Co-utilization of L-arabinose and D-xylose by laboratory and industrial Saccharomyces cerevisiae strains

BACKGROUND: Fermentation of lignocellulosic biomass is an attractive alternative for the production of bioethanol. Traditionally, the yeast Saccharomyces cerevisiae is used in industrial ethanol fermentations. However, S. cerevisiae is naturally not able to ferment the pentose sugars D-xylose and L-arabinose, which are present in high amounts in lignocellulosic raw materials. RESULTS: We describe the engineering of laboratory and industrial S. cerevisiae strains to co-ferment the pentose sugars D-xylose and L-arabinose. Introduction of a fungal xylose and a bacterial arabinose pathway resulted in strains able to grow on both pentose sugars. Introduction of a xylose pathway into an arabinose-fermenting laboratory strain resulted in nearly complete conversion of arabinose into arabitol due to the L-arabinose reductase activity of the xylose reductase. The industrial strain displayed lower arabitol yield and increased ethanol yield from xylose and arabinose. CONCLUSION: Our work demonstrates simultaneous co-utilization of xylose and arabinose in recombinant strains of S. cerevisiae. In addition, the co-utilization of arabinose together with xylose significantly reduced formation of the by-product xylitol, which contributed to improved ethanol production

Spatial heterogeneity of flesh-cell osmotic potential in sweet cherry affects partitioning of absorbed water

A fleshy fruit is commonly assumed to resemble a thin-walled pressure vessel containing a homogenous carbohydrate solution. Using sweet cherry (Prunus avium L.) as a model system, we investigate how local differences in cell water potential affect H2O and D2O (heavy water) partitioning. The partitioning of H2O and D2O was mapped non-destructively using magnetic resonance imaging (MRI). The change in size of mesocarp cells due to water movement was monitored by optical coherence tomography (OCT, non-destructive). Osmotic potential was mapped using micro-osmometry (destructive). Virtual sections through the fruit revealed that the H2O distribution followed a net pattern in the outer mesocarp and a radial pattern in the inner mesocarp. These patterns align with the disposition of the vascular bundles. D2O uptake through the skin paralleled the acropetal gradient in cell osmotic potential gradient (from less negative to more negative). Cells in the vicinity of a vascular bundle were of more negative osmotic potential than cells more distant from a vascular bundle. OCT revealed net H2O uptake was the result of some cells loosing volume and other cells increasing volume. H2O and D2O partitioning following uptake is non-uniform and related to the spatial heterogeneity in the osmotic potential of mesocarp cells

Föderalismuskommission II: Neue Schuldenregelung für Bund und Länder und Altschuldenhilfe - wie sollten die Finanzbeziehungen von Bund und Ländern neu geordnet werden?

Um die öffentliche Verschuldung in Deutschland tatsächlich zurückzuführen, ist eine grundsätzliche Neuordnung der Bund-Länder-Finanzbeziehungen nötig. Nach Meinung von Jörg-Uwe Hahn, FDP Hessen und Mitglied der Föderalismuskommission II, bedarf es, neben eines möglichst strikten Neuverschuldungsverbots, einer Stärkung der Finanzautonomie insbesondere der Bundesländer, aber auch von Bund und Gemeinden. Notwendig sei es, im Sinne einer echten Steuerautonomie den Ländern dort, wo ihnen der Steuerertrag zusteht, auch die Gesetzgebungskompetenz einzuräumen. Kai A. Konrad, Wissenschaftszentrum Berlin für Sozialforschung und Freie Universität Berlin, sieht weniger beim Bund, sondern vor allem bei den Ländern das zentrale Problem. Sie könnten in der extremen Haushaltsnotlage auf eine Rettung durch die Bund-Länder-Gemeinschaft hoffen. Die Reform werde anscheinend von vielen Akteuren "als willkommene Chance gesehen, damit Umverteilungsgewinne zu Lasten anderer Gebietskörperschaften zu erzielen". Eckhard Janeba, Universität Mannheim und Mitglied des wissenschaftlichen Beirats beim Bundesministerium für Wirtschaft und Technologie, unterstreicht, dass konstitutionelle Regeln zur Begrenzung von Verschuldung ein wichtiges Instrument seien, um eine langfristig solide Finanzpolitik zu erreichen, sieht aber darin die Gefahr, "dass die Entscheidung über den Haushalt und damit die Verschuldung zu einem Expertenproblem wird, von der die politische Öffentlichkeit abgekoppelt ist. Diesem sollte entgegengewirkt werden. Der Vorschlag des Wissenschaftlichen Beirats beim BMWI geht in die richtige Richtung, indem er auf eine Identifikation der Verschuldungsursachen verzichtet und durch eine qualifizierte Mehrheitsentscheidung den Haushaltsbeschluss in den politischen Mittelpunkt zurückführt." Max Groneck und Robert C. Plachta, Universität zu Köln, stellen ein Reformkonzept vor.Föderalismus, Reform, Öffentliche Schulden, Deutschland

