The influence of cultivation methods on Shewanella oneidensis physiology and proteome expression

High-throughput analyses that are central to microbial systems biology and ecophysiology research benefit from highly homogeneous and physiologically well-defined cell cultures. While attention has focused on the technical variation associated with high-throughput technologies, biological variation introduced as a function of cell cultivation methods has been largely overlooked. This study evaluated the impact of cultivation methods, controlled batch or continuous culture in bioreactors versus shake flasks, on the reproducibility of global proteome measurements in Shewanellaoneidensis MR-1. Variability in dissolved oxygen concentration and consumption rate, metabolite profiles, and proteome was greater in shake flask than controlled batch or chemostat cultures. Proteins indicative of suboxic and anaerobic growth (e.g., fumarate reductase and decaheme c-type cytochromes) were more abundant in cells from shake flasks compared to bioreactor cultures, a finding consistent with data demonstrating that “aerobic” flask cultures were O2 deficient due to poor mass transfer kinetics. The work described herein establishes the necessity of controlled cultivation for ensuring highly reproducible and homogenous microbial cultures. By decreasing cell to cell variability, higher quality samples will allow for the interpretive accuracy necessary for drawing conclusions relevant to microbial systems biology research

Evaluation of instrumentation used for high performance thin-layer chromatography of aflatoxins

Instrumentation used for high performance thin layer chromatography (HPTLC) of aflatoxins has been evaluated. Optimum sensitivity, accuracy and precision resulted when a combination of a fully automated TLC sampler, an unsaturated conventional TLC glass chamber and a monochromatic densitometer were employed. Benzene: acetonitrile (98: 2 v/v) was found to be the most suitable sample application solvent. These findings are being used to develop a rapid, simple and reproducible method for the analysis of aflatoxins

Erprobung der thermochemischen Waermespeicherung mit neuen Speichermaterialien Schlussbericht

The aim of the project was the continuation of the development, scientific treatment and test of new porous materials for thermomechanical storage of heat from renewable energy sources or waste heat. A number of different new materials and modified structures were made and investigated, based on the abilities of highly experienced co-workers, of the co-operating scientific enterprise ZeoSys, as well as using its proper physico-chemical methods. Among the materials developed can be found new highly performing zeolites of the X-type, zeolite like aluminophosphates and modified active carbons as composite adsorbents with better chemical stability. Those materials were tested and ranked in existing but improved lab-scaled storages of 1.5 and 35 litre volume. The latter facility was connected with a solar collector array of 12 m"2 area for practice relevant tests of the thermochemical storage of heat from solar energy by those special zeolites. (orig.)SIGLEAvailable from TIB Hannover: F04B909 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Wirtschaft und Technologie, Bonn (Germany)DEGerman

Entwicklung und Charakterisierung von mikroporoesen Festkoerpern fuer die adsorptive Langzeitspeicherung von Niedertemperaturwaerme Schlussbericht

The aim of the project was the scientific treatment of new porous materials for loss free long term thermo-chemical storage of heat from renewable energy sources or waste heat. A number of different materials and modified structures were made and investigated, based on the latest knowledge of the literature und using the abilities of highly experienced co-workers of the co-operating scientific enterprise ZeoSys, as well as using its proper physico-chemical methods and equipment. Thus, different kinds of materials with varying properties and suitability were found such as modified zeolites, mesoporous alumino silicates and silicates, mesoporous silica gels, clays and active carbons as well as composite adsorbents with different supports and salt hydrates. Those materials were tested and ranked in an especially designed labscaled storage of 1.5 litre volume and a bigger 35 litre storage. Important for the assessment of the storage materials was their producibility and the manufacture costs. (orig.)Zielstellung war die Entwicklung und wissenschaftliche Druchdringung neuartiger poroeser Materialien zur nahezu verlustfreien thermochemischen Langzeitspeicherung von Waermeenergie aus erneuerbaren Quellen bzw. Abwaerme. Ausgehend von der intensiven Auswertung des gegenwaertigen wissenschaftlichen Erkenntnisstandes und unter Nutzung jahrelanger Erfahrungen der Mitarbeiter des beteiligten Wissenschaftsunternehmens ZeoSys mit derartigen Materialien und geeigneten speziellen physikochemischen Untersuchungsmethoden und -apparaturen wurde eine grosse Anzahl unterschiedlicher Ausgangsmaterialien und modifizierter Chargen hergestellt und untersucht. Dabei konnten, im Schlussbericht naeher charakterisierte, Gruppen von Zeolithen, mesoporoesen Alumosilikaten und Silikaten, mesoporoesen Kieselgelen, Tonmineralien und Aktivkohlen und Kompositadsorbentien mit diversen Traegern und Salzhydraten unterschiedlicher Eigenschaften und Eignung gefunden und im Labormassstab bis 1,5 Liter bzw. im kleintechnischen Massstab bis 35 Liter in speziell entwickelten und gebauten Speicherversuchsstaenden getestet und beruteilt werden. Insbesondere wurden Produzierbarkeit und Preis bewertet. (orig.)SIGLEAvailable from TIB Hannover: F01B1633 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman