage cgp3 in the dtxr mutant, poss ...200818487330
effect of increased glutamate availability on l-ornithine production in corynebacterium glutamicum.glutamate availability in the argf-argr-probdelta strain of corynebacterium glutamicum was increased by addition of glutamate to the cell or inactivation of the phosphoenolpyruvate carboxykinase activity and simultaneous overexpression of the pyruvate carboxylase activity to assess its effect on lornithine production. when glutamate was increased in an lornithine- producing strain, the production of l-ornithine was not changed. this unexpected result indicated that the intracellular concentratio ...200818467864
construction of heat-inducible expression vector of corynebacterium glutamicum and c. ammoniagenes: fusion of lambda operator with promoters isolated from c. ammoniagenes.the heat-inducible expression vectors for corynebacterium glutamicum and c. ammoniagenes were constructed by using the lambdaol1 and the cryptic promoters, cj1 and cj4 that express genes constitutively in c. ammoniagenes.. although the promoters were isolated from c. ammoniagenes, cj1 and cj4 were also active in c. glutamicum. to construct vectors, the ol1 from the lambdapl promoter was isolated and fused to the cj1 and cj4 promoters by recombinant pcr. the resulting artificial promoters, cj1o a ...200818467855
a putative alpha-helical porin from corynebacterium glutamicum.the cell wall of corynebacterium glutamicum contains a mycolic acid layer, which is a protective nonpolar barrier similar to the outer membrane of gram-negative bacteria. the exchange of material across this barrier requires porins. porin b (porb) is one of them. recombinant porb has been produced in escherichia coli, purified, crystallized and analyzed by x-ray diffraction, yielding 16 independent molecular structures in four different crystal forms at resolutions up to 1.8 a. all 16 molecules ...200818462756
disruption of metf increased l-lysine production by methylophilus methylotrophus from methanol.methionine auxotrophic mutants of methylophilus methylotrophus as1 expressing a mutant form of dapa (dapa24) encoding a dihydrodipicolinate synthase desensitized from feedback inhibition by l-lysine, and mutated lyse (lyse24) encoding the l-lysine exporter from corynebacterium glutamicum 2256, produced higher amounts of l-lysine from methanol as sole carbon source than did other amino acid auxotrophic mutants. especially, the m. methylotrophus 102 strain, carrying both dapa24 and lyse24, produce ...200818460806
identification of a novel alpha(1-->6) mannopyranosyltransferase mptb from corynebacterium glutamicum by deletion of a conserved gene, ncgl1505, affords a lipomannan- and lipoarabinomannan-deficient mutant.mycobacterium tuberculosis and corynebacterium glutamicum share a similar cell wall structure and orthologous enzymes involved in cell wall assembly. herein, we have studied c. glutamicum ncgl1505, the orthologue of putative glycosyltransferases rv1459c from m. tuberculosis and msmeg3120 from mycobacterium smegmatis. deletion of ncgl1505 resulted in the absence of lipomannan (cg-lm-a), lipoarabinomannan (cg-lam) and a multi-mannosylated polymer (cg-lm-b) based on a 1,2-di-o-c(16)/c(18:1)-(alpha- ...200818452585
from the characterization of the four serine/threonine protein kinases (pkna/b/g/l) of corynebacterium glutamicum toward the role of pkna and pknb in cell division.corynebacterium glutamicum contains four serine/threonine protein kinases (stpks) named pkna, pknb, pkng, and pknl. here we present the first biochemical and comparative analysis of all four c. glutamicum stpks and investigate their potential role in cell shape control and peptidoglycan synthesis during cell division. in vitro assays demonstrated that, except for pkng, all stpks exhibited autokinase activity. we provide evidence that activation of pkng is part of a phosphorylation cascade mechan ...200818442973
structural characterization and functional properties of a novel lipomannan variant isolated from a corynebacterium glutamicum pimb' mutant.the genus corynebacterium is part of the phylogenetic group nocardioform actinomycetes, which also includes the genus mycobacterium. members of this phylogenetic group have a characteristic cell envelope structure, which is dominated by complex lipids and amongst these, lipoglycans are of particular interest. the disruption of ncgl2106 in c. glutamicum resulted in a mutant devoid of monoacylated phosphatidyl-myo-inositol dimannoside (ac(1)pim(2)) resulting in the accumulation of ac(1)pim(1) and ...200818421567
