TRR 51: Ecology, Physiology and Molecular Biology of the Roseobacter Clade: Towards a Systems Biology Understanding of a Globally Important Clade of Marine Bacteria

点击翻译按钮获取中文摘要

The overarching goal of this Transregional Collaborative Research Centre (CRC) TRR51 “Roseobacter” is a comprehensive understanding of the evolutionary and adaptational success of the Roseobacter group in marine ecosystems. Members of this group are globally distributed and often represent prominent components of the bacterial communities or carry out specific processes important in the given ecological context. Members of the Roseobacter group encompass very different and versatile physiologies. The mission of TRR51 is to investigate the Roseobacter group with respect to their evolution and phylogeny and the genome structure and content regarding its versatile physiology and ecology. These investigations cover environmental and biogeography studies on the community level as well as detailed investigations on the physiology of individual organisms and systems biology studies of the two model organisms, Dinoroseobacter shibae and Phaeobacter inhibens. Investigations in the third application phase will focus on interactions of these organisms, mainly with two cosmopolitan coastal algae Thalassiosira rotula and Prorocentrum minimum. Further, interactions with and the significance of phages will become another focus. The investigations are still structured in Project Area A, focusing on the ecology and evolution, Project Area B focusing on genetics and physiology and Project Area C focusing on systems biology of the two model organisms. The environmental studies, mainly home in project area A, will complete the analyses of samples and data collected during two cruises with Research Vessel Sonne in the Pacific Ocean investigating a longitudinal transect around 180°E between the southern polar frontal water masses at 52°S and the subarctic waters in the Bering Sea at 59°N. Work included sampling the water column and surface sediment for bacterioplankton activity and community composition, metagenomics, -transcriptomics, -proteomics and geometabolomics. These investigations aim at a comprehensive and synoptic assessment of these data together with those of previous cruises to the Southern and Atlantic Ocean in order to arrive at a synoptic and predictive model of the functional role of pelagic and benthic lineages of the Roseobacter group in the global oceans. Studies with the model organisms D. shibae and P. inhibens, home in all three project areas, will focus on interactions with the two model algae, T. rotula and P. minimum. The genome of both algae will be sequenced. Topics include the impact on the endo- and exometabolome, the role of specific exometabolites on growth of the algae, the role of quorum sensing, oxygen tension, iron and temperature in interactions, growth control and metabolite exchange, and significance of extrachromosomal elements (ECR). The different effects of direct physical interactions and interactions mediated via exchange of dissolved metabolites and how they impact the joint exometabolome of both partners will be examined