Tetrabromidocuprates(II)-Synthesis, Structure and EPR.

Metal-containing ionic liquids (ILs) are of interest for a variety of technical applications, e.g., particle synthesis and materials with magnetic or thermochromic properties.

Is it possible to optimize the protein production yield by the generation of homomultimeric fusion enzymes?

Background: The supply of industrially relevant biocatalysts demands an easy and efficient protein production in high yield. In a conventional approach, a recombinant protein is produced in a heterologous host enabling the manipulation of multiple parameters including expression plasmids, growth conditions and regulation of protein biosynthesis. In this study, the generation of homomultimeric fusion genes is tested as an additional parameter to increase the production yield of a heat-stable cellulase.

Bottom-up Fabrication of Multilayer Stacks of 3D Photonic Crystals from Titanium Dioxide.

A strategy for stacking multiple ceramic 3D photonic crystals is developed. Periodically structured porous films are produced by vertical convective self-assembly of polystyrene (PS) microspheres. After infiltration of the opaline templates by atomic layer deposition (ALD) of titania and thermal decomposition of the polystyrene matrix, a ceramic 3D photonic crystal is formed.

Influence of Linker Length Variations on the Biomass-Degrading Performance of Heat-Active Enzyme Chimeras.

Plant cell walls are composed of complex polysaccharides such as cellulose and hemicellulose. In order to efficiently hydrolyze cellulose, the synergistic action of several cellulases is required. Some anaerobic cellulolytic bacteria form multienzyme complexes, namely cellulosomes, while other microorganisms produce a portfolio of diverse enzymes that work in synergistic fashion.

Surface Morphology of Vapor-Deposited Chitosan: Evidence of Solid-State Dewetting during the Formation of Biopolymer Films.

Chitosan is a useful and versatile biopolymer with several industrial and biological applications. Whereas its physical and physicochemical bulk properties have been explored quite intensively in the past, there is a lack of studies regarding the morphology and growth mechanisms of thin films of this biopolymer. Of particular interest for applications in bionanotechnology are ultrathin films with thicknesses under 500 Å.

Visualization of multimerization and self-assembly of DNA-functionalized gold nanoparticles using in-liquid transmission electron microscopy.

Base-pairing stability in DNA-gold nanoparticle (DNA-AuNP) multimers along with their dynamics under different electron beam intensities was investigated with in-liquid transmission electron microscopy (in-liquid TEM). Multimer formation was triggered by hybridization of DNA oligonucleotides to another DNA strand (Hyb-DNA) related to the concept of DNA origami. We analyzed the degree of multimer formation for a number of samples and a series of control samples to determine the specificity of the multimerization during the TEM imaging.

High-resolution dielectric study reveals pore-size-dependent orientational order of a discotic liquid crystal confined in tubular nanopores.

We report a high-resolution dielectric study on a pyrene-based discotic liquid crystal (DLC) in the bulk state and confined in parallel tubular nanopores of monolithic silica and alumina membranes. The positive dielectric anisotropy of the DLC molecule at low frequencies (in the quasistatic case) allows us to explore the thermotropic collective orientational order. A face-on arrangement of the molecular discs on the pore walls and a corresponding radial arrangement of the molecules is found.

Exploration of extremophiles for high temperature biotechnological processes.

Industrial processes often take place under harsh conditions that are hostile to microorganisms and their biocatalysts. Microorganisms surviving at temperatures above 60°C represent a chest of biotechnological treasures for high-temperature bioprocesses by producing a large portfolio of biocatalysts (thermozymes). Due to the unique requirements to cultivate thermophilic (60-80°C) and hyperthermophilic (80-110°C) Bacteria and Archaea, less than 5% are cultivable in the laboratory.

A hydrolase-based reporter system to uncover the protein splicing performance of an archaeal intein.

Extein amino acid residues around the splice site junctions affect the functionality of inteins. To identify an optimal sequence context for efficient protein splicing of an intein from the thermoacidophilic archaeon Picrophilus torridus, single extein amino acid residues at the splice site junctions were continuously deleted. The construction of a set of different truncated extein variants showed that this intein tolerates multiple amino acid variations near the excision sites and exhibits full activity when -1 and +1 extein amino acid residues are conserved in an artificial GST-intein-HIS fusion construct.

Synthesis and thermal stability of zirconia and yttria-stabilized zirconia microspheres.

Hypothesis: Zirconia microparticles produced by sol-gel synthesis have great potential for photonic applications. To this end, identifying synthetic methods that yield reproducible control over size uniformity is important. Phase transformations during thermal cycling can disintegrate the particles.

Volatile S-nitrosothiols and the typical smell of cancer.

An unconventional approach to investigations into the identification of typical volatile emissions during illnesses gives rise to the proposal of a new class of cancer markers. Until now, cancer markers seem not to have been conclusively identified, though the obvious behavior of dogs points to their existence. The focus has been directed towards molecules containing sulfurous functionalities.

Soft matter in hard confinement: phase transition thermodynamics, structure, texture, diffusion and flow in nanoporous media.

Spatial confinement in nanoporous media affects the structure, thermodynamics and mobility of molecular soft matter often markedly. This article reviews thermodynamic equilibrium phenomena, such as physisorption, capillary condensation, crystallisation, self-diffusion, and structural phase transitions as well as selected aspects of the emerging field of spatially confined, non-equilibrium physics, i.e.

