Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| Intracellular expression of Vitreoscilla hemoglobin improves production of Yarrowia lipolytica lipase LIP2 in a recombinant Pichia pastoris. | The Yarrowia lipolytica lipase LIP2 (YlLIP2) gene lip2 and Vitreoscilla hemoglobin gene vgb were co-expressed in Pichia pastoris, both under the control of AOX1 promoter, in order to alleviate respiration limitation under conditions of high cell-density fermentation and enhance YlLIP2 production. The results showed that recombinant P. pastoris strains harboring the lip2 and vgb genes (VHb(+)) displayed higher biomass and YlLIP2 activity than control strains (VHb(-)). Compared with VHb(-) cells, ... | 2012 | 22133436 |
| Enhancing macrolide production in Streptomyces by coexpressing three heterologous genes. | Antibiotic production in Streptomyces can often be increased by introducing heterologous genes into strains that contain an antibiotic biosynthesis gene cluster. A number of genes are known to be useful for this purpose. We chose three such genes and cloned them singly or in combination under the control of the strong constitutive ermE* promoter into a ?C31-derived integrating vector that can be transferred efficiently by conjugation from Escherichia coli to Streptomyces. The three genes are adp ... | 2012 | 22133433 |
| Intracellular co-expression of Vitreoscilla hemoglobin enhances cell performance and ß-galactosidase production in Pichia pastoris. | Pichia pastoris has been used to produce various recombinant proteins under high oxygen demand conditions. To improve the heterologous production of ß-galactosidase, the vgb gene encoding Vitreoscilla hemoglobin (VHb) was co-expressed in the P. pastoris cytoplasm under the control of the methanol-inducible promoter. Co-expression of VHb under different aeration conditions improved cell performance in terms of growth, viability, respiratory rate, and ß-galactosidase production. Under limiting aer ... | 2011 | 22099376 |
| production of methionine γ- lyase in recombinant citrobacter freundii bearing the hemoglobin gene. | the production of antileukemic enzyme methionine γ-lyase (mgl) in distinctly related bacteria, citrobacter freundii and in their recombinants expressing the vitresocilla hemoglobin (vhb) has been studied. this study concerns the potential of citrobacter freundii expressing the vitreoscilla hemoglobin gene (vgb) for the methionine γ- liyase production. methionine γ- liyase production by citrobacter freundii and its vgb(-) and vgb(+) bearing recombinant strain was studied in shake-flasks under 200 ... | 2011 | 21944252 |
| vitreoscilla hemoglobin expression in engineered escherichia coli: improved performance in high cell-density batch cultivations. | high cell-density cultivations are the preferred system for biomolecules production by escherichia coli. it has been previously demonstrated that a strain of e. coli with a modified substrate transport system is able to attain high cell densities in batch mode, due to the very low overflow metabolism displayed. the use of elevated amounts of glucose from the beginning of the cultivation, eliminates the existence of substrate gradients due to deficient mixing at large-scale. however, the large am ... | 2011 | 21744499 |
| the single-domain globin of vitreoscilla: augmentation of aerobic metabolism for biotechnological applications. | extensive studies have revealed that large-scale, high-cell density bioreactor cultivations have significant impact on metabolic networks of oxygen-requiring production organisms. oxygen transfer problems associated with fluid dynamics and inefficient mixing efficiencies result in oxygen gradients, which lead to reduced performance of the bioprocess, decreased product yields, and increased production costs. these problems can be partially alleviated by improving bioreactor configuration and sett ... | 2011 | 21722792 |
| metabolic engineering of aeromonas hydrophila 4ak4 for production of copolymers of 3-hydroxybutyrate and medium-chain-length 3-hydroxyalkanoate. | a mutant termed aeromonas hydrophila aklf was constructed by deleting acetic acid pathway related genes pta and acka in a. hydrophila 4ak4. accumulation of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (phbhhx) in a. hydrophila aklf was increased by 47% from 2.11 to 3.10g/l associated with a reduction on acetic acid formation compared with a. hydrophila 4ak4 when lauric acid was used as carbon resource. a. hydrophila aklf harboring pvgab encoding vitreoscilla hemoglobin, +¦-ketothiolase and acet ... | 2011 | 21680176 |
| analytic assessment under ultraviolet light of actinic lentigines under bleaching treatment. | background actinic (solar) lentigines are melanotic tumors frequently developed during photoaging on the dorsum of the hands. bleaching (whitening) agents are commonly offered to fade their darker aspect. in general, regular colorimetric methods show poor sensitivity to disclose any bleaching effect. method the present randomized controlled study on 24 women was designed to objectively assess the clinical efficacy of a combination of bleaching agents on actinic lentigines. in the endeavor of i ... | 2011 | 21649815 |
| [regulation of vitreoscilla hemoglobin on biosynthesis of astragaloside iv]. | in the present study, the regulation of vitreoscilla hemoglobin (vhb) on astragaloside iv biosynthesis was investigated. an intermediate expression vector consisting of the camv35s promoter fused to the vgb and nopaline synthase terminator was transferred into astragalus membranaceus via agrobacterium rhizogenes. the transgenic hairy roots were confirmed by pcr amplification and southern blot hybridization. the expression of vgb in transgenic hairy roots was confirmed by rt-pcr. after 15 days cu ... | 2011 | 21626794 |
| recent advances in understanding the structure, function, and biotechnological usefulness of the hemoglobin from the bacterium vitreoscilla. | the hemoglobin from the bacterium vitreoscilla (vhb) is the first microbial hemoglobin that was conclusively identified as such (in 1986). it has been extensively studied with respect to its ligand binding properties and mechanisms, structure, biochemical functions, and the mechanisms by which its expression is controlled. in addition, cloning of its gene (vgb) into a variety of heterologous hosts has proved that its expression results substantial increases in production of a variety of useful p ... | 2011 | 21603987 |
| kinetic resolution of 3-fluoroalanine using a fusion protein of d-amino acid oxidase with vitroscilla hemoglobin. | in this study, a fusion protein (vhb-daao) of d-amino acid oxidase (daao) with vitreoscilla hemoglobin (vhb) was functionally expressed in escherichia coli and purified. the k(cat) value vhb-daao (47.1 s(-1)) towards rac-3-flouroalanine was about 2-fold higher than that of daao (21.9 s(-1)). rac-3-flouroalanine (500 mm) was kinetically resolved into (r)-3-fluoroalanine with high enatiomeric excess (>99%) by vhb-daao with about 52% conversion. | 2011 | 21512218 |
| functional cis-expression of phacab genes for poly(3-hydroxybutyrate) production by escherichia coli. | to develop a microbial strain producing poly(3-hydroxybutyrate) [p(3hb)], in the absence of antibiotic supplementation (normally required to stabilize a recombinant plasmid), by constructing a recombinant escherichia coli strain with phacab and vgb integrated into the chromosome. | 2011 | 21306405 |
| constitutive expression of vitreoscilla haemoglobin in sphingomonas elodea to improve gellan gum production. | to improve a commercially used strain for gellan production by exogenous vitreoscilla haemoglobin (vhb). | 2010 | 21091594 |
