| two-dimensional electrophoretic analysis of corynebacterium glutamicum membrane fraction and surface proteins. | an improved protocol for the two-dimensional analysis of proteins of the corynebacterium glutamicum cytoplasmic membrane fraction is described. by use of increased 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (chaps) concentrations (2-4%) and an optimized electrophoresis protocol, horizontal streaking of proteins of the cytoplasmic membrane fraction was almost completely avoided. more important, in contrast to a previously published method, both a sample tray and ipg-phor isoelectri ... | 2000 | 10726773 |
| the 51,409-bp r-plasmid ptp10 from the multiresistant clinical isolate corynebacterium striatum m82b is composed of dna segments initially identified in soil bacteria and in plant, animal, and human pathogens. | the 51,409-bp dna sequence of the multiresistance plasmid ptp10 from the gram-positive opportunistic human pathogen corynebacterium striatum m82b has been determined. fully automated genome interpretation led to the identification of 47 orfs. analysis of the genetic organization of ptp10 suggests that the plasmid is composed of eight dna segments, the boundaries of which are represented by transposons and insertion sequences. the dna segments of ptp10 are highly similar to (1) a plasmid-encoded ... | 2000 | 10732668 |
| a brevibacterium lactofermentum 16s rrna gene used as target site for homologous recombination. | genes for rrna are highly conserved and present in multiple copies in most prokaryotic organisms increasing the number of theoretical sites for homologous recombination. they might be targets for integration events between unrelated microorganisms providing that an efficient genetic transfer is present. we have used a plasmid containing a portion of the 16s rrna gene from the rrnd operon of brevibacterium lactofermentum to transform the same strain resulting in non-essential inactivation of vari ... | 2000 | 10754248 |
| a mutation in the corynebacterium glutamicum ltsa gene causes susceptibility to lysozyme, temperature-sensitive growth, and l-glutamate production. | the corynebacterium glutamicum mutant ky9714, originally isolated as a lysozyme-sensitive mutant, does not grow at 37 degrees c. complementation tests and dna sequencing analysis revealed that a mutation in a single gene of 1,920 bp, ltsa (lysozyme and temperature sensitive), was responsible for its lysozyme sensitivity and temperature sensitivity. the ltsa gene encodes a protein homologous to the glutamine-dependent asparagine synthetases of various organisms, but it could not rescue the aspara ... | 2000 | 10781535 |
| quantitative determination of metabolic fluxes during coutilization of two carbon sources: comparative analyses with corynebacterium glutamicum during growth on acetate and/or glucose. | growth of corynebacterium glutamicum on mixtures of the carbon sources glucose and acetate is shown to be distinct from growth on either substrate alone. the organism showed nondiauxic growth on media containing acetate-glucose mixtures and simultaneously metabolized these substrates. compared to those for growth on acetate or glucose alone, the consumption rates of the individual substrates were reduced during acetate-glucose cometabolism, resulting in similar total carbon consumption rates for ... | 2000 | 10809686 |
| another unusual type of citric acid cycle enzyme in helicobacter pylori: the malate:quinone oxidoreductase. | the only enzyme of the citric acid cycle for which no open reading frame (orf) was found in the helicobacter pylori genome is the nad-dependent malate dehydrogenase. here, it is shown that in this organism the oxidation of malate to oxaloacetate is catalyzed by a malate:quinone oxidoreductase (mqo). this flavin adenine dinucleotide-dependent membrane-associated enzyme donates electrons to quinones of the electron transfer chain. similar to succinate dehydrogenase, it is part of both the electron ... | 2000 | 10809701 |
| response to nitrogen starvation in corynebacterium glutamicum. | proteins strongly synthesized in corynebacterium glutamicum during nitrogen restriction were examined by two-dimensional gel electrophoresis and microsequencing. two main groups of enzymes were identified beside miscellaneous proteins, enzymes involved (i) in protein synthesis, and (ii) in carbon metabolism. biochemical measurements revealed an increase of oxygen consumption during nitrogen starvation, indicating an enhanced energy demand of the cells. by northern hybridizations, an increased tr ... | 2000 | 10828405 |
| kinetic properties of the glucose-6-phosphate and 6-phosphogluconate dehydrogenases from corynebacterium glutamicum and their application for predicting pentose phosphate pathway flux in vivo. | the glucose-6-phosphate (glc6p) and 6-phosphogluconate (6pg) dehydrogenases of the amino-acid-producing bacterium corynebacterium glutamicum were purified to homogeneity and kinetically characterized. the glc6p dehydrogenase was a heteromultimeric complex, which consists of zwf and opca subunits. the product inhibition pattern of the glc6p dehydrogenase was consistent with an ordered bi-bi mechanism. the 6pg dehydrogenase was found to operate according to a theorell-chance ordered bi-ter mechani ... | 2000 | 10848959 |
| microbiological investigation on black crusts from open-air stone monuments of bologna (italy). | samples of black crusts taken from open-air stone monuments in bologna dating back to between the twelfth and the nineteenth century were considered. the microbiological test procedures isolated from a high number of chemoorganotrophic bacteria, each of the samples although it was expected to find chemo-lithotrophic (specially sulfur-oxidizing and nitrifying) bacteria on account of the great amounts of sulphur, carbon, nitrogen dioxides and ammonia in the air. sporogenous and asporogenous specie ... | 2000 | 10872690 |
| cloning of the malic enzyme gene from corynebacterium glutamicum and role of the enzyme in lactate metabolism. | malic enzyme is one of at least five enzymes, known to be present in corynebacterium glutamicum, capable of carboxylation and decarboxylation reactions coupling glycolysis and the tricarboxylic acid cycle. to date, no information is available concerning the physiological role of the malic enzyme in this bacterium. the male gene from c. glutamicum has been cloned and sequenced. the protein encoded by this gene has been purified to homogeneity, and the biochemical properties have been established. ... | 2000 | 10877795 |
| characterization of the ribosomal rrnd operon of the cephamycin-producer 'nocardia lactamdurans' shows that this actinomycete belongs to the genus amycolatopsis. | the cephamycin producer strain 'nocardia lactamdurans' contains four ribosomal rna (rrn) operons. one of them (rrnd) was cloned from a dna library in the bifunctional cosmid pjar4. a 2229 bp region of rrnd has been sequenced. the 'n. lactamdurans' rrnd operon maintains the canonical order 5'-16s-23s-5s-3'. four of the consensus gürtler-stanisch sequences were found in the 16s rrna gene and a fifth one in the sequenced 5' region of the 23s rrna gene. the anti shine-dalgarno sequence of 'n. lactam ... | 2000 | 10879974 |
| menaquinol oxidase activity and primary structure of cytochrome bd from the amino-acid fermenting bacterium corynebacterium glutamicum. | cytochrome d was spectroscopically detected in membrane fractions of the amino-acid-fermenting, high-g+c gram-positive bacterium corynebacterium glutamicum. inhibition of nadh oxidase activity in the membranes by cyanide suggested that the main terminal respiratory oxidase during the stationary phase was a type of cytochrome bd. cytochrome bd-type quinol oxidase, purified from the membranes, was composed of two subunits. its reduced form showed absorption peaks at 627, 595, and 560 nm, which wer ... | 2000 | 10896219 |