structural and enzymatic analysis of msha from corynebacterium glutamicum: substrate-assisted catalysis.the glycosyltransferase termed msha catalyzes the transfer of n-acetylglucosamine from udp-n-acetylglucosamine to 1-l-myo-inositol-1-phosphate in the first committed step of mycothiol biosynthesis. the structure of msha from corynebacterium glutamicum was determined both in the absence of substrates and in a complex with udp and 1-l-myo-inositol-1-phosphate. msha belongs to the gt-b structural family whose members have a two-domain structure with both domains exhibiting a rossman-type fold. bind ...200818390549
corynebacterium glutamicum tailored for high-yield l-valine production.we recently engineered the wild type of corynebacterium glutamicum for the growth-decoupled production of l: -valine from glucose by inactivation of the pyruvate dehydrogenase complex and additional overexpression of the ilvbnce genes, encoding the l-valine biosynthetic enzymes acetohydroxyacid synthase, isomeroreductase, and transaminase b. based on the first generation of pyruvate-dehydrogenase-complex-deficient c. glutamicum strains, a second generation of high-yield l-valine producers was co ...200818379776
the laci/galr family transcriptional regulator urir negatively controls uridine utilization of corynebacterium glutamicum by binding to catabolite-responsive element (cre)-like sequences.the cg1547 protein of corynebacterium glutamicum atcc 13032 is a member of the laci/galr family of dna-binding transcriptional regulators. a defined deletion in the cg1547 gene, now designated urir (uridine utilization regulator), resulted in the mutant strain c. glutamicum kb1547. comparison of gene expression levels in c. glutamicum kb1547 and the wild-type strain revealed enhanced expression of the urir operon genes cg1546 (ribokinase), cg1545 (uridine transporter) and cg1543 (uridine-preferr ...200818375800
phytate utilization by genetically engineered lysine-producing corynebacterium glutamicum.heterologous expression of a phytase gene (phyc) from bacillus amyloliquefaciens dsm 7 enabled the growth of corynebacterium glutamicum with phytate (myo-inositol-1,2,3,4,5,6-hexakisphosphate) as a new, sole source of phosphorus. phytate was not used as a carbon source. during growth of the phyc-expressing amino acid (l-lysine)-producing strain c. glutamicum atcc 21253 (pwlq2::phyc) with phytate as the source of phosphorus, merely a small, transient accumulation of inorganic phosphate was observ ...200818374441
triple transcriptional control of the resuscitation promoting factor 2 (rpf2) gene of corynebacterium glutamicum by the regulators of acetate metabolism rama and ramb and the camp-dependent regulator glxr.the transcriptional regulators rama, ramb and glxr were detected to bind to the promoter region of the resuscitation promoting factor 2 (rpf2) gene involved in growth and culturability of corynebacterium glutamicum. dna-binding sites were identified by bioinformatic analysis and verified by electrophoretic mobility shift assays with purified hexahistidyl-tagged proteins. carbon source-dependent deregulation of rpf2 expression was demonstrated in vivo in rama and ramb mutants and in a c. glutamic ...200818355281
metabolic responses to pyruvate kinase deletion in lysine producing corynebacterium glutamicum.abstract:200818339202
disclosure of the mycobacterial outer membrane: cryo-electron tomography and vitreous sections reveal the lipid bilayer structure.the cell walls of mycobacteria form an exceptional permeability barrier, and they are essential for virulence. they contain extractable lipids and long-chain mycolic acids that are covalently linked to peptidoglycan via an arabinogalactan network. the lipids were thought to form an asymmetrical bilayer of considerable thickness, but this could never be proven directly by microscopy or other means. cryo-electron tomography of unperturbed or detergent-treated cells of mycobacterium smegmatis embed ...200818316738
corynebacterium glutamicum sigmae is involved in responses to cell surface stresses and its activity is controlled by the anti-sigma factor csee.in this study, we demonstrate that sigma(e), an alternative sigma factor of corynebacterium glutamicum, is involved in cell surface stresses. cells in which the sige gene was deleted evidenced increased sensitivity to magnesium deficiency, as well as to sds, lysozymes, edta and heat. we utilized physiological analyses to show that the downstream gene, designated csee, encodes an anti-sigma factor. the retarded growth of the csee mutant cells under ordinary growth conditions could be recovered by ...200818310037
