| effect of corynebacterium glutamicum on livestock material burial treatment. | in recent years, foot-and-mouth disease has occurred in all parts of the world. the animals with the disease are buried in the ground; therefore, their concentration could affect ground or groundwater. moreover, the complete degradation of carcasses is not a certainty, and their disposal is important to prevent humans, livestock, and the environment from being affected with the disease. the treatment of corynebacterium glutamicum is a feasible method to reduce the risk of carcass decomposition a ... | 2016 | 27160580 |
| recent advances in amino acid production by microbial cells. | amino acids have been utilized for the production of foods, animal feeds and pharmaceuticals. after the discovery of the glutamic acid-producing bacterium corynebacterium glutamicum by japanese researchers, the production of amino acids, which are primary metabolites, has been achieved using various microbial cells as hosts. recently, metabolic engineering studies on the rational design of amino acid-producing microbial cells have been successfully conducted. moreover, the technology of systems ... | 2016 | 27151315 |
| transcriptional regulation of the β-type carbonic anhydrase gene bca by rama in corynebacterium glutamicum. | carbonic anhydrase catalyzes the reversible hydration of carbon dioxide to bicarbonate and maintains the balance of co2/hco3- in the intracellular environment, specifically for carboxylation/decarboxylation reactions. in corynebacterium glutamicum, two putative genes, namely the bca (cg2954) and gca (cg0155) genes, coding for β-type and γ-type carbonic anhydrase, respectively, have been identified. we here analyze the transcriptional organization of these genes. the transcriptional start site (t ... | 2016 | 27119954 |
| [effect of amn gene deletion on corynebacterium glutamicum s9114 metabolism]. | to study the effect of adenosine monophosphate nucleosidase gene deletion on corynebacterium glutamicum s9114 metabolism. | 2015 | 27101699 |
| the pupylation machinery is involved in iron homeostasis by targeting the iron storage protein ferritin. | the balance of sufficient iron supply and avoidance of iron toxicity by iron homeostasis is a prerequisite for cellular metabolism and growth. here we provide evidence that, in actinobacteria, pupylation plays a crucial role in this process. pupylation is a posttranslational modification in which the prokaryotic ubiquitin-like protein pup is covalently attached to a lysine residue in target proteins, thus resembling ubiquitination in eukaryotes. pupylated proteins are recognized and unfolded by ... | 2016 | 27078093 |
| enhanced succinic acid production in corynebacterium glutamicum with increasing the available nadh supply and glucose consumption rate by decreasing h(+)-atpase activity. | to enhance succinic acid production in corynebacterium glutamicum by increasing the supply of nadh and the rate of glucose consumption by decreasing h(+)-atpase activity. | 2016 | 27053082 |
| mycothiol peroxidase mpx protects corynebacterium glutamicum against acid stress by scavenging ros. | to investigate mycothiol peroxidase (mpx) of corynebacterium glutamicum that is a novel cysgpx family peroxidase using both the mycoredoxin and thioredoxin reducing systems as proton donors for peroxide detoxification and may be involved in the relief of acid stress. | 2016 | 27053080 |
| characterization of aspartate kinase and homoserine dehydrogenase from corynebacterium glutamicum iwj001 and systematic investigation of l-isoleucine biosynthesis. | previously we have characterized a threonine dehydratase mutant td(f383v) (encoded by ilva1) and an acetohydroxy acid synthase mutant ahas(p176s, d426e, l575w) (encoded by ilvbn1) in corynebacterium glutamicum iwj001, one of the best l-isoleucine producing strains. here, we further characterized an aspartate kinase mutant ak(a279t) (encoded by lysc1) and a homoserine dehydrogenase mutant hd(g378s) (encoded by hom1) in iwj001, and analyzed the consequences of all these mutant enzymes on amino aci ... | 2016 | 27033538 |
| enhancing pentose phosphate pathway in corynebacterium glutamicum to improve l-isoleucine production. | three genes, gnd, pgl, and fbp, relevant to the pentose phosphate pathway (ppp) were overexpressed in corynebacterium glutamicum iwj001, leading to increase of l-isoleucine production. the transcriptional levels of gnd, pgl, and fbp significantly increased in iwj001/pdxw-8-gnd-fbp-pgl. compared with the control strain iwj001/pdxw-8, intracellular nadph/nadp(+) ratios in iwj001/pdxw-8-gnd and iwj001/pdxw-8-gnd-fbp cells grown for 36 h increased threefold and fourfold, respectively, indicating tha ... | 2016 | 27010514 |
| spie interacts with corynebacterium glutamicum whce and is involved in heat and oxidative stress responses. | the gene whce in corynebacterium glutamicum positively responds to oxidative and heat stress. to search for proteins that interact with whce, we employed a two-hybrid system with whce as the bait. sequencing analysis of the isolated clones revealed peptide sequences, one of which showed high sequence identity to a hydrophobe/amphiphile efflux-1 family transporter encoded by ncgl1497. the interaction of the ncgl1497-encoded protein with whce in vivo was verified using reporter gene expression by ... | 2016 | 26996627 |
| detoxification of acidic biorefinery waste liquor for production of high value amino acid. | the current study evaluates the detoxification of acid pretreatment liquor (apl) using adsorbent (ads 400 & ads 800) or ion-exchange (a-27mp & a-72mp) resins and its potential for amino acid production. the apl is generated as a by-product from the pretreatment of lignocellulosic biomass and is rich monomeric sugars as well as sugar degradation products (fermentation inhibitors) such as furfural and hydroxymethyl furfural (hmf). of the four resins compared, ads 800 removed approximately 85% and ... | 2016 | 26996259 |
| pyruvate kinase deletion as an effective phenotype to enhance lysine production in corynebacterium glutamicum atcc13032: redirecting the carbon flow to a precursor metabolite. | various attempts have been made to enhance lysine production in corynebacterium glutamicum. pyruvate kinase (pyk) defect is one of the strategies used to enhance the supply of oxaloacetic acid (oaa), a precursor metabolite for lysine biosynthesis. however, inconsistent effects of this mutation have been reported: positive effects of pyk defect in mutants having phosphoenolpyruvate carboxylase (pepc) desensitized to feedback inhibition by aspartic acid, while negative effects in simple pyk gene ( ... | 2016 | 26983943 |
| efficient production of α-ketoglutarate in the gdh deleted corynebacterium glutamicum by novel double-phase ph and biotin control strategy. | production of l-glutamate using a biotin-deficient strain of corynebacterium glutamicum has a long history. the process is achieved by controlling biotin at suboptimal dose in the initial fermentation medium, meanwhile feeding nh4oh to adjust ph so that α-ketoglutarate (α-kg) can be converted to l-glutamate. in this study, we deleted glutamate dehydrogenase (gdh1 and gdh2) of c. glutamicum gkg-047, an l-glutamate overproducing strain, to produce α-kg that is the direct precursor of l-glutamate. ... | 2016 | 26946492 |
| enhancement of 1,5-diaminopentane production in a recombinant strain of corynebacterium glutamicum by tween 40 addition. | | 2016 | 26923131 |