| cloning and analysis of the arob gene encoding dehydroquinate synthase from corynebacterium glutamicum. | the arob gene encoding dehydroquinate synthase of corynebacterium glutamicum has been cloned by complementation of an aro auxotrophic mutant of escherichia coli with the genomic dna library. the recombinant plasmid contained a 1.4-kb fragment that complemented the escherichia coli dehydroquinate-synthase-deficient mutant. the nucleotide sequences of the subcloned dna has been determined. the sequences contain an open reading frame of 360 codons, from which a protein with a molecular mass of abou ... | 1999 | 10907426 |
| characterization of glk, a gene coding for glucose kinase of corynebacterium glutamicum. | the glk gene from corynebacterium glutamicum was isolated by complementation using escherichia coli zsc113 (ptsg ptsm glk). we sequenced a total of 3072 bp containing the 969-bp open reading frame encoding glucose kinase (glk). the glk gene has a deduced molecular mass of 34.2 kda and contains a typical atp binding site. comparison with protein sequences revealed homologies to glk from streptomyces coelicolor (43%) and bacillus megaterium (35%). the glk gene in c. glutamicum was inactivated on t ... | 2000 | 10913707 |
| pyruvate carboxylase from mycobacterium smegmatis: stabilization, rapid purification, molecular and biochemical characterization and regulation of the cellular level. | this is the first report on the purification and characterization of an anaplerotic enzyme from a mycobacterium. the anaplerotic reactions play important roles in the biochemical differentiation of mycobacteria into non-replicating stages. we have purified and characterized a pyruvate carboxylase (pyc) from mycobacterium smegmatis and cloned and sequenced its gene. we have developed a very rapid and efficient purification protocol that provided pyc with very high specific activities (up to 150 u ... | 2000 | 10913817 |
| urease of corynebacterium glutamicum: organization of corresponding genes and investigation of activity. | the corynebacterium glutamicum genes encoding urease were isolated and sequenced. while urea, ureb and urec are encoding structural subunits of urease, uree, uref, ureg and ured are encoding accessory proteins. as deduced from dna sequence analyses, the ure genes are transcriptionally coupled, this was proven by rt-pcr at least for ureabc. gene disruption experiments revealed that both structural (urec) and accessory proteins (ured) are indispensable for urease activity and growth on urea. ureas ... | 2000 | 10930756 |
| response of the central metabolism in corynebacterium glutamicum to the use of an nadh-dependent glutamate dehydrogenase. | the extensive use of 13c enrichments in precursor metabolites for flux quantification does not rely on nadph stoichiometries and can therefore be used to quantify reducing power fluxes. as an application of this concept, the nadph fluxes were quantified in an l-lysine producer of corynebacterium glutamicum grown into metabolic and isotopic steady state with [1-13c]glucose. in this case, where the organism's nadph-dependent glutamate dehydrogenase consumes reducing power, the nadph flux generated ... | 1999 | 10935753 |
| metabolic engineering from a cybernetic perspective: aspartate family of amino acids. | using the modular cybernetic framework developed by varner and ramkrishna (varner and ramkrishna; 1998a, b) a cybernetic model is formulated that describes the time evolution of the aspartate family of amino acids in corynebacterium lactofermentum atcc 21799. the network model formulation is employed in the role of a diagnostic tool for the overproduction of threonine. more precisely, having determined a parameter set that describes the time evolution of a base strain (lysine producer), the mode ... | 1999 | 10935757 |
| importance of phosphoenolpyruvate carboxylase of corynebacterium glutamicum during the temperature triggered glutamic acid fermentation. | to give clues about the respective importance of phosphoenol-pyruvate carboxylase (pepc) and pyruvate carboxylase (pc) in corynebacterium glutamicum metabolism during a temperature triggered glutamic acid fermentation, pepc activity was genetically amplified and pc activity was suppressed by biotin limitation in the culture medium. in absence of pc activity, glutamate production was dramatically reduced whereas lactate excretion was strongly increased. whereas pepc amplification in excess of bio ... | 1999 | 10937826 |
| metabolic analysis of glutamate production by corynebacterium glutamicum. | the dynamic behavior of the metabolism of corynebacterium glutamicum during l-glutamic acid fermentation, was evaluated by quantitative analysis of the evolution of intracellular metabolites and key enzyme concentrations. glutamate production was induced by an increase of the temperature and a final concentration of 80 g/l was attained. during the production phase, various other compounds, notably lactate, trehalose, and dha were secreted to the medium. intracellular metabolites analysis showed ... | 1999 | 10937937 |
| glutamate excretion as a major kinetic bottleneck for the thermally triggered production of glutamic acid by corynebacterium glutamicum. | the study was aimed at evaluating the extent of flux control exercised by the amino acid excretion step on the glutamate production flux in c. glutamicum 2262 strain that is induced for glutamate excretion by an upward temperature shift. cells initially induced to excrete glutamate were cultivated at different controlled temperatures between 33 and 40 degrees c, and changes in glutamate excretion flux and intracellular concentration were determined in response to increased culture temperature. t ... | 1999 | 10937940 |
| the lyse superfamily: topology of the lysine exporter lyse of corynebacterium glutamicum, a paradyme for a novel superfamily of transmembrane solute translocators. | in corynebacterium glutamicum the lyse carrier protein exhibits the unique function of exporting l-lysine. we here analyze the membrane topology of lyse, a protein of 236 amino acyl residues, using phoa- and lacz-fusions. the amino-terminal end of lyse is located in the cytoplasm whereas the carboxy-terminal end is found in the periplasm. although 6 hydrophobic domains were identified based on hydropathy analyses, only five transmembrane spanning helices appear to be present. the additional hydr ... | 1999 | 10943564 |
| in vivo quantification of parallel and bidirectional fluxes in the anaplerosis of corynebacterium glutamicum. | the c(3)-c(4) metabolite interconversion at the anaplerotic node in many microorganisms involves a complex set of reactions. c(3) carboxylation to oxaloacetate can originate from phosphoenolpyruvate and pyruvate, and at the same time multiple c(4)-decarboxylating enzymes may be present. the functions of such parallel reactions are not yet fully understood. using a (13)c nmr-based strategy, we here quantify the individual fluxes at the anaplerotic node of corynebacterium glutamicum, which is an e ... | 2000 | 10946002 |
| 3-deoxy-d-manno-oct-2-ulosonic acid (kdo) transferase (waaa) and kdo kinase (kdka) of haemophilus influenzae are both required to complement a waaa knockout mutation of escherichia coli. | the lipopolysaccharide (lps) of the deep rough mutant haemophilus influenzae i69 consists of lipid a and a single 3-deoxy-d-manno-oct-2-ulosonic acid (kdo) residue substituted with one phosphate at position 4 or 5 (helander, i. m., lindner, b., brade, h., altmann, k., lindberg, a. a., rietschel, e. t., and zähringer, u. (1988) eur. j. biochem. 177, 483-492). the waaa gene encoding the essential lps-specific kdo transferase was cloned from this strain, and its nucleotide sequence was identical to ... | 2000 | 10952982 |