identification of amino acids and domains required for catalytic activity of dppr synthase, a cell wall biosynthetic enzyme of mycobacterium tuberculosis.decaprenylphosphoryl-d-arabinose (dpa) has been shown to be the donor of the essential d-arabinofuranosyl residues found in the cell wall of mycobacterium tuberculosis. dpa is formed from phosphoribose diphosphate in a four-step process. the first step is the nucleophilic replacement of the diphosphate group with decaprenyl phosphate. this reaction is catalysed by the integral membrane protein 5-phospho-alpha-d-ribose-1-diphosphate : decaprenyl-phosphate 5-phosphoribosyltransferase (dppr synthas ...200818310020
arnr, a novel transcriptional regulator, represses expression of the narkghji operon in corynebacterium glutamicum.the narkghji operon that comprises putative nitrate/nitrite transporter (nark) and nitrate reductase (narghji) genes is required for the anaerobic growth of corynebacterium glutamicum with nitrate as a terminal electron acceptor. in this study, we identified a gene, arnr, which encodes a transcriptional regulator that represses the expression of the narkghji operon in c. glutamicum cells under aerobic conditions. disruption of arnr induced nitrate reductase activities of c. glutamicum cells and ...200818296524
diviva is required for polar growth in the mreb-lacking rod-shaped actinomycete corynebacterium glutamicum.the actinomycete corynebacterium glutamicum grows as rod-shaped cells by zonal peptidoglycan synthesis at the cell poles. in this bacterium, experimental depletion of the polar diviva protein (diviva(cg)) resulted in the inhibition of polar growth; consequently, these cells exhibited a coccoid morphology. this result demonstrated that diviva is required for cell elongation and the acquisition of a rod shape. diviva from streptomyces or mycobacterium localized to the cell poles of diviva(cg)-depl ...200818296522
changes in enzyme activities at the pyruvate node in glutamate-overproducing corynebacterium glutamicum.glutamate is industrially produced by fermentation using corynebacterium glutamicum. the key factor for efficient glutamate production by this microorganism has been considered to be a metabolic change at the 2-oxoglutarate dehydrogenase (odh) branch point caused by a decrease in odh activity under glutamate-overproducing conditions. however, this change would be insufficient because the odh branch is merely the final branch in the glutamate biosynthetic pathway, and efficient glutamate producti ...200818295714
transcription of corynebacterium glutamicum genes involved in tricarboxylic acid cycle and glyoxylate cycle.transcription of the tricarboxylic acid cycle genes of corynebacterium glutamicum was investigated. northern hybridizations revealed that glta-fkb, odha-orfa, succ-sucd, sdhc-sdha-sdhb-orfb and mdh-orfc were transcribed as polycistronic mrnas of size 1.9, 4.5, 2.5, 4.0 and 1.7 kb, respectively. the acn-acnr-gat gene cluster was transcribed as a mono-, bi- or tricistronic mrna, depending on the carbon source. the 2.9-kb (acn) and 1.5-kb (acnr-gat) mrnas, which were regulated by different promoter ...200818285691
cell growth and cell division in the rod-shaped actinomycete corynebacterium glutamicum.bacterial cell growth and cell division are highly complicated and diversified biological processes. in most rod-shaped bacteria, actin-like mreb homologues produce helicoidal structures along the cell that support elongation of the lateral cell wall. an exception to this rule is peptidoglycan synthesis in the rod-shaped actinomycete corynebacterium glutamicum, which is mreb-independent. instead, during cell elongation this bacterium synthesizes new cell-wall material at the cell poles whereas t ...200818283557
s-adenosylhomocysteine hydrolase from corynebacterium glutamicum: cloning, overexpression, purification, and biochemical characterization.the s-adenosylhomocysteine hydrolase gene (sahase) was cloned from the gram-positive soil bacterium corynebacterium glutamicum (atcc 13032) and sequenced. the sahase gene possesses an open reading frame, which consists of 1,434 nucleotides that encode 478 amino acids. the sahase gene from c. glutamicum was expressed in escherichia coli rosetta cells by inserting the 1,434-bp fragment downstream from the isopropyl-beta-d-thiogalactopyranoside-inducible promoter of the pet28a+ expression vector. t ...200818253021
corynebacterium glutamicum possesses two seca homologous genes that are essential for viability.seca is a central component of the bacterial sec preprotein translocase. besides the housekeeping seca (seca1), some mostly pathogenic gram-positive bacteria possess an accessory seca (seca2) that is involved in the export of a few substrates only. here we show that neither of the two seca homologous genes present in the genome of the non-pathogenic bacterium corynebacterium glutamicum can be deleted, unless a copy of the respective gene is provided in trans on a plasmid. this finding is in mark ...200818246326