| mutagenesis for improvement of activity and thermostability of amylomaltase from corynebacterium glutamicum. | this work aims to improve thermostability of amylomaltase from a mesophilic corynebacterium glutamicum (cgam) by random and site-directed mutagenesis. from error prone pcr, a mutated cgam with higher thermostability at 50 °c compared to the wild-type was selected and sequenced. the result showed that the mutant contains a single mutation of a406v. site-directed mutagenesis was then performed to construct a406v and a406l. both mutated cgams showed higher intermolecular transglucosylation activity ... | 2016 | 26875536 |
| optimization of large-ring cyclodextrin production from starch by amylomaltase from corynebacterium glutamicum and effect of organic solvent on product size. | to increase yield of starch conversion to large-ring cyclodextrins (lr-cds) by amylomaltase from corynebacterium glutamicum (cgam). | 2016 | 26849173 |
| the actinobacterium corynebacterium glutamicum, an industrial workhorse. | starting as a glutamate producer, corynebacterium glutamicum has played a variety of roles in the industrial production of amino acids, one of the most important areas of white biotechnology. from shortly after its genome information became available, c. glutamicum has been applied in various production processes for value-added chemicals, fuels, and polymers, as a key organism in industrial biotechnology alongside the surprising progress in systems biology and metabolic engineering. in addition ... | 2016 | 26838341 |
| corynebacterium glutamicum metabolic engineering with crispr interference (crispri). | corynebacterium glutamicum is an important organism for the industrial production of amino acids. metabolic pathways in this organism are usually engineered by conventional methods such as homologous recombination, which depends on rare double-crossover events. to facilitate the mapping of gene expression levels to metabolic outputs, we applied crispr interference (crispri) technology using deactivated cas9 (dcas9) to repress genes in c. glutamicum. we then determined the effects of target repre ... | 2016 | 26829286 |
| characterization of a unique pathway for 4-cresol catabolism initiated by phosphorylation in corynebacterium glutamicum. | 4-cresol is not only a significant synthetic intermediate for production of many aromatic chemicals, but also a priority environmental pollutant because of its toxicity to higher organisms. in our previous studies, a gene cluster implicated to be involved in 4-cresol catabolism, crecdefghir, was identified in corynebacterium glutamicum and partially characterized in vivo. in this work, we report on the discovery of a novel 4-cresol biodegradation pathway that employs phosphorylated intermediates ... | 2016 | 26817843 |
| modular optimization of a hemicellulose-utilizing pathway in corynebacterium glutamicum for consolidated bioprocessing of hemicellulosic biomass. | hemicellulose, which is the second most abundant polysaccharide in nature after cellulose, has the potential to become a major feedstock for microbial fermentation to produce various biofuels and chemicals. to utilize hemicellulose economically, it is necessary to develop a consolidated bioprocess (cbp), in which all processes from biomass degradation to the production of target products occur in a single bioreactor. here, we report a modularly engineered corynebacterium glutamicum strain suitab ... | 2016 | 26808593 |
| adaptive evolution and metabolic engineering of a cellobiose- and xylose- negative corynebacterium glutamicum that co-utilizes cellobiose and xylose. | an efficient microbial cell factory requires a microorganism that can utilize a broad range of substrates to economically produce value-added chemicals and fuels. the industrially important bacterium corynebacterium glutamicum has been studied to broaden substrate utilizations for lignocellulose-derived sugars. however, c. glutamicum atcc 13032 is incapable of pts-dependent utilization of cellobiose because it has missing genes annotated to β-glucosidases (bg) and cellobiose-specific pts permeas ... | 2016 | 26801253 |
| the extracytoplasmic function σ factor σ(c) regulates expression of a branched quinol oxidation pathway in corynebacterium glutamicum. | bacteria modify their expression of different terminal oxidases in response to oxygen availability. corynebacterium glutamicum, a facultative anaerobic bacterium of the phylum actinobacteria, possesses aa3 -type cytochrome c oxidase and cytochrome bd-type quinol oxidase, the latter of which is induced by oxygen limitation. we report that an extracytoplasmic function σ factor, σ(c) , is responsible for the regulation of this process. chromatin immunoprecipitation with microarray analysis detected ... | 2016 | 26789738 |
| complete genome sequence of corynebacterium glutamicum cp, a chinese l-leucine producing strain. | here, we report the complete genome sequence of corynebacterium glutamicum cp, an industrial l-leucine producing strain in china. the whole genome consists of a circular chromosome and a plasmid. the comparative genomics analysis shows that there are many mutations in the key enzyme coding genes relevant to l-leucine biosynthesis compared to c. glutamicum atcc 13032. | 2016 | 26784991 |
| development of a potential stationary-phase specific gene expression system by engineering of sigb-dependent cg3141 promoter in corynebacterium glutamicum. | corynebacterium glutamicum is a non-pathogenic, non-sporulating gram-positive soil bacterium that has been used for the industrial production of various proteins and chemicals. to achieve enhanced and economical production of target molecules, the development of strong auto-inducible promoters is desired, which can be activated without expensive inducers and has significant advantages for industrial-scale use. here, we developed a stationary-phase gene expression system by engineering a sigma fa ... | 2016 | 26782746 |
| metabolic engineering of corynebacterium glutamicum atcc13032 to produce s-adenosyl-l-methionine. | as an important biological methyl group donor, s-adenosyl-l-methionine is used as nutritional supplement or drug for various diseases, but bacterial strains that can efficiently produce s-adenosyl-l-methionine are not available. in this study, corynebacterium glutamicum strain hw104 which can accumulate s-adenosyl-l-methionine was constructed from c. glutamicum atcc13032 by deleting four genes thrb, metb, mcbr and ncgl2640, and six genes metk, vgb, lysc(m), hom(m), metx and mety were overexpress ... | 2016 | 26777246 |
| structure of amtr, the global nitrogen regulator of corynebacterium glutamicum, in free and dna-bound forms. | corynebacterium glutamicum is a bacterium used for industrial amino acid production, and understanding its metabolic pathway regulation is of high biotechnological interest. here, we report crystal structures of amtr, the global nitrogen regulator of c. glutamicum, in apo (2.25-å and 2.65-å resolution) and dna-bound (3-å resolution) forms. these structures reveal an all-α homodimeric tetr family regulator composed of a helix-turn-helix-hosting n-terminal dna-binding domain and a c-terminal dimer ... | 2016 | 26744254 |
| enhanced production of recombinant proteins with corynebacterium glutamicum by deletion of insertion sequences (is elements). | in most bacteria, various jumping genetic elements including insertion sequences elements (is elements) cause a variety of genetic rearrangements resulting in harmful effects such as genome and recombinant plasmid instability. the genetic stability of a plasmid in a host is critical for high-level production of recombinant proteins, and in this regard, the development of an is element-free strain could be a useful strategy for the enhanced production of recombinant proteins. corynebacterium glut ... | 2015 | 26715464 |