| enhanced production of total flavones and exopolysaccharides viavitreoscilla hemoglobin biosynthesis in phellinus igniarius. | the vitreoscilla hemoglobin gene (vgb) was expressed by chromosomal integration in phellinus igniarius to alleviate oxygen limitation and improve metabolites yields during submerged fermentation. firstly, an expression vector containing vgb was constructed, and transformed into protoplast from p. igniarius. carbon monoxide difference spectrum absorbance assay showed that vgb was successfully expressed and had biological activity. in shake flasks, the vgb expression enhanced dry mycelial weight 1 ... | 2011 | 20855202 |
| enhanced production of l-arginine by expression of vitreoscilla hemoglobin using a novel expression system in corynebacterium crenatum. | corynebacterium crenatum sypa 5-5 is an aerobic and industrial l: -arginine producer. it was proved that the corynebacterium glutamicum/escherichia coli shuttle vector pjc1 could be extended in c. crenatum efficiently when using the chloramphenicol acetyltransferase gene (cat) as a reporter under the control of promoter tac. the expression system was applied to over-express the gene vgb coding vitreoscilla hemoglobin (vhb) to further increase the dissolved oxygen in c. crenatum. as a result, the ... | 2011 | 20835781 |
| engineering of ethanolic e. coli with the vitreoscilla hemoglobin gene enhances ethanol production from both glucose and xylose. | escherichia coli strain fbr5, which has been engineered to direct fermentation of sugars to ethanol, was further engineered, using three different constructs, to contain and express the vitreoscilla hemoglobin gene (vgb). the three resulting strains expressed vitreoscilla hemoglobin (vhb) at various levels, and the production of ethanol was inversely proportional to the vhb level. high levels of vhb were correlated with an inhibition of ethanol production; however, the strain (ts3) with the lowe ... | 2010 | 20717665 |
| vitreoscilla hemoglobin (vhb) overexpression increases hypoxia tolerance in zebrafish (danio rerio). | aquaculture farming may benefit from genetically engineering fish to tolerate environmental stress. here, we used the vector pcvcg expressing the vitreoscilla hemoglobin (vhb) gene driven by the common carp β-actin promoter to create stable transgenic zebrafish. the survival rate of the 7-day-old f(2) transgenic fish was significantly greater than that of the sibling controls under 2.5% o(2) (dissolved oxygen (do), 0.91 mg/l). meanwhile, we investigated the relative expression levels of several ... | 2011 | 20694827 |
| engineering of a novel chimera of superoxide dismutase and vitreoscilla hemoglobin for rapid detoxification of reactive oxygen species. | the genes encoding human manganese superoxide dismutase (mnsod) and vitreoscilla hemoglobin (vhb) were fused in-frame to generate a bifunctional enzyme that possessed mnsod and peroxidase-like activities. at neutral ph, the coupling of the sod and peroxidase reactions revealed that the bifunctional enzyme exhibited a 2.5 times shorter transient period and a 1.67 times higher reaction rate at steady-state conditions. furthermore, the catalytic rate of the bifunctional enzyme was not affected as m ... | 2010 | 20656555 |
| [construction of conjugal transfer system of streptomyces venezuelae var. qinlingensis and the expression of vitreoscilla hemoglobin]. | to construct of conjugal transfer system of streptomyces venezuelae var. qinlingensis and express of vitreoscilla hemoglobin. | 2010 | 20499648 |
| biochemical and cellular investigation of vitreoscilla hemoglobin (vhb) variants possessing efficient peroxidase activity. | peroxidase-like activity of vitreoscilla hemoglobin (vhb) has been recently disclosed. to maximize such activity, two catalytically conserved residues (histidine and arginine) found in distal pocket of peroxidases have successfully been introduced into that of the vhb. fifteen-fold increase in catalytic constant (k(cat)) was obtained in p54r variant, which was presumably attributable to the lower rigidity and higher hydrophilicity of distal cavity arising from substitution of proline to arginine ... | 2010 | 20372024 |
| expression of vitreoscilla hemoglobin enhances cell growth and dihydroxyacetone production in gluconobacter oxydans. | dihydroxyacetone (dha) is an important ketose sugar, which is extensively used in the cosmetic, chemical, and pharmaceutical industries. dha has been industrially produced by gluconobacter oxydans with a high demand of oxygen. to improve the production of dha, the gene vgb encoding vitreoscilla hemoglobin (vhb) was successfully introduced into g. oxydans, where it was stably maintained, and expressed at about 76.0 nmol/g dry cell weight. results indicated that the constitutively expressed vhb im ... | 2010 | 20358375 |
| improved poly-gamma-glutamic acid production by chromosomal integration of the vitreoscilla hemoglobin gene (vgb) in bacillus subtilis. | in order to alleviate oxygen limitation and improve the yield of poly-gamma-glutamic acid (gamma-pga) during fermentation, the vitreoscilla hemoglobin gene (vgb) was integrated into the chromosome of bacillus subtilis and expressed during gamma-pga production. the activity of the expressed vitreoscilla hemoglobin (vhb) was confirmed by co-difference spectrum. expression of vhb enhanced cell growth under high viscosity fermentation conditions 1.26-fold and increased the yield of gamma-pga 2.07-fo ... | 2010 | 20171882 |
| the single-domain globin from the pathogenic bacterium campylobacter jejuni: novel d-helix conformation, proximal hydrogen bonding that influences ligand binding, and peroxidase-like redox properties. | the food-borne pathogen campylobacter jejuni possesses a single-domain globin (cgb) whose role in detoxifying nitric oxide has been unequivocally demonstrated through genetic and molecular approaches. the x-ray structure of cyanide-bound cgb has been solved to a resolution of 1.35 a. the overall fold is a classic three-on-three alpha-helical globin fold, similar to that of myoglobin and vgb from vitreoscilla stercoraria. however, the d region (defined according to the standard globin fold nomenc ... | 2010 | 20164176 |
| redox-mediated interactions of vhb (vitreoscilla haemoglobin) with oxyr: novel regulation of vhb biosynthesis under oxidative stress. | the bacterial haemoglobin from vitreoscilla, vhb, displays several unusual properties that are unique among the globin family. when the gene encoding vhb, vgb, is expressed from its natural promoter in either vitreoscilla or escherichia coli, the level of vhb increases more than 50-fold under hypoxic conditions and decreases significantly during oxidative stress, suggesting similar functioning of the vgb promoter in both organisms. in the present study we show that expression of vhb in e. coli i ... | 2010 | 20025616 |
| enhanced polyhydroxybutyrate (phb) production via the coexpressed phacab and vgb genes controlled by arabinose p promoter in escherichia coli. | to develop an approach to enhance polyhydroxybutyrate (phb) production via the coexpressed phacab and vgb genes controlled by arabinose p(bad) promoter in escherichia coli. | 2010 | 19943886 |
| [expression of vitreoscilla hemoglobin gene in pseudomonas delafieldii r-8 and its application to diesel desulfurization]. | to construct an engineering strain of higher desulfurization activity with vitreoscilla hemoglobin gene (vgb) for desulfurization of diesel. | 2009 | 19835163 |