Thermal effects in dissimilar magnetic pulse welding

Magnetic pulse welding (MPW) is often categorized as a cold welding technology, whereas latest studies evidence melted and rapidly cooled regions within the joining interface. These phenomena already occur at very low impact velocities, when the heat input due to plastic deformation is comparatively low and where jetting in the kind of a distinct material flow is not initiated. As another heat source, this study investigates the cloud of particles (CoP), which is ejected as a result of the high speed impact. MPW experiments with different collision conditions are carried out in vacuum to suppress the interaction with the surrounding air for an improved process monitoring. Long time exposures and flash measurements indicate a higher temperature in the joining gap for smaller collision angles. Furthermore, the CoP becomes a finely dispersed metal vapor because of the higher degree of compression and the increased temperature. These conditions are beneficial for the surface activation of both joining partners. A numerical temperature model based on the theory of liquid state bonding is developed and considers the heating due to the CoP as well as the enthalpy of fusion and crystallization, respectively. The time offset between the heat input and the contact is identified as an important factor for a successful weld formation. Low values are beneficial to ensure high surface temperatures at the time of contact, which corresponds to the experimental results at small collision angle

Improvement, digitalization and validation of a development method for enabling the utilization of sensory functions in design elements

One key element for the advancing digitalization in industry is condition monitoring of technical systems. For this task, accurate and reliable data with ideally minimal influence of disturbance factors is necessary. This is especially challenging for information coming from within a process or product that is hard to access or highly limited by the available building space. One possible solution to achieve robust measurements is to use sensory utilizable design elements, which are design elements, which, in addition to their core function, are extended by a sensory function. This is especially appealing since often a minor - almost building space neutral - modification of a component can enable a sensory function. In order to identify suitable components within a system, a methodology has been developed that supports designers by making use of effect chains that are usually generated manually using paper based effect catalogs. To improve this methodology, a digitalized graph-based representation of an effect catalog is presented in this contribution that automatically generates effect chains and calculates a disturbance factor rating number. The implementation of this supporting effect graph into the improved methodology as well as an initial validation by a cross-over study will be presented in this paper

Jumping Mechanography: Reference Centiles in Childhood and Introduction of the Nerve–Muscle Index to Quantify Motor Efficiency

Jumping mechanography provides robust motor function indicators among children. The study aim was to develop centiles for the single 2-leg jump (S2LJ) in German children and adolescents and to identify differences in children with obesity. Data were collected in 2004–2021 through the German DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study. All participants (6–18 years, mean age 11.4) performed annually an S2LJ aiming for maximum height on a Ground Reaction Force Platform. LMS (lambda-mu-sigma), including resampling, was used to develop centiles for velocity (vmax), jump height (hmax), relative force (Fmax/BW), relative power (Pmax/mass), impulse asymmetry and a new parameter to describe jump efficiency, the Nerve–Muscle Index (NMI), defined as vmax/(Fmax/BW). Data from 882 children and adolescents were analyzed (3062 measurements, median 3 per individual). In females, Fmax/BW values were higher in younger age but remained constant in adolescence. vmax, hmax and Pmax/mass increased in childhood, reaching a plateau in adolescence. In males, vmax, hmax and Pmax/mass showed a constant increase and the Fmax/BW remained lower. Children with obesity showed lower Fmax/BW, hmax, vmax and the NMI, hence, lower velocity per relative force unit and less efficient jump. The centiles should be used to monitor motor development in childhood. The NMI is a surrogate for motor efficiency