| rnase iii mediated cleavage of the coding region of mraz mrna is required for efficient cell division in corynebacterium glutamicum. | the corynebacterium glutamicum r cgr_1959 gene encodes an endoribonuclease of the rnase iii family. deletion mutant of cgr_1959 (δrnc mutant) showed an elongated cell shape, and presence of several lines on the cell surface, indicating a required of rnase iii for maintaining normal cell morphology in c. glutamicum. the level of mraz mrna was increased, whereas cgr_1596 mrna encoding a putative cell wall hydrolase and ftsex mrna were decreased in the δrnc mutant. the half-life of mraz mrna was si ... | 2016 | 26713407 |
| high-titer biosynthesis of hyaluronic acid by recombinant corynebacterium glutamicum. | hyaluronic acid (ha) plays important roles in human tissue system, thus it is highly desirable for various applications, such as in medical, clinic and cosmetic fields. the wild microbial producer of ha, streptococcus, was restricted by its potential pathogens, hence different recombinant hosts are being explored. in this work, we engineered corynebacterium glutamicum, a gras (generally recognized as safe) organism free of exotoxins and endotoxins to produce ha with high titer and satisfied mw . ... | 2016 | 26709615 |
| altered acetylation and succinylation profiles in corynebacterium glutamicum in response to conditions inducing glutamate overproduction. | the bacterium corynebacterium glutamicum is utilized during industrial fermentation to produce amino acids such as l-glutamate. during l-glutamate fermentation, c. glutamicum changes the flux of central carbon metabolism to favor l-glutamate production, but the molecular mechanisms that explain these flux changes remain largely unknown. here, we found that the profiles of two major lysine acyl modifications were significantly altered upon glutamate overproduction in c. glutamicum; acetylation de ... | 2016 | 26663479 |
| metabolic engineering corynebacterium glutamicum to produce triacylglycerols. | in this study, we metabolically engineered corynebacterium glutamicum to produce triacylglycerols (tags) by completing and constraining a de novo tag biosynthesis pathway. first, the plasmid pz8_tag4 was constructed which allows the heterologous expression of four genes: three (atf1 and atf2, encoding the diacylglycerol acyltransferase; pgpb, encoding the phosphatidic acid phosphatase) to complete the tag biosynthesis pathway, and one gene (tada) for lipid body assembly. second, we applied four ... | 2016 | 26645801 |
| metabolic engineering of corynebacterium glutamicum for efficient production of 5-aminolevulinic acid. | 5-aminolevulinic acid (5-ala) has recently attracted attention for its potential applications in the fields of medicine and agriculture. in this study, corynebacterium glutamicum was firstly engineered for 5-ala production via the c4 pathway. hema encoding 5-aminolevulinic acid synthase from rhodobacter sphaeroides was codon optimized and expressed in c. glutamicum atcc13032, resulting in accumulation of 5-ala. deletion of all known genes responsible for the formation of acetate and lactate furt ... | 2016 | 26616115 |
| identification of the phd gene cluster responsible for phenylpropanoid utilization in corynebacterium glutamicum. | phenylpropanoids as abundant, lignin-derived compounds represent sustainable feedstocks for biotechnological production processes. we found that the biotechnologically important soil bacterium corynebacterium glutamicum is able to grow on phenylpropanoids such as p-coumaric acid, ferulic acid, caffeic acid, and 3-(4-hydroxyphenyl)propionic acid as sole carbon and energy sources. global gene expression analyses identified a gene cluster (cg0340-cg0341 and cg0344-cg0347), which showed increased tr ... | 2016 | 26610800 |
| engineering corynebacterium glutamicum to produce 5-aminolevulinic acid from glucose. | corynebacterium glutamicum is generally regarded as a safe microorganism and is used to produce many biochemicals, including l-glutamate. 5-aminolevulinic acid (ala) is an l-glutamate derived non-protein amino acid, and is widely applied in fields such as medicine and agriculture. | 2015 | 26577071 |
| metabolic engineering of corynebacterium glutamicum for the de novo production of ethylene glycol from glucose. | development of sustainable biological process for the production of bulk chemicals from renewable feedstock is an important goal of white biotechnology. ethylene glycol (eg) is a large-volume commodity chemical with an annual production of over 20 million tons, and it is currently produced exclusively by petrochemical route. herein, we report a novel biosynthetic route to produce eg from glucose by the extension of serine synthesis pathway of corynebacterium glutamicum. the eg synthesis is achie ... | 2016 | 26556130 |
| corynebacterium glutamicum ggtb encodes a functional γ-glutamyl transpeptidase with γ-glutamyl dipeptide synthetic and hydrolytic activity. | in this work the role of γ-glutamyl transpeptidase in the metabolism of γ-glutamyl dipeptides produced by corynebacterium glutamicum atcc 13032 was studied. the enzyme is encoded by the gene ggtb (cg1090) and synthesized as a 657 amino acids long preprotein. gamma-glutamyl transpeptidase activity was found to be associated with intact cells of c. glutamicum and was abolished upon deletion of ggtb. bioinformatic analysis indicated that the enzyme is a lipoprotein and is attached to the outer side ... | 2016 | 26528625 |
| non-invasive microbial metabolic activity sensing at single cell level by perfusion of calcein acetoxymethyl ester. | phase contrast microscopy cannot give sufficient information on bacterial metabolic activity, or if a cell is dead, it has the fate to die or it is in a viable but non-growing state. thus, a reliable sensing of the metabolic activity helps to distinguish different categories of viability. we present a non-invasive instantaneous sensing method using a fluorogenic substrate for online monitoring of esterase activity and calcein efflux changes in growing wild type bacteria. the fluorescent conversi ... | 2015 | 26513257 |
| monomeric corynebacterium glutamicum n-acetyl glutamate kinase maintains sensitivity to l-arginine but has a lower intrinsic catalytic activity. | n-acetyl glutamate kinase (nagk) is a key enzyme in the synthesis of l-arginine, and l-arginine-sensitive nagk typically has hexameric architecture. defining the relationship between this architecture and l-arginine inhibition can provide a foundation to identify the key amino acids involved in the allosteric regulation network of l-arginine. in the present study, the key amino acids in the n-terminal helix (n-helix) of corynebacterium glutamicum (cg) nagk required for hexamer formation were det ... | 2016 | 26512006 |
| construction of a novel twin-arginine translocation (tat)-dependent type expression vector for secretory production of heterologous proteins in corynebacterium glutamicum. | corynebacterium glutamicum is recognized as a favorable host for the secretory production of heterologous proteins. however, there are few secretion-type expression vectors available for protein production in c. glutamicum. in this study, we constructed a shuttle expression vector pau3, which harbors the strong promoter tac-m for constitutive gene transcription, the consensus rbs sequence for protein translation, and the strong cgr_0949 signal sequence for protein secretion via the tat pathway i ... | 2015 | 26499464 |
