SS2.06 Microbial Diversity in Time and Space
Date: Tuesday, June 11, 2002
Time: 2:30:00 PM
Location: Lecture Theatre
MASSANAR, Institut de Cičncies del Mar, CMIMA, Barcelona, Spain,
Guillou, L, , Institut de Cičncies del Mar, CMIMA, BArcelona, Spain,
Diez, B, , Institut de Cičncies del Mar, CMIMA, Barcelona, Spain,
Pedros-Alio, C, , Institut de Cičncies del Mar, CMIMA, Barcelona, Spain,
Marine picoeukaryotes play key roles in marine food webs. However, the extent of their diversity and the distribution and abundance of the different taxons has remained unknown until recently. Similar to marine bacteria and archaea, marine picoeukaryotes can not be identified by morphology and cultures might not represent the dominant in situ populations. Data obtained recently from genetic libraries of 18S rDNA has resulted in a list of the most important picoeukaryotic taxa found in different marine systems. The most widespread groups in these libraries are the algal classes Prasinophyceae, Prymnesiophyceae and Dinophyceae and two novel phylogenetic lineages, novel stramenopiles and novel alveolates. Fingerprinting techniques, such as DGGE or T-RFLP, allow to investigate the variability of picoeukaryotic assemblages in the marine environment, revealing a strong vertical stratification and less marked horizontal differences. Finally, we are starting to unveil the identity of the organisms harboring the novel sequences. By using specific probes, we present data about the morphology, in situ abundance and ecological role of novel stramenopiles.