Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| Efficient electricity generation from sewage sludge usingbiocathode microbial fuel cell. | Microbial fuel cells (MFCs) with abiotic cathodes require expensive catalyst (such as Pt) or catholyte (such as hexacynoferrate) to facilitate oxidation reactions. This study incorporated biocathodes into a three-chamber MFC to yield electricity from sewage sludge at maximum power output of 13.2±1.7W/m(3) during polarization, much higher than those previously reported. After 15d operation, the total chemical oxygen demand (TCOD) removal and coulombic efficiency (CE) of cell reached 40.8±9.0% and ... | 2012 | 22078254 |
| Biogenesis of cbb(3)-type cytochrome c oxidase in Rhodobacter capsulatus. | The cbb(3)-type cytochrome c oxidases (cbb(3)-Cox) constitute the second most abundant cytochrome c oxidase (Cox) group after the mitochondrial-like aa(3)-type Cox. They are present in bacteria only, and are considered to represent a primordial innovation in the domain of Eubacteria due to their phylogenetic distribution and their similarity to nitric oxide (NO) reductases. They are crucial for the onset of many anaerobic biological processes, such as anoxygenic photosynthesis or nitrogen fixati ... | 2011 | 22079199 |
| Cross-species investigation of the functions of the Rhodobacter PufX polypeptide and the composition of the RC-LH1 core complex. | In well-characterised species of the Rhodobacter (Rba.) genus of purple photosynthetic bacteria it is known that the photochemical reaction centre (RC) is intimately-associated with an encircling LH1 antenna pigment protein, and this LH1 antenna is prevented from completely surrounding the RC by a single copy of the PufX protein. In Rba. veldkampii only monomeric RC-LH1 complexes are assembled in the photosynthetic membrane, whereas in Rba. sphaeroides and Rba. blasticus a dimeric form is also a ... | 2012 | 22079525 |
| evolutionary origin of the rhodobacter sphaeroides specialized rpon sigma factors. | gene duplication and horizontal gene transfer (hgt) are two events that enable the generation of new genes. rhodobacter sphaeroides (ws8 and 2.4.1 strains) has four copies of the rpon gene that are not functionally interchangeable. until now, this is the only example of specialization of this sigma factor. in this work, we aimed to determine whether the multiple copies of this gene originated from hgt or through gene duplication. our results suggest a multiplication origin of the different rpon ... | 2011 | 22093079 |
| coherent phenomena of charge separation in reaction centers of ll131h and ll131h/lm160h/fm197h mutants of rhodobacter sphaeroides. | primary stage of charge separation and transfer of charges was studied in reaction centers (rcs) of point mutants ll131h and ll131h/lm160h/fm197h of the purple bacterium rhodobacter sphaeroides by differential absorption spectroscopy with temporal resolution of 18 fsec at 90 k. difference absorption spectra measured at 0-4 psec delays after excitation of dimer p at 870 nm with 30 fsec step were obtained in the spectral range of 935-1060 nm. it was found that a decay of p* due to charge separatio ... | 2011 | 22098236 |
| Bacterial nitrate assimilation: gene distribution and regulation. | In the context of the global nitrogen cycle, the importance of inorganic nitrate for the nutrition and growth of marine and freshwater autotrophic phytoplankton has long been recognized. In contrast, the utilization of nitrate by heterotrophic bacteria has historically received less attention because the primary role of these organisms has classically been considered to be the decomposition and mineralization of dissolved and particulate organic nitrogen. In the pre-genome sequence era, it was k ... | 2011 | 22103536 |
| Functional and structural effects of seven-residue deletions on the coiled-coil cytoplasmic domain of a chemoreceptor. | Chemoreceptors transmit signals from the environment to the flagellar motors via a histidine kinase that controls the phosphorylation level of the effector protein CheY. The cytoplasmic domain of chemoreceptors is strongly conserved and consists of a long alpha-helical hairpin that forms, in the dimer, a coiled-coil four-helix bundle. Changes in this domain during evolution are characterized by the presence of seven-residue insertions/deletions located symmetrically with respect to the hairpin t ... | 2012 | 22111959 |