| regulons of global transcription factors in corynebacterium glutamicum. | corynebacterium glutamicum, a high gc content gram-positive soil bacterium in actinobacteria, has been used for the industrial production of amino acids and engineered to produce various compounds, including polymer building blocks and biofuels. since its genome sequence was first published, its versatile metabolic pathways and their genetic components and regulatory mechanisms have been extensively studied. previous studies on transcriptional factors, including two-component systems and σ facto ... | 2016 | 26496920 |
| biosensor-driven adaptive laboratory evolution of l-valine production in corynebacterium glutamicum. | adaptive laboratory evolution has proven a valuable strategy for metabolic engineering. here, we established an experimental evolution approach for improving microbial metabolite production by imposing an artificial selective pressure on the fluorescent output of a biosensor using fluorescence-activated cell sorting. cells showing the highest fluorescent output were iteratively isolated and (re-)cultivated. the l-valine producer corynebacterium glutamicum δacee was equipped with an l-valine-resp ... | 2015 | 26453945 |
| metabolic engineering of a laboratory-evolved thermobifida fusca muc strain for malic acid production on cellulose and minimal treated lignocellulosic biomass. | malic acid is mainly used as an acidulant and taste enhancer in the beverage and food industry. previously, a mutant strain thermobifida fusca muc, obtained by adaptive evolution was found to accumulate malic acid on cellulose with low yield. in this study, the malic acid synthesis pathway in t. fusca muc was confirmed to be from phosphoenolpyruvate to oxaloacetate, followed by reduction of oxaloacetate to malate. to increase the yield of malic acid by the muc strain significantly, the carbon fl ... | 2017 | 26439318 |
| involvement of the osrr gene in the hydrogen peroxide-mediated stress response of corynebacterium glutamicum. | a transcriptional profile of the h2o2-adapted corynebacterium glutamicum ha strain reveals a list of upregulated regulatory genes. among them, we selected orf ncgl2298, designated osrr and analyzed its role in h2o2 adaptation. the osrr-deleted (δosrr) mutant had defective growth in minimal medium, which was even more pronounced in an osrr deletion mutant of an ha strain. the δosrr strain displayed increased sensitivity to h2o2. in addition to h2o2 sensitivity, the δosrr strain was found to be te ... | 2016 | 26433092 |
| arar, an l-arabinose-responsive transcriptional regulator in corynebacterium glutamicum atcc 31831, exerts different degrees of repression depending on the location of its binding sites within the three target promoter regions. | in corynebacterium glutamicum atcc 31831, a laci-type transcriptional regulator arar, represses the expression of l-arabinose catabolism (arabda), uptake (arae), and the regulator (arar) genes clustered on the chromosome. arar binds to three sites: one (bsb) between the divergent operons (arabda and galm-arar) and two (bse1 and bse2) upstream of arae. l-arabinose acts as an inducer of the arar-mediated regulation. here, we examined the roles of these arar-binding sites in the expression of the a ... | 2015 | 26416832 |
| modular pathway engineering of corynebacterium glutamicum for production of the glutamate-derived compounds ornithine, proline, putrescine, citrulline, and arginine. | the glutamate-derived bioproducts ornithine, citrulline, proline, putrescine, and arginine have applications in the food and feed, cosmetic, pharmaceutical, and chemical industries. corynebacterium glutamicum is not only an excellent producer of glutamate but also of glutamate-derived products. here, engineering targets beneficial for ornithine production were identified and the advantage of rationally constructing a platform strain for the production of the amino acids citrulline, proline, and ... | 2015 | 26393954 |
| reconstruction and analysis of a genome-scale metabolic network of corynebacterium glutamicum s9114. | corynebacterium glutamicum s9114 is commonly used for industrial glutamate production. therefore, a comprehensive understanding of the physiological and metabolic characteristics of c. glutamicum is important for developing its potential for industrial production. a genome-scale metabolic model, ijm658, was reconstructed based on genome annotation and literature mining. the model consists of 658 genes, 984 metabolites and 1065 reactions. the model quantitatively predicted c. glutamicum growth on ... | 2016 | 26392034 |
| cutting the gordian knot: identifiability of anaplerotic reactions in corynebacterium glutamicum by means of (13) c-metabolic flux analysis. | corynebacterium glutamicum is the major workhorse for the microbial production of several amino and organic acids. as long as these derive from tricarboxylic acid cycle intermediates, the activity of anaplerotic reactions is pivotal for a high biosynthetic yield. to determine single anaplerotic activities (13) c-metabolic flux analysis ((13) c-mfa) has been extensively used for c. glutamicum, however with different network topologies, inconsistent or poorly determined anaplerotic reaction rates. ... | 2016 | 26375179 |
| improving the electro-transformation efficiency of corynebacterium glutamicum by weakening its cell wall and increasing the cytoplasmic membrane fluidity. | to improve the transformation efficiency of corynebacterium glutamicum cells with heterogenous plasmid dna and single-strand dna (ssdna) using a methodology based on electro-transformation. | 2015 | 26354854 |
| spatiotemporal microbial single-cell analysis using a high-throughput microfluidics cultivation platform. | cell-to-cell heterogeneity typically evolves due to a manifold of biological and environmental factors and special phenotypes are often relevant for the fate of the whole population but challenging to detect during conventional analysis. we demonstrate a microfluidic single-cell cultivation platform that incorporates several hundred growth chambers, in which isogenic bacteria microcolonies growing in cell monolayers are tracked by automated time-lapse microscopy with spatiotemporal resolution. t ... | 2015 | 26348020 |
| dynamic transmission of protein allostery without structural change: spatial pathways or global modes? | we examine the contrast between mechanisms for allosteric signaling that involve structural change, and those that do not, from the perspective of allosteric pathways. in particular we treat in detail the case of fluctuation-allostery by which amplitude modulation of the thermal fluctuations of the elastic normal modes conveys the allosteric signal, and address the question of what an allosteric pathway means in this case. we find that a perturbation theory of thermal elastic solids and nonpertu ... | 2015 | 26338443 |
| application of granular activated carbon/mnfe₂o₄ composite immobilized on c. glutamicum mtcc 2745 to remove as(iii) and as(v): kinetic, mechanistic and thermodynamic studies. | the main objective of the present study was to investigate the efficiency of corynebacterium glutamicum mtcc 2745 immobilized on granular activated carbon/mnfe2o4 (gac/mnfe2o4) composite to treat high concentration of arsenic bearing wastewater. non-linear regression analysis was done for determining the best-fit kinetic model on the basis of three correlation coefficients and three error functions and also for predicting the parameters involved in kinetic models. the results showed that fractal ... | 2016 | 26322840 |
