Query: NC_008043:167108 Silicibacter sp. TM1040 mega plasmid, complete sequence
Lineage: Ruegeria; Ruegeria; Rhodobacteraceae; Rhodobacterales; Proteobacteria; Bacteria
General Information: This strain was isolated from a culture of the dinoflagellate Pfiesteria piscicida CCMP1830 which has been implicated in many large scale algal blooms resulting in increased mortality in fish. The bacteria are attached to the surface of the dinoflagellate and in some ways allow the dinoflagellate to grow as those lacking the bacteria die off. The bacterium also chemotaxes towards the dinoflagellate product DMSP (dimethylsulfoniopropionate) and metabolizes it. DMSP is a major source of sulfur in marine ecosystems and plays a role in the sulfur biogeochemical cycle. The implication is a tight association between these important dinoflagellates and this marine bacterium.
Subject: NC_018870:1417851 Thermacetogenium phaeum DSM 12270 chromosome, complete genome
Lineage: Thermacetogenium phaeum; Thermacetogenium; Thermoanaerobacteraceae; Thermoanaerobacterales; Firmicutes; Bacteria
General Information: Nitrogen fixation. Thermophilic strictly anaerobic bacterium oxidizing acetate to CO2 in syntrophic association with a methanogenic partner. Capable of growing with various substrates such as alcohols and methylated nitrogen compounds, and to reduce sulfate in the presence of acetate. Isolated from sludge of an anaerobic digester run at 58 degrees C. Thermacetogenium phaeum is a strictly anaerobic, homoacetogenic bacterium. It is exceptional because it can use the homoacetogenic Wood-Ljungdahl (CO- dehydrogenase) pathway both for acetate formation and acetate oxidation. Acetate oxidation is possible only in syntrophic cooperation with a methanogenic partner which maintains a low hydrogen and/or formate concentration in the coculture. With this, the bacterium operates close to the thermodynamic equilibrium of substrate conversion, similar to other syntrophically fermenting bacteria such as Syntrophomonas wolfei the genomes of which have been sequenced as well in the recent past.