dissection of ammonium uptake systems in corynebacterium glutamicum: mechanism of action and energetics of amta and amtb.corynebacterium glutamicum has two different amt-type proteins. while amtb has a low substrate affinity and is not saturable up to 3 mm methylammonium, amta has a high substrate affinity and mediates saturable, membrane potential-dependent transport, resulting in a high steady-state accumulation of methylammonium, even in the absence of metabolic trapping.200818245289
structure of a gtp-dependent bacterial pep-carboxykinase from corynebacterium glutamicum.gtp-dependent phosphoenolpyruvate carboxykinase (pck) is the key enzyme that controls the blood glucose level during fasting in higher animals. here we report the first substrate-free structure of a gtp-dependent phosphoenolpyruvate (pep) carboxykinase from a bacterium, corynebacterium glutamicum (cgpck). the protein crystallizes in space group p2(1) with four molecules per asymmetric unit. the 2.3a resolution structure was solved by molecular replacement using the human cytosolic pck (hcpck) st ...200818234538
characterization of the promoter region of ftsz from corynebacterium glutamicum and controlled overexpression of ftsz.of the five promoters detected for the ftsz gene in corynebacterium glutamicum, three were located within the coding region of the upstream ftsq gene and two within the intergenic ftsq-ftsz region. the most distant ftsz promoter showed activity in escherichia coli and controlled high-level transcriptional expression of ftsz in c. glutamicum. quantitative western blotting showed that all five promoters were active during the exponential growth phase and down-regulated during stationary phase. thi ...200718228224
influence of l-isoleucine and pantothenate auxotrophy for l-valine formation in corynebacterium glutamicum revisited by metabolome analyses.the effect of different amounts of supplemented l-isoleucine and pantothenate has been analysed with the auxotrophic strain corynebacterium glutamicum deltailva deltapanb, showing that the final biomass concentration of this preliminary l-valine production strain can be controlled by the amount of added l-isoleucine. one gramme cell dry weight is formed from 48 micromol l-isoleucine. different amounts of available pantothenate affect the intracellular pyruvate concentration. by limiting pantothe ...200818224342
secretion of streptomyces mobaraensis pro-transglutaminase by coryneform bacteria.we previously reported on the secretion of streptomyces mobaraensis transglutaminase by corynebacterium glutamicum atcc13869 (formerly classified as brevibacterium lactofermentum). in the present work, we investigated whether any other coryneform bacteria showed higher productivity than c. glutamicum atcc13869. we found that most coryneform species secreted pro-transglutaminase efficiently. moreover, we confirmed that corynebacterium ammoniagenes atcc6872 produced about 2.5 g/l pro-transglutamin ...200818219481
improvement of poly(3-hydroxybutyrate) [p(3hb)] production in corynebacterium glutamicum by codon optimization, point mutation and gene dosage of p(3hb) biosynthetic genes.in our previous study, a system for producing poly(3-hydroxybutyrate) [p(3hb)] was established by introducing a polyhydroxyalkanoate (pha) biosynthetic gene operon (phacab re) derived from ralstonia eutropha into corynebacterium glutamicum. in this study, two experimental strategies have been applied to improve p(3hb) production in recombinant c. glutamicum. one is a codon optimization of the n-terminal-coding region of the pha synthase (phac re) gene focusing on the codon usage preference for t ...200718215631
production of d-lactic acid by corynebacterium glutamicum under oxygen deprivation.in mineral salts medium under oxygen deprivation, corynebacterium glutamicum exhibits high productivity of l-lactic acid accompanied with succinic and acetic acids. in taking advantage of this elevated productivity, c. glutamicum was genetically modified to produce d-lactic acid. the modification involved expression of fermentative d-lactate dehydrogenase (d-ldh)-encoding genes from escherichia coli and lactobacillus delbrueckii in l-lactate dehydrogenase (l-ldh)-encoding ldha-null c. glutamicum ...200818188553
regulation of expression of general components of the phosphoenolpyruvate: carbohydrate phosphotransferase system (pts) by the global regulator sugr in corynebacterium glutamicum.the phosphoenolpyruvate: carbohydrate phosphotransferase system (pts) catalyzes transport of carbohydrates by coupling carbohydrate translocation and phosphorylation. enzyme i and hpr, encoded in ptsi and ptsh, respectively, are cytoplasmic proteins commonly used for transport of variety of pts sugars. in this study, we investigated the role of sugr on the expression of the ptsi and ptsh which increases in the presence of pts sugars in corynebacterium glutamicum. disruption of sugr resulted in t ...200818183389