| transcription of malp is subject to phosphotransferase system-dependent regulation in corynebacterium glutamicum. | the gram-positive corynebacterium glutamicum co-metabolizes most carbon sources such as the phosphotransferase system (pts) sugar glucose and the non-pts sugar maltose. maltose is taken up via the abc-transporter musefgk2i, and is further metabolized to glucose phosphate by amylomaltase malq, maltodextrin phosphorylase malp, glucokinase glk and phosophoglucomutase pgm. surprisingly, growth of c. glutamicum strains lacking the general pts components ei or hpr was strongly impaired on the non-pts ... | 2015 | 26296766 |
| production of carbon-13-labeled cadaverine by engineered corynebacterium glutamicum using carbon-13-labeled methanol as co-substrate. | methanol, a one-carbon compound, can be utilized by a variety of bacteria and other organisms as carbon and energy source and is regarded as a promising substrate for biotechnological production. in this study, a strain of non-methylotrophic corynebacterium glutamicum, which was able to produce the polyamide building block cadaverine as non-native product, was engineered for co-utilization of methanol. expression of the gene encoding nad+-dependent methanol dehydrogenase (mdh) from the natural m ... | 2015 | 26276544 |
| anaerobic growth of corynebacterium glutamicum via mixed-acid fermentation. | corynebacterium glutamicum, a model organism in microbial biotechnology, is known to metabolize glucose under oxygen-deprived conditions to l-lactate, succinate, and acetate without significant growth. this property is exploited for efficient production of lactate and succinate. our detailed analysis revealed that marginal growth takes place under anaerobic conditions with glucose, fructose, sucrose, or ribose as a carbon and energy source but not with gluconate, pyruvate, lactate, propionate, o ... | 2015 | 26276118 |
| improved production of poly(lactic acid)-like polyester based on metabolite analysis to address the rate-limiting step. | the biosynthesis of poly(lactic acid) (pla)-like polymers, composed of >99 mol% lactate and a trace amount of 3-hydroxybutyrate, in engineered corynebacterium glutamicum consists of two steps; the generation of the monomer substrate lactyl-coenzyme a (coa) and the polyhydroxyalkanoate (pha) synthase-catalyzed polymerization of lactyl-coa. in order to increase polymer productivity, we explored the rate-limiting step in pla-like polymer synthesis based on quantitative metabolite analysis using liq ... | 2014 | 26267112 |
| effect of tween 40 and dtsr1 on l-arginine overproduction in corynebacterium crenatum. | l-glutamate is an important precursor in the l-arginine (l-arg) biosynthetic pathway. various methods, including polyoxyethylene sorbitan monopalmitate (tween 40) addition and dtsr1 disruption, have been widely used to induce l-glutamate overproduction in corynebacterium glutamicum. in this study, a novel strategy for l-arg overproduction through tween 40 trigger and δdtsr1 mutant were proposed in corynebacterium crenatum. | 2015 | 26264811 |
| regulation of the expression of de novo pyrimidine biosynthesis genes in corynebacterium glutamicum. | expression of pyrimidine de novo biosynthesis is downregulated by an exogenous uracil in many bacteria. in this study, we show that a putative binding motif sequence of pyrr is required for uracil-mediated repression of pyrr-lacz translational fusion. however, the uracil response was still observed in the strain with the pyrr gene deleted, implying the existence of a uracil response factor other than pyrr which also acts through the pyrr binding loop region. deletion of rho, encoding the transcr ... | 2015 | 26260458 |
| exploring the role of sigma factor gene expression on production by corynebacterium glutamicum: sigma factor h and fmn as example. | bacteria are known to cope with environmental changes by using alternative sigma factors binding to rna polymerase core enzyme. sigma factor is one of the targets to modify transcription regulation in bacteria and to influence production capacities. in this study, the effect of overexpressing each annotated sigma factor gene in corynebacterium glutamicum wt was assayed using an iptg inducible plasmid system and different iptg concentrations. it was revealed that growth was severely decreased whe ... | 2015 | 26257719 |
| trna-dependent alanylation of diacylglycerol and phosphatidylglycerol in corynebacterium glutamicum. | aminoacyl-phosphatidylglycerol synthases (aapgss) are membrane proteins that utilize aminoacylated trnas to modify membrane lipids with amino acids. aminoacylation of membrane lipids alters the biochemical properties of the cytoplasmic membrane and enables bacteria to adapt to changes in environmental conditions. aapgss utilize alanine, lysine and arginine as modifying amino acids, and the primary lipid recipients have heretofore been defined as phosphatidylglycerol (pg) and cardiolipin. here we ... | 2015 | 26235234 |
| live cell imaging of sos and prophage dynamics in isogenic bacterial populations. | almost all bacterial genomes contain dna of viral origin, including functional prophages or degenerated phage elements. a frequent but often unnoted phenomenon is the spontaneous induction of prophage elements (spi) even in the absence of an external stimulus. in this study, we have analyzed spi of the large, degenerated prophage cgp3 (187 kbp), which is integrated into the genome of the gram-positive corynebacterium glutamicum atcc 13032. time-lapse fluorescence microscopy of fluorescent report ... | 2015 | 26235130 |
| engineering microbial cell factories: metabolic engineering of corynebacterium glutamicum with a focus on non-natural products. | corynebacterium glutamicum is the workhorse of biotechnological amino acid production. for more than 50 years amino acid producing strains of this actinomycete have been improved by classical breeding, metabolic engineering and systems and synthetic biology approaches. this review focusses mainly on recent developments on c. glutamicum strain development for non-natural products. recently, metabolite sensors have accelerated classical strain breeding. synthetic pathways for access to alternative ... | 2015 | 26216246 |
| co-production of s-adenosyl-l-methionine and l-isoleucine in corynebacterium glutamicum. | in this study, production of s-adenosyl-l-methionine in corynebacterium glutamicum was investigated by overexpressing genes metk and vgb. compared with vector control, overexpression of metk alone in c. glutamicum atcc13032 and iwj001 increased sam production 5.11 and 11.65 times, respectively; while overexpression of metk and vgb in c. glutamicum atcc13032 and iwj001 increased sam production 5.83 and 14.95 times, respectively. further studies on iwj001/pdxw-8-metk-vgb showed that the limiting f ... | 2015 | 26215341 |
| effects of phosphoenolpyruvate carboxylase desensitization on glutamic acid production in corynebacterium glutamicum atcc 13032. | phosphoenolpyruvate carboxylase (pepc) in corynebacterium glutamicum atcc13032, a glutamic-acid producing actinobacterium, is subject to feedback inhibition by metabolic intermediates such as aspartic acid and 2-oxoglutaric acid, which implies the importance of pepc in replenishing oxaloacetic acid into the tca cycle. here, we investigated the effects of feedback-insensitive pepc on glutamic acid production. a single amino-acid substitution in pepc, d299n, was found to relieve the feedback contr ... | 2016 | 26168906 |
