Part A | 8.2
226 Part A Marine Flora and Fauna
single cells, further suggesting that fungi may, in fact,
be true sponge symbionts and might, therefore, play an
important role in host physiology.
Sponge-associated fungi have been shown to display a range of quite diverse biological activities
through the production of a wide range of chemically diverse compounds with novel antibacterial, antiinflammatory, antiviral, and anticancer activity. Some
examples include Fusarium oxysporum DLFP2008005
isolated from Hymeniacidon perlevis, which has been
reported to exhibit antibacterial and antifungal activities
against Staphylococcus epidermidis, Bacillus subtilis,
Pseudomonas fluorescens, Pseudomonas aeruginosa,
and the yeast Candida albicans. Penicillium cf., montanense isolates obtained from Xestospongia exigua from
the Bali Sea in Indonesia have been reported to produce
xestodecalactone B, a novel decalactone metabolite
which displays antifungal activity against Candida albicans. Aspergillus versicolor, isolated from Petrosia sp.
in Korea is known to produce the cytotoxic lipopeptide fellutamide C, while Emericella variecolor isolated
from a Venezuelan sponge, has been shown to produce
varitriol, which displays activity against breast cancer
cell lines and varixanthone, which has antimicrobial activity. In addition, the fungus Microascus longirostris
SF-73 isolated from a New Zealand sponge has been
shown to produce the protease inhibitors cathestatin
A, B, and C, which may potentially be used in inactivating target proteases in the pathogenic processes of
various human diseases such as emphysema, arthritis,
pancreatitis, thrombosis, and many others. Finally, extracts from the fungus Engyodontium album isolated
from the Mediterranean sponge Suberites domuncula
have been shown to display cytotoxicity against murine
lymphoma cells.
As a result there has been an increased recent
interest in molecular-based approaches to assess the
fungal biodiversity of sponges with a view to assessing their overall chemical potential. These studies have
primarily involved the use of 18S rRNA to phylogenetically analyze the fungal ecology of these sponges,
resulting in fungi from 32 orders, from three phyla
(Ascomycota [8.22] orders, Basidiomycota [8.8] orders,
Zygomycota [8.2] orders), representing > 120 genera
having to date been found in or on sponges. In addition, at least 18 orders of fungi have been isolated in
culture. Examples of phylogenetic studies include the
analysis of 80 fungi isolated from Haliclona simulans
which were assessed by using both culture-dependent
and metagenomic approaches. With the use of different fungal media containing either agar or gellan gum,
a total of 19 different genotypes were detected, which
were subsequently classified as members of Agaricomycotina, Mucoromycotina, Saccharomycotina, and
Pezizomycotina; with the majority of the isolates being associated with the latter class. Some of these
fungal isolates showed antimicrobial activity against
Escherichia coli, Bacillus sp., Staphylococcus aureus,
and Candida glabrata. Fungal 18S rRNA gene sequences belonging to Eurotiales, Calosphaeriales, and
Chaetothyriales were amplified from deoxyribonucleic
acid (DNA) and ribonucleic acid (RNA) extracted from
this marine sponge. Further studies have reported on the
isolation of fungi from three Hawaiian sponges, from
the Mediterranean sponges Psammocinia sp. and Tethya
aurantium and from China Sea sponges. The secondary
metabolic potential of these fungal isolates is reflected
in the fact that 15 polyketide synthase (PKS) genes
and 4 NRPS (non-ribosomal peptide synthase) genes
were identified in the fungi isolated from the Chinese
sponges.
It is fair to say that, in general, fungal associations with marine sponges are less well understood than
their microbial counterparts. This may be due in part
to the fact that metagenomic 18S rRNA-based studies
typically encounter problems with respect to contamination with sponge rRNA coupled with difficulties in
extracting fungal DNA. Even though sponge specific
clusters have recently been detected in the genus Penicillium and 530 possibly obligate marine fungi have to
date been described, many if not most sponge-derived
fungal isolates or 18S rRNA clones which have been
classified as genera typically found in terrestrial environments, and many compounds derived from those
isolates, have also been shown to be present in their
terrestrial counterparts. Nonetheless, the tremendous
biochemical potential of fungi and the lack of understanding of sponge-fungi ecology should ensure that an
ongoing and active research interest is maintained in
this area.
Other Sponge-Associated Eukaryotes
Other eukaryotes have been reported to be present in
close association with sponges. Polychaetes (annelid
worms) and shrimp have been reported from Caribbean
sponges [8.133]. Ophiuroidea (brittle stars), Cnidaria
(sessile Anthozoa), Turbellaria (flatworms), Nemertinia (ribbon worms), Sipuncula (sipunculid worms),
Polychaeta, Mollusca, Crustacea, Pycnogondia (sea
spiders), Echinodermata (sea cucumbers), Ascidiacea
(sea squirts), and Pisces (fish) have all been observed
in association with the Brazilian sponge Zygomycale
226 Part A Marine Flora and Fauna
single cells, further suggesting that fungi may, in fact,
be true sponge symbionts and might, therefore, play an
important role in host physiology.