analysis of a new mannosyltransferase required for the synthesis of phosphatidylinositol mannosides and lipoarbinomannan reveals two lipomannan pools in corynebacterineae.the cell walls of the corynebacterineae, which includes the important human pathogen mycobacterium tuberculosis, contain two major lipopolysaccharides, lipoarabinomannan (lam) and lipomannan (lm). lam is assembled on a subpool of phosphatidylinositol mannosides (pims), whereas the identity of the lm lipid anchor is less well characterized. in this study we have identified a new gene (rv2188c in m. tuberculosis and ncgl2106 in corynebacterium glutamicum) that encodes a mannosyltransferase involve ...200818178556
nmr structure of protein cgl2762 from corynebacterium glutamicum implicated in dna transposition reveals a helix-turn-helix motif attached to a flexibly disordered leucine zipper. 200818175328
regulation of the expression of phosphoenolpyruvate: carbohydrate phosphotransferase system (pts) genes in corynebacterium glutamicum r.the phosphoenolpyruvate : carbohydrate phosphotransferase system (pts) catalyses the transport of carbohydrates by coupling carbohydrate translocation and phosphorylation. in corynebacterium glutamicum r, the genes ptsh and ptsi encode general components of the pts, and genes ptsf, ptss and ptsg each encode fructose-, sucrose- and glucose-specific components of the pts, respectively. in this study, we examined the mrna levels of the pts genes in the presence or absence of pts sugars. glucose ele ...200818174145
chromosomally encoded small antisense rna in corynebacterium glutamicum.the first observation of chromosomally encoded small antisense rna in corynebacterium glutamicum is reported. transcription oriented in the reverse direction to the transcription of the genes cg1934 and cg1935 was demonstrated within the chromosomal cg1934-cg1935 intergenic region. the transcription was found to be increased after heat shock. the transcriptional start point of this rna designated arna was localized 21 bp upstream of the cg1935 translational start point by primer extension analys ...200818093135
divs, a novel sos-inducible cell-division suppressor in corynebacterium glutamicum.dna damage-induced sos response elicits the induction of cell-division suppressor as well as dna repair genes. in gram-positive bacteria, cell-division suppressor genes, so far characterized from bacillus subtilis (ynea) and mycobacterium tuberculosis (rv2719c), share limited homology, but are both located in the vicinity of lexa on their respective genomes. using this proximity to lexa, corynebacterium glutamicum r divs (cgr1759) was identified as an sos-inducible cell-division suppressor in th ...200818086211
genetic and biochemical characterization of a 4-hydroxybenzoate hydroxylase from corynebacterium glutamicum.corynebacterium glutamicum uses 4-hydroxybenzoic acid (4hba) as sole carbon source for growth. previous studies showed that 4hba was taken up into cells via pcak, and the aromatic ring was cleaved via protocatechuate 3,4-dioxygenase. in this study, the gene poba ( cg ) (ncgl1032) involved in the conversion of 4hba into 3,4-dihydroxybenzoate (protocatechuate) was identified, and the gene product poba (cg) was characterized as a 4hba 3-hydroxylase, which is a homodimer of poba(cg). the poba (cg) i ...200818071645
production of chryseobacterium proteolyticum protein-glutaminase using the twin-arginine translocation pathway in corynebacterium glutamicum.the protein glutaminase (pg) secreted by the gram-negative bacterium chryseobacterium proteolyticum can deamidate glutaminyl residues in several substrate proteins, including insoluble wheat glutens. this enzyme therefore has potential application in the food industry. we assessed the possibility to produce pg containing a pro-domain in corynebacterium glutamicum which we have successfully used for production of several kinds of proteins at industrial-scale. when it was targeted to the general p ...200818064454
a new approach to study the decolorization of complex reactive dye bath effluent by biosorption technique.this work focused on the development of a practical biosorbent for the decolorization of textile effluents. the fermentation waste, corynebacterium glutamicum biomass, when decarboxylated and immobilized in polysulfone matrix performed well in decolorization of simulated reactive dye bath effluent comprised of four different reactive dyes and other auxiliary chemicals. the regeneration of polysulfone-immobilized c. glutamicum was successful with the aid of 0.01 m naoh as the eluant, which enable ...200818060770