| combination strategy to increase cyclosporin a productivity by tolypocladium niveum using random mutagenesis and protoplast transformation. | the cyclic undecapeptide cyclosporin a (cya), one of the most valuable immunosuppressive drugs, is produced nonribosomally by a multifunctional cyclosporin synthetase enzyme complex by the filamentous fungus tolypocladium niveum. to increase cya productivity by wild-type t. niveum (atcc 34921), random mutagenesis was first performed using an antifungal agar-plug colony assay (apca) selection approach. this generated a mutant strain producing more than 9-fold greater cya than the wild-type strain ... | 2009 | 19809241 |
| improvement of cephalosporin c production by recombinant dna integration in acremonium chrysogenum. | cephalosporins are widely used as anti-infectious beta-lactam antibiotics in clinic. for the purpose of increasing the yield of cephalosporin c (cpc) fermentation, especially in an industrial strain, a. chrysogenum genes cefef and cefg, which encode the ultimate and penultimate steps in cpc biosynthesis, ceft, which encodes a cpc efflux pump, and vgb, which encodes a bacterial hemoglobin gene were transformed in various combinations into an industrial strain of a. chrysogenum. both pcr and south ... | 2010 | 19787461 |
| production of l-dopa and dopamine in recombinant bacteria bearing the vitreoscilla hemoglobin gene. | given the well-established beneficial effects of vitreoscilla hemoglobin (vhb) on heterologous organisms, the potential of this protein for the production of l-dopa and dopamine in two bacteria, citrobacter freundii and erwinia herbicola, was investigated. the constructed recombinants bearing the vhb gene (vgb(+)) had substantially higher levels of cytoplasmic l-dopa (112 mg/l for c. freundii and 97 mg/l for e. herbicola) than their respective hosts (30.4 and 33.8 mg/l) and the vgb(-) control st ... | 2009 | 19585534 |
| effects of nonpathogenic gram-negative bacterium vitreoscilla filiformis lysate on atopic dermatitis: a prospective, randomized, double-blind, placebo-controlled clinical study. does this make a real difference? | 2009 | 19485997 | |
| production and characterization of homopolymer poly(3-hydroxyvalerate) (phv) accumulated by wild type and recombinant aeromonas hydrophila strain 4ak4. | aeromonas hydrophila 4ak4 normally produces copolyesters (phbhhx) consisting of 3-hydroxybutyrate (c4) and 3-hydroxyhexanoate (c6). wild type and recombinant a. hydrophila 4ak4 (psxw02) expressing vgb and fadd genes encoding vitreoscilla haemoglobin and escherichia coli acyl-coa synthase respectively, were found able to produce homopolyester poly(3-hydroxyvalerate) (phv) (c5) on undecanoic acid as a single carbon source. the recombinant grew to 5.59 g/l cell dry weight (cdw) containing 47.74 wt% ... | 2009 | 19395256 |
| intrinsic non-symbiotic and truncated haemoglobins and heterologous vitreoscilla haemoglobin expression in plants. | to date, haemoglobins (hbs) have been shown to exist in all kingdoms of life. the least studied and understood groups are plant non-symbiotic haemoglobins (nshbs) and the recently found plant truncated hbs (trhbs). from a biotechnological point of view, the best characterized and almost exclusively applied hb is the bacterial vitreoscilla haemoglobin (vhb). in this review, the present state of knowledge of structural features and ligand binding kinetics of plant nshbs and trhbs and their propose ... | 2009 | 19129158 |
| expression of the bacterial hemoglobin gene from vitreoscilla stercoraria increases rifamycin b production in amycolatopsis mediterranei. | it is well known that the culture for rifamycin b production by amycolatopsis mediterranei requires high levels of dissolved oxygen, particularly in industrial processes. in this study, we report the construction of a vector for the expression of the bacterial hemoglobin gene (vhb) from vitreoscilla stercoraria in a rifamycin b-overproducing strain of a. mediterranei. the effect was evaluated in the presence and absence of barbital. the vhb gene was cloned under the control of the perme promoter ... | 2008 | 19111646 |
| [fusion expression of d-amino acid oxidase from trignoposis variabilis with maltose binding protein and vitreoscilla hemoglobin]. | d-amino acid oxidase (daao) is one of important industrial enzymes. to increase the solubility and activity of the tvdaao from trignoposis variabilis expressed in recombinant escherichia coli (e. coli), a maltose binding protein (mbp) and vitreoscilla hemoglobin (vhb) was introduced to fuse with n-terminal of the tvdaao, respectively. fusion protein of mbp-tvdaao was constitutively expressed in jm105/pmkc-daao and inductively expressed in jm105/pmkl-daao. with respect to the control strain of bl ... | 2008 | 18807983 |
| functional implications of the proximal site hydrogen bonding network in vitreoscilla hemoglobin (vhb): role of tyr95 (g5) and tyr126 (h12). | although vitreoscilla hemoglobin (vhb) carries a conventional globin fold, its proximal site geometry is unique in having a hydrogen-bonding network between proximal site residues, hisf8-tyrg5-gluh23 and tyrg5-tyrh12. tyrg5 and tyrh12 were mutated to study their relevance in vhb function. vhb g5 mutants (tyr95phe and tyr95leu showed no stable oxyform and nitric oxide dioxygenase activity, whereas, vhb h12 mutants (tyr126phe and tyr126leu) displayed little change in their oxygen affinity indicati ... | 2008 | 18804465 |
| effects of nonpathogenic gram-negative bacterium vitreoscilla filiformis lysate on atopic dermatitis: a prospective, randomized, double-blind, placebo-controlled clinical study. | atopic dermatitis (ad) is associated with elevated ige levels and th2 responses. the oral administration of nonpathogenic bacteria such as probiotics may improve the course of atopic diseases. it is believed that nonpathogenic bacteria prevent the development of allergic diseases by modulating intestinal immune responses. however, the effects of oral probiotics on ad could not be reproduced in all studies and the direct immunomodulation of the skin-associated immune response by nonpathogenic bac ... | 2008 | 18795916 |
| proton nmr investigation of heme and surrounding proton in low-spin cyanide-ligated bacterial hemoglobin from vitreoscilla. | (1)h nmr spectra of low-spin cyanide-ligated bacterial hemoglobin from vitreoscilla (vthb-cn) are reported. the assignments of the(1)h nmr spectra of vthb-cn have been made through mcosy, noesy, 1d toe and superweft experiments. almost all resonance peaks of heme and ligated his85 are identified. the spin-lattice relaxation time t (1)'s and the variation relationships of chemical shifts of these peaks with temperature have been acquired, from which the distances between the measured protons and ... | 2000 | 18763116 |
| recombinant bacterial hemoglobin alters metabolism of aspergillus niger. | the filamentous fungus aspergillus niger is used extensively for the production of enzymes and organic acids. a major problem in industrial fermentations with this fungus is to ensure sufficient supply of oxygen required for respiratory metabolism of the fungus. in case of oxygen limitation, the fungus will produce various by-products like organic acids and polyols. in order to circumvent this problem we here study the effects of the expression of a bacterial hemoglobin protein on the metabolism ... | 2009 | 18694843 |
