Physiological Interactions - Pfiesteria Dinoflagellates

What physiological interactions may occur between Pfiesteria piscicida (and P. shumwayae) and their associated bacteria?  We have found Roseobacter species to be prevalent throughout our dinoflagellate laboratory cultures.  These bacterial species are commonly found in the bacterioplankton within blooms of harmful algae in the wild and are involved in the transformation of many organic sulfur compounds, particularly the algal osmolyte, dimethylsulfoniopropionate (DMSP). We are currently exploring the role of DMSP in cultures of Pfiesteria dinoflagellates and the function the bacteria play in DMSP metabolism.