nitrogen control in corynebacterium glutamicum: proteins, mechanisms, signals.in order to utilize different nitrogen sources and to survive in a situation of nitrogen limitation, microorganisms have developed sophisticated mechanisms to adapt their metabolism to a changing nitrogen supply. in this communication, the recent knowledge of nitrogen regulation in the amino acid producer corynebacterium glutamicum is summarized. the core adaptations of c. glutamicum to nitrogen limitation on the level of transcription are controlled by the global regulator amtr. further compone ...200718051748
expression analysis of the csp-like genes from corynebacterium glutamicum encoding homologs of the escherichia coli major cold-shock protein cspa.three csp-like genes were identified in the corynebacterium glutamicum genome and designated cspa, cspb, and cspa2. the genes cspa and cspa2 encode proteins, comprising of 67 amino acid residues, respectively. they share 83% identity with each other. identity of those proteins with escherichia coli csp proteins was near 50%. the cspb gene encodes a protein composed of 127 amino acids, which has 40% and 35% sequence identity with cspa and cspa2, respectively, especially at its n-terminal region. ...200718051605
biochemical analysis on the parallel pathways of methionine biosynthesis in corynebacterium glutamicum.two alternative pathways for methionine biosynthesis are known in corynebacterium glutamicum: one involving transsulfuration (mediated by metb and metc) and the other involving direct sulthydrylation (mediated by mety). in this study, metb (cystathionine gamma-synthase) and mety (o-acetylhomoserine sulfhydrylase) from c. glutamicum were purified to homogeneity and the biochemical parameters were compared to assess the functional and evolutionary importance of each pathway. the molecular masses o ...200718050920
co-ordinated regulation of gluconate catabolism and glucose uptake in corynebacterium glutamicum by two functionally equivalent transcriptional regulators, gntr1 and gntr2.corynebacterium glutamicum is a gram-positive soil bacterium that prefers the simultaneous catabolism of different carbon sources rather than their sequential utilization. this type of metabolism requires an adaptation of the utilization rates to the overall metabolic capacity. here we show how two functionally redundant gntr-type transcriptional regulators, designated gntr1 and gntr2, co-ordinately regulate gluconate catabolism and glucose uptake. gntr1 and gntr2 strongly repress the genes enco ...200818047570
cytoplasmic proteome reference map for a glutamic acid-producing corynebacterium glutamicum atcc 14067.we constructed a cytoplasmic proteome reference map for a glutamic acid producing corynebacterium glutamicum atcc 14067 by 2-de and protein identification by maldi-tof-ms and pmf using genome database of the type strain atcc 13032. the map allowed us to identify 166 protein spots representing 139 different proteins. a considerable strain difference was observed in the proteomic images between strains atcc 14067 and atcc 13032 grown under the glutamic acid production conditions, suggesting the im ...200718040983
microbial production of l -glutamate and l -glutamine by recombinant corynebacterium glutamicum harboring vitreoscilla hemoglobin gene vgb.vitreoscilla hemoglobin (vhb) gene vgb equipped with a native promoter pvgb or a tac promoter ptac was introduced into corynebacterium glutamicum atcc14067, respectively. ptac was proven to be more suitable for expressing vhb protein in higher concentration in both escherichia coli and c. glutamicum strains compared with the native vgb promoter pvgb. vhb-expressing c. glutamicum exhibited higher oxygen uptake rate and enhanced cell growth. recombinant c. glutamicum harboring vgb gene equipped wi ...200818040683
regulation of l-lactate utilization by the fadr-type regulator lldr of corynebacterium glutamicum.corynebacterium glutamicum can grow on l-lactate as a sole carbon and energy source. the ncgl2816-lldd operon encoding a putative transporter (ncgl2816) and a quinone-dependent l-lactate dehydrogenase (lldd) is required for l-lactate utilization. dna affinity chromatography revealed that the fadr-type regulator lldr (encoded by ncgl2814) binds to the upstream region of ncgl2816-lldd. overexpression of lldr resulted in strongly reduced ncgl2816-lldd mrna levels and strongly reduced lldd activity, ...200818039772
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