| amtr, a global repressor in the nitrogen regulation system of corynebacterium glutamicum. | the uptake and assimilation of nitrogen sources is effectively regulated in bacteria. in the gram-negative enterobacterium escherichia coli, the ntrb/c two-component system is responsible for the activation of transcription of different enzymes and transporters, depending on the nitrogen status of the cell. in this study, we investigated regulation of ammonium uptake in corynebacterium glutamicum, a gram-positive soil bacterium closely related to mycobacterium tuberculosis. as shown by northern ... | 2000 | 10972815 |
| [l-lysine production by corynebacterium glutamicum non growing cells]. | the production of l-lysine by corynebacterium glutamicum (gigo) non growing cells was studied. a system of fermentation was developed where it was possible to separate the physiologic states of growth from those of production of l-lysine. the biomass propagation step carried out in batch cultures with yeast extract and glucose substrate showed cellular growth without production of l-lysine. the production of l-lysine was achieved when the cells were collected and incubated in the mineral glucose ... | 1999 | 10974714 |
| conversion of glutamate to glutamine by permeabilized corynebacterium glutamicum. | glutamate was converted to glutamine by corynebacterium glutamicum permeabilized by ethanol (10%). atp was supplied to the reaction by dried saccharomyces cerevisiae or regenerated by acetyl kinase. high glutamine synthetase activity in c. glutamicum was induced by cultivation of the microorganism in media containing glutamate as the sole source of nitrogen. | 1999 | 10997130 |
| cloning of the histidine biosynthetic genes from corynebacterium glutamicum: organization and analysis of the hisg and hise genes. | the physically linked hisg and hise genes, encoding for atp-phosphoribosyltransferase and phosphoribosyl-atp-pyrophosphohydrolase were isolated from the corynebacterium glutamicum gene library by complementation of escherichia coli histidine auxotrophs. they are two of the nine genes that participate in the histidine biosynthetic pathway. molecular genetics and sequencing analysis of the cloned 9-kb insert dna showed that it carries the hisg and hise genes. in combining this result with our prev ... | 2000 | 11006846 |
| comparative functional characterization in vitro of heptosyltransferase i (waac) and ii (waaf) from escherichia coli. | heptosyltransferase ii, encoded by the waaf gene of escherichia coli, is a glycosyltransferase involved in the synthesis of the inner core region of lipopolysaccharide. the gene was subcloned from plasmid pwsb33 [brabetz, w., müller-loennies, s., holst, o. & brade, h. (1997) eur. j. biochem. 247, 716-724] into a shuttle vector for the expression in the gram-positive host corynebacterium glutamicum. the in vitro activity of the enzyme was investigated in comparison to that of heptosyltransferase ... | 2000 | 11054112 |
| pathway analysis and metabolic engineering in corynebacterium glutamicum. | the gram-positive bacterium corynebacterium glutamicum is used for the industrial production of amino acids, e.g. of l-glutamate and l-lysine. during the last 15 years, genetic engineering and amplification of genes have become fascinating methods for studying metabolic pathways in greater detail and for the construction of strains with the desired genotypes. in order to obtain a better understanding of the central metabolism and to quantify the in vivo fluxes in c. glutamicum, the [13c]-labelli ... | 2000 | 11076021 |
| tetz, a new tetracycline resistance determinant discovered in gram-positive bacteria, shows high homology to gram-negative regulated efflux systems. | the complete nucleotide sequence of the tetracycline resistance plasmid pag1 from the gram-positive soil bacterium corynebacterium glutamicum 22243 (formerly corynebacterium melassecola 22243) was determined. the r-plasmid has a size of 19,751 bp and contains at least 18 complete open reading frames. the resistance determinant of pag1 revealed homology to gram-negative tetracycline efflux and repressor systems of tet classes a through j. the highest levels of amino acid sequence similarity were ... | 2000 | 11078655 |
| functions of the membrane-associated and cytoplasmic malate dehydrogenases in the citric acid cycle of corynebacterium glutamicum. | like many other bacteria, corynebacterium glutamicum possesses two types of l-malate dehydrogenase, a membrane-associated malate:quinone oxidoreductase (mqo; ec 1.1.99.16) and a cytoplasmic malate dehydrogenase (mdh; ec 1.1.1.37) the regulation of mdh and of the three membrane-associated dehydrogenases mqo, succinate dehydrogenase (sdh), and nadh dehydrogenase was investigated. mqo, mdh, and sdh activities are regulated coordinately in response to the carbon and energy source for growth. compare ... | 2000 | 11092846 |
| functions of the membrane-associated and cytoplasmic malate dehydrogenases in the citric acid cycle of escherichia coli. | oxidation of malate to oxaloacetate in escherichia coli can be catalyzed by two enzymes: the well-known nad-dependent malate dehydrogenase (mdh; ec 1.1.1.37) and the membrane-associated malate:quinone-oxidoreductase (mqo; ec 1.1.99.16), encoded by the gene mqo (previously called yojh). expression of the mqo gene and, consequently, mqo activity are regulated by carbon and energy source for growth. in batch cultures, mqo activity was highest during exponential growth and decreased sharply after on ... | 2000 | 11092847 |
| rapid cloning of metk encoding methionine adenosyltransferase from corynebacterium glutamicum by screening a genomic library on a high density colony-array. | the genes sam1 and sam2 encoding the two different methionine adenosyltransferases (ec 2.5.1.6) in saccharomyces cerevisiae were used as templates to generate specific dna-probes. this heterologous mixture of dna-probes was hybridized under low stringency hybridization conditions to a corynebacterium glutamicum colony-array representing the complete genome. subsequently, one genomic fragment was isolated which contained the c. glutamicum methionine adenosyltransferase gene metk (1.224 kb). when ... | 2000 | 11094286 |
| diversity of l-methionine catabolism pathways in cheese-ripening bacteria. | enzymatic activities that could be involved in methanethiol generation in five cheese-ripening bacteria were assayed, and the major sulfur compounds produced were identified. l-methionine and alpha-keto-gamma-methyl-thio-butyric acid demethiolating activities were detected in whole cells and cell extracts (cfes) of all the bacteria tested. no l-methionine deaminase activity could be detected in any of the ripening bacteria and l-methionine aminotransferase was detected in cfes of brevibacterium ... | 2000 | 11097940 |
| the three-dimensional structure of the ternary complex of corynebacterium glutamicum diaminopimelate dehydrogenase-nadph-l-2-amino-6-methylene-pimelate. | the three-dimensional (3d) structure of corynebacterium glutamicum diaminopimelate d-dehydrogenase in a ternary complex with nadph and l-2-amino-6-methylene-pimelate has been solved and refined to a resolution of 2.1 a. l-2-amino-6-methylene-pimelate was recently synthesized and shown to be a potent competitive inhibitor (5 microm) vs. meso-diaminopimelate of the bacillus sphaericus dehydrogenase (sutherland et al., 1999). diaminopimelate dehydrogenase catalyzes the reversible nadp+ -dependent o ... | 2000 | 11106178 |
| a novel hydrophobic diheme c-type cytochrome. purification from corynebacterium glutamicum and analysis of the qcrcba operon encoding three subunit proteins of a putative cytochrome reductase complex. | electrophoresis of a corynebacterium glutamicum membrane preparation in the presence of sodium dodecyl sulfate, followed by staining for peroxidase activity (heme staining), showed only one band at about 28 kda. this 28 kda protein was purified from c. glutamicum membranes by chromatography in the presence of decylglucoside using deae-toyopearl and hydroxylapatite columns, as the sole c-type cytochrome in the bacterium. the cytochrome showed an alpha band at 551 nm, and its e(m, 7) was about 210 ... | 2001 | 11115640 |
