Aufwandschaetzung fuer die Modernisierung von Schulgebaeuden; Raumcodierung nach dem Raumzuordnungskatalog der Laenderarbeitsgemienschaft Hochbau; Raumzuordnungskatalog der Laenderarbeitsgemeinschaft Hochbau; Ueberpruefung von Planungszielen fuer den Schulbau in Niedersachsen; Arbeitshilfen zum Schulbau. Zusammenstellung von Vorschriften, Richtlinien und Normen; Hinweise

SIGLETIB: RN 2246 (22) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Non-Redfield, nutrient synergy and flexible internal elemental stoichiometry in a marine bacterium.

The stoichiometric constraints of algal growth are well understood, whereas there is less knowledge for heterotrophic bacterioplankton. Growth of the marine bacterium Phaeobacter inhibens DSM 17395, belonging to the globally distributed Roseobacter group, was studied across a wide concentration range of NH 4 + and PO 4 3- . The unique dataset covers 415 different concentration pairs, corresponding to 207 different molar N:P ratios (from 10 -2 to 10 5 ). Maximal growth (by growth rate and biomass yield) was observed within a restricted concentration range at N:P ratios (50-120) markedly above Redfield. Experimentally determined growth parameters deviated to a large part from model predictions based on Liebig's law of the minimum, thus implicating synergistic co-limitation due to biochemical dependence of resources. Internal elemental ratios of P. inhibens varied with external nutrient supply within physiological constraints, thus adding to the growing evidence that aquatic bacteria can be flexible in their internal elemental composition. Taken together, the findings reported here revealed that P. inhibens is well adapted to fluctuating availability of inorganic N and P, expected to occur in its natural habitat (e.g. colonized algae, coastal areas). Moreover, this study suggests that elemental variability in bacterioplankton needs to be considered in the ecological stoichiometry of the oceans

Adaptation of Phaeobacter inhibens DSM 17395 to growth with complex nutrients

Phaeobacter inhibensDSM 17395, a member of the Roseobacter clade, was studied for its adaptive strategies to complex and excess nutrient supply, here mimicked by cultivation with Marine Broth (MB). During growth in process-controlled fermenters, P. inhibens DSM 17395 grew faster (3.6-fold higher (max)) and reached higher optical densities (2.2-fold) with MB medium, as compared to the reference condition of glucose-containing mineral medium. Apparently, in the presence of MB medium, metabolism was tuned to maximize growth rate at the expense of efficiency. Comprehensive proteomic analysis of cells harvested at 1/2 ODmax identified 1783 (2D DIGE, membrane and extracellular protein-enriched fractions, shotgun) different proteins (50.5% coverage), 315 (based on 2D DIGE) of which displayed differential abundance profiles. Moreover, 145 different metabolites (intra- and extracellular combined) were identified, almost all of which (140) showed abundance changes. During growth with MB medium, P. inhibens DSM 17395 specifically formed the various proteins required for utilization of phospholipids and several amino acids, as well as for gluconeogenesis. Metabolic tuning on amino acid utilization is also reflected by massive discharge of urea to dispose the cell of excess ammonia. Apparently, P. inhibens DSM 17395 modulated its metabolism to simultaneously utilize diverse substrates from the complex nutrient supply