| role of hemoglobin in improving biodegradation of aromatic contaminants under hypoxic conditions. | genetic engineering of bacteria using the vitreoscilla (bacterial) hemoglobin gene has been used to enhance bioremediation of several compounds which are models for, or are themselves, toxic chemicals which may contaminate soil and water. initial experiments, done mostly in shake flasks, with escherichia coli, burkholderia sp. dnt and pseudomonas aeruginosa demonstrated that expression of vitreoscilla hemoglobin in heterologous hosts can enhance biodegradation of several aromatic compounds as we ... | 2008 | 18685270 |
| intracellular expression of vitreoscilla hemoglobin modifies microaerobic escherichia coli metabolism through elevated concentration and specific activity of cytochrome o. | the function of the reversible oxygen-binding hemoprotein from vitreoscilla (vhb), which enhances oxygen-limited cell growth and recombinant protein production when functionally expressed in escherichia coli, was investigated in wild-type e. coli and in e. coli mutants lacking one of the two terminal oxidases, cytochrome o complex (aerobic terminal oxidase, cyo) or cytochrome d complex (microaerobic terminal oxidase, cyd). deconvolution of vhb, cytochrome o, and cytochrome d bands from in vivo a ... | 1996 | 18623565 |
| effect of vitreoscilla hemoglobin dosage on microaerobic escherichia coli carbon and energy metabolism. | the amount of vitreoscilla hemoglobin (vhb) expression was modulated over a broad range with an isopropyl-beta-d-thiogalactopyranoside- (iptg-) inducible plasmid, and the consequences on microaerobic escherichia coli physiology were examined in glucose fed-batch cultivations. the effect of iptg induction on growth under oxygen-limited conditions was most visible during late fed-batch phase where the final cell density increased initially linearly with increasing vhb concentrations, ultimately sa ... | 1996 | 18623564 |
| genetic engineering to contain the vitreoscilla hemoglobin gene enhances degradation of benzoic acid by xanthomonas maltophilia. | xanthomonas maltophilia was transformed with the gene encoding vitreoscilla (bacterial) hemoglobin, vgb, and the growth of the engineered strain was compared with that of the untransformed strain using benzoic acid as the sole carbon source. in general, growth of the engineered strain was greater than that of the untransformed strain; this was true for experiments using both overnight cultures and log phase cells as inocula, but particularly for the latter. in both cases the engineered strain wa ... | 1996 | 18623559 |
| improvement of escherichia coli microaerobic oxygen metabolism by vitreoscilla hemoglobin: new insights from nad(p)h fluorescence and culture redox potential. | on-line nad(p)h fluorescence and culture redox potential (crp) measurements were utilized to investigate the role of vitreoscilla hemoglobin (vhb) in perturbing oxygen metabolism of microaerobic escherichia coli batch cultures of a vhb-synthesizing e. coli strain and the iso-genic control under fully aerated conditions were subject to several high/low oxygen transitions, and the nad(p)h fluorescence and crp were monitored during these passages. the presence of vhb decreased the rate of net nad(p ... | 1995 | 18623410 |
| effect of vitreoscilla hemoglobin expression on growth and specific tissue plasminogen activator productivity in recombinant chinese hamster ovary cells. | previous studies suggest that secretion of cloned proteins synthesized by recombinant chinese hamster ovary (cho) cells can be adenosine triphosphate (atp) limited. other research indicates that the presence of cloned vitreoscilla hemoglobin (vhb) enhances atp production in oxygen-limited escherichia coli. to evaluate the influence of vhb expression on recombinant cho cell productivity, the vhb gene has been fused to the mouse mammary tumor virus (mmtv) promoter and cloned in a cho cell line pre ... | 1994 | 18618650 |
| communication to the editor. application of the cross-regulation system as a metabolic switch. | the ability to switch metabolic flow from one pathway to another at a desired point in a bioprocess expands the horizons of metabolic engineering. such an externally inducible switch can be realized by embedding synthetic operons behind tow corss-regulated promoters. this results in coordinated cessation of transcription of one operon while transcription of a second operon is simultaneously activated. the ability to effect such coordinated and inverse control of transcription of two operons has ... | 1994 | 18615532 |
| solubilization and regeneration of vitreoscilla hemoglobin isolated from protein inclusion bodies. | vitreoscilla hemoglobin (vhb), a homodimeric protein containing two heme groups in its native state, was used as a model to investigate inclusion body approtein solubilization, prosthetic group incorporation, and reactivation. high-level expression in recombinant escherichia coli results in accumulation of a substantial portion of heme-free vhb in inclusion bodies. vhb can be solubilized from these inclusion bodies by relatively low concentrations of urea with the dissolution midpoint at approxi ... | 1992 | 18600912 |
| endogenous ptthb1 and ptttrhb, and heterologous vitreoscilla vhb haemoglobin gene expression in hybrid aspen roots with ectomycorrhizal interaction. | present knowledge on plant non-symbiotic class-1 (hb1) and truncated (trhb) haemoglobin genes is almost entirely based on herbaceous species while the corresponding tree haemoglobin genes are not well known. the function of these genes has recently been linked with endosymbioses between plants and microbes. in this work, the coding sequences of hybrid aspen (populus tremulaxtremuloides) ptthb1 and ptttrhb were characterized, indicating that the key residues of haem and ligand binding of both gen ... | 2008 | 18544611 |
| induction of the skin endogenous protective mitochondrial mnsod by vitreoscilla filiformis extract. | vitreoscilla filiformis (vf), a filamentous bacteria living in fresh water is thought to contribute to the observed beneficial effects of spa water on skin. an active fraction obtained from a vf biomass was evaluated for its ability to modulate mrna expression in cultured skin cells. cdna array analysis was conducted first using a customized membrane including 1176 selected and fully identified genes involved in skin physiology and homeostasis then the newly developed full genome u133 plus 2.0 g ... | 2006 | 18489268 |
| vitreoscilla filiformis bacterial extract to improve the efficacy of emollient used in atopic dermatitis symptoms. | 2008 | 18482031 | |
| enhancement of mussel adhesive protein production in escherichia coli by co-expression of bacterial hemoglobin. | mussel adhesive proteins (maps) have been considered as potential underwater and medical bioadhesives. previously, we reported a functional expression of recombinant map hybrid fp-151, which is a fusion protein with six type 1 (fp-1) decapeptide repeats at each type 5 (fp-5) terminus, with practical properties in escherichia coli. in the present work, we introduced the vitreoscilla hemoglobin (vhb) co-expression strategy to enhance the production levels of hybrid fp-151 since vhb has been succes ... | 2008 | 18396912 |
| shedding light on the role of vitreoscilla hemoglobin on cellular catabolic regulation by proteomic analysis. | heterologous expression of vitreoscilla hemoglobin (vhb) has been reported to improve cell growth, protein synthesis, metabolite productivity and nitric oxide detoxification. although it has been proposed that such phenomenon is attributed to the enhancement of respiration and energy metabolism by facilitating oxygen delivery, the mechanism of vhb action remains to be elucidated. in the present study, changes of protein expression profile in escherichia coli as a consequence of vhb production wa ... | 2008 | 18345284 |