| serine 187 is a crucial residue for allosteric regulation of corynebacterium glutamicum 3-deoxy-d-arabino-heptulosonate-7-phosphate synthase. | corynebacterium glutamicum 3-deoxy-d-arabino-heptulosonate-7-phosphate (dahp) synthase is sensitive to feedback inhibition by tyrosine. one feedback-insensitive mutant was obtained by in vitro chemical mutagenesis and the mutation was identified as a c-->g mutation at nucleotide 560 causing a ser(187) to cys(187) substitution. replacing ser(187) with cysteine, tyrosine or phenylalanine by site-directed mutagenesis not only reduced the enzymatic activity but also relieved its feedback inhibition ... | 2001 | 11150666 |
| multiplicity of ammonium uptake systems in corynebacterium glutamicum: role of amt and amtb. | in corynebacterium glutamicum, a gram-positive soil bacterium widely used in the industrial production of amino acids, two genes encoding (putative) ammonium uptake carriers have been described. the isolation of amt was the first report of the sequence of a gene encoding a bacterial ammonium uptake system combined with the characterization of the corresponding protein. recently, a second amt gene, amtb, with so far unknown function, was isolated. the isolation of this gene and the suggestion of ... | 2001 | 11160807 |
| the low-molecular-mass subunit of the cell wall channel of the gram-positive corynebacterium glutamicum. immunological localization, cloning and sequencing of its gene pora. | the 5-kda protein pora of the gram-positive bacterium corynebacterium glutamicum is the subunit of the cell wall channel. antibodies raised against pora specifically detected the protein on the cell surface. pora was sequenced using edman degradation and a gas phase sequencer. the primary sequence was used to create degenerate oligonucleotide primers. the gene of the channel-forming protein and its flanking regions were obtained by pcr followed by inverse pcr. the gene pora comprises 138 bp and ... | 2001 | 11168383 |
| stereochemical applications of the expression of the l-2,3-butanediol dehydrogenase gene in escherichia coli. | the l-2,3-butanediol dehydrogenase (l-bdh) gene of brevibacterium saccharolyticum was strongly expressed in escherichia coli using the tac promoter. however, the stereospecificity of the resulting l-bdh was reduced. the region upstream of the meso-bdh gene of klebsiella pneumoniae was also involved in the expression of the b. saccharolyticum gene. however, in this case, the resulting l-bdh exhibited more stable stereospecificity. a stereospecificity recognition region was located within the rear ... | 2001 | 11169050 |
| a highly specific monomeric isocitrate dehydrogenase from corynebacterium glutamicum. | the monomeric isocitrate dehydrogenase (idh) of corynebacterium glutamicum is compared to the topologically distinct dimeric idh of escherichia coli. both idhs have evolved to efficiently catalyze identical reactions with similar ph optimum as well as striking specificity toward nadp and isocitrate. however, the monomeric idh is 10-fold more active (calculated as kcat/km.isocitrate/km.nadp) and 7-fold more nadp-specific than the dimeric enzyme, favoring nadp over nad by a factor of 50,000. such ... | 2000 | 11185559 |
| l-glutamate efflux with corynebacterium glutamicum: why is penicillin treatment or tween addition doing the same? | | 2001 | 11200230 |
| a corynebacterium glutamicum mutant with a defined deletion within the rplk gene is impaired in (p)ppgpp accumulation upon amino acid starvation. | the rplk gene of corynebacterium glutamicum atcc13032 comprises 438 nucleotides and encodes a protein of 145 amino acids with a molecular mass of 15.3 kda. the amino acid sequence revealed extensive similarities to the large ribosomal subunit protein l11 from several gram-positive and gram-negative bacteria. the c. glutamicum rplk gene is located downstream of sece, representing part of the protein export apparatus, and of nusg, encoding a transcription antiterminator protein. the rplk gene is f ... | 2001 | 11238976 |
| sequence analysis of the aminoacylase-1 family. a new proposed signature for metalloexopeptidases. | the amino acid sequence analysis of the human and porcine aminoacylases-1, the carboxypeptidase s precursor from saccharomyces cerevisiae, the succinyl-diaminopimelate desuccinylase from escherichia coli, haemophilus influenzae and corynebacterium glutamicum, the acetylornithine deacetylase from escherichia coli and dictyostelium discoideum and the carboxypeptidase g(2) precursor from pseudomonas strain, using the basic local alignment search tool (blast) and the position-specific iterated blast ... | 2001 | 11250542 |
| modeling and experimental design for metabolic flux analysis of lysine-producing corynebacteria by mass spectrometry. | experimental design of (13)c-tracer studies for metabolic flux analysis with mass spectrometric determination of labeling patterns was performed for the central metabolism of corynebacterium glutamicum comprising various flux scenarios. ratio measurement of mass isotopomer pools of corynebacterium products lysine, alanine, and trehalose is sufficient to quantify the flux partitioning ratios (i) between glycolysis and pentose phosphate pathways (phi(ppp)), (ii) between the split pathways in the l ... | 2001 | 11289793 |
| application of maldi-tof ms to lysine-producing corynebacterium glutamicum: a novel approach for metabolic flux analysis. | in the present work, a novel comprehensive approach of (13)c-tracer studies with labeling measurements by maldi-tof ms, and metabolite balancing was developed to elucidate key fluxes in the central metabolism of lysine producing corynebacterium glutamicum during batch culture. maldi-tof ms methods established allow the direct quantification of labeling patterns of low molecular mass corynebacterium products from 1 microl of diluted culture supernatant. a mathematical model of the central coryneb ... | 2001 | 11298764 |
| organization and transcriptional analysis of a six-gene cluster around the rplk-rpla operon of corynebacterium glutamicum encoding the ribosomal proteins l11 and l1. | a cluster of six genes, trna(trp)-sece-nusg-rplk-rpla-pkwr, was cloned and sequenced from a corynebacterium glutamicum cosmid library and shown to be contiguous in the c. glutamicum genome. these genes encode a tryptophanyl trna, the protein translocase component sece, the antiterminator protein nusg, and the ribosomal proteins l11 and l1 in addition to pkwr, a putative regulatory protein of the laci-galr family. s1 nuclease mapping analysis revealed that nusg and rplk are expressed as separate ... | 2001 | 11319098 |
| development and validation of corynebacterium dna microarrays. | we have developed dna microarray techniques for studying corynebacterium glutamicum. a set of 52 c. glutamicum genes encoding enzymes from primary metabolism was amplified by pcr and printed in triplicate onto glass slides. total rna was extracted from cells harvested during the exponential-growth and lysine production phases of a c. glutamicum fermentation. fluorescently labeled cdnas were prepared by reverse transcription using random hexamer primers and hybridized to the microarrays. to estab ... | 2001 | 11319117 |
| pyruvate carboxylase is a major bottleneck for glutamate and lysine production by corynebacterium glutamicum. | corynebacterium glutamicum possesses both phosphoenolpyruvate carboxylase (pepcx) and pyruvate carboxylase (pcx) as anaplerotic enzymes for growth on carbohydrates. to analyze the significance of pcx for the amino acid production by this organism, the wild-type pyc gene, encoding pcx, was used for the construction of defined pyc-inactive and pyc-overexpressing strains and the glutamate, lysine and threonine production capabilities of these recombinant strains of c. glutamicum were tested in comp ... | 2001 | 11321586 |
