Microbial diversity within the low-temperature influenced deep marine biosphere along the Mid-Atlantic-Ridge

Die Tiefsee stellt das größe Ökosystem der Erde dar. Mit ihren vielen ökologischen Nischen, wie Schlammvulkane, cold seeps, heiße- und kalte Quellen stellt sie einen Lebensraum für eine Vielzahl von Bakteriengemeinschaften zur Verfügung. Mittels molekularer und mikrobiologischer Ansätze wurden Basalt- und Sedimentproben analysiert. Diese wurden gesammelt an moderaten Quellen entlang des Mittel-Atlantischen- Rückens. Die Ergebnisse offenbaren, dass eine Vielzahl von mikrobiellen Populationen die analysierten Gesteinsproben besiedeln, dominiert von Proteobakterien. Die isolierten Organismen sind andere als die in der darüber liegenden Wassersäule. Die physiologische Charakterisierung zeigte, dass die Organismen eine hohe Toleranz gegenüber einer großen Temperaturspanne, verschiedenen pH- Werten und Salzkonzentrationen aufweisen. Weiterführende chemotaxonomische Analysen deckten phylogenetische Unstimmigkeiten auf und führten zur Reklassifikation innerhalb des Ge! nus Aurantimonas (Alphaproteobakterien). Die Auswertung polarer Lipidmuster zeigte, dass das Genus Aurantimonas neu geordnet werden muß und die Genusbeschreibung von Aurantimonas und Fulvimarina müssen erweitert werden.The deep sea floor forms largest associated ecosystem on earth. With it´s numerous ecological niches such as mud-volcanoes, cold seeps and hot and low-temperature influenced vents it could provide a harbourage for a diverse microbial consortia. By several molecular and microbial approaches, basalt and sediment samples collected in the vicinity of low-temperature influenced diffuse vents along the Mid-Atlantic-Ridge, were investigated. Our study revealed that a diverse microbial population inhabiting the analysed rock samples, dominated by Proteobacteria. The isolated organisms are distinguishable from the overlaying deep sea water and by characterisation of selected isolates high tolerances against a broad range of temperatures, pH-values and salt concentrations were observed. Further chemotaxic analysis resulted in a reclassification within the Aurantimonas (Alphaproteobacteria). The examination of the polar lipid compositions of selected isolates revealed that the genus o! f Aurantimonas had to be divided and the descriptions of the genera Aurantimonas and Fulvimarina have to be emended

Effect of increasing salinity to adapted and non-adapted Anammox biofilms

<p>The Anammox process is an efficient low energy alternative for the elimination of nitrogen from wastewater. The process is already in use for side stream applications. However, some industrial wastewaters, e.g. from textile industry are highly saline. This may be a limit for the application of the Anammox process. The aim of this study was to evaluate the effects of different NaCl concentrations on the efficiency of adapted and non-adapted Anammox biofilms. The tested NaCl concentrations ranged from 0 to 50 g NaCl*L⁻¹. Concentrations below 30 g NaCl*L⁻¹ did not significantly result in different nitrogen removal rates between adapted and non-adapted bacteria. However, adapted bacteria were significantly more resilient to salt at higher concentrations (40 and 50 g NaCl*L⁻¹). The IC50 for adapted and non-adapted Anammox bacteria were 19.99 and 20.30 g NaCl*L⁻¹, respectively. Whereas adapted biomass depletes the nitrogen in ratios of / around 1.20 indicating a mainly Anammox-driven consumption of the nitrogen, the ratio increases to 2.21 at 40 g NaCl*L⁻¹ for non-adapted biomass. This indicates an increase of other processes like denitrification. At lower NaCL concentrations up to 10 g NaCl*L⁻¹, a stimulating effect of NaCl to the Anammox process has been observed.</p

From stem cells to germ cells and from germ cells to stem cells

Germline and somatic stem cells are distinct types of stem cells that are dedicated to reproduction and somatic tissue regeneration, respectively. Germline stem cells (GSCs), which can self-renew and generate gametes, are unique stem cells in that they are solely dedicated to transmit genetic information from generation to generation. We developed a strategy for the establishment of germline stem cell lines from embryonic stem cells (ES). These cells are able to undergo meiosis, generate haploid male gametes in vitro and are functional, as shown by fertilization after intra-cytoplasmic injection into mouse oocytes. In other approach, we show that bone marrow stem (BMS) cells are able to trans-differentiate into male germ cells. BMS cell-derived germ cells expressed the known molecular markers of primordial germ cells. The ability to derive male germ cells from ES and BMS cells reveals novel aspects of germ cell development and opens the possibilities for use of these cells in reproductive medicine. Conversely, we showed that adult male germline stem cells, spermatogonial stem cells (SSCs), can be converted into embryonic stem cell like cells which can differentiate into the somatic stem cells of three germ layers. Understanding how SSC can give rise to pluripotent stem cells and how somatic stem cells differentiate into germ cells could give significant insights into the regulation of developmental totipotency as well as having important implications for male fertility and regenerative medicine