| expression and purification of cgb and ctb, the no-inducible globins of the foodborne bacterial pathogen c. jejuni. | campylobacter jejuni is a gram-negative microaerophilic bacterium that occurs as a common gut commensal in many food-producing animals and birds. contamination of meat during processing is an important route of transmission, and c. jejuni is now recognized as one of the most important causes of bacterial gastroenteritis worldwide. c. jejuni is notable, but not unique, in possessing two different hemoglobins. the first is termed cgb and is a single-domain hemoglobin (i.e., having no other protein ... | 2008 | 18237639 |
| applications of the vhb gene vgb for improved microbial fermentation processes. | dissolved oxygen (do) plays an important role in cell growth, especially in industry-scale microbial production. to alleviate the defects of hypoxic conditions, vitreoscilla hemoglobin (vhb) has been used to enhance respiration and energy metabolism by promoting oxygen delivery. heterologous expression of vhb in a variety of hosts has been shown to improve cell growth, protein synthesis, metabolite productivity, and bioremediation under oxygen-restricted conditions. in this chapter, many well-st ... | 2008 | 18237638 |
| assessment of biotechnologically relevant characteristics of heterologous hemoglobins in e. coli. | the use of the heterologous bacterial hemoglobin (vhb) from vitreoscilla to enhance growth and productivity of escherichia coli under conditions of oxygen limitation has been one of the foremost examples of metabolic engineering. although vhb has earned its merits during the last two decades by providing enhanced physiological enhancements to organisms from all kingdoms of life, it has been the candidate of choice primarily for historical reasons. findings made during the last years, however, su ... | 2008 | 18237637 |
| globin interactions with lipids and membranes. | many bacterial globins have been demonstrated to interact with membrane lipids, and several hypotheses in support of a functional role for membrane localization have been set forth. bacterial globins have been suggested to facilitate oxygen diffusion to terminal oxidases, to protect oxidases from nitric oxide or eventually to preserve the integrity of the membrane lipids through peroxide-reducing activities as a response to oxidative/nitrosative stress. in this framework, methodological approach ... | 2008 | 18237636 |
| vitreoscilla filiformis biomass improves seborrheic dermatitis. | 2008 | 18194241 | |
| overexpression of shinorhizobium meliloti hemoprotein in streptomyces lividans to enhance secondary metabolite production. | it was found that shinorhizobium meliloti hemoprotein (sm) was more effective than vitreoscilla hemoglobin (vhb) in promoting secondary metabolites production when overexpressed in streptomyces lividans tk24. the transformant with sm (sm-transformant) produced 2.7-times and 3-times larger amounts of actinorhodin than the vhbtransformant in solid culture and flask culture, respectively. in both solid and flask cultures, a larger amount of undecylprodigiocin was produced by the sm-transformant. it ... | 2007 | 18167457 |
| microbial production of l -glutamate and l -glutamine by recombinant corynebacterium glutamicum harboring vitreoscilla hemoglobin gene vgb. | vitreoscilla hemoglobin (vhb) gene vgb equipped with a native promoter pvgb or a tac promoter ptac was introduced into corynebacterium glutamicum atcc14067, respectively. ptac was proven to be more suitable for expressing vhb protein in higher concentration in both escherichia coli and c. glutamicum strains compared with the native vgb promoter pvgb. vhb-expressing c. glutamicum exhibited higher oxygen uptake rate and enhanced cell growth. recombinant c. glutamicum harboring vgb gene equipped wi ... | 2008 | 18040683 |
| expressing vitreoscilla hemoglobin in statically cultured acetobacter xylinum with reduced o(2) tension maximizes bacterial cellulose pellicle production. | vitreoscilla hemoglobin (vhb) was constitutively expressed in acetobacter xylinum to enhance bacterial cellulose (bc) production. a pronounced enhancement of bc production in static culture was observed. reducing o(2) tension in gaseous phase of the culture by tightly sealing the culture tube could also enhance bc production by 70%. o(2) tension in gaseous phase reduced from 21 to 15% in the sealed and static culture of vhb-expressing a. xylinum after 7 days cultivation, while 7.36g/l of bc with ... | 2007 | 17868946 |
| genetic engineering of pseudomonas putida kt2442 for biotransformation of aromatic compounds to chiral cis-diols. | toluene dioxygenase (tdo) catalyzes asymmetric cis-dihydroxylations of aromatic compounds. pseudomonas putida kt2442 (pspm01) harboring tdo genes could effectively biotransform a wide-range of aromatic substrates into their cis-diols products. in shake-flask culture, approximately 2.7gl(-1) benzene cis-diols, 8.8gl(-1) toluene cis-diols and 6.0gl(-1) chlorobenzene cis-diols were obtained from the biotransformation process. furthermore, vgb gene encoding vitreoscilla hemoglobin protein (vhb) whic ... | 2007 | 17826856 |
| impact of the small rna ryhb on growth, physiology and heterologous protein expression in escherichia coli. | the small noncoding rna ryhb is a regulator of iron homeostasis in escherichia coli. during iron limitation, it downregulates the expression of a number of iron-containing proteins, including enzymes of the tricarboxylic acid cycle and the respiratory chain. because this infers a potential for ryhb to limit energy metabolism and biosynthetic capacity, the effect of knocking out ryhb on the physiology and heterologous protein productivity of e. coli has been analyzed. during iron limitation, indu ... | 2007 | 17784860 |
| enhanced hyaluronic acid production in bacillus subtilis by coexpressing bacterial hemoglobin. | bacillus subtilis strains that can produce hyaluronic acid (ha) were constructed by integrating the ha synthase gene (hasa) and the udp-glucose dehydrogenase gene of group c streptococcus (hasb) or of b. subtilis itself (taud) into the amye locus of the b. subtilis chromosome. all of the inserted genes were under the control of a strong constitutive vegii promoter of b. subtilis. although ha production could be achieved by expressing hasa alone, coexpressing hasb or taud with hasa could enhance ... | 2007 | 17691809 |
| analysis of the contribution of the globin and reductase domains to the ligand-binding properties of bacterial haemoglobins. | bacterial hbs (haemoglobins), like vhb (vitreoscilla sp. hb), and flavohbs (flavohaemoglobins), such as fhp (ralstonia eutropha flavohb), have different autoxidation and ligand-binding rates. to determine the influence of each domain of flavohbs on ligand binding, we have studied the kinetic ligand-binding properties of oxygen, carbon monoxide and nitric oxide to the chimaeric proteins, fhpg (truncated form of fhp comprising the globin domain alone) and vhb-red (fusion protein between vhb and th ... | 2007 | 17617059 |