| structure of the urease operon of corynebacterium glutamicum. | urease activity of corynebacterium glutamicum results in a rapid ph increase upon addition of urea to the growth medium. the urease operon c. glutamicum was isolated of and sequenced. seven open reading frames were identified; urea, ureb, and urec were homologues of other bacterial urease structural genes, uree, uref, ureg, and ured exhibited homology to urease accessory genes. disruption of urec prevented the utilization of urea as a nitrogen source by c. glutamicum. urease activity was induced ... | 2000 | 11328647 |
| l-glutamic acid production in a novel three phase fluidized bed reactor using coimmobilized bio-catalyst. | the production of l-glutamic acid has been studied using coimmobilized whole cells of pseudomonas reptilivora and micrococcus glutamicus in a three phase fluidized bed bioreactor with selected production medium enriched with glucose. the effect of initial substrate concentration, temperature, ph and aeration rate on the yield of glutamic acid has been investigated. it has been found that the acid production increases exponentially with substrate concentration and mass transfer co-efficient varie ... | 2001 | 11347434 |
| properties of the corynebacterium glutamicum metc gene encoding cystathionine beta-lyase. | the metc gene encoding the cystathionine beta-lyase, the third enzyme in the methionine biosynthetic pathway, was isolated from corynebacterium glutamicum by heterologous complementation of the escherichia coli metc mutant. a dna-sequence analysis of the cloned dna identified two open-reading frames (orfs) of orf1 and orf2 that consisted of 1,107 and 978 bp, respectively. a sds-page analysis identified a putative cystathionine beta-lyase band with approximate mr of 41,000 that consisted of 368 a ... | 2001 | 11355704 |
| corynebacterium glutamicum: a dissection of the pts. | the high-gc gram-positive actinomycete corynebacterium glutamicum is commercially exploited as a producer of amino acids that are used as animal feed additives and flavor enhancers. despite its beneficial role, carbon metabolism and its possible influence on amino acid metabolism is poorly understood. we have addressed this issue by analyzing the phosphotransferase system (pts), which in many bacteria controls the flux of nutrients and therefore regulates carbon metabolism. the general pts phosp ... | 2001 | 11361073 |
| identification of essential cysteine residues in 3-deoxy-d-arabino-heptulosonate-7-phosphate synthase from corynebacterium glutamicum. | to ascertain the functional role of cysteine residue in 3-deoxy-d-arabino-heptulosonate-7-phosphate (dahp) synthase from corynebacterium glutamicum, site-directed mutagenesis was performed to change each of the three residues to serine. plasmids were constructed for high-level overproduction and one-step purification of histidine-tagged dahp synthase. analysis of the purified wild-type and mutant enzymes by sds-polyacrylamide gel electrophoresis showed an apparent protein band with a molecular m ... | 2001 | 11381336 |
| molecular analysis of the cytochrome bc1-aa3 branch of the corynebacterium glutamicum respiratory chain containing an unusual diheme cytochrome c1. | in this work, the genes for cytochrome aa3 oxidase and the cytochrome bc1 complex in the gram-positive soil bacterium corynebacterium glutamicum were identified. the monocistronic ctad gene encoded a 65-kda protein with all features typical for subunit i of cytochrome aa3 oxidases. a ctad deletion mutant lacked the characteristic 600 nm peak in redox difference spectra, and growth in glucose minimal medium was strongly impaired. the genes encoding subunit iii of cytochrome aa3 (ctae) and the thr ... | 2001 | 11382224 |
| effect of gluconic acid as a secondary carbon source on non-growing l-lysine producers cells of corynebacterium glutamicum. purification and properties of 6-phosphogluconate dehydrogenase. | we studied the production of l-lysine in corynebacterium glutamicum atcc 21543 non growing cells obtained by nutrient limitation. statistical analysis revealed significant differences in the l-lysine titers of glucose, gluconic acid or glucose-gluconic acid cultures. higher l-lysine titer obtained in batch cultures with mixed carbon sources or gluconic acid alone were found to be associated with a high 6-phosphogluconate dehydrogenase activity (6pgdh, e.c.1.1.1.44). this enzyme is a pivotal enzy ... | 2001 | 11397455 |
| isolation of ftsi and mure genes involved in peptidoglycan synthesis from corynebacterium glutamicum. | corynebacterium glutamicum is known to excrete large amounts of l-glutamic acid upon treatment by penicillin. however, the mechanism of l-glutamate overproduction by penicillin treatment is still unknown. a 5.3-kb hindiii fragment was isolated by directly introducing the c. glutamicum (brevibacterium lactofermentum) atcc 13869 gene library into the temperature-sensitive escherichia coli mure mutant and selecting temperature resistant clones. two open reading frames (orfs) were found in this frag ... | 2001 | 11398928 |
| proteome analysis of corynebacterium glutamicum. | by the use of different corynebacterium glutamicum strains more than 1.4 million tons of amino acids, mainly l-glutamate and l-lysine, are produced per year. a project was started recently to elucidate the complete dna sequence of this bacterium. in this communication we describe an approach to analyze the c. glutamicum proteome, based on this genetic information, by a combination of two-dimensional (2-d) gel electrophoresis and protein identification via microsequencing or mass spectrometry. we ... | 2001 | 11425227 |
| expression control and specificity of the basic amino acid exporter lyse of corynebacterium glutamicum. | lyse of corynebacterium glutamicum belongs to a large new superfamily of translocators whose members are probably all involved in the export of small solutes. here, the transcript initiation site of lyse, and its divergently transcribed regulator gene, lysg, are identified. single-copy transcriptional fusions of lyse with lacz, and titration experiments, show that lysg is the positive regulator of lyse expression enabling its up to 20-fold induction. this induction requires the presence of a coi ... | 2001 | 11429454 |
| expression and functional analysis of a gene cluster involved in the synthesis of decaprenoxanthin reveals the mechanisms for c50 carotenoid formation. | corynebacterium glutamicum accumulates the c50 carotenoid decaprenoxanthin. rescued dna from transposon color mutants of this gram-positive bacterium was used to clone the carotenoid biosynthetic gene cluster. by sequence comparison and functional complementation, the genes involved in the synthesis of carotenoids with 50 carbon atoms were identified. the genes crte, encoding a geranylgeranyl pyrophosphate synthase, crtb, encoding a phytoene synthase, and crti, encoding a phytoene desaturase, ar ... | 2001 | 11432736 |
| digested bacterial cell powder (dbcp) as a source of reduced-form folates for pigs: use of a trimethoprim-resistant strain and the bioavailability of folates in dbcp. | the production of digested bacterial cell powder (dbcp) as a source of reduced-form folates for pigs was studied. trimethoprim-resistant mutants of brevibacterium lactofermentum atcc 13869 accumulated a significantly higher amount of the reduced form of folate in the cells than the wild-type strain. dbcps were prepared from the resistant mutant strain and the wild-type strain. the utilization of the reduced-form of folate in dbcp was evaluated by measuring the plasma folate level after orally ad ... | 2001 | 11440122 |