| regulatory role of charged clusters in the n-terminal domain of betp from corynebacterium glutamicum. | the trimeric transporter betp counteracts hyperosmotic stress by a fast increase in transport rate in order to accumulate the compatible solute betaine. the positively charged α-helical c-terminal domain acts as an osmosensor perceiving the increase in the internal potassium (k+) concentration. a second, still unidentified stimulus originates from stress-induced changes in the physical state of the membrane and depends on the amount of negatively charged lipids. betp possesses a 60-amino acid (a ... | 2015 | 26146128 |
| specific γ-aminobutyric acid decomposition by gabp and gabt under neutral ph in recombinant corynebacterium glutamicum. | corynebacterium glutamicum that expresses the exogenous l-glutamate decarboxylase (gad) gene can synthesize γ-aminobutyric acid (gaba). to prevent gaba decomposition in the recombinant c. glutamicum gad strain, gaba uptake and the gaba shunt pathway were blocked. | 2015 | 26140901 |
| generation of mutant threonine dehydratase and its effects on isoleucine synthesis in corynebacterium glutamicum. | isoleucine synthesis is strongly regulated by its end product (isoleucine) in corynebacterium glutamicum, especially at threonine dehydratase (td) node. multiple alignments of td sequences of c. glutamicum and other sources were performed. according to the structural analysis, three td variants were constructed by site-directed mutagenesis. these td variants improved the performance of the holoenzyme. the specific activity of v140m variant was 1.5-fold higher than that of the wild-type td, where ... | 2015 | 26070433 |
| msccg from corynebacterium glutamicum: functional significance of the c-terminal domain. | corynebacterium glutamicum is used in microbial biotechnology for the production of amino acids, e.g., glutamate and lysine. excretion of glutamate into the surrounding medium under production conditions is mediated by msccg, an mscs-type mechanosensitive channel. in difference to most other mscs-type channel proteins, msccg carries, in addition to the n-terminal pore domain, a long c-terminal domain that amounts to about half of the size of the protein and harbors an additional transmembrane se ... | 2015 | 26033538 |
| regulation of the pstscab operon in corynebacterium glutamicum by the regulator of acetate metabolism ramb. | the pstscab operon of corynebacterium glutamicum, which encodes an abc transport system for uptake of phosphate (pi), is induced during the pi starvation response. the two-component regulatory system phors is involved in this response, but partial pi starvation induction of pstscab in a δphors mutant indicated the involvement of additional regulator(s). regulation of pstscab also involves the global transcriptional regulator glxr. | 2015 | 26021728 |
| ribosome binding site libraries and pathway modules for shikimic acid synthesis with corynebacterium glutamicum. | the shikimic acid (sa) pathway is a fundamental route to synthesize aromatic building blocks for cell growth and metabolic processes, as well as for fermentative production of various aromatic compounds. genes encoding enzymes of sa pathway are not continuous on genome and they are differently regulated. | 2015 | 25981633 |
| engineering of a hybrid route to enhance shikimic acid production in corynebacterium glutamicum. | to exploit the archaeal shikimic acid (sa) synthesis pathway toenhance sa production in corynebacterium glutamicum. | 2015 | 25967037 |
| complete genome sequence of corynebacterium glutamicum b253, a chinese lysine-producing strain. | we disclosed the complete genome sequence of corynebacterium glutamicum b253, an important lysine-producing strain in china. the genome consists a circular chromosome (3,159,203bp) and a plasmid (24,775bp), encoding 2767 protein coding genes in total. the genome contains all genes for lysine biosynthesis, and some mutations potentially relevant to lysine production were detected in comparison with sequence of other c. glutamicum. | 2015 | 25953304 |
| increasing succinic acid production using the pts-independent glucose transport system in a corynebacterium glutamicum pts-defective mutant. | succinic acid synthesized from glucose shows potential as a bio-based platform chemical. however, the need for a high glucose concentration, and the accompanying low yields, limit its industrial applications. despite efficient glucose uptake by the phosphotransferase system (pts), 1 mol of phosphoenolpyruvate is required for each mole of internalized glucose. therefore, a pts-defective corynebacterium glutamicum mutant was constructed to increase phosphoenolpyruvate availability for succinic aci ... | 2015 | 25952119 |
| structural insight into the thermostable nadp(+)-dependent meso-diaminopimelate dehydrogenase from ureibacillus thermosphaericus. | crystal structures of the thermostable meso-diaminopimelate dehydrogenase (dapdh) from ureibacillus thermosphaericus were determined for the enzyme in the apo form and in complex with nadp(+) and n-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid. the main-chain coordinates of the enzyme showed notable similarity to those of symbiobacterium thermophilum dapdh. however, the subunit arrangement of u. thermosphaericus dapdh (a dimer) was totally different from that of the s. thermophilum enzyme ... | 2015 | 25945579 |
| corynebacterium glutamicum atp-phosphoribosyl transferases suitable for l-histidine production--strategies for the elimination of feedback inhibition. | l-histidine biosynthesis in corynebacterium glutamicum is mainly regulated by l-histidine feedback inhibition of the atp-phosphoribosyltransferase hisg that catalyzes the first step of the pathway. the elimination of this feedback inhibition is the first and most important step in the development of an l-histidine production strain. for this purpose, a combined approach of random mutagenesis and rational enzyme redesign was performed. mutants spontaneously resistant to the toxic l-histidine anal ... | 2015 | 25892668 |
| functional characterization of a mycothiol peroxidase in corynebacterium glutamicum that uses both mycoredoxin and thioredoxin reducing systems in the response to oxidative stress. | previous studies have identified a putative mycothiol peroxidase (mpx) in corynebacterium glutamicum that shared high sequence similarity to sulfur-containing gpx (glutathione peroxidase; cysgpx). in the present study, we investigated the mpx function by examining its potential peroxidase activity using different proton donors. the mpx degrades hydrogen peroxide and alkyl hydroperoxides in the presence of either the thioredoxin/trx reductase (trx/trxr) or the mycoredoxin 1/mycothione reductase/m ... | 2015 | 25891483 |
| bioprocess automation on a mini pilot plant enables fast quantitative microbial phenotyping. | the throughput of cultivation experiments in bioprocess development has drastically increased in recent years due to the availability of sophisticated microliter scale cultivation devices. however, as these devices still require time-consuming manual work, the bottleneck was merely shifted to media preparation, inoculation and finally the analyses of cultivation samples. a first step towards solving these issues was undertaken in our former study by embedding a biolector in a robotic workstation ... | 2015 | 25888907 |
