Potential Biomedical Applications of Collagen Filaments Derived from the Marine Demosponges Ircinia oros (Schmidt, 1864) and Sarcotragus foetidus (Schmidt, 1862)

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A multi-bioassay integrated approach to assess antifouling potential of extracts from the Mediterranean sponge Ircinia oros

The phylum Porifera and their symbionts produce a wide variety of bioactive compounds, playing a central role in their ecology and evolution. In this study, four different extracts (obtained by non-polar and semi-polar extraction methodologies) of the Mediterranean sponge Ircinia oros were tested through a multi-bioassay integrated approach to assess their antifouling potential. Tests were performed using three common species, associated with three different endpoints: the marine bacterium Aliivibrio fischeri (inhibition of bioluminescence), the marine diatom Phaeodactylum tricornutum (inhibition of growth), and different development stages of the brackish water serpulid Ficopomatus enigmaticus (gametes: sperm motion, vitality inhibition and cellular damage; larvae: development; adults: AChE (acetylcholinesterase)-inhibitory activity). The effects of extracts were species specific and did not vary among different extraction methodologies. In particular, no significant reduction of bioluminescence of A. fischeri was observed for all tested samples. By contrast, extracts inhibited P. tricornutum growth and had toxic effects on different F. enigmaticus’ developmental stages. Our results suggest that the proposed test battery can be considered a suitable tool as bioactivity screening of marine natural products.

Potential Anti-Fouling Properties of Extracts from the Mediterranean Sponge Ircinia Oros: An Ecotoxicological Screening

The phylum Porifera and their symbionts produce a wide variety of bioactive compounds, playing a central role in their ecology and evolution. In this study, four different extracts (obtained by non-polar and semi-polar extraction methodologies) from the Mediterranean sponge Ircinia oros were tested for their potential antifouling purposes. The evaluation was performed using three different target species, associated with three different endpoints: the marine bacterium Aliivibrio fischeri (inhibition of bioluminescence), the marine diatom Phaeodactylum tricornutum (inhibition of growth) and different development stages of the brackish-water serpulid Ficopomatus enigmaticus (gametes: sperm motion, vitality inhibition and cellular damage; larvae: development; adults: AChE (acetylcholinesterase)-inhibitory activity). Effects of extracts were species-specific and did not vary among different extraction methodologies. In particular, no significant reduction of bioluminescence of A. fischeri was observed for all tested samples. By contrast, extracts inhibited P. tricornutum growth and had toxic effects on different F. enigmaticus’ developmental stages. Obtained results suggest that the proposed test battery can be considered a suitable tool as bioactivity screening of marine natural products.

Controlling complex microbial communities: a network-based approach

Microbes comprise nearly half of all biomass on Earth. Almost every habitat on Earth is teeming with microbes, from hydrothermal vents to the human gastrointestinal tract. Those microbes form complex communities and play critical roles in maintaining the integrity of their environment or the well-being of their hosts. Controlling microbial communities can help us restore natural ecosystems and maintain healthy human microbiota. Yet, our ability to precisely manipulate microbial communities has been fundamentally impeded by the lack of a systematic framework to control them. Here we fill this gap by developing a control framework based on the new notion of structural accessibility. This framework allows identifying minimal sets of “driver species” through which we can achieve feasible control of the entire microbial community. We numerically validate our control framework on large microbial communities, and then we demonstrate its application for controlling the gut microbiota of gnotobiotic mice infected withClostridium difficileand the core microbiota of the sea spongeIrcinia oros.

New Chromone, Isocoumarin, and Indole Alkaloid Derivatives from three Sponge-derived Fungal Strains

Two new chromone derivatives, 2-hydroxymethyl-3-methyl-7-methoxychromone (1) and 2-hydroxymethyl-3- tert-butyl-7-methoxychromone (2), together with a related known compound, 2,3-dimethyl-7-methoxychromone (3), were isolated from Rhinocladiella sp. (IO2), a fungus obtained from the sponge Ircinia oros. Furthermore, a new isocoumarin derivative, 3-(3-chloro-2-hydroxypropyl)-8-hydroxy-6-methoxy-isochromen-1-one (4) and a known analogue 3-[( R)-3,3-dichloro-2-hydroxypropyl]-8-hydroxy-6-methoxy-1 H-isochromen-1-one (dichlorodiaportin, 5), were identified from sponge-derived fungal strain Clonostachys sp. (AP4.1), while a new indole alkaloid 1-(4-hydroxybenzoyl)indole-3-carbaldehyde (6) was obtained from the sponge-derived fungus Engyodontium album (IVB1b). The structures of these compounds were established by NMR spectroscopic and mass spectrometric data analysis, as well as by comparison with literature reports. Compounds 4 and 6 were examined for cytotoxic and antimicrobial activities, respectively. None of them showed potent activity.

Chemical Defense and Antifouling Activity of Three Mediterranean Sponges of the Genus Ircinia

The defense roles and the antifouling activity of the organic extracts and the major metabolites of the sponges Ircinia oros, I. variabilis and I. spinosula were investigated. The antifeedant activity was tested in experimental aquaria on the generalist predator fish Thalassoma pavo as well as in coastal ecosystems rich in fishes. Some of the major metabolites exhibited high levels of antifeedant activity. The antifouling activity was tested in laboratory assays, against representatives of the major groups of fouling organisms (marine bacteria, marine fungi, diatoms, macroalgae and mussels). All extracts showed promising levels of activity. As was expected, no single extract was active in all tests and some fractions that were effective against one organism showed little or no activity against the others. The high but variable level of antifouling activity in combination with the absence of toxicity (tested on the development of oyster and sea urchin larvae) shows the potential of these metabolites to become ingredients in environmentally friendly antifouling preparations.

Iron Biomineralization in the PoriferanIrcinia Oros

Iron-containing precipitates, present within the organic matrix of the poriferanIrcinia oroswere identified as crystalline lepidocrocite (γ-FeOOH) by electron diffraction and57Fe Mössbauer spectroscopy. The crystals were located specifically within the spongin filaments, suggesting that the binding and subsequent accumulation of iron by macromolecules present in these filaments were responsible for mineralization. Iron biomineralization did not appear to serve any specific structural role, but may be involved in biological processes such as detoxification.It is well recognized that Porifera are active in the biomineralization of calcium carbonate and silica, producing beautiful and intricate skeletons (Simpson, 1984). However, the formation of other biominerals is less well documented. Iron biomineralization has been reported in a few species of keratose sponges (Töwe & Riitzler, 1968; Vacelet et al., 1988), and the mineral has been identified as lepidocrocite (γ-FeOOH). Lepidocrocite is a relatively uncommon biomineral, having previously been identified as only a minor phase in chiton teeth (Webb et al., 1989; Lowenstam & Weiner, 1989).