Multiphase Bioreactor Design

phycoerythrin conjugated antibodies used in
ELISAs and flow cytometry

red algae

Resilience® skin creams additive: extract of Caribbean sea
fan

of animals. Sponges produce a variety of interesting compounds: cytotoxic compounds
that may be used as anti-cancer drugs, antibiotics, anti-viral agents and compounds with
anti-inflammatory and cardiovascular properties and compounds that can be used as anti-
fouling agents. In Figure 17.1 screening results for different oganisms are given (Munro
et al., 1999). Shown is the percentage of organisms tested in which components have
been found with a positive cytotoxic activity. Compounds with cytotoxic activity can
potentially be used as anti-tumour agents. Less than 0.5% of the micro-organisms tested
have cytotoxic activity. In this respect marine animals are potentially much more
interesting as in almost 2% of the tested animals compounds with cytotoxic activity were
found. Sponges form a part of this group; in 10% of the sponges tested cytotoxic activity
was found.
Sponges are classified within the animal kingdom as the phylum Porifera, which
consists of approximately 10,000 described species. Some examples of the morphological
diversity within the phylum Porifera are given in Figure 17.2. With respect to the level of
body organisation, sponges (Porifera) represent one of the two most primitive groups of
multicellular animals (Metazoa). Together with the phylum Placozoa, Porifera form the
Parazoa, multicellular animals without organs and with poorly defined tissues. Hence, the
structure of the sponge body is simple: the tissue is built around a network of channels
and chambers, through which water is pumped continuously (Figure 17.3). This network,
which is called the aquiferous system, has numerous small inflowing openings (ostia) and
one or two outflowing openings. The biological material around the aquiferous system
basically consists of three tissue-like components: i. Pinacoderm, a thin layer of flat skin
cells (pinacocytes). ii; Choanoderm, a layer of flagellate cells (choanocytes) that line the
walls of the chambers. The beating of these flagellae generates the water current through
the sponge body, iii; The mesohyl, which is a gelatinous matrix containing free living
cells and skeletal components. Most of these free living cells are termed archaeocytes.
Archaeocytes are totipotent, multifunctional cells that can develop into any other cell
type present in sponges.

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