| relaxed rrn expression and amino acid requirement of a corynebacterium glutamicum rel mutant defective in (p)ppgpp metabolism. | the stringent response in corynebacterium glutamicum was investigated. sets of rrn-cat fusions were constructed in their native chromosomal position to examine the effects of amino acid starvation in a rel(+) strain and a deltarel mutant defective in (p)ppgpp metabolism. the expression of the six rrn operons in the rel(+) control was stringently regulated and reduced to 79% upon induction of amino acid starvation. the deltarel mutant displayed a relaxed regulation and was unable to reduce the rr ... | 2001 | 11445167 |
| glutamine synthetases of corynebacterium glutamicum: transcriptional control and regulation of activity. | regulation of glna expression and glutamine synthetase i activity was analyzed in corynebacterium glutamicum. transcription is regulated by the global repressor protein amtr, essential for derepression of glna transcription are glnk and uridylyltransferase, key proteins of the c. glutamicum nitrogen regulatory system. glutamine synthetase i activity is controlled by adenylylation/deadenylylation via adenylyltransferase. the gene encoding this bifunctional enzyme, glne, was isolated and its funct ... | 2001 | 11445173 |
| maldi-tof ms for quantification of substrates and products in cultivations of corynebacterium glutamicum. | the application of maldi-tof ms for the quantification of lysine, alanine, and glucose is described. the method is based on using stable isotopes as internal standards and allows fast, sensitive, and reproducible quantification of these compounds. it is demonstrated for aqueous standard solutions with concentrations of the analytes between 10 microm and 100 mm. the mean standard deviations from five replicates each were 4.3% (lysine), 3.7% (alanine), and 3.2% (glucose). in addition, sucrose coul ... | 2001 | 11460256 |
| a universal framework for 13c metabolic flux analysis. | a general methodology is presented for the modeling, simulation, design, evaluation, and statistical analysis of (13)c-labeling experiments for metabolic flux analysis. the universal software framework 13c-flux was implemented to support all steps of this process. guided by the example of anaplerotic flux determination in corynebacterium glutamicum, the technical details of the model setup, experimental design, and data evaluation are discussed. it is shown how the network structure, the input s ... | 2001 | 11461148 |
| study of mycoloyl transferase transport across the cell envelope of corynebacterium glutamicum. | ps1 is a major exported protein of corynebacterium glutamicum homologous to mycobacterial antigen 85. it is largely associated with the mycolic acid-containing cell wall and acts as a mycoloyl transferase. the transport of ps1 to the cell wall is slow and occurs through two energetically distinct steps: the first one, which includes processing by signal peptidase, is rapid and inhibited by sodium azide or carbonyl cyanide m-chlorophenylhydrazone. this step is probably associated with translocati ... | 2001 | 11470353 |
| lipoamide dehydrogenase from corynebacterium glutamicum: molecular and physiological analysis of the lpd gene and characterization of the enzyme. | lipoamide dehydrogenase (lpd) is an essential component of the pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase complexes, both playing a crucial role within the central metabolism of aerobic organisms. using oligonucleotides designed according to conserved regions of lpd amino acid sequences from several organisms, the lpd gene from corynebacterium glutamicum was identified and subsequently subcloned. the cloned lpd gene expressed in c. glutamicum cells harbouring the gene on a plasmid s ... | 2001 | 11495999 |
| the physiological effects and metabolic alterations caused by the expression of rhizobium etli pyruvate carboxylase in escherichia coli. | oxaloacetate (oaa) plays an important role in the tricarboxylic acid cycle and for the biosynthesis of a variety of cellular compounds. some microorganisms, such as rhizobium etli and corynebacterium glutamicum, are able to synthesize oaa during growth on glucose via either of the enzymes pyruvate carboxylase (pyc) or phosphoenolpyruvate carboxylase (ppc). other microorganisms, including escherichia coli, synthesize oaa during growth on glucose only via ppc because they lack pyc. in this study w ... | 2001 | 11499929 |
| detailed biosynthetic pathway to decaprenoxanthin diglucoside in corynebacterium glutamicum and identification of novel intermediates. | carotenogenic mutants of corynebacterium glutamicum were analyzed for their carotenoid content. mutant mv10 accumulated the same carotenoids as the wild-type, decaprenoxanthin, decaprenoxanthin monoglucoside, and (2r,6r,2'r,6'r)-decaprenoxanthin di-(beta-d)-glucoside, but in three-fold higher amounts. in addition, decaprenoxanthin diglucoside fatty acid esters and the intermediates nonaprene, 2-(3-methyl-2-butenyl)-epsilon,psi-carotene, and sarcinene, 2,2'-bis(3-methyl-2-butenyl)-epsilon,epsilon ... | 2001 | 11511870 |
| l-threonine export: use of peptides to identify a new translocator from corynebacterium glutamicum. | bacterial mechanisms for the uptake of peptides and their hydrolysis to amino acids are known in great detail, whereas much less is known about the fates of the peptide-derived amino acids. we show that the addition of l-threonine-containing di- or tripeptides results in reduction of the growth of corynebacterium glutamicum, with concomitant high intracellular accumulation of l-threonine to up to 130 mm. using transposon mutagenesis and isolation of mutants with increased thr peptide sensitivity ... | 2001 | 11514515 |
| single and double overexpression of c(4)-cycle genes had differential effects on the pattern of endogenous enzymes, attenuation of photorespiration and on contents of uv protectants in transgenic potato and tobacco plants. | to improve the efficiency of co(2) fixation in c(3) photosynthesis, c(4)-cycle genes were overexpressed in potato and tobacco plants either individually or in combination. overexpression of the phosphoenolpyruvate carboxylase (pepc) gene (ppc) from corynebacterium glutamicum (cppc) or from potato (stppc, deprived of the phosphorylation site) in potato resulted in a 3-6-fold induction of endogenous cytosolic nadp malic enzyme (me) and an increase in the activities of nad-me (3-fold), nadp isocitr ... | 2001 | 11520867 |
| cloning, sequencing, and functional analysis of three glycosyltransferases involved in the biosynthesis of the inner core region of klebsiella pneumoniae lipopolysaccharide. | the genes encoding the 3-deoxy-d-manno-oct-2-ulosonic acid (kdo) transferase (waaa) and heptosyltransferases i (waac) and ii (waaf) in klebsiella pneumoniae were cloned from a dna library by functional complementation of corresponding escherichia coli and salmonella enterica mutants. sequence analyses revealed extensive homologies of the deduced proteins to their counterparts in other enterobacteriaceae. however, differences were evident with regard to the chromosomal organization of the genes. ... | 2001 | 11521078 |
| the cell division genes ftsq and ftsz, but not the three downstream open reading frames yfih, orf5 and orf6, are essential for growth and viability in brevibacterium lactofermentum atcc 13869. | the three orfs (yfih, orf5 and orf6) located downstream of the cell division genes ftsq and ftsz in brevibacterium lactofermentum were disrupted by single homologous recombination events between internal fragments of the corresponding genes and the chromosomal sequences. the phenotypes of the disrupted mutants were similar to that of the wild type, suggesting that these genes are dispensable for growth and viability. however, using different plasmid constructs, it was not possible to obtain disr ... | 2001 | 11523774 |
| the involvement of cd14 in the activation of human monocytes by peptidoglycan monomers. | cell-wall components of gram-positive and gram-negative bacteria induce the production of cytokines in human peripheral blood mononuclear cells. these cytokines are the main mediators of local or systemic inflammatory reaction that can contribute to the development of innate immunity. | 2001 | 11545252 |
