Molecular Characterization of Branchial aquaporin 1aa and Effects of Seawater Acclimation, Emersion or Ammonia Exposure on Its mRNA Expression in the Gills, Gut, Kidney and Skin of the Freshwater Climbing Perch, Anabas testudineus

10.1371/journal.pone.0061163PLoS ONE84

Secondary Metabolites of Marine Microbes: From Natural Products Chemistry to Chemical Ecology

Marine natural products (MNPs) exhibit a wide range of pharmaceutically relevant bioactivities, including antibiotic, antiviral, anticancer, or anti-inflammatory properties. Besides marine macroorganisms such as sponges, algae, or corals, specifically marine bacteria and fungi have shown to produce novel secondary metabolites (SMs) with unique and diverse chemical structures that may hold the key for the development of novel drugs or drug leads. Apart from highlighting their potential benefit to humankind, this review is focusing on the manifold functions of SMs in the marine ecosystem. For example, potent MNPs have the ability to exile predators and competing organisms, act as attractants for mating purposes, or serve as dye for the expulsion or attraction of other organisms. A large compilation of literature on the role of MNPs in marine ecology is available, and several reviews evaluated the function of MNPs for the aforementioned topics. Therefore, we focused the second part of this review on the importance of bioactive compounds from crustose coralline algae (CCA) and their role during coral settlement, a topic that has received less attention. It has been shown that certain SMs derived from CCA and their associated bacteria are able to induce attachment and/or metamorphosis of many benthic invertebrate larvae, including globally threatened reef-building scleractinian corals. This review provides an overview on bioactivities of MNPs from marine microbes and their potential use in medicine as well as on the latest findings of the chemical ecology and settlement process of scleractinian corals and other invertebrate larvae

Antibacterial, antifungal and antiprotozoal activities of fungal communities present in different substrates from Antarctica

Antarctica is a pristine and extreme environment that represents a unique opportunity for taxonomic, ecological and biotechnological studies of the microorganisms. In the present work, the fungal communities of rhizosphere soil of Deschampsia antarctica, soil, ornithogenic soil, marine and lake sediments in the Antarctic Peninsula were characterized as well as their capability to produce bioactive compounds. One hundred fungal isolates were recovered and identified by molecular analysis in 35 different taxa of 20 genera. Pseudogymnoascus sp. 1 and 3, Penicillium sp., Peniophora sp. and Mortierella alpina were the most frequent taxa identified. All isolates were cultured to produce ethanolic extracts, which were assayed against different target organisms to detect antimicrobial (against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Candida krusei, Cladosporium sphaerospermum and Paracoccidioides brasiliensis), cytotoxic (against breast MCF-7 and renal TK-10 human tumoral cells) and antiprotozoal (against Leishmania amazonensis and Trypanosoma cruzi) activities. Among the three human pathogenic fungal species, 20 extracts showed moderate to high and selective antifungal activity against P. brasiliensis. The extract of Purpureocillium lilacinum displayed high trypanocidal, antifungal and antibacterial activities, but with moderate toxicity over normal cells. Proton nuclear magnetic resonance (1H NMR) spectral analysis indicated the presence of compounds containing a highly functionalized aromatic ring system. Our results suggest that the Antarctic ecosystems represent an interesting habitat for the isolation and characterization of fungal taxa capable to producing bioactive compounds. The fungus P. lilacinum showed strong trypanocidal and antimicrobial activities with moderate toxicity over normal cells, which might be used as scaffold for the development of new drugs