| identification of the regulators binding to the upstream region of glxr in corynebacterium glutamicum. | glxr is considered as a global transcriptional regulator controlling a large number of genes having broad physiological aspects in corynebacterium glutamicum. however, the expression profile revealing the transcriptional control of glxr has not yet been studied in detail. dna affinity chromatography experiments revealed the binding of transcriptional regulators sucr, ramb, glxr, and a gntr-type protein (hereafter denoted as gntr3) to the upstream region of glxr. the binding of different regulato ... | 2015 | 25876601 |
| involvement of the tetr-type regulator paar in the regulation of pristinamycin i biosynthesis through an effect on precursor supply in streptomyces pristinaespiralis. | pristinamycin i (pi), produced by streptomyces pristinaespiralis, is a streptogramin type b antibiotic, which contains two proteinogenic and five aproteinogenic amino acid precursors. pi is coproduced with pristinamycin ii (pii), a member of streptogramin type a antibiotics. the pi biosynthetic gene cluster has been cloned and characterized. however, thus far little is understood about the regulation of pi biosynthesis. in this study, a tetr family regulator (encoded by ssdg_03033) was identifie ... | 2015 | 25868645 |
| functional characterization of corynebacterium alkanolyticum β-xylosidase and xyloside abc transporter in corynebacterium glutamicum. | the corynebacterium alkanolyticum xylefgd gene cluster comprises the xyld gene that encodes an intracellular β-xylosidase next to the xylefg operon encoding a substrate-binding protein and two membrane permease proteins of a xyloside abc transporter. cloning of the cluster revealed a recombinant β-xylosidase of moderately high activity (turnover for p-nitrophenyl-β-d-xylopyranoside of 111 ± 4 s(-1)), weak α-l-arabinofuranosidase activity (turnover for p-nitrophenyl-α-l-arabinofuranoside of 5 ± 1 ... | 2015 | 25862223 |
| overexpression of the phosphofructokinase encoding gene is crucial for achieving high production of d-lactate in corynebacterium glutamicum under oxygen deprivation. | we previously reported on the impacts of the overexpression of individual genes of the glycolytic pathway encoding glucokinase (glk), glyceraldehyde phosphate dehydrogenase (gapdh), phosphofructokinase (pfk), triosephosphate isomerase (tpi), and bisphosphate aldolase (fba) on d-lactate productivity in corynebacterium glutamicum under oxygen-deprived conditions. searching for synergies, in the current study, we simultaneously overexpressed the five glycolytic genes in a stepwise fashion to evalua ... | 2015 | 25820644 |
| deletion of odha or pyc improves production of γ-aminobutyric acid and its precursor l-glutamate in recombinant corynebacterium glutamicum. | to enhance γ-aminobutyric acid (gaba) production in recombinant corynebacterium glutamicum, metabolic engineering strategies were used to improve the supply of the gaba precursor, l-glutamate. | 2015 | 25801673 |
| the manganese-responsive regulator mntr represses transcription of a predicted zip family metal ion transporter in corynebacterium glutamicum. | manganese is an important trace element required as an enzyme cofactor and for protection against oxidative stress. in this study, we characterized the dtxr-type transcriptional regulator mntr (cg0741) of corynebacterium glutamicum atcc 13032 as a manganese-dependent repressor of the predicted zip family metal transporter cg1623. comparative transcriptome analysis of a δmntr strain and the wild type led to the identification of cg1623 as potential target gene of mntr which was about 50-fold upre ... | 2015 | 25790484 |
| metabolic engineering of corynebacterium glutamicum atcc13869 for l-valine production. | in this study, an l-valine-producing strain was developed from corynebacterium glutamicum atcc13869 through deletion of the three genes acee, alat and ilva combined with the overexpression of six genes ilvb, ilvn, ilvc, lrp1, brnf and brne. overexpression of lrp1 alone increased l-valine production by 16-fold. deletion of the acee, alat and ilva increased l-valine production by 44-fold. overexpression of the six genes ilvb, ilvn, ilvc, lrp1, brne and brnf in the triple deletion mutant wcc003 fur ... | 2015 | 25769288 |
| the corynebacterium glutamicum mycothiol peroxidase is a reactive oxygen species-scavenging enzyme that shows promiscuity in thiol redox control. | cysteine glutathione peroxidases (cysgpxs) control oxidative stress levels by reducing hydroperoxides at the expense of cysteine thiol (-sh) oxidation, and the recovery of their peroxidatic activity is generally accomplished by thioredoxin (trx). corynebacterium glutamicum mycothiol peroxidase (mpx) is a member of the cysgpx family. we discovered that its recycling is controlled by both the trx and the mycothiol (msh) pathway. after h2 o2 reduction, a sulfenic acid (-soh) is formed on the peroxi ... | 2015 | 25766783 |
| a giant market and a powerful metabolism: l-lysine provided by corynebacterium glutamicum. | l-lysine is made in an exceptional large quantity of currently 2,200,000 tons/year and belongs therefore to one of the leading biotechnological products. production is done almost exclusively with mutants of corynebacterium glutamicum. the increasing l-lysine market forces companies to improve the production process fostering also a deeper understanding of the microbial physiology of c. glutamicum. current major challenges are the identification of ancillary mutations not intuitively related wit ... | 2015 | 25761623 |
| mutational analysis to identify the residues essential for the inhibition of n-acetyl glutamate kinase of corynebacterium glutamicum. | n-acetyl glutamate kinase (nagk) is a key enzyme in the synthesis of l-arginine that is inhibited by its end product l-arginine in corynebacterium glutamicum (c. glutamicum). in this study, the potential binding sites of arginine and the residues essential for its inhibition were identified by homology modeling, inhibitor docking, and site-directed mutagenesis. the allosteric inhibition of nagk was successfully alleviated by a mutation, as determined through analysis of mutant enzymes, which wer ... | 2015 | 25750030 |
| response of corynebacterium glutamicum exposed to oscillating cultivation conditions in a two- and a novel three-compartment scale-down bioreactor. | the oscillatory conditions in substrate and oxygen supply that typically occur on a large (industrial) scale are usually simulated in two-compartment scale-down reactors. in this study, the performance of nutrient-limited fed-batch cultivations of corynebacterium glutamicum in a standard two-compartment reactor (two-cr) is compared to the performance in a novel three-compartment reactor (three-cr). the three-cr is designed to mimic three distinct zones of an industrial scale bioreactor that occu ... | 2015 | 25728062 |
| structural insights into domain movement and cofactor specificity of glutamate dehydrogenase from corynebacterium glutamicum. | glutamate dehydrogenase (gdh) is an enzyme involved in the synthesis of amino acids by converting glutamate to α-ketoglutarate, and vice versa. to investigate the molecular mechanism of gdh, we determined a crystal structure of the corynebacterium glutamicum-derived gdh (cggdh) in complex with its nadp cofactor and α-ketoglutarate substrate. cggdh functions as a hexamer, and each cggdh monomer comprises 2 separate domains; a rossmann fold cofactor-binding domain and a substrate-binding domain. t ... | 2015 | 25727019 |
