Dinoflagellate-associated bacterium. Ruegeria sp. TM1040

Ruegeria sp. TM1040. 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.