| Fusing two cytochromes b of Rhodobacter capsulatus cytochrome bc1 using various linkers defines a set of protein templates for asymmetric mutagenesis. | Cytochrome bc(1) (mitochondrial complex III), one of the key enzymes of biological energy conversion, is a functional homodimer in which each monomer contains three catalytic subunits: cytochrome c(1), the iron-sulfur subunit and cytochrome b. The latter is composed of eight transmembrane a-helices which, in duplicate, form a hydrophobic core of a dimer. We show that two cytochromes b can be fused into one 16-helical subunit using a number of different peptide linkers that vary in length but all ... | 2012 | 22119789 |
| Role of PufX in Photochemical Charge Separation in the RC-LH1 Complex from Rhodobacter sphaeroides : An Ultrafast Mid-IR Pump-Probe Investigation. | Photochemical charge separation in isolated reaction center-light harvesting 1 (RC-LH1) complexes from Rhodobacter sphaeroides was examined using time-resolved mid-infrared pump-probe spectroscopy. Absorption difference spectra were recorded between 1760 and 1610 cm(-1) with subpicosecond time resolution to characterize excited-state and radical pair dynamics in these complexes, via the induced absorption changes in the keto carbonyl modes of the bacteriochlorophylls and bacteriopheophytins. E ... | 2011 | 22146012 |
| role of protein dynamics in guiding electron-transfer pathways in reaction centers from rhodobacter sphaeroides. | the role of protein dynamics in guiding multistep electron transfer is explored in the photosynthetic reaction center of rhodobacter sphaeroides . the energetics of the charge-separated intermediates, p(+)b(a)(-) and p(+)h(a)(-) (p is the initial electron donor bacteriochlorophyll pair and b(a) and h(a) are early bacteriochlorophyll and bacteriopheophytin acceptors, respectively), were systematically varied in a series of mutants. a fast phase of p(+)h(a)(-) recombination was resolved that is v ... | 2011 | 22148392 |
| investigation of the redox interaction between mn-bicarbonate complexes and reaction centers from rhodobacter sphaeroides r-26, chromatium minutissimum, and chloroflexus aurantiacus. | the change in the dark reduction rate of photooxidized reaction centers (rc) of type ii from three anoxygenic bacteria (rhodobacter sphaeroides r-26, chromatium minutissimum, and chloroflexus aurantiacus) having different redox potentials of the p(+)/p pair and availability of rc for exogenous electron donors was investigated upon the addition of mn(2+) and hco(3)(-). it was found that the dark reduction of p(870)(+) from rb. sphaeroides r-26 is considerably accelerated upon the combined additio ... | 2011 | 22150281 |
| heterologous high-level gene expression in the photosynthetic bacterium rhodobacter capsulatus. | the functional expression of heterologous genes in standard hosts such as escherichia coli is often hampered by various limitations including improper folding, incomplete targeting, and missassembly of the corresponding enzymes. this observation led to the development of numerous expression systems that are based on alternative, metabolic versatile hosts. one such organism is the gram-negative phototrophic nonsulfur purple bacterium rhodobacter capsulatus. during photosynthetic growth, r. capsul ... | 2012 | 22160903 |
| [in process citation]. | 2011 | 22168003 | |
| a comparative spectroscopic and kinetic study of photoexcitations in detergent-isolated and membrane-embedded lh2 light-harvesting complexes. | integral membrane proteins constitute more than third of the total number of proteins present in organisms. solubilization with mild detergents is a common technique to study the structure, dynamics, and catalytic activity of these proteins in purified form. however beneficial the use of detergents may be for protein extraction, the membrane proteins are often denatured by detergent solubilization as a result of native lipid membrane interactions having been modified. versatile investigations of ... | 2011 | 22172735 |
| proton transfer in ba(3) cytochrome c oxidase from thermus thermophilus. | the respiratory heme-copper oxidases catalyze reduction of o(2) to h(2)o, linking this process to transmembrane proton pumping. these oxidases have been classified according to the architecture, location and number of proton pathways. most structural and functional studies to date have been performed on the a-class oxidases, which includes those that are found in the inner mitochondrial membrane and bacteria such as rhodobacter sphaeroides and paracoccus denitrificans (aa(3)-type oxidases in the ... | 2011 | 22172736 |