Sponge-associated fungi have been shown to display a range of quite diverse biological activities
through the production of a wide range of chemically diverse compounds with novel antibacterial, antiinflammatory, antiviral, and anticancer activity. Some
examples include Fusarium oxysporum DLFP2008005
isolated from Hymeniacidon perlevis, which has been
reported to exhibit antibacterial and antifungal activities
against Staphylococcus epidermidis, Bacillus subtilis,
Pseudomonas fluorescens, Pseudomonas aeruginosa,
and the yeast Candida albicans. Penicillium cf., montanense isolates obtained from Xestospongia exigua from
the Bali Sea in Indonesia have been reported to produce
xestodecalactone B, a novel decalactone metabolite
which displays antifungal activity against Candida albicans. Aspergillus versicolor, isolated from Petrosia sp.
in Korea is known to produce the cytotoxic lipopeptide fellutamide C, while Emericella variecolor isolated
from a Venezuelan sponge, has been shown to produce
varitriol, which displays activity against breast cancer
cell lines and varixanthone, which has antimicrobial activity. In addition, the fungus Microascus longirostris
SF-73 isolated from a New Zealand sponge has been
shown to produce the protease inhibitors cathestatin
A, B, and C, which may potentially be used in inactivating target proteases in the pathogenic processes of
various human diseases such as emphysema, arthritis,
pancreatitis, thrombosis, and many others. Finally, extracts from the fungus Engyodontium album isolated
from the Mediterranean sponge Suberites domuncula
have been shown to display cytotoxicity against murine
lymphoma cells.
As a result there has been an increased recent
interest in molecular-based approaches to assess the
fungal biodiversity of sponges with a view to assessing their overall chemical potential. These studies have
primarily involved the use of 18S rRNA to phylogenetically analyze the fungal ecology of these sponges,
resulting in fungi from 32 orders, from three phyla
(Ascomycota [8.22] orders, Basidiomycota [8.8] orders,
Zygomycota [8.2] orders), representing > 120 genera
having to date been found in or on sponges. In addition, at least 18 orders of fungi have been isolated in
culture. Examples of phylogenetic studies include the
analysis of 80 fungi isolated from Haliclona simulans
which were assessed by using both culture-dependent
and metagenomic approaches. With the use of different fungal media containing either agar or gellan gum,
a total of 19 different genotypes were detected, which
were subsequently classified as members of Agaricomycotina, Mucoromycotina, Saccharomycotina, and
Pezizomycotina; with the majority of the isolates being associated with the latter class. Some of these
fungal isolates showed antimicrobial activity against
Escherichia coli, Bacillus sp., Staphylococcus aureus,
and Candida glabrata. Fungal 18S rRNA gene sequences belonging to Eurotiales, Calosphaeriales, and
Chaetothyriales were amplified from deoxyribonucleic
acid (DNA) and ribonucleic acid (RNA) extracted from
this marine sponge. Further studies have reported on the
isolation of fungi from three Hawaiian sponges, from
the Mediterranean sponges Psammocinia sp. and Tethya
aurantium and from China Sea sponges. The secondary
metabolic potential of these fungal isolates is reflected
in the fact that 15 polyketide synthase (PKS) genes
and 4 NRPS (non-ribosomal peptide synthase) genes
were identified in the fungi isolated from the Chinese
sponges.
It is fair to say that, in general, fungal associations with marine sponges are less well understood than
their microbial counterparts. This may be due in part
to the fact that metagenomic 18S rRNA-based studies
typically encounter problems with respect to contamination with sponge rRNA coupled with difficulties in
extracting fungal DNA. Even though sponge specific
clusters have recently been detected in the genus Penicillium and 530 possibly obligate marine fungi have to
date been described, many if not most sponge-derived
fungal isolates or 18S rRNA clones which have been
classified as genera typically found in terrestrial environments, and many compounds derived from those
isolates, have also been shown to be present in their
terrestrial counterparts. Nonetheless, the tremendous
biochemical potential of fungi and the lack of understanding of sponge-fungi ecology should ensure that an
ongoing and active research interest is maintained in
this area.
Other Sponge-Associated Eukaryotes
Other eukaryotes have been reported to be present in
close association with sponges. Polychaetes (annelid
worms) and shrimp have been reported from Caribbean
sponges [8.133]. Ophiuroidea (brittle stars), Cnidaria
(sessile Anthozoa), Turbellaria (flatworms), Nemertinia (ribbon worms), Sipuncula (sipunculid worms),
Polychaeta, Mollusca, Crustacea, Pycnogondia (sea
spiders), Echinodermata (sea cucumbers), Ascidiacea
(sea squirts), and Pisces (fish) have all been observed
in association with the Brazilian sponge Zygomycale