| regulation of aromatic amino acid biosynthesis in gamma-proteobacteria. | computational comparative techniques were applied to analysis of the aromatic amino acid regulons in gamma-proteobacteria. this resulted in characterization of the trpr and tyrr regulons in the genomes of yersinia pestis, haemophilus influenzae, vibrio cholerae and other bacteria and identification of new members of the phhr regulon in the genome of pseudomonas aeruginosa. candidate attenuators were constructed for all studied genomes, including the trpba operon of the very distantly related bac ... | 2001 | 11545272 |
| identification of two mycobacterium avium subspecies paratuberculosis gene products differentially recognised by sera from rabbits immunised with live mycobacteria but not heat-killed mycobacteria. | the investigation of environmentally regulated proteins has led to a better understanding of host-pathogen interactions and identified novel vaccine candidate antigens for several bacterial pathogens. in an effort to identify such proteins in mycobacterium avium subsp. paratuberculosis (m. paratuberculosis), a genomic expression library was differentially screened with sera from rabbits that had been immunised with live m. paratuberculosis (alpha-live) as well as sera from rabbits immunised with ... | 2001 | 11549181 |
| gene lmrb of corynebacterium glutamicum confers efflux-mediated resistance to lincomycin. | the lmrb gene of corynebacterium glutamicum, which confers specific resistance to lincosamides, such as lincomycin and clindamycin, was isolated. c. glutamicum cells, carrying the lmrb gene in a multicopy plasmid, showed increased resistance to lincomycin with a mic of 230 microg/ml, which is a 9-fold increase compared to that of the wild type. the lmrb-disrupted mutant became sensitive to the compound. no difference in sensitivity to erythromycin, penicillin g, tetracycline, chloramphenicol, sp ... | 2001 | 11561719 |
| characterization of the phosphoenolpyruvate carboxykinase gene from corynebacterium glutamicum and significance of the enzyme for growth and amino acid production. | corynebacterium glutamicum possesses phosphoenolpyruvate (pep) carboxykinase, oxaloacetate decarboxylase and malic enzyme, all three in principle being able to catalyze the first step in gluconeogenesis. to investigate the role of pep carboxykinase for growth and amino acid production, the respective pck gene was isolated, characterized and used for construction and analysis of mutants and overexpressing strains. sequence analysis of the pck gene predicts a polypeptide of 610 amino acids showing ... | 2001 | 11565516 |
| the osmoreactive betaine carrier betp from corynebacterium glutamicum is a sensor for cytoplasmic k+. | the isolated glycine betaine uptake carrier betp from corynebacterium glutamicum was reconstituted in escherichia coli phospholipid liposomes and its response to osmotic stress studied. the transport activity of betp, which was previously shown to comprise both osmosensory and osmoregulatory functions, was used to identify the nature of the physicochemical stimulus related to hyperosmotic stress. putative factors modulating transport activity in response to osmotic stress were dissected. these i ... | 2001 | 11574473 |
| cytochrome c oxidase contains an extra charged amino acid cluster in a new type of respiratory chain in the amino-acid-producing gram-positive bacterium corynebacterium glutamicum. | the membranes from corynebacterium glutamicum cells contain a hydrophobic di-haem c protein as the cytochrome c subunit of the new type of cytochrome bc complex (complex iii in the respiratory chain) encoded by the qcrcab operon [sone, n., nagata, k., kojima, h., tajima, j., kodera, y., kanamaru, t., noguchi, s. & sakamoto, j. (2001). biochim biophys acta 1503, 279-290]. to characterize complex iv, cytochrome c oxidase and its structural genes were isolated. the oxidase is of the cytochrome aa(3 ... | 2001 | 11577165 |
| purification and characterization of l-2,3-butanediol dehydrogenase of brevibacterium saccharolyticum c-1012 expressed in escherichia coli. | the l-2,3-butanediol dehydrogenase produced in e. coli jm109/plbd2-ctc was purified by 5 steps. the molecular mass of this enzyme was estimated at 110 kda and the subunit was measured to be 30 kda. the l-bdh had some differences from the bdhs from other sources in substrate specificity, pi value, ph stability, effects of divalent cations, and organic acids. | 2001 | 11577733 |
| growth rate influences reductive biodegradation of the organophosphorus pesticide demeton by corynebacterium glutamicum. | the organophosphorous pesticide, demeton-s-methyl was transformed by corynebacterium glutamicum in co-metabolism with more readily degradable substrates. glucose, acetate and fructose were tested as growth substrates, and the highest demeton-s-methyl biotransformation average rate (0.78 mg l(-1) h(-1)) and maximum instantaneous rate (1.4 mg l(-1) h(-1)) were achieved on fructose. this higher efficiency seems to be linked to the atypical behavior of c. glutamicum grown on fructose, characterized ... | 2000 | 11587440 |
| metabolic consequences of altered phosphoenolpyruvate carboxykinase activity in corynebacterium glutamicum reveal anaplerotic regulation mechanisms in vivo. | corynebacterium glutamicum possesses high in vivo activity of the gluconeogenic phosphoenolpyruvate carboxykinase (pepck) during growth on glucose, resulting together with anaplerotic carboxylation reactions in a pep/pyruvate/oxaloacetate substrate cycle. the present study investigated the changes in intracellular fluxes and metabolite concentrations that are caused by altered pepck activity in l-lysine-producing c. glutamicum mh20-22b, applying a recently developed (13)c labeling-based strategy ... | 2001 | 11676569 |
| cloning and transcriptional characterization of two sigma factor genes, siga and sigb, from brevibacterium flavum. | using a dna fragment containing the principal sigma factor gene hrdb of streptomyces aureofaciens, we identified two sigma70-like genes in a library of brevibacterium flavum. sequence analysis of the complete genes revealed two orfs coding for gene products of 498 and 331 amino acid residues, which showed the greatest similarity to siga and sigb sigma factors from brevibacterium lactofermentum. we designated them similarly siga and sigb. transcription of b. flavum siga and sigb has been investig ... | 2001 | 11683358 |
| l-glutamate production by lysozyme-sensitive corynebacterium glutamicum ltsa mutant strains. | a non-pathogenic species of coryneform bacteria, corynebacterium glutamicum, was originally isolated as an l-glutamate producing bacterium and is now used for fermentative production of various amino acids. a mutation in the c. glutamicum ltsa gene caused susceptibility to lysozyme, temperature-sensitive growth, and l-glutamate production. | 2001 | 11696248 |
| glutamate synthase of corynebacterium glutamicum is not essential for glutamate synthesis and is regulated by the nitrogen status. | the corynebacterium glutamicum gltb and gltd genes, encoding the large (alpha) and small (beta) subunit of glutamate synthase (gogat), were investigated in this study. using rt-pcr, a common transcript of gltb and gltd was shown. reporter gene assays and northern hybridization experiments revealed that transcription of this operon depends on nitrogen starvation. the expression of gltbd is under control of the global repressor protein amtr as demonstrated by gel shift experiments and analysis of ... | 2001 | 11700347 |
