Phytoplankton blooms, the most common of which is the "Red Tide," are an increasingly frequent phenomenon in coastal and upwelling parts of the world’s oceans. Due to interactions between heterotrophic bacterial activity and harmful algal blooms (HAB) species, profound and unforeseen effects on global primary productivity as well as economics and ecosystem modifications are likely to occur.  We are interested in studying the symbiosis between toxin-producing phytoplankton species and heterotrophic bacteria associated with them.  A possible link in this relationship is the bacterial control of the supply of iron via siderophores.  Siderophores are low molecular-weight compounds that possess a high affinity for iron and therefore may function as a nutrient-provider to both.  In addition, we have been examining the phytoplankton/bacterial interactions via molecular biology techniques especially that we have acquired two genome sequences of our bacteria.

In addition, we are interested in the biological uptake of Boron by phytoplankton and bacteria.  Due to Boron requirement for growth and the scarce number of biological compounds containing it, boron may have a strong connection to the symbiotic relationship between heterotrophic bacteria and the phytoplankton.  In addition, many siderophores have recently been found to bind boron in addition to iron (portrayed in figure 1).  This may suggest the duality of function of siderophores as iron chelators as well as possible quorum-signaling molecules.

Finally, we are examining the role bacteria play in the precipitation of biological nanostructured materials, like CaCO₃ as in figure 2 taken by a Scanning Electron Microscope (SEM). Such phenomena are attracting a lot of attention due to their possible role in the global Carbon cycle as well as possible industrial uses.