| Theoretical Study of the Electronic-Vibrational Coupling in the Q_Y States of the Photosynthetic Reaction Center in Purple Bacteria. | Inspired by the recent observation of correlated excitation energy fluctuations of neighboring chromophores (Lee et al. Science 316, 1462 (2007)), quantum chemistry calculations and molecular dynamics simulations were employed to calculate the electronic-vibrational coupling in the excited states of photosynthetic reaction center of purple bacteria Rhodobacter (Rb.) sphaeroides. The ground states and lowest excited (Qy) states of isolated bacteriochlorophyll a (BChla) and bacteriopheophytin (BPh ... | 2011 | 22188530 |
| two-dimensional spectroscopy can distinguish between decoherence and dephasing of zero-quantum coherences. | recent experiments on a variety of photosynthetic antenna systems have revealed that coherences among electronic states persist longer than previously anticipated. in an ensemble measurement, the observed dephasing of a coherent state can occur because of either disorder across the ensemble or decoherence from interactions with the bath. distinguishing how much such disorder affects the experimentally observed dephasing rate is paramount for understanding the role that quantum coherence may play ... | 2011 | 22191993 |
| primary charge separation within p870* in wild type and heterodimer mutants in femtosecond time domain. | primary charge separation dynamics in the reaction center (rc) of purple bacterium rhodobacter sphaeroides and its p870 heterodimer mutants have been studied using femtosecond time-resolved spectroscopy with 20 and 40fs excitation at 870nm at 293k. absorbance increase in the 1060-1130nm region that is presumably attributed to p(a)(δ+) cation radical molecule as a part of mixed state with a charge transfer character p*(p(a)(δ+)p(b)(δ-)) was found. this state appears at 120-180fs time delay in the ... | 2011 | 22209778 |
| effect of pumping on the spatio-temporal distribution of microbial communities in a water well field. | a water well field adjacent to the north saskatchewan river (city of north battleford, saskatchewan, canada) with a history of rapid deterioration of both well water quality and yield was selected to study the spatial and temporal distribution of subsurface microbial communities and their response to water pumping. a range of conventional cultural, microscopic and molecular techniques, including confocal laser scanning microscopy (clsm), biolog, qpcr and denaturing gradient gel electrophoresis ( ... | 2012 | 22227241 |
| photocurrent and electronic activities of oriented-his-tagged photosynthetic light-harvesting/reaction centre core complexes assembled onto a gold electrode. | a poly-histidine (his) tag was fused to the c- or n-terminus of the light-harvesting (lh1)-αchain of the photosynthetic antenna core complex (lh1-rc) from rhodobacter sphaeroides to allow immobilization of the complex on a solid substrate with defined orientation. his-tagged lh1-rcs were adsorbed onto a gold electrode modified with ni-nta. the lh1-rc with the c-terminal his-tag (c-his lh1-rc) on the modified electrode produced a photovoltaic response upon illumination. electron transfer is un ... | 2012 | 22239547 |
| exploring the in situ accessibility of small subunit ribosomal rna of members of the domains bacteria and eukarya to oligonucleotide probes. | the principle that the small subunit ribosomal rna (ssu rrna) is generally accessible to oligonucleotide probes designed to have high thermodynamic affinity was tested with stenotrophomonas maltophilia, rhodobacter sphaeroides, bacillus subtilis, and saccharomyces cerevisiae. fluorescein-labeled probes, designed to have δg(overall)°=-14±1 and to avoid the potential of nucleobase-specific quenching, were used to target 20 randomly selected sites in each organism. a site was considered accessible ... | 2012 | 22264799 |
| transient absorption study of two-photon excitation mechanism in lh<sub>2</sub> complex from purple bacterium rhodobacter sphaeroides. | the mechanism of two-photon excitation of a peripheral light-harvesting complex lh2 (в800-850) from purple bacterium rhodobacter sphaeroides was explained on the basis of femtosecond transient absorption data. fast bleaching of the b850 absorption band was measured under two-photon excitation by 1350 nm femtosecond pulses, showing fast sub-picosecond arrival of excitation energy to b850 circular aggregates. any spectral changes connected with the b800 absorption band of b800-bchl molecules were ... | 2012 | 22268655 |