Bringing functions together with fusion enzymes--from nature's inventions to biotechnological applications.

It is a mammoth task to develop a modular protein toolbox enabling the production of posttranslational organized multifunctional enzymes that catalyze reactions in complex pathways. However, nature has always guided scientists to mimic evolutionary inventions in the laboratory and, nowadays, versatile methods have been established to experimentally connect enzymatic activities with multiple advantages. Among the oldest known natural examples is the linkage of two or more juxtaposed proteins catalyzing consecutive, non-consecutive, or opposing reactions by a native peptide bond.

Impact of deforestation on soil carbon stock and its spatial distribution in the Western Black Sea Region of Turkey.

Land use management is one of the most critical factors influencing soil carbon storage and the global carbon cycle. This study evaluates the impact of land use change on the soil carbon stock in the Karasu region of Turkey which in the last two decades has undergone substantial deforestation to expand hazelnut plantations. Analysis of seasonal soil data indicated that the carbon content decreased rapidly with depth for both land uses.

Towards bio-silicon interfaces: formation of an ultra-thin self-hydrated artificial membrane composed of dipalmitoylphosphatidylcholine (DPPC) and chitosan deposited in high vacuum from the gas-phase.

The recent combination of nanoscale developments with biological molecules for biotechnological research has opened a wide field related to the area of biosensors. In the last years, device manufacturing for medical applications adapted the so-called bottom-up approach, from nanostructures to larger devices. Preparation and characterization of artificial biological membranes is a necessary step for the formation of nano-devices or sensors.

Generating bifunctional fusion enzymes composed of heat-active endoglucanase (Cel5A) and endoxylanase (XylT).

Bifunctional enzyme constructs were generated comprising two genes encoding heat-active endoglucanase (cel5A) and endoxylanase (xylT). The fused proteins Cel5A-XylT and XylT-Cel5A were active on both β-glucan and beechwood xylan. An improvement in endoglucanase and endoxylanase catalytic activities was observed.

Purification and characterization of a cold-adapted pullulanase from a psychrophilic bacterial isolate.

There is a considerable potential of cold-active biocatalysts for versatile industrial applications. A psychrophilic bacterial strain, Shewanella arctica 40-3, has been isolated from arctic sea ice and was shown to exhibit pullulan-degrading activity. Purification of a monomeric, 150-kDa pullulanase was achieved using a five-step purification approach.

Thermotropic orientational order of discotic liquid crystals in nanochannels: an optical polarimetry study and a Landau-de Gennes analysis.

Optical polarimetry measurements of the orientational order of a discotic liquid crystal based on a pyrene derivative confined in parallelly aligned nanochannels of monolithic, mesoporous alumina, silica, and silicon as a function of temperature, channel radius (3-22 nm) and surface chemistry reveal a competition of radial and axial columnar orders. The evolution of the orientational order parameter of the confined systems is continuous, in contrast to the discontinuous transition in the bulk. For channel radii larger than 10 nm we suggest several, alternative defect structures, which are compatible both with the optical experiments on the collective molecular orientation presented here and with a translational, radial columnar order reported in previous diffraction studies.

Extremozymes--biocatalysts with unique properties from extremophilic microorganisms.

Extremozymes are enzymes derived from extremophilic microorganisms that are able to withstand harsh conditions in industrial processes that were long thought to be destructive to proteins. Heat-stable and solvent-tolerant biocatalysts are valuable tools for processes in which for example hardly decomposable polymers need to be liquefied and degraded, while cold-active enzymes are of relevance for food and detergent industries. Extremophilic microorganisms are a rich source of naturally tailored enzymes, which are more superior over their mesophilic counterparts for applications at extreme conditions.

Electrical Stimulation of NIH-3T3 Cells with Platinum-PEDOT-Electrodes Integrated in a Bioreactor.

The objective of this work involves the development and integration of electrodes for the electrical stimulation of cells within a bioreactor. Electrodes need to fit properties such as biocompatibility, large reversible charge transfer and high flexibility in view of their future application as implants on the tympanic membrane. Flexible thin-film platinum-poly(3,4-ethylene-dioxythiophene)-electrodes on a poly(ethylene terephthalate)-foil manufactured using microsystems technology were integrated into a bioreactor based on the design of a 24 well plate.

Group III alcohol dehydrogenase from Pectobacterium atrosepticum: insights into enzymatic activity and organization of the metal ion-containing region.

NAD(P)(+)-dependent alcohol dehydrogenases (ADH) are widely distributed in all phyla. These proteins can be assigned to three nonhomologous groups of isozymes, with group III being highly diverse with regards to catalytic activity and primary structure. Members of group III ADHs share a conserved stretch of amino acid residues important for cofactor binding and metal ion coordination, while sequence identities for complete proteins are highly diverse (<20 to >90 %).

Structural and biochemical characterisation of a NAD⁺-dependent alcohol dehydrogenase from Oenococcus oeni as a new model molecule for industrial biotechnology applications.

Alcohol dehydrogenases are highly diverse enzymes catalysing the interconversion of alcohols and aldehydes or ketones. Due to their versatile specificities, these biocatalysts are of great interest for industrial applications. The adh3-gene encoding a group III alcohol dehydrogenase was isolated from the gram-positive bacterium Oenococcus oeni and was characterised after expression in the heterologous host Escherichia coli.