| increased l-ornithine production in corynebacterium glutamicum by overexpression of a gene encoding a putative aminotransferase. | overexpression of the ncgl0462 open reading frame, encoding a class ii aminotransferase, was studied in conjunction with other enzymes in l-ornithine biosynthesis in an l-ornithine-producing strain. expression of the wild-type ncgl0462 open reading frame, which displayed aminotransferase activity, was amplified by placing it under the control of the glyceraldehyde 3-phosphate dehydrogenase gene promoter in the pek0 plasmid and in the genome. l-ornithine production in corynebacterium glutamicum s ... | 2015 | 25720798 |
| technical bias of microcultivation environments on single-cell physiology. | microscale cultivation systems are important tools to elucidate cellular dynamics beyond the population average and understand the functional architecture of single cells. however, there is scant knowledge about the bias of different microcultivation technologies on cellular functions. we therefore performed a systematic cross-platform comparison of three different microscale cultivation systems commonly harnessed in single-cell analysis: microfluidic non-contact cell traps driven by negative di ... | 2015 | 25710324 |
| overexpression of ribosome elongation factor g and recycling factor increases l-isoleucine production in corynebacterium glutamicum. | ribosome elongation factor g encoded by fusa promotes the translocation step of protein synthesis in bacteria; ribosome recycling factor encoded by frr, together with the elongation factor g, dissociates ribosomes from messenger rna after the termination of translation. both factors play important roles during protein synthesis in bacteria. in this study, we found that overexpression of fusa and/or frr led to the increase of l-isoleucine production in corynebacterium glutamicum iwj001, an l-isol ... | 2015 | 25707863 |
| analysis of acetohydroxyacid synthase variants from branched-chain amino acids-producing strains and their effects on the synthesis of branched-chain amino acids in corynebacterium glutamicum. | acetohydroxy acid synthase (ahas) controls carbon flux through the branch point and determines the relative rates of the synthesis of isoleucine, valine and leucine, respectively. however, it is strongly regulated by its end products. in this study, we characterized ahas variants from five branched-chain amino acids-producing strains. amino acid substitution occurred in both catalytic subunit and regulatory subunit. interestingly, ahas variants reduced sensitivity to feedback inhibition by branc ... | 2015 | 25697867 |
| the α-glucan phosphorylase malp of corynebacterium glutamicum is subject to transcriptional regulation and competitive inhibition by adp-glucose. | α-glucan phosphorylases contribute to degradation of glycogen and maltodextrins formed in the course of maltose metabolism in bacteria. accordingly, bacterial α-glucan phosphorylases are classified as either glycogen or maltodextrin phosphorylase, glgp or malp, respectively. glgp and malp enzymes follow the same catalytic mechanism, and thus their substrate spectra overlap; however, they differ in their regulation: glgp genes are constitutively expressed and the enzymes are controlled on the act ... | 2015 | 25666133 |
| rational engineering of multiple module pathways for the production of l-phenylalanine in corynebacterium glutamicum. | microbial production of l-phenylalanine (l-phe) from renewable sources has attracted much attention recently. in the present study, corynebacterium glutamicum 13032 was rationally engineered to produce l-phe from inexpensive glucose. first, all the l-phe biosynthesis pathway genes were investigated and the results demonstrated that in addition to arof and phea, the native ppsa, tkta, aroe and aroa, and the heterologous arol and tyrb were also the key enzymes for l-phe biosynthesis. through combi ... | 2015 | 25665502 |
| implication of ornithine acetyltransferase activity on l-ornithine production in corynebacterium glutamicum. | l-ornithine is an intermediate of the l-arginine biosynthetic pathway in corynebacterium glutamicum. the effect of ornithine acetyltransferase (oatase; argj) on l-ornithine production was investigated, and c. glutamicum 1006 was engineered to overproduce l-ornithine as a major product by inactivating regulatory repressor argr gene and overexpressing argj gene. a genome sequence analysis indicated that the argf gene encoding ornithine carbamoyltransferase in c. glutamicum 1006 was mutated, result ... | 2016 | 25630515 |
| thermal and solvent stress cross-tolerance conferred to corynebacterium glutamicum by adaptive laboratory evolution. | reinforcing microbial thermotolerance is a strategy to enable fermentation with flexible temperature settings and thereby to save cooling costs. here, we report on adaptive laboratory evolution (ale) of the amino acid-producing bacterium corynebacterium glutamicum under thermal stress. after 65 days of serial passage of the transgenic strain gly3, in which the glycolytic pathway is optimized for alanine production under oxygen deprivation, three strains adapted to supraoptimal temperatures were ... | 2015 | 25595768 |
| copper homeostasis-related genes in three separate transcriptional units regulated by csor in corynebacterium glutamicum. | in corynebacterium glutamicum r, csor acts as a transcriptional repressor not only of the cognate copa-csor operon but also of the copz1-copb-cgr_0126 operon. it is predicted that copa and copb encode p-type atpases for copper efflux and copz1 encodes a metallochaperone. here, a csor-binding motif was found upstream of another copz-like gene, copz2, and the in vitro binding of the csor protein to its promoter was confirmed. the monocistronic copz2 transcript was upregulated by excess copper in a ... | 2015 | 25592736 |
| expression of a bacterial 3-dehydroshikimate dehydratase reduces lignin content and improves biomass saccharification efficiency. | lignin confers recalcitrance to plant biomass used as feedstocks in agro-processing industries or as source of renewable sugars for the production of bioproducts. the metabolic steps for the synthesis of lignin building blocks belong to the shikimate and phenylpropanoid pathways. genetic engineering efforts to reduce lignin content typically employ gene knockout or gene silencing techniques to constitutively repress one of these metabolic pathways. recently, new strategies have emerged offering ... | 2015 | 25583257 |
| involvement of the nadh oxidase-encoding noxa gene in oxidative stress responses in corynebacterium glutamicum. | corynebacterium glutamicum orf ncgl0328, designated noxa, encodes an nadh oxidase enzyme. the noxa gene, which was preferentially expressed in the log growth phase, was found to be under the control of the whca, whcb, and whce genes, which play regulatory roles in cells under oxidative stress. while noxa transcription was minimal in whce-deleted mutant cells (δwhce) during growth, its transcription was maximal even in the stationary phase in δwhca cells. the transcription levels of noxa in δwhcb ... | 2015 | 25549620 |
| a third glucose uptake bypass in corynebacterium glutamicum atcc 31833. | in corynebacterium glutamicum, the phosphoenolpyruvate-dependent sugar phosphotransferase system (pts) has long been the only known glucose uptake system, but we recently found suppressor mutants emerging from a pts-negative strain of c. glutamicum atcc 31833 on glucose agar plates, and identified two alternative potential glucose uptake systems, the myo-inositol transporters encoded by iolt1 and iolt2. the expression of either gene renders the pts-negative strain wtδptsh capable of growing on g ... | 2015 | 25549619 |