Obiettivo The aim of the study is to determine the effect of UV-B on the microbial, and in particular, on the bacterial community over a wide range of aquatic systems. Main focus will be put on the interaction between dissolved organic matter (DOM) and the bacterial consortia responsible for processing this DOM and its modification due to UV-B radiation. Additional measurements on phytoplankton primary production and extracellular release as influenced by UV-B radiation should allow us to estimate the influence of UV-B radiation on the carbon and energy flux through the microbial loop in representative European waters.UV-B penetration into the water column and the response of the microbial community to UV-B will be assessed in a variety of different European waters ranging from humic acid-rich Nordic to high altitude, oligotrophic Alpine lakes to mesotrophic lakes. These data will be compared to oligotrophic and eutrophic marine situations (Adriatic Sea). UV-B penetration into the water column will be correlated with the concentration of dissolved organic carbon (DOC) and with humic acids.The photolytic activity of UV-B on dissolved organic matter (DOM) will be evaluated and the availability of this UV-B processed DOM to bacterial consortia compared with unprocessed DOM. The influence of UV-B on bacterial production, growth yield and respiration will be examined and the role of UV-A in activating photorepair mechanisms tested using bacteria previously exposed to UV-B (from surface waters) and from below thermocline waters (assumed not exposed to UV-B).In mesocosm experiments the role of UV-B on the carbon and energy flux through the microbial loop will be examined. These experiments involve investigations and measurements on phytoplankton composition, phytoplankton primary production and extracellular release, bacterial production and flagellate grazing. Campo scientifico natural sciencesbiological sciencesmicrobiologybacteriology Programma(i) FP3-ENV 1C - Specific research and technological development programme (EEC) in the field of the environment, 1990-1994 Argomento(i) 040202 - Regional aspects of ecosystems protection Invito a presentare proposte Data not available Meccanismo di finanziamento CSC - Cost-sharing contracts Coordinatore Universität Wien Contributo UE Nessun dato Indirizzo 14,Althanstrasse 1090 Wien Austria Mostra sulla mappa Costo totale Nessun dato Partecipanti (4) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto LEOPOLD-FRANZENS-UNIVERSITAET INNSBRUCK Austria Contributo UE Nessun dato Indirizzo 25,Technikerstrasse 25 6020 INNSBRUCK Mostra sulla mappa Costo totale Nessun dato Lund University Svezia Contributo UE Nessun dato Indirizzo 5,Helgonavaegen 223 62 Lund Mostra sulla mappa Costo totale Nessun dato NATIONAL RESEARCH COUNCIL OF ITALY Italia Contributo UE Nessun dato Indirizzo Largo Vittorio Tonolli 50-52 28922 VERBANIA Mostra sulla mappa Costo totale Nessun dato UNIVERSITAT DE BARCELONA Spagna Contributo UE Nessun dato Indirizzo 645,Avinguda Diagonal 645 08028 BARCELONA Mostra sulla mappa Costo totale Nessun dato