Sponges (phylum Porifera) are known to be very rich sources for bioactive compounds, mainly secondary metabolites. Main efforts are devoted to cell- and mariculture of sponges to assure a sustainable exploitation of bioactive compounds from biological starting material. These activities are flanked by improved technologies to cultivate bacteria and fungi which are associated with the sponges. It is the hope that by elucidating the strategies of interaction between microorganisms and their host (sponge), by modern cell and molecular biological methods, a more comprehensive cultivation of the...