Primmorphs from sponges as bioreactors for a sustainable production of bioactive compounds

Sponges (phylum Porifera) are a rich source for the isolation of biologically active and pharmacologically valuable compounds with a high potential to become effective drugs for therapeutic use. However, until now, only one compound could be introduced into clinics because of the limited amounts of starting material available for extraction. To overcome this serious problem in line with the rules for a sustainable use of marine resources, the following routes can be pursued: first, chemical synthesis, second, cultivation of sponges in the sea (mariculture), third, growth of sponge specimens in a bioreactor, and fourth, cultivation of sponge cells in vitro in a bioreactor. The main efforts to follow the latter strategy have been undertaken with the marine sponge Suberites domuncula. A sponge cell culture was established after finding that single sponge cells require cell-cell contact in order to retain their telomerase activity, one prerequisite for continuous cell proliferation. The sponge cell culture system, the primmorphs, comprises proliferating cells which have the potency to differentiate. Future strategies to improve the sponge cell culture are discussed.