| control of degp-dependent degradation of c-type cytochromes by heme and the cytochrome c maturation system in escherichia coli. | c-type cytochromes are located partially or completely in the periplasm of gram-negative bacteria, and the heme prosthetic group is covalently bound to the protein. the cytochrome c maturation (ccm) multiprotein system is required for transport of heme to the periplasm and its covalent linkage to the peptide. other cytochromes and hemoglobins contain a noncovalently bound heme and do not require accessory proteins for assembly. here we show that bradyrhizobium japonicum cytochrome c550 polypepti ... | 2007 | 17616605 |
| heterologous expression of vitreoscilla haemoglobin in barley (hordeum vulgare). | the vhb gene encoding vitreoscilla haemoglobin (vhb) was transferred to barley with the aim of studying the role of oxygen availability in germination and growth. previous findings indicate that vhb expression improves the efficiency of energy generation during oxygen-limited growth, and germination is known to be an energy demanding growth stage during which the embryos also suffer from oxygen deficiency. when subjected to oxygen deficiency, the roots of vhb-expressing barley plants showed a sm ... | 2007 | 17569049 |
| folding propensity and biological activity of peptides: new insights from conformational properties of a novel peptide derived from vitreoscilla haemoglobin. | the synthetic peptide vitr-p-13 (ypivgqellgaik-nh(2)), derived from the bacterial dimeric vitreoscilla haemoglobin (vhb) in the position 95-107, is characterized by a pre-eminent "statistical coil" conformation in water as demonstrated by cd experiments and long time-scale md simulations. in particular, vitr-p-13 does not spontaneously adopt an alpha-helix folding in water, but it is rather preferentially found in beta-hairpin-like conformations. long time-scale md simulations have also shown th ... | 2007 | 17554783 |
| vitreoscilla hemoglobin aids respiration under hypoxic conditions in its native host. | when vitreoscilla were grown in medium containing 60mm sodium nitrite under both normal and limited aeration conditions, the levels of vitreoscilla hemoglobin (vhb) were decreased by greater than 90%, while the levels of the terminal respiratory oxidase, cytochrome bo, were increased 350% under normal aeration and 7-23% under limited aeration. cytochrome function, as measured by both nadh and ubiquinol oxidases for cells grown under both conditions, increased in parallel (by 150-222% and 8-56%, ... | 2009 | 17403602 |
| intracellular expression of vitreoscilla hemoglobin improves s-adenosylmethionine production in a recombinant pichia pastoris. | to develop an efficient way to produce s-adenosylmethionine (sam), methionine adenosyltransferase gene (mat) from streptomyces spectabilis and vitreoscilla hemoglobin gene (vgb) were coexpressed intracellularly in pichia pastoris, both under control of methanol-inducible promoter. expression of mat in p. pastoris resulted in about 27 times higher specific activity of methionine adenosyltransferase (smat) and about 19 times higher sam production relative to their respective control, suggesting th ... | 2007 | 17334759 |
| construction of pha-operon-defined knockout mutants of pseudomonas putida kt2442 and their applications in poly(hydroxyalkanoate) production. | pseudomonas putida kt2442 could accumulate medium-chain-length poly(hydroxyalkanoate)s (pha) consisting of 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and 3-hydroxydodecanoate from a wide range of carbon sources. in this study, the pha synthase pha operon (phac1-phaz-phac2) was knocked out and the vgb gene encoding vitreoscilla hemoglobin protein (vhb), which could enhance oxygen uptake rate especially at low oxygen concentration, was integrated into the p. putida kt2442 genome t ... | 2007 | 17295412 |
| enhancement of biodesulfurization in two-liquid systems by heterogeneous expression of vitreoscilla hemoglobin. | the vgb gene, encoding vitreoscilla hemoglobin (vhb), was introduced into a specific desulfurization bacterium, rhodococcus erythropolis lsse8-1. the vhb-specific spectrum was observed for the recombinant. compared to the wild type, the strain bearing vgb showed a higher biomass yield and desulfurizing activity. | 2007 | 17293512 |
| an investigation of the peroxidase activity of vitreoscilla hemoglobin. | in order to investigate the ability of the vitreoscilla hemoglobin (vhb) to act as a peroxidase, the protein was overexpressed in escerichia coli and purified using a 6xhis-tag. the peroxidase activity of vhb was studied using 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (abts), ferrocene carboxylic acid (fccooh) dopamine and l-dopa as substrates. the effects of external agents such as ph, salt concentration/ionic strength, and the thermal stability of vhb on the catalytic activity were ... | 2007 | 17219165 |
| recent developments and future prospects of vitreoscilla hemoglobin application in metabolic engineering. | in hypoxic conditions, bacteria express a kind of hemoglobin, which is proposed to enhance respiration and energy metabolism by promoting oxygen delivery. bacteria hemoglobin from vitreoscilla stercoraria - vitreoscilla hemoglobin (vhb), when expressed in various hosts in oxygen-limited conditions, has been shown to improve growth, protein secretion, metabolite productivity and stress resistance of hosts, thus rendering the protein promising in metabolic engineering, especially in plant metaboli ... | 2007 | 17184955 |
| expression of vitreoscilla haemoglobin in hybrid aspen (populus tremula x tremuloides). | we describe the first ever expression of vitreoscilla haemoglobin (vhb) in an economically important boreal woody plant hybrid aspen (populus tremula x tremuloides). vhb has mainly been expressed in biotechnologically important unicellular organisms of both prokaryotic and eukaryotic origin. vhb expression, in this study, was analysed under different greenhouse cultivation conditions and under elevated uv-b illumination. microscope analyses of leaves grown under optimized conditions revealed sig ... | 2003 | 17163905 |
| expression of vitreoscilla haemoglobin in tobacco cell cultures relieves nitrosative stress in vivo and protects from no in vitro. | targeted expression of vitreoscilla haemoglobin (vhb) has been analysed in nicotiana tabacum plants and suspension cultures under various growth and stress conditions. vhb localization to different cell compartments (cytoplasm, chloroplast and mitochondria) was successful, as judged by signal peptide cleavage. the presence of vhb in subcellular compartments did not result in phenotypical differences between these plant lines. in contrast with previous reports, we were unable to discern any signi ... | 2004 | 17147613 |
| enhancement of cellulose pellicle production by constitutively expressing vitreoscilla hemoglobin in acetobacter xylinum. | vitreoscilla hemoglobin (vhb) gene driven by the constitutive bla promoter was expressed in the cellulose-producing acetobacter xylinum. the expressed vhb was biochemically active and could enhance cell growth in a shaken culture containing cellulase. vhb-expressing a. xylinum (vhb+) exhibited a specific growth rate 50% higher than that of the host strain (vhb-). probably because of its faster growth rate, the size of tentacled cellulose beads produced by vhb+ was about 20% of that produced by v ... | 2006 | 17137307 |
| expression of vitreoscilla hemoglobin in bacillus thuringiensis improve the cell density and insecticidal crystal proteins yield. | the vitreoscilla hemoglobin (vhb) gene (vgb) was integrated into the chromosome of bacillus thuringiensis bmb171 using integrative vector peg491. the production of vhb was confirmed by co-difference spectra analysis. fermentation experiments results showed that with the production of vhb, the critical oxygen concentration (coc) of the host strain was reduced from 18 to 12%. the maximum viable cell counts of the vhb+ strain in high, middle, and low aeration/agitation fermentations were 0.94-, 1.2 ... | 2007 | 17089120 |