| purification and characterization of an enzyme from mycobacterium sp. pyr-1, with nitroreductase activity and an n-terminal sequence similar to lipoamide dehydrogenase. | mycobacterium sp. pyr-1 produces an enzyme with nitroreductase activity that reduces 1-nitropyrene and 4-nitrobenzoic acid to the corresponding aromatic amines. this enzyme was constitutive and required nadh; and its activity was enhanced by fad. it was inhibited by antimycin a, dicumarol, and o-iodosobenzoic acid; and it was inactivated by ammonium sulfate precipitation. after purification to homogeneity, the protein produced a single band on native and sds-polyacrylamide gels and had a single ... | 2001 | 11702081 |
| construction of a xylanase-producing strain of brevibacterium lactofermentum by stable integration of an engineered xysa gene from streptomyces halstedii jm8. | a xylanolytic strain of brevibacterium lactofermentum containing the streptomyces halstedii his-tagged xysa gene was generated. the new strain contains dna derived from s. halstedii, expresses xylanolytic activity, and was obtained by an integrative process mediated by a conjugative plasmid targeted to a dispensable chromosomal region located downstream from the essential cell division gene ftsz. the his-tagged xys1 enzyme was constitutively expressed under the control of the kan promoter from t ... | 2001 | 11722888 |
| nadh dehydrogenase of corynebacterium glutamicum. purification of an nadh dehydrogenase ii homolog able to oxidize nadph. | nadph oxidase activity, in addition to nadh oxidase activity, has been shown to be present in the respiratory chain of corynebacterium glutamicum. in this study, we tried to purify nadph oxidase and nadh dehydrogenase activities from the membranes of c. glutamicum. both the enzyme activities were simultaneously purified in the same fraction, and the purified enzyme was shown to be a single polypeptide of 55 kda. the n-terminal sequence of the enzyme was consistent with the sequence deduced from ... | 2001 | 11731134 |
| identification of a novel gene involved in stable maintenance of plasmid pga1 from corynebacterium glutamicum. | the cryptic plasmid pga1 (4.8 kb) from corynebacterium glutamicum, replicating in the rolling-circle mode, has been reported to contain four open reading frames longer than 200 bp (orfa/per, orfa2, orfb, orfc/rep). here we present another pga1 gene, orfe (174 bp), located in the region downstream of the per-orfa2 gene cluster. the orfe is transcribed into two rna species in a direction opposite to that of the per-orfa2 rna. introduction of orfe in trans into the cells harboring the pga1 derivati ... | 2001 | 11735365 |
| the ptsi gene encoding enzyme i of the phosphotransferase system of corynebacterium glutamicum. | the phosphoenolpyruvate:carbohydrate phosphotransferase system (pts) is widespread among bacteria where it mediates carbohydrate uptake and often serves in carbon control. here we present cloning and analysis of the monocistronic ptsi gene of corynebacterium glutamicum r, which encodes pts enzyme i (ei). ei catalyzes the first reaction of pts and the reported ptsi was shown to complement the corresponding defect in escherichia coli. the deduced 59.2-kda ei of 564 amino acids shares more than 50% ... | 2001 | 11741338 |
| nitrogen and carbon regulation of glutamine synthetase and glutamate synthase in corynebacterium glutamicum atcc 13032. | the effect of nitrogen and carbon status on the regulation of glutamine synthetase (gs) and glutamate synthase (gogat) were investigated in corynebacterium glutamicum 13032. under carbon-sufficient, nitrogen-limiting conditions, gs and gogat activities were five- and seven-fold higher, respectively, and transcription of the corresponding genes (glna and gltbd) was similarly induced. gs activity was also induced in complete medium with added glucose, while gogat activity was unaffected. under car ... | 2001 | 11750828 |
| optimization of l-phenylalanine production of corynebacterium glutamicum under product feedback inhibition by elevated oxygen transfer rate. | production feedback inhibition both on cell growth and on product formation of phenylalanine fermentation might be alleviated by elevated oxygen supply. batch fermentations by a high phenylalanine producing strain corynebacterium glutamicum ccrc 18335 at various initial phenylalanine concentrations (p(0)) ranging from 0 to 20 g/l and different oxygen transfer rate coefficients (k(l)a) ranging from 23 to 76 h(-1) were studied. the fermentation parameters with respect to p(0) were strongly depende ... | 2002 | 11753919 |
| h+-atpase defect in corynebacterium glutamicum abolishes glutamic acid production with enhancement of glucose consumption rate. | a mutant of corynebacterim glutamicum ('brevibacterium flayum') atcc14067 with a reduced h+-atpase activity, f172-8, was obtained as a spontaneous neomycin-resistant mutant. the atpase activity of strain f172-8 was reduced to about 25% of that of the parental strain. strain f172-8 was cultured in a glutamic-acid fermentation medium containing 100 g/l of glucose using ajar fermentor. it was found that glucose consumption per cell during the exponential phase was higher by 70% in the mutant than i ... | 2001 | 11762601 |
| heterologous expression of cyanophycin synthetase and cyanophycin synthesis in the industrial relevant bacteria corynebacterium glutamicum and ralstonia eutropha and in pseudomonas putida. | | 2001 | 11777412 |
| metabolic redirection of carbon flow toward isoleucine by expressing a catabolic threonine dehydratase in a threonine-overproducing corynebacterium glutamicum. | carbon destined for lysine synthesis in corynebacterium glutamicum atcc 21799 can be diverted toward threonine by overexpression of genes encoding a feedback-insensitive homoserine dehydrogenase (hom(dr)) and homoserine kinase (thrb). we studied the effects of introducing two different threonine dehydratase genes into this threonine-producing system to gauge their effects on isoleucine production. co-expression of hom(dr), thrb, and ilva, which encodes a native threonine dehydratase, caused isol ... | 2001 | 11778876 |
| expression of the genes coding for the xylanase xys1 and the cellulase cel1 from the straw-decomposing streptomyces halstedii jm8 cloned into the amino-acid producer brevibacterium lactofermentum atcc13869. | the xylanase ( xysa) and the cellulase ( cela1) genes from streptomyces halstedii jm8 were cloned into escherichia coli/ brevibacterium lactofermentum shuttle vectors and successfully expressed in both hosts when placed downstream from the kanamycin resistance promoter (pkan) from tn 5 but not when under the control of their own promoters. xylanase was secreted into the culture media of b. lactofermentum by removal of the same leader peptide as is removed in s. halstedii. the main difference bet ... | 2001 | 11797049 |
| metabolic engineering for l-lysine production by corynebacterium glutamicum. | corynebacterium glutamicum has been used since several decades for the large-scale production of amino acids, esp. l-glutamate and l-lysine. after initial successes of random mutagenesis and screening approaches, further strain improvements now require a much more rational design, i.e. metabolic engineering. not only recombinant dna technology but also mathematical modelling of metabolism as well as metabolic flux analysis represent important metabolic engineering tools. this review covers as st ... | 2001 | 11816814 |
| priming and activation of mouse macrophages by trehalose 6,6'-dicorynomycolate vesicles from corynebacterium glutamicum. | vesicles consisting of pure trehalose dicorynomycolate (tdcm), the corynebacterial analog of the most studied mycobacterial glycolipid 'cord factor', were isolated from corynebacterium glutamicum cells by mild detergent treatment; these induced in vivo a macrophage priming similar to that obtained with mycobacterial-derived trehalose dimycolate. in vitro, both tdcm and bacterial lipopolysaccharide (lps) induced in macrophages the production of nitric oxide (no) and tumor necrosis factor-alpha (t ... | 2002 | 11821236 |