Alexandrium associated bacterial communities

Microbial interactions within the aquatic environment are interesting since the biogeochemical cycling of nutrients depend on them. In this study we have identified which bacteria can be found associated with the dinoflagellates Alexandrium ostenfeldii and Alexandrium minutum in xenic cultures. These dinoflagellates area known to cause harmful algal blooms both in the Baltic sea and the Mediterranean sea, respectivelly. Can we find signs of a species specific bacterial composition that is associated with the Alexandrium? What implications can the maintenance of these associations have for the biogeochemical cycles of the Baltic sea?The BCC's found associated with the A.ostefeldii in the Baltic Sea, were very similar, regardless of the location of sampling. The bacterial community of the A.ostenfeldii is dominated by Betaproteobacteria, Alphaproteobacteria and Flavobacteria. The A.minutum associated bacterial communities were dominated by Alphaproteobacteria, Gammaproteobacteria and Bacteroidetes. The bacteria found associated with the A.ostenfeldii are species specific, and is not affected by the location of sampling, within the Baltic Sea. Different phytoplankton host their specific bacterial communities. Interactions between the phytoplankton must be driven by context. Thus if the environmental conditions change, both the phytoplankton and the bacteria will change, which might affect the overall effectiveness of the biogeochemical cycles.