| effects of carbon source and vitreoscilla hemoglobin (vhb) on the production of beta-galactosidase in enterobacter aerogenes. | at fixed concentration (0.5%), lactose and galactose acted as inducers while glucose and other tested carbon sugars showed repression effects on beta-galactosidase production in enterobacter aerogenes strain. the expression of vitreoscilla hemoglobin gene (vgb) in this bacterial strain managed to overcome the repression effects as well as improving the induction of beta-galactosidase formation by carbon sources. in parallel, the bacterial o(2) consumption was increased correspondingly to the vgb ... | 2006 | 16972134 |
| chimeric antibody-binding vitreoscilla hemoglobin (vhb) mediates redox-catalysis reaction: new insight into the functional role of vhb. | experimentation was initiated to explore insight into the redox-catalysis reaction derived from the heme prosthetic group of chimeric vitreoscilla hemoglobin (vhb). two chimeric genes encoding chimeric vhbs harboring one and two consecutive sequences of fc-binding motif (z-domain) were successfully constructed and expressed in e. coli strain tg1. the chimeric zvhb and zzvhb were purified to a high purity of more than 95% using igg-sepharose affinity chromatography. from surface plasmon resonance ... | 2006 | 16967102 |
| improvement of atopic dermatitis skin symptoms by vitreoscilla filiformis bacterial extract. | atopic dermatitis (ad) is a chronically relapsing inflammatory skin disease. the first line treatment of ad relies on the daily use of emollients to restore the skin barrier impairment associated with the disease. vitreoscilla filiformis (v.f.) is a non photosynthetic bacterium and extracts of v.f. are endowed with properties which balance cutaneous immune-homeostasis. the aim of our study was to investigate the efficacy and safety of a 5% v.f. extract-containing ointment on mild to moderate ad ... | 2006 | 16935794 |
| role of asp544 in subunit i for na(+) pumping by vitreoscilla cytochrome bo. | the conserved glu540 in subunit i of escherichia coli cytochrome bo (a h(+) pump) is replaced by asp544 in the vitreoscilla enzyme (a na(+) pump). site-directed mutagenesis of the vitreoscilla cytochrome bo operon changed this asp to glu, and both wild type and mutant cyo's were transformed into e. coli strain gv100, which lacks cytochrome bo. compared to the wild type transformant the asp544glu transformant had decreased ability to pump na(+) as well as decreased stimulation in respiratory acti ... | 2006 | 16919598 |
| effect of vitreoscilla hemoglobin on production of a chemotherapeutic enzyme, l-asparaginase, by pseudomonas aeruginosa. | the production of l-asparaginase, an enzyme widely used in cancer chemotherapy, is mainly regulated by carbon catabolite repression and oxygen. this study was carried out to understand how different carbon sources and vitreoscilla hemoglobin (vhb) affect the production of this enzyme in pseudomonas aeruginosa and its vhb-expressing recombinant strain (pajc). both strains grown with various carbon sources showed a distinct profile of the enzyme activity. compared to no carbohydrate supplemented m ... | 2006 | 16892249 |
| comparison of 2-chlorobenzoic acid biodegradation in a membrane bioreactor by b. cepacia and b. cepacia bearing the bacterial hemoglobin gene. | degradation of 2-chlorobenzoic acid (2-cba), a model recalcitrant chlorinated organic compound, by pure cultures of burkholderia cepacia strain dnt with (transformed b. cepacia) and without (untransformed b. cepacia) the bacterial hemoglobin (vitreoscilla hemoglobin, vhb) gene, vgb, was investigated in parallel membrane bioreactors (mbrs). this was done aseptically to prevent contamination during the operation of the mbrs. the objective was to determine whether the degradation of 2-cba by cometa ... | 2006 | 16876227 |
| expression of vitreoscilla hemoglobin enhances growth and levels of alpha-amylase in schwanniomyces occidentalis. | a metabolic engineering approach was exploited to improve growth and protein secretion in the non-conventional yeast, schwanniomyces occidentalis. vitreoscilla hemoglobin (vhb) gene was expressed in s. occidentalis under the control of the native alpha-amylase (amy1) promoter. expression of vhb was confirmed by reverse transcriptase polymerase chain reaction and western blot hybridization analysis. effect of vhb on growth and protein secretion was studied in synthetic medium under both limiting ... | 2006 | 16642333 |
| heterologous expression of vitreoscilla hemoglobin (vhb) and cultivation conditions affect the alkaloid profile of hyoscyamus muticus hairy roots. | fast-growing hairy root cultures of hyoscyamus muticus induced by agrobacterium rhizogenes offer a potential production system for tropane alkaloids. oxygen deficiency has been shown to limit growth and biomass accumulation of hairy roots, whereas little experimental data is available on the effect of oxygen on alkaloid production. we have investigated the effect of vitreoscilla hemoglobin (vhb) expression and cultivation conditions on the complete alkaloid profile of h. muticus hairy roots in s ... | 2006 | 16599546 |
| interaction of vitreoscilla hemoglobin with membrane lipids. | the interaction of the recombinant hemoglobin from vitreoscilla sp. (vhb) with the bacterial membrane of escherichia coli cells has been investigated by measuring the propensity of vhb to interact with monolayers formed by natural bacterial phosholipids. the measurements showed that the protein is capable of penetrating the monolayers, possibly establishing interactions with the hydrophobic acyl chains. vhb is also capable of binding reversibly phospholipids and free fatty acids in solution with ... | 2006 | 16566580 |
| chromosomal integration of the vitreoscilla hemoglobin gene and its physiological actions in tremella fuciformis. | the vitreoscilla hemoglobin (vhb) gene was expressed in yeast-like conidia (ylcs) of tremella fuciformis (t. fuciformis) to increase cell density in submerged fermentation by enhancing oxygen uptake. with the intention of doing this, an integrated expression vector containing the vhb gene and the hygromycin b phosphotransferase (hph) gene derived from escherichia coli (e. coli) as the selectable marker was constructed, and then transformed into protoplasts of ylcs from t. fuciformis with restric ... | 2006 | 16501972 |
| expression of vitreoscilla hemoglobin in gordonia amarae enhances biosurfactant production. | the gene (vgb) encoding vitreoscilla (bacterial) hemoglobin (vhb) was electroporated into gordonia amarae, where it was stably maintained, and expressed at about 4 nmol vhb g(-1) of cells. the maximum cell mass (od(600)) of vgb-bearing g. amarae was greater than that of untransformed g. amarae for a variety of media and aeration conditions (2.8-fold under normal aeration and 3.4-fold under limited aeration in rich medium, and 3.5-fold under normal aeration and 3.2-fold under limited aeration in ... | 2006 | 16491354 |
