Mecanismes reguladors de les xarxes tròfiques microbianes en sistemes aquàtics

The main objective of the present project is to elucide the mechanisms governing the composition and functioning of aquatic microbial food webs. This objective will be approached at three different levels. First, an empirical study will try to ascertain the relationships between the components of the webs in the different eosystems. Second, an experimental study will be carried out with whole communities incubated in controlled microcosms. The two variables whose effects will be studied will be turbulence and inorganic nutrients. Several variables will be followed: macromolecular composition of the plankton (nucleic acids, proteins, pigments, and polysaccharides), size distribution and taxonomic diversity. The objective consists of identifying those variables which can be used in the field to identify the importance of turbulence and nutrients on planktonic assemblages in the sea. Finally, a few representative species of microorganisms will be selected for continuous culture studies which will reveal the physiological response of these organisms to turbulence and nutrients.