The strain Aspergillus chevalieri TM2-S6 was isolated from the sponge Axinella and identified according to internal transcribed spacer (ITS) molecular sequence homology with Aspergillus species from the section Restricti. The strain was cultivated 9 days on potato dextrose broth (PDB), and the medium evaluated as antioxidant on primary normal human dermal fibroblasts (NHDF). The cultivation broth was submitted to sterile filtration, lyophilized and used without any further processing to give the Aspergillus chevalieri TM2-S6 cultivation broth ingredient named ACBB. ACCB contains two main compounds: tetrahydroauroglaucin and flavoglaucin. Under oxidative stress, ACCB showed a significant promotion of cell viability. To elucidate the mechanism of action, the impact on a panel of hundreds of genes involved in fibroblast physiology was evaluated. Thus, ACCB stimulates cell proliferation (VEGFA, TGFB3), antioxidant response (GPX1, SOD1, NRF2), and extracellular matrix organization (COL1A1, COL3A1, CD44, MMP14). ACCD also reduced aging (SIRT1, SIRT2, FOXO3). These findings indicate that Aspergillus chevalieri TM2-S6 cultivation broth exhibits significant in vitro skin protection of human fibroblasts under oxidative stress, making it a potential cosmetic ingredient.
The fungi Chrysosporium lobatum TM-237-S5 was isolated from the sponge Acanthella cavernosa, collected from the mesophotic coral ecosystem of the Red Sea. The strain was cultivated on a potato dextrose agar (PDA) medium, coupling solid-state fermentation and solid-state extraction (SSF/SSE) with a neutral macroreticular polymeric adsorbent XAD Amberlite resin (AMBERLITE XAD1600N). The SSF/SSE lead to high chemodiversity and productivity compared to classical submerged cultivation. Ten phenalenone related compounds were isolated and fully characterized by one-dimensional and two-dimensional NMR and HRMS. Among them, four were found to be new compounds corresponding to isoconiolactone, (-)-peniciphenalenin F, (+)-8-hydroxyscleroderodin, and (+)-8-hydroxysclerodin. It is concluded that SSF/SSE is a powerful strategy, opening a new era for the exploitation of microbial secondary metabolites.
Antifouling booster biocides are chemicals used in protective paints to tackle the adhesion of fouling organisms to maritime artificial structures. However, they are also known to exert toxic effects on non-target organisms. Recent research developments have highlighted the potential use of engineered micro/nanomaterials (EMNMs) as carriers of antifouling booster biocides in order to control their release and to reduce the harmful effects on living biota. In the present study, we sought to assess the toxicity of two commercially-available booster biocides: (zinc pyrithione (ZnPT) and copper pyrithione (CuPT)); three unloaded engineered micro/nanomaterials (EMNMs); layered double hydroxides (LDH), silica nanocapsules (SiNC), polyurea microcapsules (PU); , and six novel EMNMs (loaded with each of the two biocides). The exposure tests were conducted on the larval stage (nauplii) of the brine shrimp Artemia salina and on two embryonic developmental stages of the European purple sea urchin Paracentrotus lividus. The findings indicate that the unloaded LDH and PU (i.e. both biocide-free EMNMs) have non/low toxic effects on both species. The unloaded SiNC, in contrast, exerted a mild toxic effect on the A. salina nauplii and P. lividus embryos. The free biocides presented different toxicity values, with ZnPT being more toxic than CuPT in the P. lividus assays. LDH-based pyrithiones demonstrated lower toxicity compared to the free forms of the state-of-the-art compounds, and constitute good candidates in terms of their antifouling efficacy.
Mesophotic coral ecosystems (MCEs), which comprise the light-dependent communities of corals and other organisms found at depths between 30 and similar to 150 m, have become a topic that increasingly draws the attention of coral reef researchers. It is well established that after the reef-building scleractinian corals, octocorals are the second most common group of macrobenthic animals on many shallow Indo-Pacific reefs. This chapter reviews the existing knowledge (e.g., species composition and depth of occurrence) on octocorals from selected Indo-Pacific MCEs: Okinawa (Japan), Palau, South Africa, the northern Red Sea, and the Great Barrier Reef (Australia). For all reefs, zooxanthellate taxa are not found below 65 m. We, therefore, suggest that physiological constraints of their symbiotic algae limit the depth distribution of zooxanthellate octocorals. More studies of lower MCEs (60-150 m) and their transition to deepwater communities are needed to answer questions regarding the taxonomy, evolutionary origins, and phylogenetic uniqueness of these mesophotic octocorals. New findings on mesophotic octocoral sexual reproduction indicate a temporal reproductive isolation between shallow and mesophotic octocoral populations, thus challenging the possibility of connectivity between the two populations. The existing data should encourage future studies aimed at a greater understanding of the spatiotemporal features and ecological role of mesophotic octocorals in reef ecosystems.
The application of nano-structured compounds has been increasing rapidly in recent years, in several fields. The use of engineered nano-materials as carriers of antifouling compounds is just beginning and already reveals clear advantages compared to bulk active compounds, such as slowed and controlled release, novel functionality, and high loading capacity. This present study assesses the antifouling efficacy of two nanostructured materials, spherical mesoporous silica nanocapsules (SiNC) and Zn-Al layered double hydroxides (LDH), loaded with two commercial biocides, zinc prithione (ZnPT) and copper pyrithione (CuPT). The study used adult mussels from three geographical regions, the Atlantic Ocean, Mediterranean Sea, and the Red Sea, to examine the efficacy of the innovative compounds. The efficacy of these compounds on larvae of the bryozoan Bugula neritina from the Mediterranean Sea and the Red Sea was also examined. The results of this study demonstrated the environmentally friendly properties of unloaded LDH against the two-model systems, adult mussels or bryozoan larvae. ZnPT entrapped in LDH demonstrated the most effective antifouling compound against the two model systems. A comparison of the impact of the two compounds on macrofouling organisms from the different marine habitats examined in this study indicates a distinction associated with the organisms’ different ecosystems. The Red Sea mussels and bryozoans, representing a tropical marine ecosystem, yielded the highest efficacy values among tested Atlantic Ocean and Mediterranean Sea mussels and bryozoans.