| antioxidant status, alpha-amylase production, growth, and survival of hemoglobin bearing escherichia coli exposed to hypochlorous acid. | in the present work, two matched strains of e. coli that bear a recombinant r-amylase gene (mk57) or the r-amylase gene and vgb (mk79-hemoglobin expressing strain) were exposed to hocl. in these cells, glutathione (gsh), superoxide dismutase (sod), catalase (cat), alpha-amylase production, growth and lethality were assessed in the presence and absence of hocl. it was observed that the hemoglobin makes cells highly susceptible to killing by hocl. the maximum survival for both strains was with sta ... | 2005 | 16417460 |
| correlation between bacterial hemoglobin and carbon sources: their effect on copper uptake by transformed e. coli strain alpha dh5. | escherichia coli alphadh5 harboring vitreoscilla hemoglobin gene, vgb (escherichia:puc8:16), and control strains (parental and vgb-lacking transformed strains, e. coli:puc9) were employed for studying the potential ability of copper uptake. the strains were grown on a minimal medium, 5xm9, that contained different carbon (mannitol, fructose, lactose, and maltose) and nitrogen (casein and yeast extract) sources. a clear type-response relationship between the level of copper uptake and the type of ... | 2006 | 16392001 |
| arca works with fnr as a positive regulator of vitreoscilla (bacterial) hemoglobin gene expression in escherichia coli. | low oxygen induction of the bacterial (vitreoscilla) hemoglobin gene (vgb) by the arc system was investigated, as the presumptive vgb crp site was found to have 73% identity to the escherichia coli consensus arca site. the role of arca by itself and with fnr was examined in e. coli using the wild type vgb promoter and promoter mutants affecting the fnr and crp (presumptive arca) sites and e. coli strains with all combinations of fnr+/fnr-, arca+/arca- genotypes. high-level transcription required ... | 2005 | 16255146 |
| construction and selection of the novel recombinant escherichia coli strain for poly(beta-hydroxybutyrate) production. | heterogeneous cloning of vitreoscilla hemoglobin gene (vgb), lytic genes of phage lambda with s amber mutation (s(-)rrz) and phb biosynthetic genes (phbcab) in the same host strain e. coli jm105 was carried out for production of poly(beta-hydroxybutyrate) (phb). a superior novel strain, vg1 (ptu14), was constructed and selected, which contained the vgb gene in the chromosomal dna and the plasmid ptu14 containing s(-)rrz and phbcab genes. when cultured in 100 ml of lbg medium in a 300-ml flask, a ... | 2000 | 16232750 |
| expression of bacterial hemoglobin in the yeast, pichia pastoris, with a low o2-induced promoter. | the psadh2-promoter of pichia stipitis alcohol dehydrogenase ii (adh ii) gene was employed to control the expression of vitreoscilla hemoglobin (vhb) gene in pichia pastoris. as in p. stipitis, the promoter was also induced microaerobically in p. pastoris. the expression level of vhb in p. pastoris at low o2 tension (<5% air saturation) was 16 nmol/g dry cell wt, i.e. about 24-fold higher than that at 60% air saturation. the expressed vhb enhanced growth of p. pastoris under microaerobic conditi ... | 2005 | 16231222 |
| [current research status of vitreoscilla hemoglobin and the prospective application in traditional chinese medicine]. | 2005 | 16159562 | |
| metabolic engineering of aeromonas hydrophila for the enhanced production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). | wild-type aeromonas hydrophila 4ak4 produced 35-45 wt.% poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (phbhhx) consisting of 10-15 mol% 3-hydroxyhexanoate (3hhx). to enhance phbhhx production, vgb gene encoding vitreoscilla haemoglobin or fadd gene encoding escherichia coli acyl-coa synthase was co-expressed with polyhydroxyalkanoates (pha) synthesis-related genes including phbab from wautersia eutropha and phapcj from a. hydrophila. expression of vgb increased phbhhx content from 46 to 53 wt.% ... | 2006 | 15983806 |
| [expression of vitreoscilla hemoglobin and nitrilase in the yeast pichia pastoris]. | the expression of the vgb gene in vivo could improve the fermentation density and then contribute the extracellular secretion of the product of bxn gene. constructed the recombination plasmid ppic9k-vgbbxn and transformed into pichia pastoris gs115. the results of pcr and sds-page indicate that the vgb gene and bxn gene had integrated into the genome of pichia pastoris gs115 and expressed in efficient level. also, the protein activity of their products had been verified respectively. shake flask ... | 2004 | 15973999 |
| [enhanced ergosterol production by recombinant saccharomyces cerevisiae 1190 harboring vitreoscilla hemoglobin gene (vgb)]. | ergosterol is a principal sterol of fungi. it is a raw material for production of vitamin d2, hydrocortisone, progesterone and brassinolide. synthesis of ergosterol requires molecular oxygen, and low oxygen tensions was reported to dramatically reduce ergosterol concentration. vitreoscilla hemoglobin gene (vgb), a homodimeric hemoglobin gene from gram-negative obligate aerobic bacterium vitreoscilla, enables a higher specific cellular oxygen uptake rate, it also improves the oxygen transportatio ... | 2004 | 15971621 |
| [recent advances in the study of vitreoscilla hemoglobin(vhb) and related proteins - cloning, expression and physiological actions in heterologons hosts and in transgenic tobacco plants]. | the first bacterial hemoglobin(vhb) was found in a strictly aerobic bacterium, vitreoscilla strain c1, occurring in marshes low in oxygen, but rich in organic matter. the hemoglobin gene is induced under low oxygen tension and may amount to 20 times as high. the expression of vhb promotes cell growth, protein biosynthesis and primary and secondary metabolism of the host cells, because the increased intracellular oxygen accelerates both the function of respiratory chain and terminal oxidases. the ... | 2003 | 15969050 |
| evidence that na+-pumping occurs through the d-channel in vitreoscilla cytochrome bo. | the operon (cyo) encoding the na(+)-pumping respiratory terminal oxidase (cytochrome bo) of the bacterium vitreoscilla was transformed into escherichia coli gv100, a deletion mutant of cytochrome bo. this was done for the wild type operon and five mutants in three conserved cyo subunit i amino acids known to be crucial for h(+) transport in the e. coli enzyme, one near the nuclear center, one in the k-channel, and one in the d-channel. co-binding, nadh and ubiquinol oxidase, and na(+)-pumping ac ... | 2005 | 15910742 |
| improvement of bioremediation by pseudomonas and burkholderia by mutants of the vitreoscilla hemoglobin gene (vgb) integrated into their chromosomes. | using genetic engineering, the vitreoscilla (bacterial) hemoglobin gene (vgb) was integrated stably into the chromosomes of pseudomonas aeruginosa and burkholderia sp. strain dnt. this was done for both wild type vgb and two site-directed mutants of vgb that produce vitreoscilla hemoglobin (vhb) with lowered oxygen affinities; in all cases functional vhb was expressed. similar to previous results, the wild type vhb improved growth for both species and degradation of 2,4-dinitrotoluene (burkholde ... | 2005 | 15806390 |
| vitreoscilla hemoglobin overexpression increases submergence tolerance in cabbage. | agrobacterium tumefaciens was used to deliver the vhb gene into cabbage (brassica oleracea var. cabitata) cv. xiaguang's parent line, 103. using hypocotyls and cotyledon petioles as explants for infection, we obtained a transformation efficiency of 3-5% based on the number of transgenic shoots produced from the number of explants used for infection. molecular analysis indicated that the vhb gene was stably integrated into the cabbage genome and that the vhb gene was expressed at the rna level. c ... | 2004 | 15747159 |